feat(parallel): add --jobs auto to cap concurrency at CPU cores#771

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Merged
Chemaclass merged 1 commit into from
Jul 12, 2026
Merged

feat(parallel): add --jobs auto to cap concurrency at CPU cores #771

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3 changes: 3 additions & 0 deletions CHANGELOG.md
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Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -2,6 +2,9 @@

## Unreleased

### Added
- `--jobs auto` (and `-j auto`) caps parallel concurrency at the detected CPU core count, portable across Linux/macOS/BSD (`nproc`, then `sysctl`, then `getconf`, falling back to 4). The default stays unlimited (`--jobs 0`) (#766)

### Changed
- Faster test execution: removed avoidable subshell forks from the per-test hot path (runtime-error detection, subshell-output decode, name normalization, test-id generation, retry-count lookup, and the passing-test line are now fork-free), and per-test temp-file cleanup no longer forks `rm` when the test created none (`rm` 102 -> 2 on a 100-test file). No behaviour change (#764)
- Per-test execution time now defaults to `auto` (`BASHUNIT_SHOW_EXECUTION_TIME=true|false|auto`): shown when the shell has a fork-free clock (Bash 5.0+, GNU `date`), hidden when measuring would fork an interpreter (e.g. Bash 3.2 on macOS, which falls back to `perl`). This removes ~2 `perl` forks per test on those shells. `--profile`, `--verbose`, reports, and `=true` still measure. See `adrs/adr-008-auto-skip-per-test-timing.md` (#765)
Expand Down
8 changes: 5 additions & 3 deletions docs/command-line.md
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Original file line numberDiff line numberDiff line change
Expand Up@@ -67,7 +67,7 @@ bashunit test tests/ --parallel --simple
| `-w, --watch` | Watch files and re-run tests on change |
| `--log-junit, --report-junit <file>` | Write JUnit XML report |
| `--log-gha <file>` | Write GitHub Actions workflow-commands log |
| `-j, --jobs <N>` | Run tests in parallel with max N concurrent jobs |
| `-j, --jobs <N\|auto>` | Run tests in parallel with max N concurrent jobs (`auto` = CPU cores) |
| `-p, --parallel` | Run tests in parallel |
| `--no-parallel` | Run tests sequentially |
| `-r, --report-html <file>` | Write HTML report |
Expand DownExpand Up@@ -314,22 +314,24 @@ run sequentially.

### Jobs

> `bashunit test -j|--jobs <N>`
> `bashunit test -j|--jobs <N|auto>`

Run tests in parallel with a maximum of N concurrent jobs. This implicitly
enables parallel mode.

Use this to limit CPU usage on CI or machines with constrained resources.
Pass `auto` to cap concurrency at the number of detected CPU cores.

::: code-group
```bash [Example]
bashunit test tests/ --jobs 4
bashunit test tests/ --jobs auto
```
:::

::: tip
`--jobs 0` (the default) means unlimited concurrency, which is equivalent to
`--parallel`.
`--parallel`. `--jobs auto` caps at the detected CPU core count.
:::

### Output Style
Expand Down
25 changes: 25 additions & 0 deletions src/check_os.sh
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -61,6 +61,30 @@ function bashunit::check_os::is_windows() {
esac
}

##
# Detects the number of online CPU cores, portably across Linux/macOS/BSD.
# Tries nproc, then sysctl, then getconf; falls back to 4 when none report a
# usable positive integer. Takes the first whitespace-delimited token so a
# stray flag or trailing text never poisons the arithmetic guard.
# Returns: prints the core count (>= 1) to stdout.
##
function bashunit::check_os::nproc() {
local cores=""
cores="$(nproc 2>/dev/null)" || cores=""
if [ -z "$cores" ]; then
cores="$(sysctl -n hw.ncpu 2>/dev/null)" || cores=""
fi
if [ -z "$cores" ]; then
cores="$(getconf _NPROCESSORS_ONLN 2>/dev/null)" || cores=""
fi
cores="${cores%% *}"
case "$cores" in
'' | *[!0-9]*) cores=4 ;;
esac
[ "$cores" -lt 1 ] && cores=4
echo "$cores"
}

function bashunit::check_os::is_busybox() {

case "$_BASHUNIT_DISTRO" in
Expand All@@ -78,6 +102,7 @@ bashunit::check_os::init

export _BASHUNIT_OS
export _BASHUNIT_DISTRO
export -f bashunit::check_os::nproc
export -f bashunit::check_os::is_alpine
export -f bashunit::check_os::is_busybox
export -f bashunit::check_os::is_ubuntu
Expand Down
2 changes: 1 addition & 1 deletion src/console_header.sh
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -119,7 +119,7 @@ Options:
--tag <name> Only run tests with matching @tag (repeatable, OR logic)
--exclude-tag <name> Skip tests with matching @tag (repeatable, exclude wins)
--log-junit, --report-junit <file> Write JUnit XML report
-j, --jobs <N> Run tests in parallel with max N concurrent jobs
-j, --jobs <N|auto> Run tests in parallel with max N concurrent jobs ("auto" = CPU cores)
-p, --parallel Run tests in parallel (unlimited concurrency)
--no-parallel Run tests sequentially
-r, --report-html <file> Write HTML report
Expand Down
8 changes: 7 additions & 1 deletion src/main.sh
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -99,7 +99,13 @@ function bashunit::main::cmd_test() {
;;
-j | --jobs)
export BASHUNIT_PARALLEL_RUN=true
export BASHUNIT_PARALLEL_JOBS="$2"
# "auto" caps at the detected core count; wait_for_job_slot needs an
# integer, so resolve it here rather than leaking the string downstream.
if [ "$2" = "auto" ]; then
export BASHUNIT_PARALLEL_JOBS="$(bashunit::check_os::nproc)"
else
export BASHUNIT_PARALLEL_JOBS="$2"
fi
shift
;;
--no-parallel)
Expand Down
19 changes: 19 additions & 0 deletions tests/acceptance/bashunit_parallel_consistency_test.sh
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Original file line numberDiff line numberDiff line change
Expand Up@@ -23,3 +23,22 @@ function test_parallel_and_sequential_results_match() {

assert_equals "$sequential_summary" "$parallel_summary"
}

function test_jobs_auto_caps_at_detected_cores_and_matches_sequential() {
local file1=tests/acceptance/fixtures/test_bashunit_when_a_test_passes.sh
local file2=tests/acceptance/fixtures/test_bashunit_when_a_test_fail.sh

local sequential_output
sequential_output=$(./bashunit --no-parallel --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

local auto_output
auto_output=$(./bashunit --jobs auto --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

local sequential_summary
sequential_summary=$(echo "$sequential_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

local auto_summary
auto_summary=$(echo "$auto_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

assert_equals "$sequential_summary" "$auto_summary"
}
29 changes: 29 additions & 0 deletions tests/unit/check_os_test.sh
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -77,3 +77,32 @@ function test_not_alpine_is_not_busybox() {
assert_general_error "$(bashunit::check_os::is_alpine)"
assert_general_error "$(bashunit::check_os::is_busybox)"
}

function test_nproc_uses_nproc_when_available() {
bashunit::mock nproc echo "8"

assert_same "8" "$(bashunit::check_os::nproc)"
}

function test_nproc_falls_back_to_sysctl_when_nproc_unavailable() {
bashunit::mock nproc mock_false
bashunit::mock sysctl echo "6"

assert_same "6" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_no_detector_available() {
bashunit::mock nproc mock_false
bashunit::mock sysctl mock_false
bashunit::mock getconf mock_false

assert_same "4" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_output_is_not_numeric() {
bashunit::mock nproc echo "not-a-number"
bashunit::mock sysctl mock_false
bashunit::mock getconf mock_false

assert_same "4" "$(bashunit::check_os::nproc)"
}
Loading
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

Skip to content
feat(parallel): add --jobs auto to cap concurrency at CPU cores#771

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 Merged

Chemaclass
merged 1 commit into

from

Jul 12, 2026
 Merged


feat(parallel): add --jobs auto to cap concurrency at CPU cores
#771
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3 changes: 3 additions & 0 deletions
CHANGELOG.md

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -2,6 +2,9 @@

## Unreleased

### Added
- `--jobs auto` (and `-j auto`) caps parallel concurrency at the detected CPU core count, portable across Linux/macOS/BSD (`nproc`, then `sysctl`, then `getconf`, falling back to 4). The default stays unlimited (`--jobs 0`) (#766)

### Changed
- Faster test execution: removed avoidable subshell forks from the per-test hot path (runtime-error detection, subshell-output decode, name normalization, test-id generation, retry-count lookup, and the passing-test line are now fork-free), and per-test temp-file cleanup no longer forks `rm` when the test created none (`rm` 102 -> 2 on a 100-test file). No behaviour change (#764)
- Per-test execution time now defaults to `auto` (`BASHUNIT_SHOW_EXECUTION_TIME=true|false|auto`): shown when the shell has a fork-free clock (Bash 5.0+, GNU `date`), hidden when measuring would fork an interpreter (e.g. Bash 3.2 on macOS, which falls back to `perl`). This removes ~2 `perl` forks per test on those shells. `--profile`, `--verbose`, reports, and `=true` still measure. See `adrs/adr-008-auto-skip-per-test-timing.md` (#765)
Expand Down

8 changes: 5 additions & 3 deletions
docs/command-line.md

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -67,7 +67,7 @@ bashunit test tests/ --parallel --simple
| `-w, --watch` | Watch files and re-run tests on change |
| `--log-junit, --report-junit <file>` | Write JUnit XML report |
| `--log-gha <file>` | Write GitHub Actions workflow-commands log |
| `-j, --jobs <N>` | Run tests in parallel with max N concurrent jobs |
| `-j, --jobs <N\|auto>` | Run tests in parallel with max N concurrent jobs (`auto` = CPU cores) |
| `-p, --parallel` | Run tests in parallel |
| `--no-parallel` | Run tests sequentially |
| `-r, --report-html <file>` | Write HTML report |
Expand DownExpand Up@@ -314,22 +314,24 @@ run sequentially.

### Jobs

> `bashunit test -j|--jobs <N>`
> `bashunit test -j|--jobs <N|auto>`

Run tests in parallel with a maximum of N concurrent jobs. This implicitly
enables parallel mode.

Use this to limit CPU usage on CI or machines with constrained resources.
Pass `auto` to cap concurrency at the number of detected CPU cores.

::: code-group
```bash [Example]
bashunit test tests/ --jobs 4
bashunit test tests/ --jobs auto
```
:::

::: tip
`--jobs 0` (the default) means unlimited concurrency, which is equivalent to
`--parallel`.
`--parallel`. `--jobs auto` caps at the detected CPU core count.
:::

### Output Style
Expand Down

25 changes: 25 additions & 0 deletions
src/check_os.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -61,6 +61,30 @@ function bashunit::check_os::is_windows() {
 esac
}

##
# Detects the number of online CPU cores, portably across Linux/macOS/BSD.
# Tries nproc, then sysctl, then getconf; falls back to 4 when none report a
# usable positive integer. Takes the first whitespace-delimited token so a
# stray flag or trailing text never poisons the arithmetic guard.
# Returns: prints the core count (>= 1) to stdout.
##
function bashunit::check_os::nproc() {
 local cores=""
 cores="$(nproc 2>/dev/null)" || cores=""
 if [ -z "$cores" ]; then
 cores="$(sysctl -n hw.ncpu 2>/dev/null)" || cores=""
 fi
 if [ -z "$cores" ]; then
 cores="$(getconf _NPROCESSORS_ONLN 2>/dev/null)" || cores=""
 fi
 cores="${cores%% *}"
 case "$cores" in
 '' | *[!0-9]*) cores=4 ;;
 esac
 [ "$cores" -lt 1 ] && cores=4
 echo "$cores"
}

function bashunit::check_os::is_busybox() {

 case "$_BASHUNIT_DISTRO" in
Expand All@@ -78,6 +102,7 @@ bashunit::check_os::init

export _BASHUNIT_OS
export _BASHUNIT_DISTRO
export -f bashunit::check_os::nproc
export -f bashunit::check_os::is_alpine
export -f bashunit::check_os::is_busybox
export -f bashunit::check_os::is_ubuntu
Expand Down

2 changes: 1 addition & 1 deletion
src/console_header.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -119,7 +119,7 @@ Options:
 --tag <name> Only run tests with matching @tag (repeatable, OR logic)
 --exclude-tag <name> Skip tests with matching @tag (repeatable, exclude wins)
 --log-junit, --report-junit <file> Write JUnit XML report
 -j, --jobs <N> Run tests in parallel with max N concurrent jobs
 -j, --jobs <N|auto> Run tests in parallel with max N concurrent jobs ("auto" = CPU cores)
 -p, --parallel Run tests in parallel (unlimited concurrency)
 --no-parallel Run tests sequentially
 -r, --report-html <file> Write HTML report
Expand Down

8 changes: 7 additions & 1 deletion
src/main.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -99,7 +99,13 @@ function bashunit::main::cmd_test() {
 ;;
 -j | --jobs)
 export BASHUNIT_PARALLEL_RUN=true
 export BASHUNIT_PARALLEL_JOBS="$2"
 # "auto" caps at the detected core count; wait_for_job_slot needs an
 # integer, so resolve it here rather than leaking the string downstream.
 if [ "$2" = "auto" ]; then
 export BASHUNIT_PARALLEL_JOBS="$(bashunit::check_os::nproc)"
 else
 export BASHUNIT_PARALLEL_JOBS="$2"
 fi
 shift
 ;;
 --no-parallel)
Expand Down

19 changes: 19 additions & 0 deletions
tests/acceptance/bashunit_parallel_consistency_test.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -23,3 +23,22 @@ function test_parallel_and_sequential_results_match() {

 assert_equals "$sequential_summary" "$parallel_summary"
}

function test_jobs_auto_caps_at_detected_cores_and_matches_sequential() {
 local file1=tests/acceptance/fixtures/test_bashunit_when_a_test_passes.sh
 local file2=tests/acceptance/fixtures/test_bashunit_when_a_test_fail.sh

 local sequential_output
 sequential_output=$(./bashunit --no-parallel --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

 local auto_output
 auto_output=$(./bashunit --jobs auto --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

 local sequential_summary
 sequential_summary=$(echo "$sequential_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

 local auto_summary
 auto_summary=$(echo "$auto_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

 assert_equals "$sequential_summary" "$auto_summary"
}

29 changes: 29 additions & 0 deletions
tests/unit/check_os_test.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -77,3 +77,32 @@ function test_not_alpine_is_not_busybox() {
 assert_general_error "$(bashunit::check_os::is_alpine)"
 assert_general_error "$(bashunit::check_os::is_busybox)"
}

function test_nproc_uses_nproc_when_available() {
 bashunit::mock nproc echo "8"

 assert_same "8" "$(bashunit::check_os::nproc)"
}

function test_nproc_falls_back_to_sysctl_when_nproc_unavailable() {
 bashunit::mock nproc mock_false
 bashunit::mock sysctl echo "6"

 assert_same "6" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_no_detector_available() {
 bashunit::mock nproc mock_false
 bashunit::mock sysctl mock_false
 bashunit::mock getconf mock_false

 assert_same "4" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_output_is_not_numeric() {
 bashunit::mock nproc echo "not-a-number"
 bashunit::mock sysctl mock_false
 bashunit::mock getconf mock_false

 assert_same "4" "$(bashunit::check_os::nproc)"
}
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
feat(parallel): add --jobs auto to cap concurrency at CPU cores#771

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Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

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Already on GitHub?
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to your account

 Merged

Chemaclass
merged 1 commit into

from

Jul 12, 2026
 Merged


feat(parallel): add --jobs auto to cap concurrency at CPU cores
#771
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3 changes: 3 additions & 0 deletions
CHANGELOG.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -2,6 +2,9 @@

## Unreleased

### Added
- `--jobs auto` (and `-j auto`) caps parallel concurrency at the detected CPU core count, portable across Linux/macOS/BSD (`nproc`, then `sysctl`, then `getconf`, falling back to 4). The default stays unlimited (`--jobs 0`) (#766)

### Changed
- Faster test execution: removed avoidable subshell forks from the per-test hot path (runtime-error detection, subshell-output decode, name normalization, test-id generation, retry-count lookup, and the passing-test line are now fork-free), and per-test temp-file cleanup no longer forks `rm` when the test created none (`rm` 102 -> 2 on a 100-test file). No behaviour change (#764)
- Per-test execution time now defaults to `auto` (`BASHUNIT_SHOW_EXECUTION_TIME=true|false|auto`): shown when the shell has a fork-free clock (Bash 5.0+, GNU `date`), hidden when measuring would fork an interpreter (e.g. Bash 3.2 on macOS, which falls back to `perl`). This removes ~2 `perl` forks per test on those shells. `--profile`, `--verbose`, reports, and `=true` still measure. See `adrs/adr-008-auto-skip-per-test-timing.md` (#765)
Expand Down

8 changes: 5 additions & 3 deletions
docs/command-line.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -67,7 +67,7 @@ bashunit test tests/ --parallel --simple
| `-w, --watch` | Watch files and re-run tests on change |
| `--log-junit, --report-junit <file>` | Write JUnit XML report |
| `--log-gha <file>` | Write GitHub Actions workflow-commands log |
| `-j, --jobs <N>` | Run tests in parallel with max N concurrent jobs |
| `-j, --jobs <N\|auto>` | Run tests in parallel with max N concurrent jobs (`auto` = CPU cores) |
| `-p, --parallel` | Run tests in parallel |
| `--no-parallel` | Run tests sequentially |
| `-r, --report-html <file>` | Write HTML report |
Expand DownExpand Up@@ -314,22 +314,24 @@ run sequentially.

### Jobs

> `bashunit test -j|--jobs <N>`
> `bashunit test -j|--jobs <N|auto>`

Run tests in parallel with a maximum of N concurrent jobs. This implicitly
enables parallel mode.

Use this to limit CPU usage on CI or machines with constrained resources.
Pass `auto` to cap concurrency at the number of detected CPU cores.

::: code-group
```bash [Example]
bashunit test tests/ --jobs 4
bashunit test tests/ --jobs auto
```
:::

::: tip
`--jobs 0` (the default) means unlimited concurrency, which is equivalent to
`--parallel`.
`--parallel`. `--jobs auto` caps at the detected CPU core count.
:::

### Output Style
Expand Down

25 changes: 25 additions & 0 deletions
src/check_os.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -61,6 +61,30 @@ function bashunit::check_os::is_windows() {
 esac
}

##
# Detects the number of online CPU cores, portably across Linux/macOS/BSD.
# Tries nproc, then sysctl, then getconf; falls back to 4 when none report a
# usable positive integer. Takes the first whitespace-delimited token so a
# stray flag or trailing text never poisons the arithmetic guard.
# Returns: prints the core count (>= 1) to stdout.
##
function bashunit::check_os::nproc() {
 local cores=""
 cores="$(nproc 2>/dev/null)" || cores=""
 if [ -z "$cores" ]; then
 cores="$(sysctl -n hw.ncpu 2>/dev/null)" || cores=""
 fi
 if [ -z "$cores" ]; then
 cores="$(getconf _NPROCESSORS_ONLN 2>/dev/null)" || cores=""
 fi
 cores="${cores%% *}"
 case "$cores" in
 '' | *[!0-9]*) cores=4 ;;
 esac
 [ "$cores" -lt 1 ] && cores=4
 echo "$cores"
}

function bashunit::check_os::is_busybox() {

 case "$_BASHUNIT_DISTRO" in
Expand All@@ -78,6 +102,7 @@ bashunit::check_os::init

export _BASHUNIT_OS
export _BASHUNIT_DISTRO
export -f bashunit::check_os::nproc
export -f bashunit::check_os::is_alpine
export -f bashunit::check_os::is_busybox
export -f bashunit::check_os::is_ubuntu
Expand Down

2 changes: 1 addition & 1 deletion
src/console_header.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -119,7 +119,7 @@ Options:
 --tag <name> Only run tests with matching @tag (repeatable, OR logic)
 --exclude-tag <name> Skip tests with matching @tag (repeatable, exclude wins)
 --log-junit, --report-junit <file> Write JUnit XML report
 -j, --jobs <N> Run tests in parallel with max N concurrent jobs
 -j, --jobs <N|auto> Run tests in parallel with max N concurrent jobs ("auto" = CPU cores)
 -p, --parallel Run tests in parallel (unlimited concurrency)
 --no-parallel Run tests sequentially
 -r, --report-html <file> Write HTML report
Expand Down

8 changes: 7 additions & 1 deletion
src/main.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -99,7 +99,13 @@ function bashunit::main::cmd_test() {
 ;;
 -j | --jobs)
 export BASHUNIT_PARALLEL_RUN=true
 export BASHUNIT_PARALLEL_JOBS="$2"
 # "auto" caps at the detected core count; wait_for_job_slot needs an
 # integer, so resolve it here rather than leaking the string downstream.
 if [ "$2" = "auto" ]; then
 export BASHUNIT_PARALLEL_JOBS="$(bashunit::check_os::nproc)"
 else
 export BASHUNIT_PARALLEL_JOBS="$2"
 fi
 shift
 ;;
 --no-parallel)
Expand Down

19 changes: 19 additions & 0 deletions
tests/acceptance/bashunit_parallel_consistency_test.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -23,3 +23,22 @@ function test_parallel_and_sequential_results_match() {

 assert_equals "$sequential_summary" "$parallel_summary"
}

function test_jobs_auto_caps_at_detected_cores_and_matches_sequential() {
 local file1=tests/acceptance/fixtures/test_bashunit_when_a_test_passes.sh
 local file2=tests/acceptance/fixtures/test_bashunit_when_a_test_fail.sh

 local sequential_output
 sequential_output=$(./bashunit --no-parallel --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

 local auto_output
 auto_output=$(./bashunit --jobs auto --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

 local sequential_summary
 sequential_summary=$(echo "$sequential_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

 local auto_summary
 auto_summary=$(echo "$auto_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

 assert_equals "$sequential_summary" "$auto_summary"
}

29 changes: 29 additions & 0 deletions
tests/unit/check_os_test.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -77,3 +77,32 @@ function test_not_alpine_is_not_busybox() {
 assert_general_error "$(bashunit::check_os::is_alpine)"
 assert_general_error "$(bashunit::check_os::is_busybox)"
}

function test_nproc_uses_nproc_when_available() {
 bashunit::mock nproc echo "8"

 assert_same "8" "$(bashunit::check_os::nproc)"
}

function test_nproc_falls_back_to_sysctl_when_nproc_unavailable() {
 bashunit::mock nproc mock_false
 bashunit::mock sysctl echo "6"

 assert_same "6" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_no_detector_available() {
 bashunit::mock nproc mock_false
 bashunit::mock sysctl mock_false
 bashunit::mock getconf mock_false

 assert_same "4" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_output_is_not_numeric() {
 bashunit::mock nproc echo "not-a-number"
 bashunit::mock sysctl mock_false
 bashunit::mock getconf mock_false

 assert_same "4" "$(bashunit::check_os::nproc)"
}
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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feat(parallel): add --jobs auto to cap concurrency at CPU cores#771

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 Merged

Chemaclass
merged 1 commit into

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Jul 12, 2026
 Merged


feat(parallel): add --jobs auto to cap concurrency at CPU cores
#771
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3 changes: 3 additions & 0 deletions
CHANGELOG.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -2,6 +2,9 @@

## Unreleased

### Added
- `--jobs auto` (and `-j auto`) caps parallel concurrency at the detected CPU core count, portable across Linux/macOS/BSD (`nproc`, then `sysctl`, then `getconf`, falling back to 4). The default stays unlimited (`--jobs 0`) (#766)

### Changed
- Faster test execution: removed avoidable subshell forks from the per-test hot path (runtime-error detection, subshell-output decode, name normalization, test-id generation, retry-count lookup, and the passing-test line are now fork-free), and per-test temp-file cleanup no longer forks `rm` when the test created none (`rm` 102 -> 2 on a 100-test file). No behaviour change (#764)
- Per-test execution time now defaults to `auto` (`BASHUNIT_SHOW_EXECUTION_TIME=true|false|auto`): shown when the shell has a fork-free clock (Bash 5.0+, GNU `date`), hidden when measuring would fork an interpreter (e.g. Bash 3.2 on macOS, which falls back to `perl`). This removes ~2 `perl` forks per test on those shells. `--profile`, `--verbose`, reports, and `=true` still measure. See `adrs/adr-008-auto-skip-per-test-timing.md` (#765)
Expand Down

8 changes: 5 additions & 3 deletions
docs/command-line.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -67,7 +67,7 @@ bashunit test tests/ --parallel --simple
| `-w, --watch` | Watch files and re-run tests on change |
| `--log-junit, --report-junit <file>` | Write JUnit XML report |
| `--log-gha <file>` | Write GitHub Actions workflow-commands log |
| `-j, --jobs <N>` | Run tests in parallel with max N concurrent jobs |
| `-j, --jobs <N\|auto>` | Run tests in parallel with max N concurrent jobs (`auto` = CPU cores) |
| `-p, --parallel` | Run tests in parallel |
| `--no-parallel` | Run tests sequentially |
| `-r, --report-html <file>` | Write HTML report |
Expand DownExpand Up@@ -314,22 +314,24 @@ run sequentially.

### Jobs

> `bashunit test -j|--jobs <N>`
> `bashunit test -j|--jobs <N|auto>`

Run tests in parallel with a maximum of N concurrent jobs. This implicitly
enables parallel mode.

Use this to limit CPU usage on CI or machines with constrained resources.
Pass `auto` to cap concurrency at the number of detected CPU cores.

::: code-group
```bash [Example]
bashunit test tests/ --jobs 4
bashunit test tests/ --jobs auto
```
:::

::: tip
`--jobs 0` (the default) means unlimited concurrency, which is equivalent to
`--parallel`.
`--parallel`. `--jobs auto` caps at the detected CPU core count.
:::

### Output Style
Expand Down

25 changes: 25 additions & 0 deletions
src/check_os.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -61,6 +61,30 @@ function bashunit::check_os::is_windows() {
 esac
}

##
# Detects the number of online CPU cores, portably across Linux/macOS/BSD.
# Tries nproc, then sysctl, then getconf; falls back to 4 when none report a
# usable positive integer. Takes the first whitespace-delimited token so a
# stray flag or trailing text never poisons the arithmetic guard.
# Returns: prints the core count (>= 1) to stdout.
##
function bashunit::check_os::nproc() {
 local cores=""
 cores="$(nproc 2>/dev/null)" || cores=""
 if [ -z "$cores" ]; then
 cores="$(sysctl -n hw.ncpu 2>/dev/null)" || cores=""
 fi
 if [ -z "$cores" ]; then
 cores="$(getconf _NPROCESSORS_ONLN 2>/dev/null)" || cores=""
 fi
 cores="${cores%% *}"
 case "$cores" in
 '' | *[!0-9]*) cores=4 ;;
 esac
 [ "$cores" -lt 1 ] && cores=4
 echo "$cores"
}

function bashunit::check_os::is_busybox() {

 case "$_BASHUNIT_DISTRO" in
Expand All@@ -78,6 +102,7 @@ bashunit::check_os::init

export _BASHUNIT_OS
export _BASHUNIT_DISTRO
export -f bashunit::check_os::nproc
export -f bashunit::check_os::is_alpine
export -f bashunit::check_os::is_busybox
export -f bashunit::check_os::is_ubuntu
Expand Down

2 changes: 1 addition & 1 deletion
src/console_header.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -119,7 +119,7 @@ Options:
 --tag <name> Only run tests with matching @tag (repeatable, OR logic)
 --exclude-tag <name> Skip tests with matching @tag (repeatable, exclude wins)
 --log-junit, --report-junit <file> Write JUnit XML report
 -j, --jobs <N> Run tests in parallel with max N concurrent jobs
 -j, --jobs <N|auto> Run tests in parallel with max N concurrent jobs ("auto" = CPU cores)
 -p, --parallel Run tests in parallel (unlimited concurrency)
 --no-parallel Run tests sequentially
 -r, --report-html <file> Write HTML report
Expand Down

8 changes: 7 additions & 1 deletion
src/main.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -99,7 +99,13 @@ function bashunit::main::cmd_test() {
 ;;
 -j | --jobs)
 export BASHUNIT_PARALLEL_RUN=true
 export BASHUNIT_PARALLEL_JOBS="$2"
 # "auto" caps at the detected core count; wait_for_job_slot needs an
 # integer, so resolve it here rather than leaking the string downstream.
 if [ "$2" = "auto" ]; then
 export BASHUNIT_PARALLEL_JOBS="$(bashunit::check_os::nproc)"
 else
 export BASHUNIT_PARALLEL_JOBS="$2"
 fi
 shift
 ;;
 --no-parallel)
Expand Down

19 changes: 19 additions & 0 deletions
tests/acceptance/bashunit_parallel_consistency_test.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -23,3 +23,22 @@ function test_parallel_and_sequential_results_match() {

 assert_equals "$sequential_summary" "$parallel_summary"
}

function test_jobs_auto_caps_at_detected_cores_and_matches_sequential() {
 local file1=tests/acceptance/fixtures/test_bashunit_when_a_test_passes.sh
 local file2=tests/acceptance/fixtures/test_bashunit_when_a_test_fail.sh

 local sequential_output
 sequential_output=$(./bashunit --no-parallel --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

 local auto_output
 auto_output=$(./bashunit --jobs auto --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

 local sequential_summary
 sequential_summary=$(echo "$sequential_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

 local auto_summary
 auto_summary=$(echo "$auto_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

 assert_equals "$sequential_summary" "$auto_summary"
}

29 changes: 29 additions & 0 deletions
tests/unit/check_os_test.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -77,3 +77,32 @@ function test_not_alpine_is_not_busybox() {
 assert_general_error "$(bashunit::check_os::is_alpine)"
 assert_general_error "$(bashunit::check_os::is_busybox)"
}

function test_nproc_uses_nproc_when_available() {
 bashunit::mock nproc echo "8"

 assert_same "8" "$(bashunit::check_os::nproc)"
}

function test_nproc_falls_back_to_sysctl_when_nproc_unavailable() {
 bashunit::mock nproc mock_false
 bashunit::mock sysctl echo "6"

 assert_same "6" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_no_detector_available() {
 bashunit::mock nproc mock_false
 bashunit::mock sysctl mock_false
 bashunit::mock getconf mock_false

 assert_same "4" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_output_is_not_numeric() {
 bashunit::mock nproc echo "not-a-number"
 bashunit::mock sysctl mock_false
 bashunit::mock getconf mock_false

 assert_same "4" "$(bashunit::check_os::nproc)"
}
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
feat(parallel): add --jobs auto to cap concurrency at CPU cores#771

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Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

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privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
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to your account

 Merged

Chemaclass
merged 1 commit into

from

Jul 12, 2026
 Merged


feat(parallel): add --jobs auto to cap concurrency at CPU cores
#771
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3 changes: 3 additions & 0 deletions
CHANGELOG.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -2,6 +2,9 @@

## Unreleased

### Added
- `--jobs auto` (and `-j auto`) caps parallel concurrency at the detected CPU core count, portable across Linux/macOS/BSD (`nproc`, then `sysctl`, then `getconf`, falling back to 4). The default stays unlimited (`--jobs 0`) (#766)

### Changed
- Faster test execution: removed avoidable subshell forks from the per-test hot path (runtime-error detection, subshell-output decode, name normalization, test-id generation, retry-count lookup, and the passing-test line are now fork-free), and per-test temp-file cleanup no longer forks `rm` when the test created none (`rm` 102 -> 2 on a 100-test file). No behaviour change (#764)
- Per-test execution time now defaults to `auto` (`BASHUNIT_SHOW_EXECUTION_TIME=true|false|auto`): shown when the shell has a fork-free clock (Bash 5.0+, GNU `date`), hidden when measuring would fork an interpreter (e.g. Bash 3.2 on macOS, which falls back to `perl`). This removes ~2 `perl` forks per test on those shells. `--profile`, `--verbose`, reports, and `=true` still measure. See `adrs/adr-008-auto-skip-per-test-timing.md` (#765)
Expand Down

8 changes: 5 additions & 3 deletions
docs/command-line.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -67,7 +67,7 @@ bashunit test tests/ --parallel --simple
| `-w, --watch` | Watch files and re-run tests on change |
| `--log-junit, --report-junit <file>` | Write JUnit XML report |
| `--log-gha <file>` | Write GitHub Actions workflow-commands log |
| `-j, --jobs <N>` | Run tests in parallel with max N concurrent jobs |
| `-j, --jobs <N\|auto>` | Run tests in parallel with max N concurrent jobs (`auto` = CPU cores) |
| `-p, --parallel` | Run tests in parallel |
| `--no-parallel` | Run tests sequentially |
| `-r, --report-html <file>` | Write HTML report |
Expand DownExpand Up@@ -314,22 +314,24 @@ run sequentially.

### Jobs

> `bashunit test -j|--jobs <N>`
> `bashunit test -j|--jobs <N|auto>`

Run tests in parallel with a maximum of N concurrent jobs. This implicitly
enables parallel mode.

Use this to limit CPU usage on CI or machines with constrained resources.
Pass `auto` to cap concurrency at the number of detected CPU cores.

::: code-group
```bash [Example]
bashunit test tests/ --jobs 4
bashunit test tests/ --jobs auto
```
:::

::: tip
`--jobs 0` (the default) means unlimited concurrency, which is equivalent to
`--parallel`.
`--parallel`. `--jobs auto` caps at the detected CPU core count.
:::

### Output Style
Expand Down

25 changes: 25 additions & 0 deletions
src/check_os.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -61,6 +61,30 @@ function bashunit::check_os::is_windows() {
 esac
}

##
# Detects the number of online CPU cores, portably across Linux/macOS/BSD.
# Tries nproc, then sysctl, then getconf; falls back to 4 when none report a
# usable positive integer. Takes the first whitespace-delimited token so a
# stray flag or trailing text never poisons the arithmetic guard.
# Returns: prints the core count (>= 1) to stdout.
##
function bashunit::check_os::nproc() {
 local cores=""
 cores="$(nproc 2>/dev/null)" || cores=""
 if [ -z "$cores" ]; then
 cores="$(sysctl -n hw.ncpu 2>/dev/null)" || cores=""
 fi
 if [ -z "$cores" ]; then
 cores="$(getconf _NPROCESSORS_ONLN 2>/dev/null)" || cores=""
 fi
 cores="${cores%% *}"
 case "$cores" in
 '' | *[!0-9]*) cores=4 ;;
 esac
 [ "$cores" -lt 1 ] && cores=4
 echo "$cores"
}

function bashunit::check_os::is_busybox() {

 case "$_BASHUNIT_DISTRO" in
Expand All@@ -78,6 +102,7 @@ bashunit::check_os::init

export _BASHUNIT_OS
export _BASHUNIT_DISTRO
export -f bashunit::check_os::nproc
export -f bashunit::check_os::is_alpine
export -f bashunit::check_os::is_busybox
export -f bashunit::check_os::is_ubuntu
Expand Down

2 changes: 1 addition & 1 deletion
src/console_header.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -119,7 +119,7 @@ Options:
 --tag <name> Only run tests with matching @tag (repeatable, OR logic)
 --exclude-tag <name> Skip tests with matching @tag (repeatable, exclude wins)
 --log-junit, --report-junit <file> Write JUnit XML report
 -j, --jobs <N> Run tests in parallel with max N concurrent jobs
 -j, --jobs <N|auto> Run tests in parallel with max N concurrent jobs ("auto" = CPU cores)
 -p, --parallel Run tests in parallel (unlimited concurrency)
 --no-parallel Run tests sequentially
 -r, --report-html <file> Write HTML report
Expand Down

8 changes: 7 additions & 1 deletion
src/main.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -99,7 +99,13 @@ function bashunit::main::cmd_test() {
 ;;
 -j | --jobs)
 export BASHUNIT_PARALLEL_RUN=true
 export BASHUNIT_PARALLEL_JOBS="$2"
 # "auto" caps at the detected core count; wait_for_job_slot needs an
 # integer, so resolve it here rather than leaking the string downstream.
 if [ "$2" = "auto" ]; then
 export BASHUNIT_PARALLEL_JOBS="$(bashunit::check_os::nproc)"
 else
 export BASHUNIT_PARALLEL_JOBS="$2"
 fi
 shift
 ;;
 --no-parallel)
Expand Down

19 changes: 19 additions & 0 deletions
tests/acceptance/bashunit_parallel_consistency_test.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -23,3 +23,22 @@ function test_parallel_and_sequential_results_match() {

 assert_equals "$sequential_summary" "$parallel_summary"
}

function test_jobs_auto_caps_at_detected_cores_and_matches_sequential() {
 local file1=tests/acceptance/fixtures/test_bashunit_when_a_test_passes.sh
 local file2=tests/acceptance/fixtures/test_bashunit_when_a_test_fail.sh

 local sequential_output
 sequential_output=$(./bashunit --no-parallel --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

 local auto_output
 auto_output=$(./bashunit --jobs auto --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

 local sequential_summary
 sequential_summary=$(echo "$sequential_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

 local auto_summary
 auto_summary=$(echo "$auto_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

 assert_equals "$sequential_summary" "$auto_summary"
}

29 changes: 29 additions & 0 deletions
tests/unit/check_os_test.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -77,3 +77,32 @@ function test_not_alpine_is_not_busybox() {
 assert_general_error "$(bashunit::check_os::is_alpine)"
 assert_general_error "$(bashunit::check_os::is_busybox)"
}

function test_nproc_uses_nproc_when_available() {
 bashunit::mock nproc echo "8"

 assert_same "8" "$(bashunit::check_os::nproc)"
}

function test_nproc_falls_back_to_sysctl_when_nproc_unavailable() {
 bashunit::mock nproc mock_false
 bashunit::mock sysctl echo "6"

 assert_same "6" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_no_detector_available() {
 bashunit::mock nproc mock_false
 bashunit::mock sysctl mock_false
 bashunit::mock getconf mock_false

 assert_same "4" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_output_is_not_numeric() {
 bashunit::mock nproc echo "not-a-number"
 bashunit::mock sysctl mock_false
 bashunit::mock getconf mock_false

 assert_same "4" "$(bashunit::check_os::nproc)"
}
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
feat(parallel): add --jobs auto to cap concurrency at CPU cores#771

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

 Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and
privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
Sign in
to your account

 Merged

Chemaclass
merged 1 commit into

from

Jul 12, 2026
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feat(parallel): add --jobs auto to cap concurrency at CPU cores
#771
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3 changes: 3 additions & 0 deletions
CHANGELOG.md

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -2,6 +2,9 @@

## Unreleased

### Added
- `--jobs auto` (and `-j auto`) caps parallel concurrency at the detected CPU core count, portable across Linux/macOS/BSD (`nproc`, then `sysctl`, then `getconf`, falling back to 4). The default stays unlimited (`--jobs 0`) (#766)

### Changed
- Faster test execution: removed avoidable subshell forks from the per-test hot path (runtime-error detection, subshell-output decode, name normalization, test-id generation, retry-count lookup, and the passing-test line are now fork-free), and per-test temp-file cleanup no longer forks `rm` when the test created none (`rm` 102 -> 2 on a 100-test file). No behaviour change (#764)
- Per-test execution time now defaults to `auto` (`BASHUNIT_SHOW_EXECUTION_TIME=true|false|auto`): shown when the shell has a fork-free clock (Bash 5.0+, GNU `date`), hidden when measuring would fork an interpreter (e.g. Bash 3.2 on macOS, which falls back to `perl`). This removes ~2 `perl` forks per test on those shells. `--profile`, `--verbose`, reports, and `=true` still measure. See `adrs/adr-008-auto-skip-per-test-timing.md` (#765)
Expand Down

8 changes: 5 additions & 3 deletions
docs/command-line.md

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Original file line numberDiff line numberDiff line change
Expand Up@@ -67,7 +67,7 @@ bashunit test tests/ --parallel --simple
| `-w, --watch` | Watch files and re-run tests on change |
| `--log-junit, --report-junit <file>` | Write JUnit XML report |
| `--log-gha <file>` | Write GitHub Actions workflow-commands log |
| `-j, --jobs <N>` | Run tests in parallel with max N concurrent jobs |
| `-j, --jobs <N\|auto>` | Run tests in parallel with max N concurrent jobs (`auto` = CPU cores) |
| `-p, --parallel` | Run tests in parallel |
| `--no-parallel` | Run tests sequentially |
| `-r, --report-html <file>` | Write HTML report |
Expand DownExpand Up@@ -314,22 +314,24 @@ run sequentially.

### Jobs

> `bashunit test -j|--jobs <N>`
> `bashunit test -j|--jobs <N|auto>`

Run tests in parallel with a maximum of N concurrent jobs. This implicitly
enables parallel mode.

Use this to limit CPU usage on CI or machines with constrained resources.
Pass `auto` to cap concurrency at the number of detected CPU cores.

::: code-group
```bash [Example]
bashunit test tests/ --jobs 4
bashunit test tests/ --jobs auto
```
:::

::: tip
`--jobs 0` (the default) means unlimited concurrency, which is equivalent to
`--parallel`.
`--parallel`. `--jobs auto` caps at the detected CPU core count.
:::

### Output Style
Expand Down

25 changes: 25 additions & 0 deletions
src/check_os.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -61,6 +61,30 @@ function bashunit::check_os::is_windows() {
 esac
}

##
# Detects the number of online CPU cores, portably across Linux/macOS/BSD.
# Tries nproc, then sysctl, then getconf; falls back to 4 when none report a
# usable positive integer. Takes the first whitespace-delimited token so a
# stray flag or trailing text never poisons the arithmetic guard.
# Returns: prints the core count (>= 1) to stdout.
##
function bashunit::check_os::nproc() {
 local cores=""
 cores="$(nproc 2>/dev/null)" || cores=""
 if [ -z "$cores" ]; then
 cores="$(sysctl -n hw.ncpu 2>/dev/null)" || cores=""
 fi
 if [ -z "$cores" ]; then
 cores="$(getconf _NPROCESSORS_ONLN 2>/dev/null)" || cores=""
 fi
 cores="${cores%% *}"
 case "$cores" in
 '' | *[!0-9]*) cores=4 ;;
 esac
 [ "$cores" -lt 1 ] && cores=4
 echo "$cores"
}

function bashunit::check_os::is_busybox() {

 case "$_BASHUNIT_DISTRO" in
Expand All@@ -78,6 +102,7 @@ bashunit::check_os::init

export _BASHUNIT_OS
export _BASHUNIT_DISTRO
export -f bashunit::check_os::nproc
export -f bashunit::check_os::is_alpine
export -f bashunit::check_os::is_busybox
export -f bashunit::check_os::is_ubuntu
Expand Down

2 changes: 1 addition & 1 deletion
src/console_header.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -119,7 +119,7 @@ Options:
 --tag <name> Only run tests with matching @tag (repeatable, OR logic)
 --exclude-tag <name> Skip tests with matching @tag (repeatable, exclude wins)
 --log-junit, --report-junit <file> Write JUnit XML report
 -j, --jobs <N> Run tests in parallel with max N concurrent jobs
 -j, --jobs <N|auto> Run tests in parallel with max N concurrent jobs ("auto" = CPU cores)
 -p, --parallel Run tests in parallel (unlimited concurrency)
 --no-parallel Run tests sequentially
 -r, --report-html <file> Write HTML report
Expand Down

8 changes: 7 additions & 1 deletion
src/main.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -99,7 +99,13 @@ function bashunit::main::cmd_test() {
 ;;
 -j | --jobs)
 export BASHUNIT_PARALLEL_RUN=true
 export BASHUNIT_PARALLEL_JOBS="$2"
 # "auto" caps at the detected core count; wait_for_job_slot needs an
 # integer, so resolve it here rather than leaking the string downstream.
 if [ "$2" = "auto" ]; then
 export BASHUNIT_PARALLEL_JOBS="$(bashunit::check_os::nproc)"
 else
 export BASHUNIT_PARALLEL_JOBS="$2"
 fi
 shift
 ;;
 --no-parallel)
Expand Down

19 changes: 19 additions & 0 deletions
tests/acceptance/bashunit_parallel_consistency_test.sh

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -23,3 +23,22 @@ function test_parallel_and_sequential_results_match() {

 assert_equals "$sequential_summary" "$parallel_summary"
}

function test_jobs_auto_caps_at_detected_cores_and_matches_sequential() {
 local file1=tests/acceptance/fixtures/test_bashunit_when_a_test_passes.sh
 local file2=tests/acceptance/fixtures/test_bashunit_when_a_test_fail.sh

 local sequential_output
 sequential_output=$(./bashunit --no-parallel --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

 local auto_output
 auto_output=$(./bashunit --jobs auto --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

 local sequential_summary
 sequential_summary=$(echo "$sequential_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

 local auto_summary
 auto_summary=$(echo "$auto_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

 assert_equals "$sequential_summary" "$auto_summary"
}

29 changes: 29 additions & 0 deletions
tests/unit/check_os_test.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -77,3 +77,32 @@ function test_not_alpine_is_not_busybox() {
 assert_general_error "$(bashunit::check_os::is_alpine)"
 assert_general_error "$(bashunit::check_os::is_busybox)"
}

function test_nproc_uses_nproc_when_available() {
 bashunit::mock nproc echo "8"

 assert_same "8" "$(bashunit::check_os::nproc)"
}

function test_nproc_falls_back_to_sysctl_when_nproc_unavailable() {
 bashunit::mock nproc mock_false
 bashunit::mock sysctl echo "6"

 assert_same "6" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_no_detector_available() {
 bashunit::mock nproc mock_false
 bashunit::mock sysctl mock_false
 bashunit::mock getconf mock_false

 assert_same "4" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_output_is_not_numeric() {
 bashunit::mock nproc echo "not-a-number"
 bashunit::mock sysctl mock_false
 bashunit::mock getconf mock_false

 assert_same "4" "$(bashunit::check_os::nproc)"
}
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
feat(parallel): add --jobs auto to cap concurrency at CPU cores#771

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 Merged

Chemaclass
merged 1 commit into

from

Jul 12, 2026
 Merged


feat(parallel): add --jobs auto to cap concurrency at CPU cores
#771
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3 changes: 3 additions & 0 deletions
CHANGELOG.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -2,6 +2,9 @@

## Unreleased

### Added
- `--jobs auto` (and `-j auto`) caps parallel concurrency at the detected CPU core count, portable across Linux/macOS/BSD (`nproc`, then `sysctl`, then `getconf`, falling back to 4). The default stays unlimited (`--jobs 0`) (#766)

### Changed
- Faster test execution: removed avoidable subshell forks from the per-test hot path (runtime-error detection, subshell-output decode, name normalization, test-id generation, retry-count lookup, and the passing-test line are now fork-free), and per-test temp-file cleanup no longer forks `rm` when the test created none (`rm` 102 -> 2 on a 100-test file). No behaviour change (#764)
- Per-test execution time now defaults to `auto` (`BASHUNIT_SHOW_EXECUTION_TIME=true|false|auto`): shown when the shell has a fork-free clock (Bash 5.0+, GNU `date`), hidden when measuring would fork an interpreter (e.g. Bash 3.2 on macOS, which falls back to `perl`). This removes ~2 `perl` forks per test on those shells. `--profile`, `--verbose`, reports, and `=true` still measure. See `adrs/adr-008-auto-skip-per-test-timing.md` (#765)
Expand Down

8 changes: 5 additions & 3 deletions
docs/command-line.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -67,7 +67,7 @@ bashunit test tests/ --parallel --simple
| `-w, --watch` | Watch files and re-run tests on change |
| `--log-junit, --report-junit <file>` | Write JUnit XML report |
| `--log-gha <file>` | Write GitHub Actions workflow-commands log |
| `-j, --jobs <N>` | Run tests in parallel with max N concurrent jobs |
| `-j, --jobs <N\|auto>` | Run tests in parallel with max N concurrent jobs (`auto` = CPU cores) |
| `-p, --parallel` | Run tests in parallel |
| `--no-parallel` | Run tests sequentially |
| `-r, --report-html <file>` | Write HTML report |
Expand DownExpand Up@@ -314,22 +314,24 @@ run sequentially.

### Jobs

> `bashunit test -j|--jobs <N>`
> `bashunit test -j|--jobs <N|auto>`

Run tests in parallel with a maximum of N concurrent jobs. This implicitly
enables parallel mode.

Use this to limit CPU usage on CI or machines with constrained resources.
Pass `auto` to cap concurrency at the number of detected CPU cores.

::: code-group
```bash [Example]
bashunit test tests/ --jobs 4
bashunit test tests/ --jobs auto
```
:::

::: tip
`--jobs 0` (the default) means unlimited concurrency, which is equivalent to
`--parallel`.
`--parallel`. `--jobs auto` caps at the detected CPU core count.
:::

### Output Style
Expand Down

25 changes: 25 additions & 0 deletions
src/check_os.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -61,6 +61,30 @@ function bashunit::check_os::is_windows() {
 esac
}

##
# Detects the number of online CPU cores, portably across Linux/macOS/BSD.
# Tries nproc, then sysctl, then getconf; falls back to 4 when none report a
# usable positive integer. Takes the first whitespace-delimited token so a
# stray flag or trailing text never poisons the arithmetic guard.
# Returns: prints the core count (>= 1) to stdout.
##
function bashunit::check_os::nproc() {
 local cores=""
 cores="$(nproc 2>/dev/null)" || cores=""
 if [ -z "$cores" ]; then
 cores="$(sysctl -n hw.ncpu 2>/dev/null)" || cores=""
 fi
 if [ -z "$cores" ]; then
 cores="$(getconf _NPROCESSORS_ONLN 2>/dev/null)" || cores=""
 fi
 cores="${cores%% *}"
 case "$cores" in
 '' | *[!0-9]*) cores=4 ;;
 esac
 [ "$cores" -lt 1 ] && cores=4
 echo "$cores"
}

function bashunit::check_os::is_busybox() {

 case "$_BASHUNIT_DISTRO" in
Expand All@@ -78,6 +102,7 @@ bashunit::check_os::init

export _BASHUNIT_OS
export _BASHUNIT_DISTRO
export -f bashunit::check_os::nproc
export -f bashunit::check_os::is_alpine
export -f bashunit::check_os::is_busybox
export -f bashunit::check_os::is_ubuntu
Expand Down

2 changes: 1 addition & 1 deletion
src/console_header.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -119,7 +119,7 @@ Options:
 --tag <name> Only run tests with matching @tag (repeatable, OR logic)
 --exclude-tag <name> Skip tests with matching @tag (repeatable, exclude wins)
 --log-junit, --report-junit <file> Write JUnit XML report
 -j, --jobs <N> Run tests in parallel with max N concurrent jobs
 -j, --jobs <N|auto> Run tests in parallel with max N concurrent jobs ("auto" = CPU cores)
 -p, --parallel Run tests in parallel (unlimited concurrency)
 --no-parallel Run tests sequentially
 -r, --report-html <file> Write HTML report
Expand Down

8 changes: 7 additions & 1 deletion
src/main.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -99,7 +99,13 @@ function bashunit::main::cmd_test() {
 ;;
 -j | --jobs)
 export BASHUNIT_PARALLEL_RUN=true
 export BASHUNIT_PARALLEL_JOBS="$2"
 # "auto" caps at the detected core count; wait_for_job_slot needs an
 # integer, so resolve it here rather than leaking the string downstream.
 if [ "$2" = "auto" ]; then
 export BASHUNIT_PARALLEL_JOBS="$(bashunit::check_os::nproc)"
 else
 export BASHUNIT_PARALLEL_JOBS="$2"
 fi
 shift
 ;;
 --no-parallel)
Expand Down

19 changes: 19 additions & 0 deletions
tests/acceptance/bashunit_parallel_consistency_test.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -23,3 +23,22 @@ function test_parallel_and_sequential_results_match() {

 assert_equals "$sequential_summary" "$parallel_summary"
}

function test_jobs_auto_caps_at_detected_cores_and_matches_sequential() {
 local file1=tests/acceptance/fixtures/test_bashunit_when_a_test_passes.sh
 local file2=tests/acceptance/fixtures/test_bashunit_when_a_test_fail.sh

 local sequential_output
 sequential_output=$(./bashunit --no-parallel --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

 local auto_output
 auto_output=$(./bashunit --jobs auto --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

 local sequential_summary
 sequential_summary=$(echo "$sequential_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

 local auto_summary
 auto_summary=$(echo "$auto_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

 assert_equals "$sequential_summary" "$auto_summary"
}

29 changes: 29 additions & 0 deletions
tests/unit/check_os_test.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -77,3 +77,32 @@ function test_not_alpine_is_not_busybox() {
 assert_general_error "$(bashunit::check_os::is_alpine)"
 assert_general_error "$(bashunit::check_os::is_busybox)"
}

function test_nproc_uses_nproc_when_available() {
 bashunit::mock nproc echo "8"

 assert_same "8" "$(bashunit::check_os::nproc)"
}

function test_nproc_falls_back_to_sysctl_when_nproc_unavailable() {
 bashunit::mock nproc mock_false
 bashunit::mock sysctl echo "6"

 assert_same "6" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_no_detector_available() {
 bashunit::mock nproc mock_false
 bashunit::mock sysctl mock_false
 bashunit::mock getconf mock_false

 assert_same "4" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_output_is_not_numeric() {
 bashunit::mock nproc echo "not-a-number"
 bashunit::mock sysctl mock_false
 bashunit::mock getconf mock_false

 assert_same "4" "$(bashunit::check_os::nproc)"
}
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

Skip to content
feat(parallel): add --jobs auto to cap concurrency at CPU cores#771

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 Merged

Chemaclass
merged 1 commit into

from

Jul 12, 2026
 Merged


feat(parallel): add --jobs auto to cap concurrency at CPU cores
#771
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3 changes: 3 additions & 0 deletions
CHANGELOG.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -2,6 +2,9 @@

## Unreleased

### Added
- `--jobs auto` (and `-j auto`) caps parallel concurrency at the detected CPU core count, portable across Linux/macOS/BSD (`nproc`, then `sysctl`, then `getconf`, falling back to 4). The default stays unlimited (`--jobs 0`) (#766)

### Changed
- Faster test execution: removed avoidable subshell forks from the per-test hot path (runtime-error detection, subshell-output decode, name normalization, test-id generation, retry-count lookup, and the passing-test line are now fork-free), and per-test temp-file cleanup no longer forks `rm` when the test created none (`rm` 102 -> 2 on a 100-test file). No behaviour change (#764)
- Per-test execution time now defaults to `auto` (`BASHUNIT_SHOW_EXECUTION_TIME=true|false|auto`): shown when the shell has a fork-free clock (Bash 5.0+, GNU `date`), hidden when measuring would fork an interpreter (e.g. Bash 3.2 on macOS, which falls back to `perl`). This removes ~2 `perl` forks per test on those shells. `--profile`, `--verbose`, reports, and `=true` still measure. See `adrs/adr-008-auto-skip-per-test-timing.md` (#765)
Expand Down

8 changes: 5 additions & 3 deletions
docs/command-line.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -67,7 +67,7 @@ bashunit test tests/ --parallel --simple
| `-w, --watch` | Watch files and re-run tests on change |
| `--log-junit, --report-junit <file>` | Write JUnit XML report |
| `--log-gha <file>` | Write GitHub Actions workflow-commands log |
| `-j, --jobs <N>` | Run tests in parallel with max N concurrent jobs |
| `-j, --jobs <N\|auto>` | Run tests in parallel with max N concurrent jobs (`auto` = CPU cores) |
| `-p, --parallel` | Run tests in parallel |
| `--no-parallel` | Run tests sequentially |
| `-r, --report-html <file>` | Write HTML report |
Expand DownExpand Up@@ -314,22 +314,24 @@ run sequentially.

### Jobs

> `bashunit test -j|--jobs <N>`
> `bashunit test -j|--jobs <N|auto>`

Run tests in parallel with a maximum of N concurrent jobs. This implicitly
enables parallel mode.

Use this to limit CPU usage on CI or machines with constrained resources.
Pass `auto` to cap concurrency at the number of detected CPU cores.

::: code-group
```bash [Example]
bashunit test tests/ --jobs 4
bashunit test tests/ --jobs auto
```
:::

::: tip
`--jobs 0` (the default) means unlimited concurrency, which is equivalent to
`--parallel`.
`--parallel`. `--jobs auto` caps at the detected CPU core count.
:::

### Output Style
Expand Down

25 changes: 25 additions & 0 deletions
src/check_os.sh

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -61,6 +61,30 @@ function bashunit::check_os::is_windows() {
 esac
}

##
# Detects the number of online CPU cores, portably across Linux/macOS/BSD.
# Tries nproc, then sysctl, then getconf; falls back to 4 when none report a
# usable positive integer. Takes the first whitespace-delimited token so a
# stray flag or trailing text never poisons the arithmetic guard.
# Returns: prints the core count (>= 1) to stdout.
##
function bashunit::check_os::nproc() {
 local cores=""
 cores="$(nproc 2>/dev/null)" || cores=""
 if [ -z "$cores" ]; then
 cores="$(sysctl -n hw.ncpu 2>/dev/null)" || cores=""
 fi
 if [ -z "$cores" ]; then
 cores="$(getconf _NPROCESSORS_ONLN 2>/dev/null)" || cores=""
 fi
 cores="${cores%% *}"
 case "$cores" in
 '' | *[!0-9]*) cores=4 ;;
 esac
 [ "$cores" -lt 1 ] && cores=4
 echo "$cores"
}

function bashunit::check_os::is_busybox() {

 case "$_BASHUNIT_DISTRO" in
Expand All@@ -78,6 +102,7 @@ bashunit::check_os::init

export _BASHUNIT_OS
export _BASHUNIT_DISTRO
export -f bashunit::check_os::nproc
export -f bashunit::check_os::is_alpine
export -f bashunit::check_os::is_busybox
export -f bashunit::check_os::is_ubuntu
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2 changes: 1 addition & 1 deletion
src/console_header.sh

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Original file line numberDiff line numberDiff line change
Expand Up@@ -119,7 +119,7 @@ Options:
 --tag <name> Only run tests with matching @tag (repeatable, OR logic)
 --exclude-tag <name> Skip tests with matching @tag (repeatable, exclude wins)
 --log-junit, --report-junit <file> Write JUnit XML report
 -j, --jobs <N> Run tests in parallel with max N concurrent jobs
 -j, --jobs <N|auto> Run tests in parallel with max N concurrent jobs ("auto" = CPU cores)
 -p, --parallel Run tests in parallel (unlimited concurrency)
 --no-parallel Run tests sequentially
 -r, --report-html <file> Write HTML report
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8 changes: 7 additions & 1 deletion
src/main.sh

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Original file line numberDiff line numberDiff line change
Expand Up@@ -99,7 +99,13 @@ function bashunit::main::cmd_test() {
 ;;
 -j | --jobs)
 export BASHUNIT_PARALLEL_RUN=true
 export BASHUNIT_PARALLEL_JOBS="$2"
 # "auto" caps at the detected core count; wait_for_job_slot needs an
 # integer, so resolve it here rather than leaking the string downstream.
 if [ "$2" = "auto" ]; then
 export BASHUNIT_PARALLEL_JOBS="$(bashunit::check_os::nproc)"
 else
 export BASHUNIT_PARALLEL_JOBS="$2"
 fi
 shift
 ;;
 --no-parallel)
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19 changes: 19 additions & 0 deletions
tests/acceptance/bashunit_parallel_consistency_test.sh

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Expand Up@@ -23,3 +23,22 @@ function test_parallel_and_sequential_results_match() {

 assert_equals "$sequential_summary" "$parallel_summary"
}

function test_jobs_auto_caps_at_detected_cores_and_matches_sequential() {
 local file1=tests/acceptance/fixtures/test_bashunit_when_a_test_passes.sh
 local file2=tests/acceptance/fixtures/test_bashunit_when_a_test_fail.sh

 local sequential_output
 sequential_output=$(./bashunit --no-parallel --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

 local auto_output
 auto_output=$(./bashunit --jobs auto --env "$TEST_ENV_FILE" "$file1" "$file2" 2>&1) || true

 local sequential_summary
 sequential_summary=$(echo "$sequential_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

 local auto_summary
 auto_summary=$(echo "$auto_output" | grep -e "Tests:" -e "Assertions:" | tr '\n' ' ') || true

 assert_equals "$sequential_summary" "$auto_summary"
}

29 changes: 29 additions & 0 deletions
tests/unit/check_os_test.sh

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Original file line numberDiff line numberDiff line change
Expand Up@@ -77,3 +77,32 @@ function test_not_alpine_is_not_busybox() {
 assert_general_error "$(bashunit::check_os::is_alpine)"
 assert_general_error "$(bashunit::check_os::is_busybox)"
}

function test_nproc_uses_nproc_when_available() {
 bashunit::mock nproc echo "8"

 assert_same "8" "$(bashunit::check_os::nproc)"
}

function test_nproc_falls_back_to_sysctl_when_nproc_unavailable() {
 bashunit::mock nproc mock_false
 bashunit::mock sysctl echo "6"

 assert_same "6" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_no_detector_available() {
 bashunit::mock nproc mock_false
 bashunit::mock sysctl mock_false
 bashunit::mock getconf mock_false

 assert_same "4" "$(bashunit::check_os::nproc)"
}

function test_nproc_defaults_to_four_when_output_is_not_numeric() {
 bashunit::mock nproc echo "not-a-number"
 bashunit::mock sysctl mock_false
 bashunit::mock getconf mock_false

 assert_same "4" "$(bashunit::check_os::nproc)"
}
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