fix(config): make prefer-offline and prefer-online exclusive by mvanhorn · Pull Request #9129 · npm/cli

mvanhorn · 2026-03-18T17:53:08Z

Summary

Adds a warning when both prefer-offline and prefer-online are set to true in config, telling the user that prefer-offline takes precedence.

Why this matters

When both flags are active, npm silently prioritizes prefer-offline, causing commands like npm view <package> version to return stale cached data with no indication that prefer-online is being ignored (#9113). Users end up debugging registry connectivity, token issues, or package naming when the actual problem is a config conflict.

Changes

workspaces/config/lib/index.js: After all config sources are loaded, check if both prefer-offline and prefer-online are truthy. If so, emit a warning via queueWarning() so it follows the standard warning lifecycle.
workspaces/config/test/index.js: Added test that passes both --prefer-offline and --prefer-online via CLI args and verifies the warning is emitted.

Testing

New test passes: "warn when both prefer-offline and prefer-online are set"
Warning text: config Both prefer-offline and prefer-online are set. prefer-offline takes precedence.
Warning fires once at config load, not on every command invocation

Fixes#9113

This contribution was developed with AI assistance (Claude Code).

When both prefer-offline and prefer-online are set to true in config, npm silently prioritizes prefer-offline without any indication to the user. This causes commands like npm view to return stale cached data with no warning. Add a conflict detection check during config load that emits a warning when both flags are active, telling the user which flag takes precedence. Fixesnpm#9113

wraithgar · 2026-03-18T18:18:46Z

We have a precedent in config to label config items as mutually exclusive. Probably best to do that than to throw a very specific if statement in to our main config loop for one condition.

Example:

cli/workspaces/config/lib/definitions/definitions.js

Line 249 in 7e9d538

exclusive: ['min-release-age'],

Instead of a one-off if check in the config load loop, use the existing exclusive property on config definitions to mark prefer-offline and prefer-online as mutually exclusive. This matches the established pattern used by before/min-release-age, expect-results/expect-result-count, and the save-* flags. Fixesnpm#9113

mvanhorn · 2026-03-18T18:25:22Z

Updated - moved to exclusive definitions on both prefer-offline and prefer-online instead of the one-off check. Removed the custom if from config load.

wraithgar · 2026-03-18T18:42:03Z

 })

-t.test('warn when both prefer-offline and prefer-online are set', async t => {
+t.test('error when both prefer-offline and prefer-online are set', async t => {


we don't need a test for config settings. We have tests that make sure that exclusive works but it doesn't make a lot of sense to add tests for each thing we've added an exclusive tag for. The config is the config.

Makes sense - I'll remove the test. The exclusive mechanism is already covered generically so a per-field test is redundant.

The exclusive mechanism is already tested generically. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mvanhorn · 2026-03-19T01:04:26Z

Thanks for the review and the pointer to the exclusive config pattern - much cleaner than the one-off check.

mvanhorn · 2026-03-18T17:53:08Z

Summary

Adds a warning when both prefer-offline and prefer-online are set to true in config, telling the user that prefer-offline takes precedence.

Why this matters

When both flags are active, npm silently prioritizes prefer-offline, causing commands like npm view <package> version to return stale cached data with no indication that prefer-online is being ignored (#9113). Users end up debugging registry connectivity, token issues, or package naming when the actual problem is a config conflict.

Changes

workspaces/config/lib/index.js: After all config sources are loaded, check if both prefer-offline and prefer-online are truthy. If so, emit a warning via queueWarning() so it follows the standard warning lifecycle.
workspaces/config/test/index.js: Added test that passes both --prefer-offline and --prefer-online via CLI args and verifies the warning is emitted.

Testing

New test passes: "warn when both prefer-offline and prefer-online are set"
Warning text: config Both prefer-offline and prefer-online are set. prefer-offline takes precedence.
Warning fires once at config load, not on every command invocation

Fixes#9113

This contribution was developed with AI assistance (Claude Code).

When both prefer-offline and prefer-online are set to true in config, npm silently prioritizes prefer-offline without any indication to the user. This causes commands like npm view to return stale cached data with no warning. Add a conflict detection check during config load that emits a warning when both flags are active, telling the user which flag takes precedence. Fixesnpm#9113

wraithgar · 2026-03-18T18:18:46Z

We have a precedent in config to label config items as mutually exclusive. Probably best to do that than to throw a very specific if statement in to our main config loop for one condition.

Example:

cli/workspaces/config/lib/definitions/definitions.js

Line 249 in 7e9d538

exclusive: ['min-release-age'],

Instead of a one-off if check in the config load loop, use the existing exclusive property on config definitions to mark prefer-offline and prefer-online as mutually exclusive. This matches the established pattern used by before/min-release-age, expect-results/expect-result-count, and the save-* flags. Fixesnpm#9113

mvanhorn · 2026-03-18T18:25:22Z

Updated - moved to exclusive definitions on both prefer-offline and prefer-online instead of the one-off check. Removed the custom if from config load.

wraithgar · 2026-03-18T18:42:03Z

 })

-t.test('warn when both prefer-offline and prefer-online are set', async t => {
+t.test('error when both prefer-offline and prefer-online are set', async t => {


we don't need a test for config settings. We have tests that make sure that exclusive works but it doesn't make a lot of sense to add tests for each thing we've added an exclusive tag for. The config is the config.

Makes sense - I'll remove the test. The exclusive mechanism is already covered generically so a per-field test is redundant.

The exclusive mechanism is already tested generically. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mvanhorn · 2026-03-19T01:04:26Z

Thanks for the review and the pointer to the exclusive config pattern - much cleaner than the one-off check.

mvanhorn · 2026-03-18T17:53:08Z

Summary

Adds a warning when both prefer-offline and prefer-online are set to true in config, telling the user that prefer-offline takes precedence.

Why this matters

When both flags are active, npm silently prioritizes prefer-offline, causing commands like npm view <package> version to return stale cached data with no indication that prefer-online is being ignored (#9113). Users end up debugging registry connectivity, token issues, or package naming when the actual problem is a config conflict.

Changes

workspaces/config/lib/index.js: After all config sources are loaded, check if both prefer-offline and prefer-online are truthy. If so, emit a warning via queueWarning() so it follows the standard warning lifecycle.
workspaces/config/test/index.js: Added test that passes both --prefer-offline and --prefer-online via CLI args and verifies the warning is emitted.

Testing

New test passes: "warn when both prefer-offline and prefer-online are set"
Warning text: config Both prefer-offline and prefer-online are set. prefer-offline takes precedence.
Warning fires once at config load, not on every command invocation

Fixes#9113

This contribution was developed with AI assistance (Claude Code).

When both prefer-offline and prefer-online are set to true in config, npm silently prioritizes prefer-offline without any indication to the user. This causes commands like npm view to return stale cached data with no warning. Add a conflict detection check during config load that emits a warning when both flags are active, telling the user which flag takes precedence. Fixesnpm#9113

wraithgar · 2026-03-18T18:18:46Z

We have a precedent in config to label config items as mutually exclusive. Probably best to do that than to throw a very specific if statement in to our main config loop for one condition.

Example:

cli/workspaces/config/lib/definitions/definitions.js

Line 249 in 7e9d538

exclusive: ['min-release-age'],

Instead of a one-off if check in the config load loop, use the existing exclusive property on config definitions to mark prefer-offline and prefer-online as mutually exclusive. This matches the established pattern used by before/min-release-age, expect-results/expect-result-count, and the save-* flags. Fixesnpm#9113

mvanhorn · 2026-03-18T18:25:22Z

Updated - moved to exclusive definitions on both prefer-offline and prefer-online instead of the one-off check. Removed the custom if from config load.

wraithgar · 2026-03-18T18:42:03Z

 })

-t.test('warn when both prefer-offline and prefer-online are set', async t => {
+t.test('error when both prefer-offline and prefer-online are set', async t => {


we don't need a test for config settings. We have tests that make sure that exclusive works but it doesn't make a lot of sense to add tests for each thing we've added an exclusive tag for. The config is the config.

Makes sense - I'll remove the test. The exclusive mechanism is already covered generically so a per-field test is redundant.

The exclusive mechanism is already tested generically. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mvanhorn · 2026-03-19T01:04:26Z

Thanks for the review and the pointer to the exclusive config pattern - much cleaner than the one-off check.

mvanhorn · 2026-03-18T17:53:08Z

Summary

Adds a warning when both prefer-offline and prefer-online are set to true in config, telling the user that prefer-offline takes precedence.

Why this matters

When both flags are active, npm silently prioritizes prefer-offline, causing commands like npm view <package> version to return stale cached data with no indication that prefer-online is being ignored (#9113). Users end up debugging registry connectivity, token issues, or package naming when the actual problem is a config conflict.

Changes

workspaces/config/lib/index.js: After all config sources are loaded, check if both prefer-offline and prefer-online are truthy. If so, emit a warning via queueWarning() so it follows the standard warning lifecycle.
workspaces/config/test/index.js: Added test that passes both --prefer-offline and --prefer-online via CLI args and verifies the warning is emitted.

Testing

New test passes: "warn when both prefer-offline and prefer-online are set"
Warning text: config Both prefer-offline and prefer-online are set. prefer-offline takes precedence.
Warning fires once at config load, not on every command invocation

Fixes#9113

This contribution was developed with AI assistance (Claude Code).

When both prefer-offline and prefer-online are set to true in config, npm silently prioritizes prefer-offline without any indication to the user. This causes commands like npm view to return stale cached data with no warning. Add a conflict detection check during config load that emits a warning when both flags are active, telling the user which flag takes precedence. Fixesnpm#9113

wraithgar · 2026-03-18T18:18:46Z

We have a precedent in config to label config items as mutually exclusive. Probably best to do that than to throw a very specific if statement in to our main config loop for one condition.

Example:

cli/workspaces/config/lib/definitions/definitions.js

Line 249 in 7e9d538

exclusive: ['min-release-age'],

Instead of a one-off if check in the config load loop, use the existing exclusive property on config definitions to mark prefer-offline and prefer-online as mutually exclusive. This matches the established pattern used by before/min-release-age, expect-results/expect-result-count, and the save-* flags. Fixesnpm#9113

mvanhorn · 2026-03-18T18:25:22Z

Updated - moved to exclusive definitions on both prefer-offline and prefer-online instead of the one-off check. Removed the custom if from config load.

wraithgar · 2026-03-18T18:42:03Z

 })

-t.test('warn when both prefer-offline and prefer-online are set', async t => {
+t.test('error when both prefer-offline and prefer-online are set', async t => {


we don't need a test for config settings. We have tests that make sure that exclusive works but it doesn't make a lot of sense to add tests for each thing we've added an exclusive tag for. The config is the config.

Makes sense - I'll remove the test. The exclusive mechanism is already covered generically so a per-field test is redundant.

The exclusive mechanism is already tested generically. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mvanhorn · 2026-03-19T01:04:26Z

Thanks for the review and the pointer to the exclusive config pattern - much cleaner than the one-off check.

mvanhorn · 2026-03-18T17:53:08Z

Summary

Adds a warning when both prefer-offline and prefer-online are set to true in config, telling the user that prefer-offline takes precedence.

Why this matters

When both flags are active, npm silently prioritizes prefer-offline, causing commands like npm view <package> version to return stale cached data with no indication that prefer-online is being ignored (#9113). Users end up debugging registry connectivity, token issues, or package naming when the actual problem is a config conflict.

Changes

workspaces/config/lib/index.js: After all config sources are loaded, check if both prefer-offline and prefer-online are truthy. If so, emit a warning via queueWarning() so it follows the standard warning lifecycle.
workspaces/config/test/index.js: Added test that passes both --prefer-offline and --prefer-online via CLI args and verifies the warning is emitted.

Testing

New test passes: "warn when both prefer-offline and prefer-online are set"
Warning text: config Both prefer-offline and prefer-online are set. prefer-offline takes precedence.
Warning fires once at config load, not on every command invocation

Fixes#9113

This contribution was developed with AI assistance (Claude Code).

When both prefer-offline and prefer-online are set to true in config, npm silently prioritizes prefer-offline without any indication to the user. This causes commands like npm view to return stale cached data with no warning. Add a conflict detection check during config load that emits a warning when both flags are active, telling the user which flag takes precedence. Fixesnpm#9113

wraithgar · 2026-03-18T18:18:46Z

We have a precedent in config to label config items as mutually exclusive. Probably best to do that than to throw a very specific if statement in to our main config loop for one condition.

Example:

cli/workspaces/config/lib/definitions/definitions.js

Line 249 in 7e9d538

exclusive: ['min-release-age'],

Instead of a one-off if check in the config load loop, use the existing exclusive property on config definitions to mark prefer-offline and prefer-online as mutually exclusive. This matches the established pattern used by before/min-release-age, expect-results/expect-result-count, and the save-* flags. Fixesnpm#9113

mvanhorn · 2026-03-18T18:25:22Z

Updated - moved to exclusive definitions on both prefer-offline and prefer-online instead of the one-off check. Removed the custom if from config load.

wraithgar · 2026-03-18T18:42:03Z

 })

-t.test('warn when both prefer-offline and prefer-online are set', async t => {
+t.test('error when both prefer-offline and prefer-online are set', async t => {


we don't need a test for config settings. We have tests that make sure that exclusive works but it doesn't make a lot of sense to add tests for each thing we've added an exclusive tag for. The config is the config.

Makes sense - I'll remove the test. The exclusive mechanism is already covered generically so a per-field test is redundant.

The exclusive mechanism is already tested generically. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mvanhorn · 2026-03-19T01:04:26Z

Thanks for the review and the pointer to the exclusive config pattern - much cleaner than the one-off check.

mvanhorn · 2026-03-18T17:53:08Z

Summary

Adds a warning when both prefer-offline and prefer-online are set to true in config, telling the user that prefer-offline takes precedence.

Why this matters

When both flags are active, npm silently prioritizes prefer-offline, causing commands like npm view <package> version to return stale cached data with no indication that prefer-online is being ignored (#9113). Users end up debugging registry connectivity, token issues, or package naming when the actual problem is a config conflict.

Changes

workspaces/config/lib/index.js: After all config sources are loaded, check if both prefer-offline and prefer-online are truthy. If so, emit a warning via queueWarning() so it follows the standard warning lifecycle.
workspaces/config/test/index.js: Added test that passes both --prefer-offline and --prefer-online via CLI args and verifies the warning is emitted.

Testing

New test passes: "warn when both prefer-offline and prefer-online are set"
Warning text: config Both prefer-offline and prefer-online are set. prefer-offline takes precedence.
Warning fires once at config load, not on every command invocation

Fixes#9113

This contribution was developed with AI assistance (Claude Code).

When both prefer-offline and prefer-online are set to true in config, npm silently prioritizes prefer-offline without any indication to the user. This causes commands like npm view to return stale cached data with no warning. Add a conflict detection check during config load that emits a warning when both flags are active, telling the user which flag takes precedence. Fixesnpm#9113

wraithgar · 2026-03-18T18:18:46Z

We have a precedent in config to label config items as mutually exclusive. Probably best to do that than to throw a very specific if statement in to our main config loop for one condition.

Example:

cli/workspaces/config/lib/definitions/definitions.js

Line 249 in 7e9d538

exclusive: ['min-release-age'],

Instead of a one-off if check in the config load loop, use the existing exclusive property on config definitions to mark prefer-offline and prefer-online as mutually exclusive. This matches the established pattern used by before/min-release-age, expect-results/expect-result-count, and the save-* flags. Fixesnpm#9113

mvanhorn · 2026-03-18T18:25:22Z

Updated - moved to exclusive definitions on both prefer-offline and prefer-online instead of the one-off check. Removed the custom if from config load.

wraithgar · 2026-03-18T18:42:03Z

 })

-t.test('warn when both prefer-offline and prefer-online are set', async t => {
+t.test('error when both prefer-offline and prefer-online are set', async t => {


we don't need a test for config settings. We have tests that make sure that exclusive works but it doesn't make a lot of sense to add tests for each thing we've added an exclusive tag for. The config is the config.

Makes sense - I'll remove the test. The exclusive mechanism is already covered generically so a per-field test is redundant.

The exclusive mechanism is already tested generically. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mvanhorn · 2026-03-19T01:04:26Z

Thanks for the review and the pointer to the exclusive config pattern - much cleaner than the one-off check.

mvanhorn · 2026-03-18T17:53:08Z

Summary

Adds a warning when both prefer-offline and prefer-online are set to true in config, telling the user that prefer-offline takes precedence.

Why this matters

When both flags are active, npm silently prioritizes prefer-offline, causing commands like npm view <package> version to return stale cached data with no indication that prefer-online is being ignored (#9113). Users end up debugging registry connectivity, token issues, or package naming when the actual problem is a config conflict.

Changes

workspaces/config/lib/index.js: After all config sources are loaded, check if both prefer-offline and prefer-online are truthy. If so, emit a warning via queueWarning() so it follows the standard warning lifecycle.
workspaces/config/test/index.js: Added test that passes both --prefer-offline and --prefer-online via CLI args and verifies the warning is emitted.

Testing

New test passes: "warn when both prefer-offline and prefer-online are set"
Warning text: config Both prefer-offline and prefer-online are set. prefer-offline takes precedence.
Warning fires once at config load, not on every command invocation

Fixes#9113

This contribution was developed with AI assistance (Claude Code).

When both prefer-offline and prefer-online are set to true in config, npm silently prioritizes prefer-offline without any indication to the user. This causes commands like npm view to return stale cached data with no warning. Add a conflict detection check during config load that emits a warning when both flags are active, telling the user which flag takes precedence. Fixesnpm#9113

wraithgar · 2026-03-18T18:18:46Z

We have a precedent in config to label config items as mutually exclusive. Probably best to do that than to throw a very specific if statement in to our main config loop for one condition.

Example:

cli/workspaces/config/lib/definitions/definitions.js

Line 249 in 7e9d538

exclusive: ['min-release-age'],

Instead of a one-off if check in the config load loop, use the existing exclusive property on config definitions to mark prefer-offline and prefer-online as mutually exclusive. This matches the established pattern used by before/min-release-age, expect-results/expect-result-count, and the save-* flags. Fixesnpm#9113

mvanhorn · 2026-03-18T18:25:22Z

Updated - moved to exclusive definitions on both prefer-offline and prefer-online instead of the one-off check. Removed the custom if from config load.

wraithgar · 2026-03-18T18:42:03Z

 })

-t.test('warn when both prefer-offline and prefer-online are set', async t => {
+t.test('error when both prefer-offline and prefer-online are set', async t => {


we don't need a test for config settings. We have tests that make sure that exclusive works but it doesn't make a lot of sense to add tests for each thing we've added an exclusive tag for. The config is the config.

Makes sense - I'll remove the test. The exclusive mechanism is already covered generically so a per-field test is redundant.

The exclusive mechanism is already tested generically. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mvanhorn · 2026-03-19T01:04:26Z

Thanks for the review and the pointer to the exclusive config pattern - much cleaner than the one-off check.

mvanhorn · 2026-03-18T17:53:08Z

Summary

Adds a warning when both prefer-offline and prefer-online are set to true in config, telling the user that prefer-offline takes precedence.

Why this matters

When both flags are active, npm silently prioritizes prefer-offline, causing commands like npm view <package> version to return stale cached data with no indication that prefer-online is being ignored (#9113). Users end up debugging registry connectivity, token issues, or package naming when the actual problem is a config conflict.

Changes

workspaces/config/lib/index.js: After all config sources are loaded, check if both prefer-offline and prefer-online are truthy. If so, emit a warning via queueWarning() so it follows the standard warning lifecycle.
workspaces/config/test/index.js: Added test that passes both --prefer-offline and --prefer-online via CLI args and verifies the warning is emitted.

Testing

New test passes: "warn when both prefer-offline and prefer-online are set"
Warning text: config Both prefer-offline and prefer-online are set. prefer-offline takes precedence.
Warning fires once at config load, not on every command invocation

Fixes#9113

This contribution was developed with AI assistance (Claude Code).

When both prefer-offline and prefer-online are set to true in config, npm silently prioritizes prefer-offline without any indication to the user. This causes commands like npm view to return stale cached data with no warning. Add a conflict detection check during config load that emits a warning when both flags are active, telling the user which flag takes precedence. Fixesnpm#9113

wraithgar · 2026-03-18T18:18:46Z

We have a precedent in config to label config items as mutually exclusive. Probably best to do that than to throw a very specific if statement in to our main config loop for one condition.

Example:

cli/workspaces/config/lib/definitions/definitions.js

Line 249 in 7e9d538

exclusive: ['min-release-age'],

Instead of a one-off if check in the config load loop, use the existing exclusive property on config definitions to mark prefer-offline and prefer-online as mutually exclusive. This matches the established pattern used by before/min-release-age, expect-results/expect-result-count, and the save-* flags. Fixesnpm#9113

mvanhorn · 2026-03-18T18:25:22Z

Updated - moved to exclusive definitions on both prefer-offline and prefer-online instead of the one-off check. Removed the custom if from config load.

wraithgar · 2026-03-18T18:42:03Z

 })

-t.test('warn when both prefer-offline and prefer-online are set', async t => {
+t.test('error when both prefer-offline and prefer-online are set', async t => {


we don't need a test for config settings. We have tests that make sure that exclusive works but it doesn't make a lot of sense to add tests for each thing we've added an exclusive tag for. The config is the config.

Makes sense - I'll remove the test. The exclusive mechanism is already covered generically so a per-field test is redundant.

The exclusive mechanism is already tested generically. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mvanhorn · 2026-03-19T01:04:26Z

Thanks for the review and the pointer to the exclusive config pattern - much cleaner than the one-off check.

mvanhorn requested a review from a team as a code owner March 18, 2026 17:53

mvanhorn mentioned this pull request Mar 18, 2026
[BUG] Silent conflict when both prefer-offline=true and prefer-online=true are set, causing npm view to return stale cached data #9113
Open
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wraithgar reviewed Mar 18, 2026
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fix(config): remove redundant exclusive config test
9e9f3ca
The exclusive mechanism is already tested generically. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

wraithgar changed the title ~~fix(config): warn when both prefer-offline and prefer-online are set~~fix(config): make prefer-offline and prefer-online exclusiveMar 18, 2026

wraithgar approved these changes Mar 18, 2026
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wraithgar merged commit d273380 into npm:latestMar 18, 2026
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github-actionsBot mentioned this pull request Mar 18, 2026
chore: release 11.12.0 #9119
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g-wn mentioned this pull request Mar 19, 2026
[BUG] Exclusive configuration for --prefer-online and --prefer-offline breaks git dependency preparation flow #9133
Closed
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owlstronaut pushed a commit that referenced this pull request Mar 24, 2026
fix: revert prefer-offline/prefer-online exclusivity (#9129)
d153d33

owlstronaut pushed a commit that referenced this pull request Mar 24, 2026
fix: revert prefer-offline/prefer-online exclusivity (#9129)
9789716

owlstronaut pushed a commit that referenced this pull request Mar 24, 2026
fix: revert prefer-offline/prefer-online exclusivity (#9129)
596706a

github-actionsBot mentioned this pull request Mar 23, 2026
chore: release 11.12.1 #9143
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npm-cli-bot mentioned this pull request Mar 26, 2026
deps: upgrade npm to 11.12.1 nodejs/node#62448
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github-actionsBot mentioned this pull request May 27, 2026
chore: release 12.0.0-pre.1 #9387
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