fix: keep terminal prompts on fresh lines#79

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Merged
kbuffardi merged 4 commits into from
Aug 22, 2026
Merged

fix: keep terminal prompts on fresh lines #79

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912712d
fix: keep terminal prompts on fresh lines
kbuffardi Aug 22, 2026
56dbb7b
chore: bump patch version to 0.4.7
kbuffardi Aug 22, 2026
356c9a0
fix: satisfy terminal lint rules
kbuffardi Aug 22, 2026
80c4af9
fix: isolate terminal line tracking
kbuffardi Aug 22, 2026
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2 changes: 1 addition & 1 deletion manifest.json
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Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
"name": "browser.cpp",
"short_name": "browser.cpp",
"description": "In-browser C++20 IDE powered by Monaco Editor and WASM Clang",
"version": "0.4.6",
"version": "0.4.7",
"minimum_chrome_version": "105",
"icons": {
"16": "icons/icon16.png",
Expand Down
4 changes: 2 additions & 2 deletions package-lock.json
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Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.

2 changes: 1 addition & 1 deletion package.json
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Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
{
"name": "browser.cpp",
"version": "0.4.6",
"version": "0.4.7",
"description": "In-browser C++20 IDE with WASM Clang toolchain",
"private": true,
"scripts": {
Expand Down
26 changes: 26 additions & 0 deletions scripts/e2e-terminal-stop.test.mjs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -13,6 +13,7 @@ import {
showInitialPrompt,
startRun,
stopRun,
writeStdout,
} from '../src/ui/terminal.js';

function setupTerminalHarness({
Expand DownExpand Up@@ -123,6 +124,31 @@ test('e2e: clearing during startup does not reveal the initial prompt early', ()
assert.ok(output.indexOf('Clang WASM compiler loaded') < output.indexOf('browser.cpp'));
});

test('e2e: clearing discards typed input and homes the fresh prompt', () => {
const ctx = setupTerminalHarness();

showInitialPrompt();
__handleTerminalKeyForTesting('c', { key: 'c', ctrlKey: false, altKey: false });
__handleTerminalKeyForTesting('a', { key: 'a', ctrlKey: false, altKey: false });
clearTerminal();

assert.equal(__getTerminalStateForTesting().inputBuffer, '');
assert.equal(ctx.clearCalls.length, 1);
assert.equal(ctx.writes.at(-2), '\x1b[2J\x1b[H');
assert.match(ctx.writes.at(-1), /browser\.cpp.*:~\$ /);
});

test('e2e: prompt restoration follows newline-less program output on a new line', () => {
const ctx = setupTerminalHarness();

showInitialPrompt();
onRunStart({ stdinMode: 'interactive' });
writeStdout('program output');
onRunResult({ exitCode: 0 });

assert.match(ctx.writes.join(''), /program output\r\n.*browser\.cpp.*:~\$ /);
});

test('e2e: Ctrl+C while running stops the program once and restores the prompt', async () => {
const ctx = setupTerminalHarness();

Expand Down
58 changes: 51 additions & 7 deletions src/ui/terminal.js
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -60,6 +60,8 @@ const C = {
};

const CRLF = '\r\n';
const CLEAR_SCREEN = '\x1b[2J\x1b[H';
const CSI_SEQUENCE = new RegExp(`${String.fromCharCode(27)}\\[[0-?]*[ -/]*[@-~]`, 'g');

/** Maximum number of commands retained in shell history. */
const MAX_HISTORY_SIZE = 200;
Expand All@@ -69,6 +71,8 @@ const TAB_COMMANDS = ['g++ ', 'g++ main.cpp', './a.out', 'clear', 'echo ', 'ls',

let term = null;
let fitAddon = null;
let terminalLineHasContent = false;
const trackedTerminals = new WeakSet();

/** Current line being typed */
let inputBuffer = '';
Expand DownExpand Up@@ -301,7 +305,7 @@ export function createTerminal(container, {
initialPromptShown = false;
busy = true;

term = new Terminal({
setTerminal(new Terminal({
fontFamily: "'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace",
fontSize: 13,
lineHeight: 1.4,
Expand DownExpand Up@@ -330,7 +334,7 @@ export function createTerminal(container, {
cursorBlink: true,
scrollback: 5000,
convertEol: false,
});
}));

fitAddon = new FitAddon();
term.loadAddon(fitAddon);
Expand All@@ -357,7 +361,9 @@ export function fitTerminal() {

/** Clear the terminal screen. */
export function clearTerminal() {
term?.clear();
inputBuffer = '';
historyIdx = -1;
clearScreen();
if (!initialPromptShown) return;
writePrompt();
}
Expand All@@ -371,7 +377,7 @@ export function resetTerminalSession(workspace = null) {
inputBuffer = '';
historyIdx = -1;
setWorkspace(workspace);
term?.clear();
clearScreen();
if (initialPromptShown) writePrompt();
}

Expand DownExpand Up@@ -685,7 +691,7 @@ function handleKey({ key, domEvent }) {

// Ctrl+L – clear screen
if (domEvent.ctrlKey && code === 'l') {
term.clear();
clearScreen();
writePrompt();
term.write(inputBuffer);
return;
Expand DownExpand Up@@ -766,7 +772,7 @@ async function executeCommand(cmdLine) {
cmdGxx(args);
break;
case 'clear':
term.clear();
clearScreen();
writePrompt();
break;
case 'echo':
Expand DownExpand Up@@ -1072,9 +1078,47 @@ function cmdHelp() {
// ── Utilities ─────────────────────────────────────────────────────────────────

function writePrompt() {
if (terminalLineHasContent) term?.write(CRLF);
term?.write(`${C.green}${C.bold}browser.cpp${C.reset}${C.dim}:${promptPath()}$ ${C.reset}`);
}

/** Clear the terminal and place the next prompt at the top-left of the screen. */
function clearScreen() {
term?.clear();
terminalLineHasContent = false;
if (initialPromptShown) term?.write(CLEAR_SCREEN);
}

/**
* Keep prompt placement independent of the many existing terminal write sites.
* xterm writes are asynchronous, so record the logical line state as output is queued.
*/
function setTerminal(nextTerm) {
term = nextTerm;
terminalLineHasContent = false;
if (!term || trackedTerminals.has(term)) return;

const terminalInstance = term;
const write = terminalInstance.write.bind(terminalInstance);
terminalInstance.write = (text, ...args) => {
if (term === terminalInstance) trackTerminalLine(text);
return write(text, ...args);
};
trackedTerminals.add(terminalInstance);
}

function trackTerminalLine(text) {
if (typeof text !== 'string') return;

const visibleText = text.replace(CSI_SEQUENCE, '');
const lastLineBreak = Math.max(visibleText.lastIndexOf('\n'), visibleText.lastIndexOf('\r'));
if (lastLineBreak >= 0) {
terminalLineHasContent = visibleText.slice(lastLineBreak + 1).length > 0;
} else if (visibleText.length > 0) {
terminalLineHasContent = true;
}
}

function setRunState(nextRunning) {
if (running === nextRunning) return;
running = nextRunning;
Expand DownExpand Up@@ -1105,7 +1149,7 @@ export function __setTerminalTestHarness({
supportsMessageInteractiveStdin: supportsMessageInteractiveStdinForTest = () => false,
createStdinSessionId: createStdinSessionIdForTest = () => 'stdin-session-test',
} = {}) {
term = terminalInstance || null;
setTerminal(terminalInstance || null);
fitAddon = null;
_onCompile = onCompile;
_onRun = onRun;
Expand Down
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" + '

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fix: keep terminal prompts on fresh lines#79

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 Merged

kbuffardi
merged 4 commits into

from

Aug 22, 2026
 Merged


fix: keep terminal prompts on fresh lines
#79
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912712d

fix: keep terminal prompts on fresh lines


kbuffardi Aug 22, 2026
56dbb7b

chore: bump patch version to 0.4.7


kbuffardi Aug 22, 2026
356c9a0

fix: satisfy terminal lint rules


kbuffardi Aug 22, 2026
80c4af9

fix: isolate terminal line tracking


kbuffardi Aug 22, 2026

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2 changes: 1 addition & 1 deletion
manifest.json

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Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
 "name": "browser.cpp",
 "short_name": "browser.cpp",
 "description": "In-browser C++20 IDE powered by Monaco Editor and WASM Clang",
 "version": "0.4.6",
 "version": "0.4.7",
 "minimum_chrome_version": "105",
 "icons": {
 "16": "icons/icon16.png",
Expand Down

4 changes: 2 additions & 2 deletions
package-lock.json

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2 changes: 1 addition & 1 deletion
package.json

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Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
{
 "name": "browser.cpp",
 "version": "0.4.6",
 "version": "0.4.7",
 "description": "In-browser C++20 IDE with WASM Clang toolchain",
 "private": true,
 "scripts": {
Expand Down

26 changes: 26 additions & 0 deletions
scripts/e2e-terminal-stop.test.mjs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -13,6 +13,7 @@ import {
 showInitialPrompt,
 startRun,
 stopRun,
 writeStdout,
} from '../src/ui/terminal.js';

function setupTerminalHarness({
Expand DownExpand Up@@ -123,6 +124,31 @@ test('e2e: clearing during startup does not reveal the initial prompt early', ()
 assert.ok(output.indexOf('Clang WASM compiler loaded') < output.indexOf('browser.cpp'));
});

test('e2e: clearing discards typed input and homes the fresh prompt', () => {
 const ctx = setupTerminalHarness();

 showInitialPrompt();
 __handleTerminalKeyForTesting('c', { key: 'c', ctrlKey: false, altKey: false });
 __handleTerminalKeyForTesting('a', { key: 'a', ctrlKey: false, altKey: false });
 clearTerminal();

 assert.equal(__getTerminalStateForTesting().inputBuffer, '');
 assert.equal(ctx.clearCalls.length, 1);
 assert.equal(ctx.writes.at(-2), '\x1b[2J\x1b[H');
 assert.match(ctx.writes.at(-1), /browser\.cpp.*:~\$ /);
});

test('e2e: prompt restoration follows newline-less program output on a new line', () => {
 const ctx = setupTerminalHarness();

 showInitialPrompt();
 onRunStart({ stdinMode: 'interactive' });
 writeStdout('program output');
 onRunResult({ exitCode: 0 });

 assert.match(ctx.writes.join(''), /program output\r\n.*browser\.cpp.*:~\$ /);
});

test('e2e: Ctrl+C while running stops the program once and restores the prompt', async () => {
 const ctx = setupTerminalHarness();

Expand Down

58 changes: 51 additions & 7 deletions
src/ui/terminal.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -60,6 +60,8 @@ const C = {
};

const CRLF = '\r\n';
const CLEAR_SCREEN = '\x1b[2J\x1b[H';
const CSI_SEQUENCE = new RegExp(`${String.fromCharCode(27)}\\[[0-?]*[ -/]*[@-~]`, 'g');

/** Maximum number of commands retained in shell history. */
const MAX_HISTORY_SIZE = 200;
Expand All@@ -69,6 +71,8 @@ const TAB_COMMANDS = ['g++ ', 'g++ main.cpp', './a.out', 'clear', 'echo ', 'ls',

let term = null;
let fitAddon = null;
let terminalLineHasContent = false;
const trackedTerminals = new WeakSet();

/** Current line being typed */
let inputBuffer = '';
Expand DownExpand Up@@ -301,7 +305,7 @@ export function createTerminal(container, {
 initialPromptShown = false;
 busy = true;

term = new Terminal({
setTerminal(new Terminal({
 fontFamily: "'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace",
 fontSize: 13,
 lineHeight: 1.4,
Expand DownExpand Up@@ -330,7 +334,7 @@ export function createTerminal(container, {
 cursorBlink: true,
 scrollback: 5000,
 convertEol: false,
 });
 }));

 fitAddon = new FitAddon();
 term.loadAddon(fitAddon);
Expand All@@ -357,7 +361,9 @@ export function fitTerminal() {

/** Clear the terminal screen. */
export function clearTerminal() {
 term?.clear();
 inputBuffer = '';
 historyIdx = -1;
 clearScreen();
 if (!initialPromptShown) return;
 writePrompt();
}
Expand All@@ -371,7 +377,7 @@ export function resetTerminalSession(workspace = null) {
 inputBuffer = '';
 historyIdx = -1;
 setWorkspace(workspace);
term?.clear();
clearScreen();
 if (initialPromptShown) writePrompt();
}

Expand DownExpand Up@@ -685,7 +691,7 @@ function handleKey({ key, domEvent }) {

 // Ctrl+L – clear screen
 if (domEvent.ctrlKey && code === 'l') {
term.clear();
clearScreen();
 writePrompt();
 term.write(inputBuffer);
 return;
Expand DownExpand Up@@ -766,7 +772,7 @@ async function executeCommand(cmdLine) {
 cmdGxx(args);
 break;
 case 'clear':
term.clear();
clearScreen();
 writePrompt();
 break;
 case 'echo':
Expand DownExpand Up@@ -1072,9 +1078,47 @@ function cmdHelp() {
// ── Utilities ─────────────────────────────────────────────────────────────────

function writePrompt() {
 if (terminalLineHasContent) term?.write(CRLF);
 term?.write(`${C.green}${C.bold}browser.cpp${C.reset}${C.dim}:${promptPath()}$ ${C.reset}`);
}

/** Clear the terminal and place the next prompt at the top-left of the screen. */
function clearScreen() {
 term?.clear();
 terminalLineHasContent = false;
 if (initialPromptShown) term?.write(CLEAR_SCREEN);
}

/**
 * Keep prompt placement independent of the many existing terminal write sites.
 * xterm writes are asynchronous, so record the logical line state as output is queued.
 */
function setTerminal(nextTerm) {
 term = nextTerm;
 terminalLineHasContent = false;
 if (!term || trackedTerminals.has(term)) return;

 const terminalInstance = term;
 const write = terminalInstance.write.bind(terminalInstance);
 terminalInstance.write = (text, ...args) => {
 if (term === terminalInstance) trackTerminalLine(text);
 return write(text, ...args);
 };
 trackedTerminals.add(terminalInstance);
}

function trackTerminalLine(text) {
 if (typeof text !== 'string') return;

 const visibleText = text.replace(CSI_SEQUENCE, '');
 const lastLineBreak = Math.max(visibleText.lastIndexOf('\n'), visibleText.lastIndexOf('\r'));
 if (lastLineBreak >= 0) {
 terminalLineHasContent = visibleText.slice(lastLineBreak + 1).length > 0;
 } else if (visibleText.length > 0) {
 terminalLineHasContent = true;
 }
}

function setRunState(nextRunning) {
 if (running === nextRunning) return;
 running = nextRunning;
Expand DownExpand Up@@ -1105,7 +1149,7 @@ export function __setTerminalTestHarness({
 supportsMessageInteractiveStdin: supportsMessageInteractiveStdinForTest = () => false,
 createStdinSessionId: createStdinSessionIdForTest = () => 'stdin-session-test',
} = {}) {
term = terminalInstance || null;
setTerminal(terminalInstance || null);
 fitAddon = null;
 _onCompile = onCompile;
 _onRun = onRun;
Expand Down
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
fix: keep terminal prompts on fresh lines#79

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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

kbuffardi
merged 4 commits into

from

Aug 22, 2026
 Merged


fix: keep terminal prompts on fresh lines
#79
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912712d

fix: keep terminal prompts on fresh lines


kbuffardi Aug 22, 2026
56dbb7b

chore: bump patch version to 0.4.7


kbuffardi Aug 22, 2026
356c9a0

fix: satisfy terminal lint rules


kbuffardi Aug 22, 2026
80c4af9

fix: isolate terminal line tracking


kbuffardi Aug 22, 2026

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2 changes: 1 addition & 1 deletion
manifest.json

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
 "name": "browser.cpp",
 "short_name": "browser.cpp",
 "description": "In-browser C++20 IDE powered by Monaco Editor and WASM Clang",
 "version": "0.4.6",
 "version": "0.4.7",
 "minimum_chrome_version": "105",
 "icons": {
 "16": "icons/icon16.png",
Expand Down

4 changes: 2 additions & 2 deletions
package-lock.json

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2 changes: 1 addition & 1 deletion
package.json

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Open in desktop

Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
{
 "name": "browser.cpp",
 "version": "0.4.6",
 "version": "0.4.7",
 "description": "In-browser C++20 IDE with WASM Clang toolchain",
 "private": true,
 "scripts": {
Expand Down

26 changes: 26 additions & 0 deletions
scripts/e2e-terminal-stop.test.mjs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -13,6 +13,7 @@ import {
 showInitialPrompt,
 startRun,
 stopRun,
 writeStdout,
} from '../src/ui/terminal.js';

function setupTerminalHarness({
Expand DownExpand Up@@ -123,6 +124,31 @@ test('e2e: clearing during startup does not reveal the initial prompt early', ()
 assert.ok(output.indexOf('Clang WASM compiler loaded') < output.indexOf('browser.cpp'));
});

test('e2e: clearing discards typed input and homes the fresh prompt', () => {
 const ctx = setupTerminalHarness();

 showInitialPrompt();
 __handleTerminalKeyForTesting('c', { key: 'c', ctrlKey: false, altKey: false });
 __handleTerminalKeyForTesting('a', { key: 'a', ctrlKey: false, altKey: false });
 clearTerminal();

 assert.equal(__getTerminalStateForTesting().inputBuffer, '');
 assert.equal(ctx.clearCalls.length, 1);
 assert.equal(ctx.writes.at(-2), '\x1b[2J\x1b[H');
 assert.match(ctx.writes.at(-1), /browser\.cpp.*:~\$ /);
});

test('e2e: prompt restoration follows newline-less program output on a new line', () => {
 const ctx = setupTerminalHarness();

 showInitialPrompt();
 onRunStart({ stdinMode: 'interactive' });
 writeStdout('program output');
 onRunResult({ exitCode: 0 });

 assert.match(ctx.writes.join(''), /program output\r\n.*browser\.cpp.*:~\$ /);
});

test('e2e: Ctrl+C while running stops the program once and restores the prompt', async () => {
 const ctx = setupTerminalHarness();

Expand Down

58 changes: 51 additions & 7 deletions
src/ui/terminal.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -60,6 +60,8 @@ const C = {
};

const CRLF = '\r\n';
const CLEAR_SCREEN = '\x1b[2J\x1b[H';
const CSI_SEQUENCE = new RegExp(`${String.fromCharCode(27)}\\[[0-?]*[ -/]*[@-~]`, 'g');

/** Maximum number of commands retained in shell history. */
const MAX_HISTORY_SIZE = 200;
Expand All@@ -69,6 +71,8 @@ const TAB_COMMANDS = ['g++ ', 'g++ main.cpp', './a.out', 'clear', 'echo ', 'ls',

let term = null;
let fitAddon = null;
let terminalLineHasContent = false;
const trackedTerminals = new WeakSet();

/** Current line being typed */
let inputBuffer = '';
Expand DownExpand Up@@ -301,7 +305,7 @@ export function createTerminal(container, {
 initialPromptShown = false;
 busy = true;

term = new Terminal({
setTerminal(new Terminal({
 fontFamily: "'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace",
 fontSize: 13,
 lineHeight: 1.4,
Expand DownExpand Up@@ -330,7 +334,7 @@ export function createTerminal(container, {
 cursorBlink: true,
 scrollback: 5000,
 convertEol: false,
 });
 }));

 fitAddon = new FitAddon();
 term.loadAddon(fitAddon);
Expand All@@ -357,7 +361,9 @@ export function fitTerminal() {

/** Clear the terminal screen. */
export function clearTerminal() {
 term?.clear();
 inputBuffer = '';
 historyIdx = -1;
 clearScreen();
 if (!initialPromptShown) return;
 writePrompt();
}
Expand All@@ -371,7 +377,7 @@ export function resetTerminalSession(workspace = null) {
 inputBuffer = '';
 historyIdx = -1;
 setWorkspace(workspace);
term?.clear();
clearScreen();
 if (initialPromptShown) writePrompt();
}

Expand DownExpand Up@@ -685,7 +691,7 @@ function handleKey({ key, domEvent }) {

 // Ctrl+L – clear screen
 if (domEvent.ctrlKey && code === 'l') {
term.clear();
clearScreen();
 writePrompt();
 term.write(inputBuffer);
 return;
Expand DownExpand Up@@ -766,7 +772,7 @@ async function executeCommand(cmdLine) {
 cmdGxx(args);
 break;
 case 'clear':
term.clear();
clearScreen();
 writePrompt();
 break;
 case 'echo':
Expand DownExpand Up@@ -1072,9 +1078,47 @@ function cmdHelp() {
// ── Utilities ─────────────────────────────────────────────────────────────────

function writePrompt() {
 if (terminalLineHasContent) term?.write(CRLF);
 term?.write(`${C.green}${C.bold}browser.cpp${C.reset}${C.dim}:${promptPath()}$ ${C.reset}`);
}

/** Clear the terminal and place the next prompt at the top-left of the screen. */
function clearScreen() {
 term?.clear();
 terminalLineHasContent = false;
 if (initialPromptShown) term?.write(CLEAR_SCREEN);
}

/**
 * Keep prompt placement independent of the many existing terminal write sites.
 * xterm writes are asynchronous, so record the logical line state as output is queued.
 */
function setTerminal(nextTerm) {
 term = nextTerm;
 terminalLineHasContent = false;
 if (!term || trackedTerminals.has(term)) return;

 const terminalInstance = term;
 const write = terminalInstance.write.bind(terminalInstance);
 terminalInstance.write = (text, ...args) => {
 if (term === terminalInstance) trackTerminalLine(text);
 return write(text, ...args);
 };
 trackedTerminals.add(terminalInstance);
}

function trackTerminalLine(text) {
 if (typeof text !== 'string') return;

 const visibleText = text.replace(CSI_SEQUENCE, '');
 const lastLineBreak = Math.max(visibleText.lastIndexOf('\n'), visibleText.lastIndexOf('\r'));
 if (lastLineBreak >= 0) {
 terminalLineHasContent = visibleText.slice(lastLineBreak + 1).length > 0;
 } else if (visibleText.length > 0) {
 terminalLineHasContent = true;
 }
}

function setRunState(nextRunning) {
 if (running === nextRunning) return;
 running = nextRunning;
Expand DownExpand Up@@ -1105,7 +1149,7 @@ export function __setTerminalTestHarness({
 supportsMessageInteractiveStdin: supportsMessageInteractiveStdinForTest = () => false,
 createStdinSessionId: createStdinSessionIdForTest = () => 'stdin-session-test',
} = {}) {
term = terminalInstance || null;
setTerminal(terminalInstance || null);
 fitAddon = null;
 _onCompile = onCompile;
 _onRun = onRun;
Expand Down
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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fix: keep terminal prompts on fresh lines#79

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 Merged

kbuffardi
merged 4 commits into

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Aug 22, 2026
 Merged


fix: keep terminal prompts on fresh lines
#79
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912712d

fix: keep terminal prompts on fresh lines


kbuffardi Aug 22, 2026
56dbb7b

chore: bump patch version to 0.4.7


kbuffardi Aug 22, 2026
356c9a0

fix: satisfy terminal lint rules


kbuffardi Aug 22, 2026
80c4af9

fix: isolate terminal line tracking


kbuffardi Aug 22, 2026

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2 changes: 1 addition & 1 deletion
manifest.json

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
 "name": "browser.cpp",
 "short_name": "browser.cpp",
 "description": "In-browser C++20 IDE powered by Monaco Editor and WASM Clang",
 "version": "0.4.6",
 "version": "0.4.7",
 "minimum_chrome_version": "105",
 "icons": {
 "16": "icons/icon16.png",
Expand Down

4 changes: 2 additions & 2 deletions
package-lock.json

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2 changes: 1 addition & 1 deletion
package.json

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Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
{
 "name": "browser.cpp",
 "version": "0.4.6",
 "version": "0.4.7",
 "description": "In-browser C++20 IDE with WASM Clang toolchain",
 "private": true,
 "scripts": {
Expand Down

26 changes: 26 additions & 0 deletions
scripts/e2e-terminal-stop.test.mjs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -13,6 +13,7 @@ import {
 showInitialPrompt,
 startRun,
 stopRun,
 writeStdout,
} from '../src/ui/terminal.js';

function setupTerminalHarness({
Expand DownExpand Up@@ -123,6 +124,31 @@ test('e2e: clearing during startup does not reveal the initial prompt early', ()
 assert.ok(output.indexOf('Clang WASM compiler loaded') < output.indexOf('browser.cpp'));
});

test('e2e: clearing discards typed input and homes the fresh prompt', () => {
 const ctx = setupTerminalHarness();

 showInitialPrompt();
 __handleTerminalKeyForTesting('c', { key: 'c', ctrlKey: false, altKey: false });
 __handleTerminalKeyForTesting('a', { key: 'a', ctrlKey: false, altKey: false });
 clearTerminal();

 assert.equal(__getTerminalStateForTesting().inputBuffer, '');
 assert.equal(ctx.clearCalls.length, 1);
 assert.equal(ctx.writes.at(-2), '\x1b[2J\x1b[H');
 assert.match(ctx.writes.at(-1), /browser\.cpp.*:~\$ /);
});

test('e2e: prompt restoration follows newline-less program output on a new line', () => {
 const ctx = setupTerminalHarness();

 showInitialPrompt();
 onRunStart({ stdinMode: 'interactive' });
 writeStdout('program output');
 onRunResult({ exitCode: 0 });

 assert.match(ctx.writes.join(''), /program output\r\n.*browser\.cpp.*:~\$ /);
});

test('e2e: Ctrl+C while running stops the program once and restores the prompt', async () => {
 const ctx = setupTerminalHarness();

Expand Down

58 changes: 51 additions & 7 deletions
src/ui/terminal.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -60,6 +60,8 @@ const C = {
};

const CRLF = '\r\n';
const CLEAR_SCREEN = '\x1b[2J\x1b[H';
const CSI_SEQUENCE = new RegExp(`${String.fromCharCode(27)}\\[[0-?]*[ -/]*[@-~]`, 'g');

/** Maximum number of commands retained in shell history. */
const MAX_HISTORY_SIZE = 200;
Expand All@@ -69,6 +71,8 @@ const TAB_COMMANDS = ['g++ ', 'g++ main.cpp', './a.out', 'clear', 'echo ', 'ls',

let term = null;
let fitAddon = null;
let terminalLineHasContent = false;
const trackedTerminals = new WeakSet();

/** Current line being typed */
let inputBuffer = '';
Expand DownExpand Up@@ -301,7 +305,7 @@ export function createTerminal(container, {
 initialPromptShown = false;
 busy = true;

term = new Terminal({
setTerminal(new Terminal({
 fontFamily: "'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace",
 fontSize: 13,
 lineHeight: 1.4,
Expand DownExpand Up@@ -330,7 +334,7 @@ export function createTerminal(container, {
 cursorBlink: true,
 scrollback: 5000,
 convertEol: false,
 });
 }));

 fitAddon = new FitAddon();
 term.loadAddon(fitAddon);
Expand All@@ -357,7 +361,9 @@ export function fitTerminal() {

/** Clear the terminal screen. */
export function clearTerminal() {
 term?.clear();
 inputBuffer = '';
 historyIdx = -1;
 clearScreen();
 if (!initialPromptShown) return;
 writePrompt();
}
Expand All@@ -371,7 +377,7 @@ export function resetTerminalSession(workspace = null) {
 inputBuffer = '';
 historyIdx = -1;
 setWorkspace(workspace);
term?.clear();
clearScreen();
 if (initialPromptShown) writePrompt();
}

Expand DownExpand Up@@ -685,7 +691,7 @@ function handleKey({ key, domEvent }) {

 // Ctrl+L – clear screen
 if (domEvent.ctrlKey && code === 'l') {
term.clear();
clearScreen();
 writePrompt();
 term.write(inputBuffer);
 return;
Expand DownExpand Up@@ -766,7 +772,7 @@ async function executeCommand(cmdLine) {
 cmdGxx(args);
 break;
 case 'clear':
term.clear();
clearScreen();
 writePrompt();
 break;
 case 'echo':
Expand DownExpand Up@@ -1072,9 +1078,47 @@ function cmdHelp() {
// ── Utilities ─────────────────────────────────────────────────────────────────

function writePrompt() {
 if (terminalLineHasContent) term?.write(CRLF);
 term?.write(`${C.green}${C.bold}browser.cpp${C.reset}${C.dim}:${promptPath()}$ ${C.reset}`);
}

/** Clear the terminal and place the next prompt at the top-left of the screen. */
function clearScreen() {
 term?.clear();
 terminalLineHasContent = false;
 if (initialPromptShown) term?.write(CLEAR_SCREEN);
}

/**
 * Keep prompt placement independent of the many existing terminal write sites.
 * xterm writes are asynchronous, so record the logical line state as output is queued.
 */
function setTerminal(nextTerm) {
 term = nextTerm;
 terminalLineHasContent = false;
 if (!term || trackedTerminals.has(term)) return;

 const terminalInstance = term;
 const write = terminalInstance.write.bind(terminalInstance);
 terminalInstance.write = (text, ...args) => {
 if (term === terminalInstance) trackTerminalLine(text);
 return write(text, ...args);
 };
 trackedTerminals.add(terminalInstance);
}

function trackTerminalLine(text) {
 if (typeof text !== 'string') return;

 const visibleText = text.replace(CSI_SEQUENCE, '');
 const lastLineBreak = Math.max(visibleText.lastIndexOf('\n'), visibleText.lastIndexOf('\r'));
 if (lastLineBreak >= 0) {
 terminalLineHasContent = visibleText.slice(lastLineBreak + 1).length > 0;
 } else if (visibleText.length > 0) {
 terminalLineHasContent = true;
 }
}

function setRunState(nextRunning) {
 if (running === nextRunning) return;
 running = nextRunning;
Expand DownExpand Up@@ -1105,7 +1149,7 @@ export function __setTerminalTestHarness({
 supportsMessageInteractiveStdin: supportsMessageInteractiveStdinForTest = () => false,
 createStdinSessionId: createStdinSessionIdForTest = () => 'stdin-session-test',
} = {}) {
term = terminalInstance || null;
setTerminal(terminalInstance || null);
 fitAddon = null;
 _onCompile = onCompile;
 _onRun = onRun;
Expand Down
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
fix: keep terminal prompts on fresh lines#79

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 Merged

kbuffardi
merged 4 commits into

from

Aug 22, 2026
 Merged


fix: keep terminal prompts on fresh lines
#79
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912712d

fix: keep terminal prompts on fresh lines


kbuffardi Aug 22, 2026
56dbb7b

chore: bump patch version to 0.4.7


kbuffardi Aug 22, 2026
356c9a0

fix: satisfy terminal lint rules


kbuffardi Aug 22, 2026
80c4af9

fix: isolate terminal line tracking


kbuffardi Aug 22, 2026

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2 changes: 1 addition & 1 deletion
manifest.json

View file


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Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
 "name": "browser.cpp",
 "short_name": "browser.cpp",
 "description": "In-browser C++20 IDE powered by Monaco Editor and WASM Clang",
 "version": "0.4.6",
 "version": "0.4.7",
 "minimum_chrome_version": "105",
 "icons": {
 "16": "icons/icon16.png",
Expand Down

4 changes: 2 additions & 2 deletions
package-lock.json

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2 changes: 1 addition & 1 deletion
package.json

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Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
{
 "name": "browser.cpp",
 "version": "0.4.6",
 "version": "0.4.7",
 "description": "In-browser C++20 IDE with WASM Clang toolchain",
 "private": true,
 "scripts": {
Expand Down

26 changes: 26 additions & 0 deletions
scripts/e2e-terminal-stop.test.mjs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -13,6 +13,7 @@ import {
 showInitialPrompt,
 startRun,
 stopRun,
 writeStdout,
} from '../src/ui/terminal.js';

function setupTerminalHarness({
Expand DownExpand Up@@ -123,6 +124,31 @@ test('e2e: clearing during startup does not reveal the initial prompt early', ()
 assert.ok(output.indexOf('Clang WASM compiler loaded') < output.indexOf('browser.cpp'));
});

test('e2e: clearing discards typed input and homes the fresh prompt', () => {
 const ctx = setupTerminalHarness();

 showInitialPrompt();
 __handleTerminalKeyForTesting('c', { key: 'c', ctrlKey: false, altKey: false });
 __handleTerminalKeyForTesting('a', { key: 'a', ctrlKey: false, altKey: false });
 clearTerminal();

 assert.equal(__getTerminalStateForTesting().inputBuffer, '');
 assert.equal(ctx.clearCalls.length, 1);
 assert.equal(ctx.writes.at(-2), '\x1b[2J\x1b[H');
 assert.match(ctx.writes.at(-1), /browser\.cpp.*:~\$ /);
});

test('e2e: prompt restoration follows newline-less program output on a new line', () => {
 const ctx = setupTerminalHarness();

 showInitialPrompt();
 onRunStart({ stdinMode: 'interactive' });
 writeStdout('program output');
 onRunResult({ exitCode: 0 });

 assert.match(ctx.writes.join(''), /program output\r\n.*browser\.cpp.*:~\$ /);
});

test('e2e: Ctrl+C while running stops the program once and restores the prompt', async () => {
 const ctx = setupTerminalHarness();

Expand Down

58 changes: 51 additions & 7 deletions
src/ui/terminal.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -60,6 +60,8 @@ const C = {
};

const CRLF = '\r\n';
const CLEAR_SCREEN = '\x1b[2J\x1b[H';
const CSI_SEQUENCE = new RegExp(`${String.fromCharCode(27)}\\[[0-?]*[ -/]*[@-~]`, 'g');

/** Maximum number of commands retained in shell history. */
const MAX_HISTORY_SIZE = 200;
Expand All@@ -69,6 +71,8 @@ const TAB_COMMANDS = ['g++ ', 'g++ main.cpp', './a.out', 'clear', 'echo ', 'ls',

let term = null;
let fitAddon = null;
let terminalLineHasContent = false;
const trackedTerminals = new WeakSet();

/** Current line being typed */
let inputBuffer = '';
Expand DownExpand Up@@ -301,7 +305,7 @@ export function createTerminal(container, {
 initialPromptShown = false;
 busy = true;

term = new Terminal({
setTerminal(new Terminal({
 fontFamily: "'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace",
 fontSize: 13,
 lineHeight: 1.4,
Expand DownExpand Up@@ -330,7 +334,7 @@ export function createTerminal(container, {
 cursorBlink: true,
 scrollback: 5000,
 convertEol: false,
 });
 }));

 fitAddon = new FitAddon();
 term.loadAddon(fitAddon);
Expand All@@ -357,7 +361,9 @@ export function fitTerminal() {

/** Clear the terminal screen. */
export function clearTerminal() {
 term?.clear();
 inputBuffer = '';
 historyIdx = -1;
 clearScreen();
 if (!initialPromptShown) return;
 writePrompt();
}
Expand All@@ -371,7 +377,7 @@ export function resetTerminalSession(workspace = null) {
 inputBuffer = '';
 historyIdx = -1;
 setWorkspace(workspace);
term?.clear();
clearScreen();
 if (initialPromptShown) writePrompt();
}

Expand DownExpand Up@@ -685,7 +691,7 @@ function handleKey({ key, domEvent }) {

 // Ctrl+L – clear screen
 if (domEvent.ctrlKey && code === 'l') {
term.clear();
clearScreen();
 writePrompt();
 term.write(inputBuffer);
 return;
Expand DownExpand Up@@ -766,7 +772,7 @@ async function executeCommand(cmdLine) {
 cmdGxx(args);
 break;
 case 'clear':
term.clear();
clearScreen();
 writePrompt();
 break;
 case 'echo':
Expand DownExpand Up@@ -1072,9 +1078,47 @@ function cmdHelp() {
// ── Utilities ─────────────────────────────────────────────────────────────────

function writePrompt() {
 if (terminalLineHasContent) term?.write(CRLF);
 term?.write(`${C.green}${C.bold}browser.cpp${C.reset}${C.dim}:${promptPath()}$ ${C.reset}`);
}

/** Clear the terminal and place the next prompt at the top-left of the screen. */
function clearScreen() {
 term?.clear();
 terminalLineHasContent = false;
 if (initialPromptShown) term?.write(CLEAR_SCREEN);
}

/**
 * Keep prompt placement independent of the many existing terminal write sites.
 * xterm writes are asynchronous, so record the logical line state as output is queued.
 */
function setTerminal(nextTerm) {
 term = nextTerm;
 terminalLineHasContent = false;
 if (!term || trackedTerminals.has(term)) return;

 const terminalInstance = term;
 const write = terminalInstance.write.bind(terminalInstance);
 terminalInstance.write = (text, ...args) => {
 if (term === terminalInstance) trackTerminalLine(text);
 return write(text, ...args);
 };
 trackedTerminals.add(terminalInstance);
}

function trackTerminalLine(text) {
 if (typeof text !== 'string') return;

 const visibleText = text.replace(CSI_SEQUENCE, '');
 const lastLineBreak = Math.max(visibleText.lastIndexOf('\n'), visibleText.lastIndexOf('\r'));
 if (lastLineBreak >= 0) {
 terminalLineHasContent = visibleText.slice(lastLineBreak + 1).length > 0;
 } else if (visibleText.length > 0) {
 terminalLineHasContent = true;
 }
}

function setRunState(nextRunning) {
 if (running === nextRunning) return;
 running = nextRunning;
Expand DownExpand Up@@ -1105,7 +1149,7 @@ export function __setTerminalTestHarness({
 supportsMessageInteractiveStdin: supportsMessageInteractiveStdinForTest = () => false,
 createStdinSessionId: createStdinSessionIdForTest = () => 'stdin-session-test',
} = {}) {
term = terminalInstance || null;
setTerminal(terminalInstance || null);
 fitAddon = null;
 _onCompile = onCompile;
 _onRun = onRun;
Expand Down
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
fix: keep terminal prompts on fresh lines#79

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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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to your account

 Merged

kbuffardi
merged 4 commits into

from

Aug 22, 2026
 Merged


fix: keep terminal prompts on fresh lines
#79
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912712d

fix: keep terminal prompts on fresh lines


kbuffardi Aug 22, 2026
56dbb7b

chore: bump patch version to 0.4.7


kbuffardi Aug 22, 2026
356c9a0

fix: satisfy terminal lint rules


kbuffardi Aug 22, 2026
80c4af9

fix: isolate terminal line tracking


kbuffardi Aug 22, 2026

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2 changes: 1 addition & 1 deletion
manifest.json

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
 "name": "browser.cpp",
 "short_name": "browser.cpp",
 "description": "In-browser C++20 IDE powered by Monaco Editor and WASM Clang",
 "version": "0.4.6",
 "version": "0.4.7",
 "minimum_chrome_version": "105",
 "icons": {
 "16": "icons/icon16.png",
Expand Down

4 changes: 2 additions & 2 deletions
package-lock.json

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2 changes: 1 addition & 1 deletion
package.json

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
{
 "name": "browser.cpp",
 "version": "0.4.6",
 "version": "0.4.7",
 "description": "In-browser C++20 IDE with WASM Clang toolchain",
 "private": true,
 "scripts": {
Expand Down

26 changes: 26 additions & 0 deletions
scripts/e2e-terminal-stop.test.mjs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -13,6 +13,7 @@ import {
 showInitialPrompt,
 startRun,
 stopRun,
 writeStdout,
} from '../src/ui/terminal.js';

function setupTerminalHarness({
Expand DownExpand Up@@ -123,6 +124,31 @@ test('e2e: clearing during startup does not reveal the initial prompt early', ()
 assert.ok(output.indexOf('Clang WASM compiler loaded') < output.indexOf('browser.cpp'));
});

test('e2e: clearing discards typed input and homes the fresh prompt', () => {
 const ctx = setupTerminalHarness();

 showInitialPrompt();
 __handleTerminalKeyForTesting('c', { key: 'c', ctrlKey: false, altKey: false });
 __handleTerminalKeyForTesting('a', { key: 'a', ctrlKey: false, altKey: false });
 clearTerminal();

 assert.equal(__getTerminalStateForTesting().inputBuffer, '');
 assert.equal(ctx.clearCalls.length, 1);
 assert.equal(ctx.writes.at(-2), '\x1b[2J\x1b[H');
 assert.match(ctx.writes.at(-1), /browser\.cpp.*:~\$ /);
});

test('e2e: prompt restoration follows newline-less program output on a new line', () => {
 const ctx = setupTerminalHarness();

 showInitialPrompt();
 onRunStart({ stdinMode: 'interactive' });
 writeStdout('program output');
 onRunResult({ exitCode: 0 });

 assert.match(ctx.writes.join(''), /program output\r\n.*browser\.cpp.*:~\$ /);
});

test('e2e: Ctrl+C while running stops the program once and restores the prompt', async () => {
 const ctx = setupTerminalHarness();

Expand Down

58 changes: 51 additions & 7 deletions
src/ui/terminal.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -60,6 +60,8 @@ const C = {
};

const CRLF = '\r\n';
const CLEAR_SCREEN = '\x1b[2J\x1b[H';
const CSI_SEQUENCE = new RegExp(`${String.fromCharCode(27)}\\[[0-?]*[ -/]*[@-~]`, 'g');

/** Maximum number of commands retained in shell history. */
const MAX_HISTORY_SIZE = 200;
Expand All@@ -69,6 +71,8 @@ const TAB_COMMANDS = ['g++ ', 'g++ main.cpp', './a.out', 'clear', 'echo ', 'ls',

let term = null;
let fitAddon = null;
let terminalLineHasContent = false;
const trackedTerminals = new WeakSet();

/** Current line being typed */
let inputBuffer = '';
Expand DownExpand Up@@ -301,7 +305,7 @@ export function createTerminal(container, {
 initialPromptShown = false;
 busy = true;

term = new Terminal({
setTerminal(new Terminal({
 fontFamily: "'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace",
 fontSize: 13,
 lineHeight: 1.4,
Expand DownExpand Up@@ -330,7 +334,7 @@ export function createTerminal(container, {
 cursorBlink: true,
 scrollback: 5000,
 convertEol: false,
 });
 }));

 fitAddon = new FitAddon();
 term.loadAddon(fitAddon);
Expand All@@ -357,7 +361,9 @@ export function fitTerminal() {

/** Clear the terminal screen. */
export function clearTerminal() {
 term?.clear();
 inputBuffer = '';
 historyIdx = -1;
 clearScreen();
 if (!initialPromptShown) return;
 writePrompt();
}
Expand All@@ -371,7 +377,7 @@ export function resetTerminalSession(workspace = null) {
 inputBuffer = '';
 historyIdx = -1;
 setWorkspace(workspace);
term?.clear();
clearScreen();
 if (initialPromptShown) writePrompt();
}

Expand DownExpand Up@@ -685,7 +691,7 @@ function handleKey({ key, domEvent }) {

 // Ctrl+L – clear screen
 if (domEvent.ctrlKey && code === 'l') {
term.clear();
clearScreen();
 writePrompt();
 term.write(inputBuffer);
 return;
Expand DownExpand Up@@ -766,7 +772,7 @@ async function executeCommand(cmdLine) {
 cmdGxx(args);
 break;
 case 'clear':
term.clear();
clearScreen();
 writePrompt();
 break;
 case 'echo':
Expand DownExpand Up@@ -1072,9 +1078,47 @@ function cmdHelp() {
// ── Utilities ─────────────────────────────────────────────────────────────────

function writePrompt() {
 if (terminalLineHasContent) term?.write(CRLF);
 term?.write(`${C.green}${C.bold}browser.cpp${C.reset}${C.dim}:${promptPath()}$ ${C.reset}`);
}

/** Clear the terminal and place the next prompt at the top-left of the screen. */
function clearScreen() {
 term?.clear();
 terminalLineHasContent = false;
 if (initialPromptShown) term?.write(CLEAR_SCREEN);
}

/**
 * Keep prompt placement independent of the many existing terminal write sites.
 * xterm writes are asynchronous, so record the logical line state as output is queued.
 */
function setTerminal(nextTerm) {
 term = nextTerm;
 terminalLineHasContent = false;
 if (!term || trackedTerminals.has(term)) return;

 const terminalInstance = term;
 const write = terminalInstance.write.bind(terminalInstance);
 terminalInstance.write = (text, ...args) => {
 if (term === terminalInstance) trackTerminalLine(text);
 return write(text, ...args);
 };
 trackedTerminals.add(terminalInstance);
}

function trackTerminalLine(text) {
 if (typeof text !== 'string') return;

 const visibleText = text.replace(CSI_SEQUENCE, '');
 const lastLineBreak = Math.max(visibleText.lastIndexOf('\n'), visibleText.lastIndexOf('\r'));
 if (lastLineBreak >= 0) {
 terminalLineHasContent = visibleText.slice(lastLineBreak + 1).length > 0;
 } else if (visibleText.length > 0) {
 terminalLineHasContent = true;
 }
}

function setRunState(nextRunning) {
 if (running === nextRunning) return;
 running = nextRunning;
Expand DownExpand Up@@ -1105,7 +1149,7 @@ export function __setTerminalTestHarness({
 supportsMessageInteractiveStdin: supportsMessageInteractiveStdinForTest = () => false,
 createStdinSessionId: createStdinSessionIdForTest = () => 'stdin-session-test',
} = {}) {
term = terminalInstance || null;
setTerminal(terminalInstance || null);
 fitAddon = null;
 _onCompile = onCompile;
 _onRun = onRun;
Expand Down
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('^' + ".*" + '

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fix: keep terminal prompts on fresh lines#79

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 Merged

kbuffardi
merged 4 commits into

from

Aug 22, 2026
 Merged


fix: keep terminal prompts on fresh lines
#79
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912712d

fix: keep terminal prompts on fresh lines


kbuffardi Aug 22, 2026
56dbb7b

chore: bump patch version to 0.4.7


kbuffardi Aug 22, 2026
356c9a0

fix: satisfy terminal lint rules


kbuffardi Aug 22, 2026
80c4af9

fix: isolate terminal line tracking


kbuffardi Aug 22, 2026

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2 changes: 1 addition & 1 deletion
manifest.json

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
 "name": "browser.cpp",
 "short_name": "browser.cpp",
 "description": "In-browser C++20 IDE powered by Monaco Editor and WASM Clang",
 "version": "0.4.6",
 "version": "0.4.7",
 "minimum_chrome_version": "105",
 "icons": {
 "16": "icons/icon16.png",
Expand Down

4 changes: 2 additions & 2 deletions
package-lock.json

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2 changes: 1 addition & 1 deletion
package.json

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Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
{
 "name": "browser.cpp",
 "version": "0.4.6",
 "version": "0.4.7",
 "description": "In-browser C++20 IDE with WASM Clang toolchain",
 "private": true,
 "scripts": {
Expand Down

26 changes: 26 additions & 0 deletions
scripts/e2e-terminal-stop.test.mjs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -13,6 +13,7 @@ import {
 showInitialPrompt,
 startRun,
 stopRun,
 writeStdout,
} from '../src/ui/terminal.js';

function setupTerminalHarness({
Expand DownExpand Up@@ -123,6 +124,31 @@ test('e2e: clearing during startup does not reveal the initial prompt early', ()
 assert.ok(output.indexOf('Clang WASM compiler loaded') < output.indexOf('browser.cpp'));
});

test('e2e: clearing discards typed input and homes the fresh prompt', () => {
 const ctx = setupTerminalHarness();

 showInitialPrompt();
 __handleTerminalKeyForTesting('c', { key: 'c', ctrlKey: false, altKey: false });
 __handleTerminalKeyForTesting('a', { key: 'a', ctrlKey: false, altKey: false });
 clearTerminal();

 assert.equal(__getTerminalStateForTesting().inputBuffer, '');
 assert.equal(ctx.clearCalls.length, 1);
 assert.equal(ctx.writes.at(-2), '\x1b[2J\x1b[H');
 assert.match(ctx.writes.at(-1), /browser\.cpp.*:~\$ /);
});

test('e2e: prompt restoration follows newline-less program output on a new line', () => {
 const ctx = setupTerminalHarness();

 showInitialPrompt();
 onRunStart({ stdinMode: 'interactive' });
 writeStdout('program output');
 onRunResult({ exitCode: 0 });

 assert.match(ctx.writes.join(''), /program output\r\n.*browser\.cpp.*:~\$ /);
});

test('e2e: Ctrl+C while running stops the program once and restores the prompt', async () => {
 const ctx = setupTerminalHarness();

Expand Down

58 changes: 51 additions & 7 deletions
src/ui/terminal.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -60,6 +60,8 @@ const C = {
};

const CRLF = '\r\n';
const CLEAR_SCREEN = '\x1b[2J\x1b[H';
const CSI_SEQUENCE = new RegExp(`${String.fromCharCode(27)}\\[[0-?]*[ -/]*[@-~]`, 'g');

/** Maximum number of commands retained in shell history. */
const MAX_HISTORY_SIZE = 200;
Expand All@@ -69,6 +71,8 @@ const TAB_COMMANDS = ['g++ ', 'g++ main.cpp', './a.out', 'clear', 'echo ', 'ls',

let term = null;
let fitAddon = null;
let terminalLineHasContent = false;
const trackedTerminals = new WeakSet();

/** Current line being typed */
let inputBuffer = '';
Expand DownExpand Up@@ -301,7 +305,7 @@ export function createTerminal(container, {
 initialPromptShown = false;
 busy = true;

term = new Terminal({
setTerminal(new Terminal({
 fontFamily: "'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace",
 fontSize: 13,
 lineHeight: 1.4,
Expand DownExpand Up@@ -330,7 +334,7 @@ export function createTerminal(container, {
 cursorBlink: true,
 scrollback: 5000,
 convertEol: false,
 });
 }));

 fitAddon = new FitAddon();
 term.loadAddon(fitAddon);
Expand All@@ -357,7 +361,9 @@ export function fitTerminal() {

/** Clear the terminal screen. */
export function clearTerminal() {
 term?.clear();
 inputBuffer = '';
 historyIdx = -1;
 clearScreen();
 if (!initialPromptShown) return;
 writePrompt();
}
Expand All@@ -371,7 +377,7 @@ export function resetTerminalSession(workspace = null) {
 inputBuffer = '';
 historyIdx = -1;
 setWorkspace(workspace);
term?.clear();
clearScreen();
 if (initialPromptShown) writePrompt();
}

Expand DownExpand Up@@ -685,7 +691,7 @@ function handleKey({ key, domEvent }) {

 // Ctrl+L – clear screen
 if (domEvent.ctrlKey && code === 'l') {
term.clear();
clearScreen();
 writePrompt();
 term.write(inputBuffer);
 return;
Expand DownExpand Up@@ -766,7 +772,7 @@ async function executeCommand(cmdLine) {
 cmdGxx(args);
 break;
 case 'clear':
term.clear();
clearScreen();
 writePrompt();
 break;
 case 'echo':
Expand DownExpand Up@@ -1072,9 +1078,47 @@ function cmdHelp() {
// ── Utilities ─────────────────────────────────────────────────────────────────

function writePrompt() {
 if (terminalLineHasContent) term?.write(CRLF);
 term?.write(`${C.green}${C.bold}browser.cpp${C.reset}${C.dim}:${promptPath()}$ ${C.reset}`);
}

/** Clear the terminal and place the next prompt at the top-left of the screen. */
function clearScreen() {
 term?.clear();
 terminalLineHasContent = false;
 if (initialPromptShown) term?.write(CLEAR_SCREEN);
}

/**
 * Keep prompt placement independent of the many existing terminal write sites.
 * xterm writes are asynchronous, so record the logical line state as output is queued.
 */
function setTerminal(nextTerm) {
 term = nextTerm;
 terminalLineHasContent = false;
 if (!term || trackedTerminals.has(term)) return;

 const terminalInstance = term;
 const write = terminalInstance.write.bind(terminalInstance);
 terminalInstance.write = (text, ...args) => {
 if (term === terminalInstance) trackTerminalLine(text);
 return write(text, ...args);
 };
 trackedTerminals.add(terminalInstance);
}

function trackTerminalLine(text) {
 if (typeof text !== 'string') return;

 const visibleText = text.replace(CSI_SEQUENCE, '');
 const lastLineBreak = Math.max(visibleText.lastIndexOf('\n'), visibleText.lastIndexOf('\r'));
 if (lastLineBreak >= 0) {
 terminalLineHasContent = visibleText.slice(lastLineBreak + 1).length > 0;
 } else if (visibleText.length > 0) {
 terminalLineHasContent = true;
 }
}

function setRunState(nextRunning) {
 if (running === nextRunning) return;
 running = nextRunning;
Expand DownExpand Up@@ -1105,7 +1149,7 @@ export function __setTerminalTestHarness({
 supportsMessageInteractiveStdin: supportsMessageInteractiveStdinForTest = () => false,
 createStdinSessionId: createStdinSessionIdForTest = () => 'stdin-session-test',
} = {}) {
term = terminalInstance || null;
setTerminal(terminalInstance || null);
 fitAddon = null;
 _onCompile = onCompile;
 _onRun = onRun;
Expand Down
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
fix: keep terminal prompts on fresh lines#79

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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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 Merged

kbuffardi
merged 4 commits into

from

Aug 22, 2026
 Merged


fix: keep terminal prompts on fresh lines
#79
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912712d

fix: keep terminal prompts on fresh lines


kbuffardi Aug 22, 2026
56dbb7b

chore: bump patch version to 0.4.7


kbuffardi Aug 22, 2026
356c9a0

fix: satisfy terminal lint rules


kbuffardi Aug 22, 2026
80c4af9

fix: isolate terminal line tracking


kbuffardi Aug 22, 2026

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2 changes: 1 addition & 1 deletion
manifest.json

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
 "name": "browser.cpp",
 "short_name": "browser.cpp",
 "description": "In-browser C++20 IDE powered by Monaco Editor and WASM Clang",
 "version": "0.4.6",
 "version": "0.4.7",
 "minimum_chrome_version": "105",
 "icons": {
 "16": "icons/icon16.png",
Expand Down

4 changes: 2 additions & 2 deletions
package-lock.json

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2 changes: 1 addition & 1 deletion
package.json

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Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
{
 "name": "browser.cpp",
 "version": "0.4.6",
 "version": "0.4.7",
 "description": "In-browser C++20 IDE with WASM Clang toolchain",
 "private": true,
 "scripts": {
Expand Down

26 changes: 26 additions & 0 deletions
scripts/e2e-terminal-stop.test.mjs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -13,6 +13,7 @@ import {
 showInitialPrompt,
 startRun,
 stopRun,
 writeStdout,
} from '../src/ui/terminal.js';

function setupTerminalHarness({
Expand DownExpand Up@@ -123,6 +124,31 @@ test('e2e: clearing during startup does not reveal the initial prompt early', ()
 assert.ok(output.indexOf('Clang WASM compiler loaded') < output.indexOf('browser.cpp'));
});

test('e2e: clearing discards typed input and homes the fresh prompt', () => {
 const ctx = setupTerminalHarness();

 showInitialPrompt();
 __handleTerminalKeyForTesting('c', { key: 'c', ctrlKey: false, altKey: false });
 __handleTerminalKeyForTesting('a', { key: 'a', ctrlKey: false, altKey: false });
 clearTerminal();

 assert.equal(__getTerminalStateForTesting().inputBuffer, '');
 assert.equal(ctx.clearCalls.length, 1);
 assert.equal(ctx.writes.at(-2), '\x1b[2J\x1b[H');
 assert.match(ctx.writes.at(-1), /browser\.cpp.*:~\$ /);
});

test('e2e: prompt restoration follows newline-less program output on a new line', () => {
 const ctx = setupTerminalHarness();

 showInitialPrompt();
 onRunStart({ stdinMode: 'interactive' });
 writeStdout('program output');
 onRunResult({ exitCode: 0 });

 assert.match(ctx.writes.join(''), /program output\r\n.*browser\.cpp.*:~\$ /);
});

test('e2e: Ctrl+C while running stops the program once and restores the prompt', async () => {
 const ctx = setupTerminalHarness();

Expand Down

58 changes: 51 additions & 7 deletions
src/ui/terminal.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -60,6 +60,8 @@ const C = {
};

const CRLF = '\r\n';
const CLEAR_SCREEN = '\x1b[2J\x1b[H';
const CSI_SEQUENCE = new RegExp(`${String.fromCharCode(27)}\\[[0-?]*[ -/]*[@-~]`, 'g');

/** Maximum number of commands retained in shell history. */
const MAX_HISTORY_SIZE = 200;
Expand All@@ -69,6 +71,8 @@ const TAB_COMMANDS = ['g++ ', 'g++ main.cpp', './a.out', 'clear', 'echo ', 'ls',

let term = null;
let fitAddon = null;
let terminalLineHasContent = false;
const trackedTerminals = new WeakSet();

/** Current line being typed */
let inputBuffer = '';
Expand DownExpand Up@@ -301,7 +305,7 @@ export function createTerminal(container, {
 initialPromptShown = false;
 busy = true;

term = new Terminal({
setTerminal(new Terminal({
 fontFamily: "'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace",
 fontSize: 13,
 lineHeight: 1.4,
Expand DownExpand Up@@ -330,7 +334,7 @@ export function createTerminal(container, {
 cursorBlink: true,
 scrollback: 5000,
 convertEol: false,
 });
 }));

 fitAddon = new FitAddon();
 term.loadAddon(fitAddon);
Expand All@@ -357,7 +361,9 @@ export function fitTerminal() {

/** Clear the terminal screen. */
export function clearTerminal() {
 term?.clear();
 inputBuffer = '';
 historyIdx = -1;
 clearScreen();
 if (!initialPromptShown) return;
 writePrompt();
}
Expand All@@ -371,7 +377,7 @@ export function resetTerminalSession(workspace = null) {
 inputBuffer = '';
 historyIdx = -1;
 setWorkspace(workspace);
term?.clear();
clearScreen();
 if (initialPromptShown) writePrompt();
}

Expand DownExpand Up@@ -685,7 +691,7 @@ function handleKey({ key, domEvent }) {

 // Ctrl+L – clear screen
 if (domEvent.ctrlKey && code === 'l') {
term.clear();
clearScreen();
 writePrompt();
 term.write(inputBuffer);
 return;
Expand DownExpand Up@@ -766,7 +772,7 @@ async function executeCommand(cmdLine) {
 cmdGxx(args);
 break;
 case 'clear':
term.clear();
clearScreen();
 writePrompt();
 break;
 case 'echo':
Expand DownExpand Up@@ -1072,9 +1078,47 @@ function cmdHelp() {
// ── Utilities ─────────────────────────────────────────────────────────────────

function writePrompt() {
 if (terminalLineHasContent) term?.write(CRLF);
 term?.write(`${C.green}${C.bold}browser.cpp${C.reset}${C.dim}:${promptPath()}$ ${C.reset}`);
}

/** Clear the terminal and place the next prompt at the top-left of the screen. */
function clearScreen() {
 term?.clear();
 terminalLineHasContent = false;
 if (initialPromptShown) term?.write(CLEAR_SCREEN);
}

/**
 * Keep prompt placement independent of the many existing terminal write sites.
 * xterm writes are asynchronous, so record the logical line state as output is queued.
 */
function setTerminal(nextTerm) {
 term = nextTerm;
 terminalLineHasContent = false;
 if (!term || trackedTerminals.has(term)) return;

 const terminalInstance = term;
 const write = terminalInstance.write.bind(terminalInstance);
 terminalInstance.write = (text, ...args) => {
 if (term === terminalInstance) trackTerminalLine(text);
 return write(text, ...args);
 };
 trackedTerminals.add(terminalInstance);
}

function trackTerminalLine(text) {
 if (typeof text !== 'string') return;

 const visibleText = text.replace(CSI_SEQUENCE, '');
 const lastLineBreak = Math.max(visibleText.lastIndexOf('\n'), visibleText.lastIndexOf('\r'));
 if (lastLineBreak >= 0) {
 terminalLineHasContent = visibleText.slice(lastLineBreak + 1).length > 0;
 } else if (visibleText.length > 0) {
 terminalLineHasContent = true;
 }
}

function setRunState(nextRunning) {
 if (running === nextRunning) return;
 running = nextRunning;
Expand DownExpand Up@@ -1105,7 +1149,7 @@ export function __setTerminalTestHarness({
 supportsMessageInteractiveStdin: supportsMessageInteractiveStdinForTest = () => false,
 createStdinSessionId: createStdinSessionIdForTest = () => 'stdin-session-test',
} = {}) {
term = terminalInstance || null;
setTerminal(terminalInstance || null);
 fitAddon = null;
 _onCompile = onCompile;
 _onRun = onRun;
Expand Down
Loading