outputMonitor: fix two false-positive families pausing the agent loop

[ba-work]

Fixes #315476.

This change addresses two related false-positive families in RunInTerminalTool's input-needed heuristic that pause the agent loop on benign terminal output. Both surfaced live: the $Ri family on log lines ending in : or ?, and the Vyo family on every command return when the shell uses an oh-my-zsh-style git-aware PS1 prompt.

Family 1 — detectsInputRequiredPattern's broad fallbacks match log output

detectsInputRequiredPattern augmented detectsHighConfidenceInputPattern's strict pattern set with two over-broad fallbacks:

/: +$/                              // any line ending colon + spaces
/\? *(?:\([a-z\s]+\))? +$/i     // any line ending question + spaces

These fire on benign log output like:

[INFO] Starting:
Last Command:
find: /tmp/x: No such file:
Are you sure you want to do this?

The strict guard at the original call site is shell-integration's isActive flag, which is only true when the foreground process is actively holding stdin open. _handleIdleState was using the broad pattern unconditionally, with no isActive evidence.

Fix: split the function into two:

• detectsInputRequiredPattern(line): strict-only — delegates to detectsHighConfidenceInputPattern. Safe to call from any path, including unconditionally on the last line of a finished command.
• detectsLikelyInputRequiredPattern(line): strict + broad fallbacks. Should only be called when an out-of-band signal already confirms the process is awaiting input (isActive === true).

Update the callers:

• _handleIdleState: switch to the strict detectsInputRequiredPattern. Eliminates the log-line false positives.
• _waitForIdle: keep using the broad detectsLikelyInputRequiredPattern. This call is gated by recentlyIdle && isActive === true, which provides the out-of-band evidence the broad fallbacks need.

Family 2 — detectsHighConfidenceInputPattern's paren-default rule matches every oh-my-zsh prompt

detectsHighConfidenceInputPattern contained this rule:

/:\s*\([^)]*\) +$/      // "package name: (test) "

intended for npm-init / yarn-init style prompts. Because \s* allows zero spaces between : and (, it also matches every git-aware shell prompt:

➜  myrepo git:(main)
➜  vscode git:(ba-work/output-monitor)

(oh-my-zsh's robbyrussell theme; bash with __git_ps1; etc.) Live trigger rate: every shell-prompt return, on every benign command, on every machine running oh-my-zsh. The agent loop pauses for ~2 minutes (the _handleTimeoutState recovery window) before resuming on every command, making multi-step tasks unusable.

Fix: tighten \s* → \s+ so at least one space is required between : and (. npm-init prompts always render a space (name: (default)); shell-prompt PS1 themes never do (git:(main)). Single-byte regex change, no behavioural change to the npm-init / yarn-init matches.

Tests

• Update Line ends with colon to use the strict path and assert that bare Enter your name: , File to overwrite: , and log lines like Last Command: , [INFO] Starting: , find: /tmp/x: No such file: , error: subprocess returned: , and 2025-05-09 12:34:56 INFO Starting: all return false under the strict detectsInputRequiredPattern.
• Update detects trailing questions similarly.
• Add a new suite for detectsLikelyInputRequiredPattern covering strict-set parity, bare-colon/question matching, non-prompt rejection, and the documented false positives (log lines with colons) so the broad surface stays understood.
• Add regression cases in detectsHighConfidenceInputPattern asserting that oh-my-zsh / git-aware prompts return false while npm-init prompts continue to return true.
• Add the same oh-my-zsh regression cases in detectsInputRequiredPattern (strict) and detectsLikelyInputRequiredPattern so the rule's flow through both call paths is pinned.
• Add three end-to-end OutputMonitor integration tests asserting onDidDetectInputNeeded does NOT fire for (a) log lines ending in : , (b) lines ending in ? , (c) oh-my-zsh git-aware shell prompts. These pin the wiring at _handleIdleState, not just the regex behaviour in isolation.

How to verify

Family 2 (oh-my-zsh prompts): in the integrated terminal with shell integration enabled, on a machine using oh-my-zsh's robbyrussell theme (or any git-aware PS1 that renders git:(branch) with no space after the colon), run any command from agent mode that returns to the prompt:

cd ~/anywhere && git status

Without the fix: the agent pauses for ~2 minutes after every command return. With the fix: the agent continues immediately.

Family 1 (broad-fallback log lines): from agent mode, run a slow-ish command whose visible buffer ends in : while the command is still being polled (the strict path is what fires onDidDetectInputNeeded; running command output, not the post-prompt return, is what _handleIdleState evaluates):

printf 'Compiling: \n' && sleep 2

Without the fix: the agent pauses with the input-needed wrapper because detectsInputRequiredPattern's broad /: +$/ fallback matches the trailing : . With the fix: _handleIdleState calls the strict path, which no longer carries those fallbacks, and the wrapper does not fire.

Scope

This PR is intentionally limited to the two false-positive families called out in #315476. While reading the surrounding code I noticed detectsGenericPressAnyKeyPattern is invoked with outputTail rather than outputLastLine (line ~370), which is inconsistent with sibling line-oriented detectors. That predates this PR and is out of scope here; happy to file a separate fix if a maintainer agrees it's worth addressing.

[Copilot]

Pull request overview

This PR refines the terminal OutputMonitor input-needed heuristics used by the chat agent terminal tooling to reduce false positives that pause the agent loop on benign output (e.g., log lines ending in : / ? and git-aware shell prompts like git:(main)).

Changes:

• Split “input-needed” detection into a strict path (detectsInputRequiredPattern → high-confidence only) and a broader, gated path (detectsLikelyInputRequiredPattern).
• Tighten the parenthesized-default regex to avoid matching oh-my-zsh / git-aware prompts (:\s* → :\s+).
• Expand unit/integration-style tests to cover the reported false-positive families and regressions.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
src/vs/workbench/contrib/terminalContrib/chatAgentTools/browser/tools/monitoring/outputMonitor.ts	Splits strict vs broad prompt detection, updates idle polling gating, and tightens the parenthesized-default regex.
src/vs/workbench/contrib/terminalContrib/chatAgentTools/test/browser/outputMonitor.test.ts	Adds regressions and new suites validating strict vs likely behavior and prompt false-positive avoidance.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

[meganrogge]

Thank you!

[meganrogge]

Good catch on detectsGenericPressAnyKeyPattern being invoked with outputTail rather than outputLastLine — that does look inconsistent with the sibling detectors. Please go ahead and file a separate issue/PR for it. Thanks for flagging it and for keeping this PR focused.