fix(pager): avoid less in captured text pagers

[benvinegar]

Summary

• pass non-diff hunk pager input through when running under captured pager hosts like LazyGit
• also avoid launching a text pager for non-diff input when TERM=dumb
• add startup-plan regression tests and changelog entry

Fixes #337

Testing

• bun run typecheck
• bun test src/core/startup.test.ts src/core/pager.test.ts test/cli/entrypoint.test.ts
• Manual LazyGit PTY smoke test with HUNK_TEXT_PAGER pointed at a wrapper around real less -R; LazyGit invoked hunk pager while advertising TERM=dumb, the less wrapper was invoked 0 times, and no live less processes remained.

This PR description was generated by Pi using OpenAI GPT-5.1 Codex

[greptile-apps]

Greptile Summary

This PR fixes hunk pager so that non-diff text (e.g. branch lists from LazyGit) is written directly to stdout instead of being handed to an interactive less session when the host advertises TERM=dumb or is a recognized captured-pager environment. Two regression tests are added alongside a fix to an existing test that was missing explicit env and stdoutIsTTY deps.

• src/core/startup.ts: A new guard short-circuits the non-diff pager path with a passthrough plan when isCapturedPagerHost(env) or env.TERM === "dumb", preventing less from being spawned in contexts that cannot host an interactive pager.
• src/core/startup.test.ts: Two new tests cover the captured-pager-host and plain-dumb-terminal passthrough cases; the pre-existing plain-text-pager test is hardened with explicit env and stdoutIsTTY values.

Confidence Score: 4/5

Safe to merge; the change is a small, well-tested guard that avoids launching an interactive pager in dumb-terminal contexts.

The logic change is narrow and the new tests cover both target cases. The one notable point is that isCapturedPagerHost(env) || env.TERM === "dumb" collapses to just env.TERM === "dumb" because the helper function itself requires TERM=dumb, making the captured-host branch unreachable in this expression — a minor clarity issue rather than a behavioral defect.

src/core/startup.ts — specifically the redundant OR condition on the new guard at line 147

Important Files Changed

Filename	Overview
src/core/startup.ts	Adds a passthrough guard for non-diff pager input when TERM=dumb or a captured pager host is detected; the guard condition contains a redundant isCapturedPagerHost branch since that function already requires TERM=dumb
src/core/startup.test.ts	Adds two regression tests for the new passthrough paths (captured-pager-host and plain dumb-terminal); also correctly backfills stdoutIsTTY and env deps on the pre-existing plain-text-pager test to avoid relying on ambient process.env
CHANGELOG.md	Adds a user-visible changelog entry for the pager passthrough fix; no issues

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[hunk pager invoked] --> B[read stdin text]
    B --> C{looksLikePatchInput?}
    C -- No --> D{isCapturedPagerHost OR TERM=dumb?}
    D -- Yes --> E[passthrough: write text to stdout]
    D -- No --> F[plain-text-pager: launch less]
    C -- Yes --> G{stdoutIsTTY?}
    G -- No --> E
    G -- Yes --> H{TERM=dumb AND NOT capturedHost?}
    H -- Yes --> E
    H -- No --> I{isCapturedPagerHost?}
    I -- Yes --> J[static-diff-pager: colored diff output]
    I -- No --> K[openControllingTerminal]
    K -- null --> J
    K -- terminal --> L[app: interactive TUI]

Loading

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
src/core/startup.ts:146-147
The condition `isCapturedPagerHost(env) || env.TERM === "dumb"` is logically equivalent to just `env.TERM === "dumb"`, because `isCapturedPagerHost` itself requires `env.TERM === "dumb"` as its first operand — the captured-host check can never be true when the dumb-terminal check is false. The `isCapturedPagerHost` arm is therefore dead code here. This contrasts with the diff path (lines 167–178) where the two conditions produce different outcomes (`passthrough` vs `static-diff-pager`), making the distinction meaningful — but for non-diff input both arms return `passthrough`, collapsing the distinction entirely. The comment "Captured pager and dumb-terminal hosts" implies these are separate categories, which may mislead future readers.

```suggestion
      // Dumb-terminal and captured pager hosts (which also advertise TERM=dumb) cannot safely own an interactive text pager.
      if (env.TERM === "dumb") {
```

_{Reviews (1): Last reviewed commit: "fix(pager): avoid less in captured text ..." | Re-trigger Greptile}

[greptile-apps]

The condition isCapturedPagerHost(env) || env.TERM === "dumb" is logically equivalent to just env.TERM === "dumb", because isCapturedPagerHost itself requires env.TERM === "dumb" as its first operand — the captured-host check can never be true when the dumb-terminal check is false. The isCapturedPagerHost arm is therefore dead code here. This contrasts with the diff path (lines 167–178) where the two conditions produce different outcomes (passthrough vs static-diff-pager), making the distinction meaningful — but for non-diff input both arms return passthrough, collapsing the distinction entirely. The comment "Captured pager and dumb-terminal hosts" implies these are separate categories, which may mislead future readers.

Suggested change

	// Captured pager and dumb-terminal hosts cannot safely own an interactive text pager.
	if (isCapturedPagerHost(env) || env.TERM === "dumb") {
	// Dumb-terminal and captured pager hosts (which also advertise TERM=dumb) cannot safely own an interactive text pager.
	if (env.TERM === "dumb") {

Prompt To Fix With AI

This is a comment left during a code review.
Path: src/core/startup.ts
Line: 146-147

Comment:
The condition `isCapturedPagerHost(env) || env.TERM === "dumb"` is logically equivalent to just `env.TERM === "dumb"`, because `isCapturedPagerHost` itself requires `env.TERM === "dumb"` as its first operand — the captured-host check can never be true when the dumb-terminal check is false. The `isCapturedPagerHost` arm is therefore dead code here. This contrasts with the diff path (lines 167–178) where the two conditions produce different outcomes (`passthrough` vs `static-diff-pager`), making the distinction meaningful — but for non-diff input both arms return `passthrough`, collapsing the distinction entirely. The comment "Captured pager and dumb-terminal hosts" implies these are separate categories, which may mislead future readers.

```suggestion
      // Dumb-terminal and captured pager hosts (which also advertise TERM=dumb) cannot safely own an interactive text pager.
      if (env.TERM === "dumb") {
```

How can I resolve this? If you propose a fix, please make it concise.

[benvinegar]

Good catch — simplified this to check TERM=dumb directly and updated the comment so it does not imply a separate captured-host branch in the non-diff path.

This comment was generated by Pi using OpenAI GPT-5.1 Codex