* feat(tui): expand light-terminal auto-detection (HERMES_TUI_THEME, BG hex)
Modern terminals (Ghostty, Warp, iTerm2) don't set COLORFGBG, so the
auto-light path was effectively COLORFGBG-only and silently broken for
many users. Two pragmatic additions, both opt-in, plus a clearer
priority chain:
1. **`HERMES_TUI_THEME=light|dark`** as a symmetric explicit override.
The existing `HERMES_TUI_LIGHT` is fine but reads as boolean noise;
a named theme env var matches `display.skin` muscle memory.
2. **`HERMES_TUI_BACKGROUND` hex/rgb hint.** Lets advanced users
(or a future OSC11 query helper that caches the answer) state a
ground-truth background colour. Decoded to Rec. 709 luma; ≥ 0.6
counts as light.
Priority order is now fully ordered and explainable:
1. `HERMES_TUI_LIGHT` (1/0/true/false/on/off).
2. `HERMES_TUI_THEME=light|dark`.
3. `HERMES_TUI_BACKGROUND` luminance.
4. `COLORFGBG` last field — light slots 7/15 → light, 0–15 → dark
(authoritative when set, so the new TERM_PROGRAM path can never
stomp on a terminal that already volunteered a dark answer).
5. `TERM_PROGRAM` allow-list — empty by default. The slot is left
in place because folks asked for it but populating it risks
wrongly flipping users on Apple_Terminal / iTerm2 dark profiles
to light. Easy to add per terminal once we have signal.
Tests: 5 new cases in `theme.test.ts` covering theme env, background
hex (3- and 6-char), invalid hex falling through, and COLORFGBG taking
precedence over the future allow-list.
Validation: `npm run type-check` clean, `npm test --run` 392/392.
* review(copilot): tighten theme detection comments + drop unnecessary cast
* review(copilot): strict hex regex so partial garbage doesn't slip into luminance
* test(tui): make TERM_PROGRAM allow-list injectable so precedence is provable
Copilot review on PR #17113: `LIGHT_DEFAULT_TERM_PROGRAMS` is empty
in production, so the prior assertion would have passed even if
`detectLightMode` ignored `COLORFGBG` entirely. That defeats the
test's purpose.
`detectLightMode` now takes the allow-list as an optional second
argument (defaults to the production set). The test injects a set
containing `Apple_Terminal`, asserts the allow-list alone WOULD
return light, then asserts `COLORFGBG: '15;0'` overrides it — the
precedence rule is now exercised, not assumed.
* fix(tui): COLORFGBG empty-trailing-field falls through; isolate DEFAULT_THEME tests
Round 2 Copilot review on PR #17113:
1. `Number(colorfgbg.split(';').at(-1))` returns 0 for an empty trailing
field (e.g. `COLORFGBG='15;'` → bg===0), which would have looked
like an authoritative dark slot and incorrectly blocked the
TERM_PROGRAM allow-list. Added a `/^\d+$/` guard before coercion;
non-numeric trailing fields now fall through.
2. Fixed the misleading '0–6 / 8–15 ranges are dark' comment — the
block returns true for bg===15, so the range is actually 0–6 / 8–14.
3. `DEFAULT_THEME` is computed from `process.env` at module-load.
A developer shell with `HERMES_TUI_THEME=light` (or a bright
`HERMES_TUI_BACKGROUND`) would flip it and break local tests.
The DEFAULT_THEME describe blocks now sterilize the relevant env
vars + dynamically import theme.ts (vi.resetModules pattern from
platform.test.ts). fromSkin tests compare against DARK_THEME
directly to decouple them from ambient env.
* test(tui): isolate ALL env-coupled theme symbols, not just DEFAULT_THEME
Round 3 Copilot review on PR #17113: the static top-level imports of
`fromSkin`, `DARK_THEME`, `LIGHT_THEME` evaluated theme.ts before
`importThemeWithCleanEnv` had a chance to clean the env. Because
`fromSkin` closes over `DEFAULT_THEME`, an ambient `HERMES_TUI_THEME=light`
or bright `HERMES_TUI_BACKGROUND` would still flip the base palette
and cause local-only failures.
Removed the static import entirely. Every test now obtains its theme
symbols via `importThemeWithCleanEnv`, including `detectLightMode`
(for consistency, even though it takes env as a parameter).
`fromSkin` tests assert against the cleaned `DEFAULT_THEME` from the
same dynamic import — preserves the actual contract (skins extend the
ambient base palette) without coupling the test to dev-shell state.
Verified by running with HERMES_TUI_THEME=light + HERMES_TUI_BACKGROUND=#ffffff:
all 20 theme tests still pass.
Self-review (avoid round 4):
- Audited other test files importing DEFAULT_THEME (syntax.test.ts,
streamingMarkdown.test.ts, constants.test.ts) — all just pass it as
a parameter or assert palette property existence (works on both
light + dark), so no env coupling there.