Commit Graph

4 Commits

Author SHA1 Message Date
Felipe Coury
3b5996f988 fix(tui): promote windows terminal diff ansi16 to truecolor (#13016)
## Summary

- Promote ANSI-16 to truecolor for diff rendering when running inside
Windows Terminal
- Respect explicit `FORCE_COLOR` override, skipping promotion when set
- Extract a pure `diff_color_level_for_terminal` function for
testability
- Strip background tints from ANSI-16 diff output, rendering add/delete
lines with foreground color only
- Introduce `RichDiffColorLevel` to type-safely restrict background
fills to truecolor and ansi256

## Problem

Windows Terminal fully supports 24-bit (truecolor) rendering but often
does not provide the usual TERM metadata (`TERM`, `TERM_PROGRAM`,
`COLORTERM`) in `cmd.exe`/PowerShell sessions. In those environments,
`supports-color` can report only ANSI-16 support. The diff renderer
therefore falls back to a 16-color palette, producing washed-out,
hard-to-read diffs.

The screenshots below demonstrate that both PowerShell and cmd.exe don't
set any `*TERM*` environment variables.

| PowerShell | cmd.exe |
|---|---|
| <img width="2032" height="1162" alt="SCR-20260226-nfvy"
src="https://github.com/user-attachments/assets/59e968cc-4add-4c7b-a415-07163297e86a"
/> | <img width="2032" height="1162" alt="SCR-20260226-nfyc"
src="https://github.com/user-attachments/assets/d06b3e39-bf91-4ce3-9705-82bf9563a01b"
/> |


## Mental model

`StdoutColorLevel` (from `supports-color`) is the _detected_ capability.
`DiffColorLevel` is the _intended_ capability for diff rendering. A new
intermediary — `diff_color_level_for_terminal` — maps one to the other
and is the single place where terminal-specific overrides live.

Windows Terminal is detected two independent ways: the `TerminalName`
parsed by `terminal_info()` and the raw presence of `WT_SESSION`. When
`WT_SESSION` is present and `FORCE_COLOR` is not set, we promote
unconditionally to truecolor. When `WT_SESSION` is absent but
`TerminalName::WindowsTerminal` is detected, we promote only the ANSI-16
level (not `Unknown`).

A single override helper — `has_force_color_override()` — checks whether
`FORCE_COLOR` is set. When it is, both the `WT_SESSION` fast-path and
the `TerminalName`-based promotion are suppressed, preserving explicit
user intent.

| PowerShell | cmd.exe | WSL | Bash for Windows |
|---|---|---|---|
|
![SCR-20260226-msrh](https://github.com/user-attachments/assets/0f6297a6-4241-4dbf-b7ff-cf02da8941b0)
|
![SCR-20260226-nbao](https://github.com/user-attachments/assets/bb5ff8a9-903c-4677-a2de-1f6e1f34b18e)
|
![SCR-20260226-nbej](https://github.com/user-attachments/assets/26ecec2c-a7e9-410a-8702-f73995b490a6)
|
![SCR-20260226-nbkz](https://github.com/user-attachments/assets/80c4bf9a-3b41-40e1-bc87-f5c565f96075)
|

## Non-goals

- This does not change color detection for anything outside the diff
renderer (e.g. the chat widget, markdown rendering).
- This does not add a user-facing config knob; `FORCE_COLOR` already
serves that role.

## Tradeoffs

- The `has_wt_session` signal is intentionally kept separate from
`TerminalName::WindowsTerminal`. `terminal_info()` is derived with
`TERM_PROGRAM` precedence, so it can differ from raw `WT_SESSION`.
- Real-world validation in this issue: in both `cmd.exe` and PowerShell,
`TERM`/`TERM_PROGRAM`/`COLORTERM` were absent, so TERM-based capability
hints were unavailable in those sessions.
- Checking `FORCE_COLOR` for presence rather than parsing its value is a
simplification. In practice `supports-color` has already parsed it, so
our check is a coarse "did the user set _anything_?" gate. The effective
color level still comes from `supports-color`.
- When `WT_SESSION` is present without `FORCE_COLOR`, we promote to
truecolor regardless of `stdout_level` (including `Unknown`). This is
aggressive but correct: `WT_SESSION` is a strong signal that we're in
Windows Terminal.
- ANSI-16 add/delete backgrounds (bright green/red) overpower
syntax-highlighted token colors, making diffs harder to read.
Foreground-only cues (colored text, gutter signs) preserve readability
on low-color terminals.

## Architecture

```
stdout_color_level()  ──┐
terminal_info().name  ──┤
WT_SESSION presence   ──┼──▶ diff_color_level_for_terminal() ──▶ DiffColorLevel
FORCE_COLOR presence  ──┘                                            │
                                                                     ▼
                                                          RichDiffColorLevel::from_diff_color_level()
                                                                     │
                                                          ┌──────────┴──────────┐
                                                          │ Some(TrueColor|256) │ → bg tints
                                                          │ None (Ansi16)       │ → fg only
                                                          └─────────────────────┘
```

`diff_color_level()` is the environment-reading entry point; it gathers
the four runtime signals and delegates to the pure, testable
`diff_color_level_for_terminal()`.

## Observability

No new logs or metrics. Incorrect color selection is immediately visible
as broken diff rendering; the test suite covers the decision matrix
exhaustively.

## Tests

Six new unit tests exercise every branch of
`diff_color_level_for_terminal`:

| Test | Inputs | Expected |
|------|--------|----------|
| `windows_terminal_promotes_ansi16_to_truecolor_for_diffs` | Ansi16 +
WindowsTerminal name | TrueColor |
| `wt_session_promotes_ansi16_to_truecolor_for_diffs` | Ansi16 +
WT_SESSION only | TrueColor |
| `non_windows_terminal_keeps_ansi16_diff_palette` | Ansi16 + WezTerm |
Ansi16 |
| `wt_session_promotes_unknown_color_level_to_truecolor` | Unknown +
WT_SESSION | TrueColor |
| `explicit_force_override_keeps_ansi16_on_windows_terminal` | Ansi16 +
WindowsTerminal + FORCE_COLOR | Ansi16 |
| `explicit_force_override_keeps_ansi256_on_windows_terminal` | Ansi256
+ WT_SESSION + FORCE_COLOR | Ansi256 |
| `ansi16_add_style_uses_foreground_only` | Dark + Ansi16 | fg=Green,
bg=None |
| (and any other new snapshot/assertion tests from commits d757fee and
d7c78b3) | | |

## Test plan

- [x] Verify all new unit tests pass (`cargo test -p codex-tui --lib`)
- [x] On Windows Terminal: confirm diffs render with truecolor
backgrounds
- [x] On Windows Terminal with `FORCE_COLOR` set: confirm promotion is
disabled and output follows the forced `supports-color` level
- [x] On macOS/Linux terminals: confirm no behavior change

Fixes https://github.com/openai/codex/issues/12904 
Fixes https://github.com/openai/codex/issues/12890
Fixes https://github.com/openai/codex/issues/12912
Fixes https://github.com/openai/codex/issues/12840
2026-02-27 10:45:59 -07:00
Jeff Mickey
c14e6813fb [codex-tui] exit when terminal is dumb (#9293)
Using terminal with TERM=dumb specifically mean that TUIs and the like
don't work. Ensure that codex doesn't run in these environments and exit
with odd errors like crossterm's "Error: The cursor position could not
be read within a normal duration"

---------

Co-authored-by: Josh McKinney <joshka@openai.com>
2026-01-20 16:17:38 -08:00
Josh McKinney
df46ea48a2 Terminal Detection Metadata for Per-Terminal Scroll Scaling (#8252)
# Terminal Detection Metadata for Per-Terminal Scroll Scaling

## Summary
Expand terminal detection into structured metadata (`TerminalInfo`) with
multiplexer awareness, plus a testable environment shim and
characterization tests.

## Context / Motivation
- TUI2 owns its viewport and scrolling model (see
`codex-rs/tui2/docs/tui_viewport_and_history.md`), so scroll behavior
must be consistent across terminals and independent of terminal
scrollback quirks.
- Prior investigations show mouse wheel scroll deltas vary noticeably by
terminal. To tune scroll scaling (line increments per wheel tick) we
need reliable terminal identification, including when running inside
tmux/zellij.
- tmux is especially tricky because it can mask the underlying terminal;
we now consult `tmux display-message` client termtype/name to attribute
sessions to the actual terminal rather than tmux itself.
- This remains backwards compatible with the existing OpenTelemetry
user-agent token because `user_agent()` is still derived from the same
environment signals (now via `TerminalInfo`).

## Changes
- Introduce `TerminalInfo`, `TerminalName`, and `Multiplexer` with
`TERM_PROGRAM`/`TERM`/multiplexer detection and user-agent formatting in
`codex-rs/core/src/terminal.rs`.
- Add an injectable `Environment` trait + `FakeEnvironment` for testing,
and comprehensive characterization tests covering known terminals, tmux
client termtype/name, and zellij.
- Document module usage and detection order; update `terminal_info()` to
be the primary interface for callers.

## Testing
- `cargo test -p codex-core terminal::tests`
- manually checked ghostty, iTerm2, Terminal.app, vscode, tmux, zellij,
Warp, alacritty, kitty.
```
2025-12-18T07:07:49.191421Z  INFO Detected terminal info terminal=TerminalInfo { name: Iterm2, term_program: Some("iTerm.app"), version: Some("3.6.6"), term: None, multiplexer: None }
2025-12-18T07:07:57.991776Z  INFO Detected terminal info terminal=TerminalInfo { name: AppleTerminal, term_program: Some("Apple_Terminal"), version: Some("455.1"), term: None, multiplexer: None }
2025-12-18T07:08:07.732095Z  INFO Detected terminal info terminal=TerminalInfo { name: WarpTerminal, term_program: Some("WarpTerminal"), version: Some("v0.2025.12.10.08.12.stable_03"), term: None, multiplexer: None }
2025-12-18T07:08:24.860316Z  INFO Detected terminal info terminal=TerminalInfo { name: Kitty, term_program: None, version: None, term: None, multiplexer: None }
2025-12-18T07:08:38.302761Z  INFO Detected terminal info terminal=TerminalInfo { name: Alacritty, term_program: None, version: None, term: None, multiplexer: None }
2025-12-18T07:08:50.887748Z  INFO Detected terminal info terminal=TerminalInfo { name: VsCode, term_program: Some("vscode"), version: Some("1.107.1"), term: None, multiplexer: None }
2025-12-18T07:10:01.309802Z  INFO Detected terminal info terminal=TerminalInfo { name: WezTerm, term_program: Some("WezTerm"), version: Some("20240203-110809-5046fc22"), term: None, multiplexer: None }
2025-12-18T08:05:17.009271Z  INFO Detected terminal info terminal=TerminalInfo { name: Ghostty, term_program: Some("ghostty"), version: Some("1.2.3"), term: None, multiplexer: None }
2025-12-18T08:05:23.819973Z  INFO Detected terminal info terminal=TerminalInfo { name: Ghostty, term_program: Some("ghostty"), version: Some("1.2.3"), term: Some("xterm-ghostty"), multiplexer: Some(Tmux { version: Some("3.6a") }) }
2025-12-18T08:05:35.572853Z  INFO Detected terminal info terminal=TerminalInfo { name: Ghostty, term_program: Some("ghostty"), version: Some("1.2.3"), term: None, multiplexer: Some(Zellij) }
```

## Notes / Follow-ups
- Next step is to wire `TerminalInfo` into TUI2’s scroll scaling
configuration and add a per-terminal tuning table.
- The log output in TUI2 helps validate real-world detection before
applying behavior changes.
2025-12-18 12:50:00 -08:00
Jeremy Rose
0ad4e11c84 detect terminal and include in request headers (#2437)
This adds the terminal version to the UA header.
2025-08-20 16:54:26 +00:00