vyncint/termlens

View on GitHub

Headless end-to-end testing for CLI and TUI apps in Rust: real PTYs, rendered-screen assertions, snapshots, and screen diffs.

Is vyncint/termlens beginner-friendly?

In the last 30 days, vyncint/termlens merged 10 of 10 pull requests from outside contributors, and its maintainers usually reply within 1 day. 27 beginner-friendly issues are open now.

Stars: 28
Forks: 24
Open beginner issues: 27
Indexed issues: 74
Avg merge: 11h 23m
Merged PRs (30d): 42

Dominant language: Rust
License: Apache-2.0
Last GitHub push: Oct 5, 2026
Latest indexed: Oct 6, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: good first issue

How to contribute to vyncint/termlens

Read the contributing guide first: it says how the maintainers want changes proposed, tested and reviewed.
Read its code of conduct: it covers issues and pull requests as well as chat.
Your contributions will be published under the project's Apache-2.0 license.
Pick one of the 27 open beginner-friendly issues below and comment that you want to work on it before you start.

Beginner friendly Everything

Open All

Issues somebody may already be working on are listed last. List everything by date

README's decode example uses `?` on an error that does not convert to `termlens::Error`
Open
- Is something wrong?
documentation good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 82/100

vyncint/termlens#660 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
SKILL.md says `Terminal::record()` refuses an application without DEC 2026; only `Recorder::stop()` does
Open
- Is something wrong?
documentation good first issue

Difficulty 1/5 Under an hour Newbie friendliness 95/100

vyncint/termlens#659 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
Release notes show a broken link: `extract-changelog.sh` copies a reference but not its definition
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 70/100

vyncint/termlens#658 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
Three CI gate scripts accept the shapes they exist to reject
Open
- Is something wrong?
bug good first issue

Difficulty 3/5 1-2 days Newbie friendliness 76/100

vyncint/termlens#657 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
CI on `main` drops queued runs, so some merged commits never get their own CI run
Open
- Is something wrong?
bug

Difficulty 2/5 1-3 hours Newbie friendliness 67/100

vyncint/termlens#656 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
Applying the `breaking` label to an open pull request does not re-run the semver gate
Open
- Is something wrong?
bug

Difficulty 2/5 1-3 hours Newbie friendliness 72/100

vyncint/termlens#655 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
The report action's documented setup breaks in a matrix, and its artifact-dir default only works by coincidence
Open
- Is something wrong?
documentation good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 83/100

vyncint/termlens#654 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
`termlens render` and `diff` read their input without any size bound
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 84/100

vyncint/termlens#653 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
Plain `termlens diff` output ends with a blank line, and says "1 rows unchanged"
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 88/100

vyncint/termlens#652 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
`termlens diff missing.snap -` waits for standard input before reporting the missing file
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 78/100

vyncint/termlens#651 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
`termlens render` and `diff` refuse `--`, so a file named with a leading `-` cannot be passed
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 88/100

vyncint/termlens#650 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
`ScreenDiff` across different sizes prints rows unclipped, so the columns and the `^` markers misalign
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 82/100

vyncint/termlens#649 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
Report action: a screen row of three backticks breaks the step summary, and a file name with a newline splits in two
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 82/100

vyncint/termlens#648 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
Multi-row `find`, `find_all` and `mask_matching` slow down with the needle's height; `contains` does not
Open
- Is something wrong?
bug good first issue

Difficulty 3/5 1-2 days Newbie friendliness 78/100

vyncint/termlens#647 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
Asciicast frames drop the cursor, so players draw it after the last row
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 82/100

vyncint/termlens#646 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
`to_html` fades a dim run's background too; `to_svg` fades only the text
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 82/100

vyncint/termlens#645 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
`rect_text` and `mask_rect` panic on an open-ended range that starts past the edge
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 84/100

vyncint/termlens#644 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
`Screen::parse` refuses text snapshots that 0.11.1 and 0.11.6 wrote
Open
- Is something wrong?
bug

Difficulty 3/5 1-2 days Newbie friendliness 74/100

vyncint/termlens#643 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
X10 mouse mode (`?9`) sends modifier bits and wheel events, which xterm never does
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 84/100

vyncint/termlens#642 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
XTSMGRAPHICS (`CSI ? Pi ; Pa ; Pv S`) is not recognised as a query, so a blocked application is not named
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 84/100

vyncint/termlens#641 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
Mouse mode 1015 (urxvt) is neither honoured nor reported, and the error blames the legacy encoding
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 77/100

vyncint/termlens#640 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
A kitty `a=q` query is answered where kitty stays silent
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 82/100

vyncint/termlens#639 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
Sixel decode crops to the declared raster size; xterm keeps what was painted
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 78/100

vyncint/termlens#638 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
Kitty data padded per chunk fails to decode
Open
- Is something wrong?
bug good first issue

Difficulty 3/5 1-2 days Newbie friendliness 78/100

vyncint/termlens#637 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
A kitty `a=p` that arrives during a chunked upload is swallowed as the upload's next chunk
Open
- Is something wrong?
bug

Difficulty 3/5 1-2 days Newbie friendliness 76/100

vyncint/termlens#636 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
A sixel past the capture bound loses its declared size, and the cursor no longer moves past it
Open
- Is something wrong?
bug

Difficulty 4/5 1-2 days Newbie friendliness 55/100

vyncint/termlens#635 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
A kitty placement with a large `r=`, `c=` or `s=` panics the emulator (u32 overflow)
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 85/100

vyncint/termlens#634 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
A failed spawn releases the PTY lock before closing the PTY
Open
- Is something wrong?
bug

Difficulty 4/5 1-2 days Newbie friendliness 55/100

vyncint/termlens#633 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
A zero timeout makes every send fail with a false "buffer full" while the bytes are delivered
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 82/100

vyncint/termlens#632 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
`spawn("sub/prog")` of a file that is missing or not executable reports a PATH search
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 83/100

vyncint/termlens#631 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
With SIGCHLD ignored, `Drop` takes 2 s per terminal and signals an already-reaped pid
Open
- Is something wrong?
bug

Difficulty 4/5 3-5 days Newbie friendliness 52/100

vyncint/termlens#630 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
Every wait panics on a large timeout ("overflow when adding duration to instant")
Open
- Is something wrong?
bug good first issue

Difficulty 3/5 1-2 days Newbie friendliness 76/100

vyncint/termlens#629 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
`Drop` hangs forever, holding the process-wide PTY lock, when the application left input unread in raw mode
Open
- Is something wrong?
bug

Difficulty 4/5 3-5 days Newbie friendliness 55/100

vyncint/termlens#628 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
After ESC, the sequence tracker drops to ground on a C0 control, where the parser runs it and stays in escape
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 83/100

vyncint/termlens#627 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
A kitty `a=p` placement takes its size from an older transmission when the newest one has none
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 82/100

vyncint/termlens#626 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
`unsupported()` lists a window title containing `;`, and misses `CSI 4;20 h`
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 86/100

vyncint/termlens#625 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
Insert-mode output depends on where the PTY splits the input
Open
- Is something wrong?
bug

Difficulty 3/5 1-2 days Newbie friendliness 78/100

vyncint/termlens#624 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
RIS leaves focus reporting on and an open synchronized update open, so `wait_stable` can never succeed
Open
- Is something wrong?
bug good first issue

Difficulty 2/5 1-3 hours Newbie friendliness 82/100

vyncint/termlens#623 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
Rows that scroll in the same read that enters the alternate screen are missing from history
Open
- Is something wrong?
bug

Difficulty 3/5 1-2 days Newbie friendliness 76/100

vyncint/termlens#622 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
`CSI ? 3 J` and `CSI 3:1 J` erase the history termlens has already retained
Open
- Is something wrong?
bug good first issue

Difficulty 3/5 1-2 days Newbie friendliness 76/100

vyncint/termlens#621 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
A resize round-trip over a soft-wrapped line makes the attribute shadow diverge (debug panic, lost wrap flag)
Open
- Is something wrong?
bug

Difficulty 4/5 3-5 days Newbie friendliness 57/100

vyncint/termlens#620 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
A VS16 emoji in the bottom-right cell panics the emulator when the row is redrawn
Open
- Is something wrong?
bug

Difficulty 4/5 3-5 days Newbie friendliness 53/100

vyncint/termlens#619 · Opened Oct 28, 2026

Maintainers usually reply within 1 day
A cursor-position reply builds a whole-screen snapshot, and 0.11.7 doubled its cost in debug builds
Open
- Is something wrong?
bug

Difficulty 3/5 1-2 days Newbie friendliness 74/100

vyncint/termlens#618 · Opened Oct 27, 2026

Maintainers usually reply within 1 day

vyncint/termlens

Is vyncint/termlens beginner-friendly?

How to contribute to vyncint/termlens

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Is something wrong?

Get new issues in your inbox