investigate-issue - SKILL.md Agent Skill

name: investigate-issue description: Investigate a GitHub issue and post structured findings as a comment. Use when the user wants to analyze a bug report, reproduce it, and share findings on the issue thread. allowed-tools: Bash(git:), Bash(gh:), Bash(uv:), Bash(grep:), Bash(find:), Bash(cat:), Read, WebFetch(domain:github.com)

Step 0 — Identify the issue

Provided issue: $ARGUMENTS

If an issue number was provided, store it as ISSUE_NUMBER and continue to Step 1. If no issue number was provided, ask the user which issue to investigate, then store the answer as ISSUE_NUMBER.

Step 1 — Fetch the issue

gh issue view ISSUE_NUMBER --repo psd-tools/psd-tools --comments

Read the full issue body, title, and all comments. Understand:

What behavior the reporter expected
What behavior they observed
Any reproduction steps or sample files mentioned
The version of psd-tools they used

Step 2 — Reproduce or locate the root cause

Based on the issue description, investigate the codebase:

Search for relevant code using grep or find in src/psd_tools/
If the issue has a code snippet, try to reproduce it:
```
uv run python -c "..."
```
If the issue mentions a specific PSD feature, trace the code path:
- High-level API: src/psd_tools/api/
- Low-level parsing: src/psd_tools/psd/
- Compositing: src/psd_tools/composite/
Look for related tests in tests/ that may already cover (or fail to cover) the case

Classify the issue into one of these categories before writing the comment:

Classification	When it applies
Bug (parsing)	Wrong data read from the PSD binary
Bug (API)	Wrong value exposed to the user
Missing feature	Behavior not implemented
Already fixed	The bug no longer reproduces on `main`
Unreproducible	Cannot reproduce without a sample file or more detail
By design / known limitation	Documented or intentional constraint (see Known Limitations in CLAUDE.md)
Needs composite deps	Only affects users without `psd-tools[composite]` installed
Documentation	User misunderstood the API
Duplicate	Same root cause as an existing issue

Step 3 — Draft investigation findings

Write a clear, structured comment in Markdown. Tailor the content to the classification:

## Investigation findings

**Classification**: [one of the categories above]

### Analysis

[2–4 paragraphs: what you found, where in the code the issue originates, and why it happens.
For "Already fixed", note the commit/PR that fixed it.
For "Unreproducible", list what you tried and what additional info is needed (sample PSD file, version, Python version, etc.).
For "By design / known limitation", cite the relevant Known Limitations entry.
For "Needs composite deps", explain which optional packages are required and how to install them.]

### Relevant code

[Point to specific files and line numbers, e.g. `src/psd_tools/psd/smart_object.py:123`.
Omit if not applicable.]

### Reproduction

[Minimal code that reproduces the bug. If unreproducible, omit this section.]

### Suggested fix

[Brief description of the approach to fix it.
Omit for "By design", "Already fixed", "Duplicate", and "Unreproducible" — use the Analysis section instead.]

Omit sections that are not applicable. Keep the tone neutral and technical.

Step 4 — Ask before posting

Show the user the draft comment and ask: "Ready to post this as a comment on issue #ISSUE_NUMBER?"

Do NOT post without explicit user confirmation.

Step 5 — Post the comment

Once the user confirms, write the comment body to a temp file and post via --body-file to safely handle multiline Markdown, backticks, and special characters:

cat > "${TMPDIR:-/tmp}/issue_comment_ISSUE_NUMBER.md" << 'EOF'
COMMENT_BODY
EOF
gh issue comment ISSUE_NUMBER --repo psd-tools/psd-tools --body-file "${TMPDIR:-/tmp}/issue_comment_ISSUE_NUMBER.md"

Print the URL of the posted comment.