fix: allow triage-permission actors to trigger review via allow-list

[lklimek]

TL;DR: Lets a trusted bot/service account without repo write access (e.g. a triage-only labeling bot) trigger the review, instead of always being rejected.

User story

As a repo maintainer, I want to let a specific triage-permission bot trigger the AI review by applying the trigger label, to achieve automated review triggering without granting that bot real write access to the repository.

Scenario

Base flow

A bot or human applies the trigger label (e.g. claudius-review) to a PR, which fires this action.

Actual behavior

The action's own preflight — and claude-code-action internally — only accept the GitHub collaborator-permission API's admin/write levels for the triggering actor. A fine-grained triage role rounds down to read via that API (it has no way to report "triage" directly), so any triage-only account is always rejected, even when it's a trusted account whose only job is applying the label. Confirmed on dashpay/dash-evo-tool run 29930647048: actor Claudius-Maginificent (triage role) reported permission read and was rejected.

Expected behavior

A repo can opt specific trusted non-write accounts into triggering the review, without loosening write access for anyone else.

Detailed discussion

What was done

• Added allowed_non_write_users input (comma-separated usernames, or *) that:
  • Bypasses this action's own fast write-access preflight by exact actor-name match (mirrors claude-code-action's own bypass semantics).
  • Is passed through to claude-code-action's own allowed_non_write_users input, which also requires github_token to be explicitly provided (previously this action only set GH_TOKEN as an env var for its own gh calls, never passed github_token as an actual input to the claude-code-action step) — without both, the upstream bypass silently never activates.
• Dropped maintain from the preflight's accepted permissions. claude-code-action itself only accepts admin/write, so a maintain-level actor was previously passing this fast preflight only to fail ~40s later inside claude-code-action with the exact opaque error this preflight exists to avoid.
• Documented the new input in the README, including a "Triggering by non-write actors" section with a usage example.

Testing

• action.yml and learn/action.yml validated with python3 -c "import yaml; yaml.safe_load(...)" (pass) and yamllint via pipx run (no new issues beyond this file's pre-existing 80-col line-length style, unrelated to this change).
• Bash allow-list parsing logic (empty input, comma-separated with whitespace, exact match) verified standalone under set -e — no false matches, no spurious failures on empty/default input.
• No functional CI in this repo (per CLAUDE.md); this action is exercised by consuming workflows once merged to main.

Breaking changes

None — new input defaults to "" (empty allow-list), identical behavior to before for anyone who doesn't set it. The only behavior change without opting in is the maintain → rejected fix (a permission level claude-code-action never actually honored anyway).

Checklist

• YAML syntax validated
• README updated
• Verified end-to-end against a real triage-permission actor (pending: dashpay/dash-evo-tool#TBD opts Claudius-Maginificent into allowed_non_write_users once this merges to main)

Prior work

• fix: TaskOutput-timeout guard, actor-permission preflight, report deps #7 added the original write-access preflight this PR extends.

Attribution

_{🤖 Co-authored by Claudius the Magnificent AI Agent}

[Copilot]

Pull request overview

This PR updates the composite action to support allowing specific trusted non-write actors (e.g., triage-permission bots) to trigger the review via an explicit allow-list, while aligning the preflight permission gate with what anthropics/claude-code-action actually enforces.

Changes:

• Adds a new allowed_non_write_users input and documents its use in the README.
• Extends the action’s fast “triggering actor permission” preflight to honor the allow-list and removes maintain from the accepted permissions.
• Passes github_token and allowed_non_write_users through to anthropics/claude-code-action@v1 so the upstream bypass can activate.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
README.md	Documents the new allowed_non_write_users input and describes how triage-only actors can trigger reviews.
action.yml	Adds the new input, implements the allow-list bypass in the preflight, tightens accepted permissions, and forwards inputs to claude-code-action.

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

action.yml:239

• To keep the fast preflight and claude-code-action in sync, pass the same normalized allowed_non_write_users value to the underlying action (e.g. the ALLOWED_NON_WRITE_USERS env var exported by the preflight). Otherwise whitespace/casing normalization only applies to the preflight, and the upstream bypass may still fail unexpectedly.

        github_token: ${{ inputs.github_token }}
        allowed_non_write_users: ${{ inputs.allowed_non_write_users }}

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (1)

action.yml:109

• The normalized allowed_non_write_users value is only exported to GITHUB_ENV after the ACTOR empty guard. When github.event.sender.login is empty, this step exits early and the downstream claude-code-action step receives an empty ${{ env.ALLOWED_NON_WRITE_USERS }}, even if the user configured inputs.allowed_non_write_users. Export the normalized value before the early-exit so pass-through remains consistent when the preflight is skipped.

        ACTOR="${{ github.event.sender.login }}"
        if [ -z "$ACTOR" ]; then
          echo "::warning::Could not determine the triggering actor (github.event.sender.login was empty) — skipping the write-access preflight. The underlying claude-code-action will still enforce this itself."
          exit 0
        fi