Lines Changed Check

A GitHub Action that calculates lines changed in a PR, excluding files that match configurable glob patterns (e.g. test files, migration snapshots). It posts a comment on the PR with the results and automatically updates it when new commits are pushed.

Usage

name: Lines Changed
on:
  pull_request:
    types: [opened, synchronize, reopened]

jobs:
  lines-changed:
    runs-on: ubuntu-latest
    steps:
      - uses: your-username/lines-changed-check@v1
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          exclude-patterns: |
            **/*.test.ts
            **/*.test.tsx
            **/*.spec.ts
            **/*.spec.tsx
            **/__tests__/**
            **/migrations/**
            **/*snapshot*

Inputs

Input	Description	Required	Default
`github-token`	GitHub token for API access	Yes	`${{ github.token }}`
`exclude-patterns`	Newline-separated glob patterns for files to exclude	No	`""`
`post-comment`	Whether to post/update a PR comment	No	`"true"`
`comment-tag`	HTML tag used to identify the comment for upserts	No	`"lines-changed-check"`

Outputs

Output	Description
`total-additions`	Lines added (excluding matched files)
`total-deletions`	Lines deleted (excluding matched files)
`total-changes`	Total lines changed (additions + deletions)
`included-file-count`	Number of files counted
`excluded-file-count`	Number of files excluded

How it works

Fetches all files changed in the PR via the GitHub API
Matches each file path against the configured exclusion glob patterns using minimatch
Sums up additions and deletions for non-excluded files
Posts (or updates) a PR comment with a summary table
Re-runs automatically on synchronize events (new pushes to the branch)

Developing

bun install
bun test
bunx @vercel/ncc build src/index.ts --out dist --minify

The dist/ directory is committed to the repo since GitHub Actions require the built output.

acusti/lines-changed-check

README