Get Diff Action

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GitHub actions to get git diff.
You can get the differences via env or action output.

Table of Contents

Screenshots

1. Example workflow

   

2. Skip

   

Usage

Basic Usage

on: pull_request
name: CI
jobs:
  eslint:
    name: ESLint
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: technote-space/get-diff-action@v6
        with:
          PATTERNS: |
            +(src|__tests__)/**/*.ts
            !src/exclude.ts
          FILES: |
            yarn.lock
            .eslintrc
      - name: Install Package dependencies
        run: yarn install
        if: env.GIT_DIFF
      - name: Check code style
        # Check only if there are differences in the source code
        run: yarn lint
        if: env.GIT_DIFF

Details of the patterns that can be specified

Example of matching files

• src/main.ts
• src/utils/abc.ts
• __tests__/test.ts
• yarn.lock
• .eslintrc
• anywhere/yarn.lock

Examples of non-matching files

• main.ts
• src/xyz.txt
• src/exclude.ts

Examples of env

Specify a little more detail

on: pull_request
name: CI
jobs:
  eslint:
    name: ESLint
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: technote-space/get-diff-action@v6
        with:
          PATTERNS: |
            +(src|__tests__)/**/*.ts
          FILES: |
            yarn.lock
            .eslintrc
      - name: Install Package dependencies
        run: yarn install
        if: env.GIT_DIFF
      - name: Check code style
        # Check only source files with differences
        run: yarn eslint ${{ env.GIT_DIFF_FILTERED }}  # e.g. yarn eslint 'src/main.ts' '__tests__/test.ts'
        if: env.GIT_DIFF && !env.MATCHED_FILES
      - name: Check code style
        # Check only if there are differences in the source code (Run a lint on all files if there are changes to yarn.lock or .eslintrc)
        run: yarn lint
        if: env.GIT_DIFF && env.MATCHED_FILES

If there is no difference in the source code below, this workflow will skip the code style check

• src/**/*.ts
• __tests__/**/*.ts

Behavior

1. Get git diff

   git diff ${FROM}${DOT}${TO} '--diff-filter=${DIFF_FILTER}' --name-only
   

   e.g. (default)

   DOT: '...'
   DIFF_FILTER: 'AMRC'
   

   =>

   git diff ${FROM}...${TO} '--diff-filter=AMRC' --name-only
   

   =>

   .github/workflows/ci.yml
   __tests__/utils/command.test.ts
   package.json
   src/main.ts
   src/utils/command.ts
   src/docs.md
   yarn.lock
   

   ${FROM}, ${TO}

2. Filtered by PATTERNS option

   e.g.

   PATTERNS: |
     src/**/*.+(ts|md)
     !src/utils/*
   

   =>

   src/main.ts
   src/docs.md
   

3. Filtered by FILES option

   e.g.

   FILES: package.json
   

   =>

   package.json
   anywhere/package.json
   

4. Mapped to absolute if ABSOLUTE option is true (default: false)

   e.g.

   /home/runner/work/my-repo-name/my-repo-name/src/main.ts
   /home/runner/work/my-repo-name/my-repo-name/src/docs.md
   

5. Combined by SEPARATOR option

   e.g. (default)

   SEPARATOR: ' '
   

   =>

   /home/runner/work/my-repo-name/my-repo-name/src/main.ts /home/runner/work/my-repo-name/my-repo-name/src/docs.md
   

Outputs

Action event details

Target events

If called on any other event, the result will be empty.

Addition

FROM, TO

Check only the latest commit differences in a draft Pull Request

on:
  pull_request:
    types: [opened, reopened, synchronize, closed, ready_for_review]

jobs:
  eslint:
    name: ESLint
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: technote-space/get-diff-action@v6
        with:
          CHECK_ONLY_COMMIT_WHEN_DRAFT: true
      # ...

To get the result in Json format

on: pull_request
name: CI
jobs:
  dump:
    name: Dump
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: technote-space/get-diff-action@v6
        with:
          PATTERNS: |
            +(src|__tests__)/**/*.ts
            !src/exclude.ts
          FORMAT: json
      - run: echo '${{ env.GIT_DIFF }}' | jq .

Result:

> Run echo '["yarn.lock"]' | jq .
[
  "yarn.lock"
]

Specify a relative path

GitHub Actions doesn't support working-directory for uses, so you can't run this action separately for monorepo configuration, etc. However, if you specify the RELATIVE option, it will be used as --relative=<RELATIVE> for git diff.

https://git-scm.com/docs/git-diff#Documentation/git-diff.txt---relativeltpathgt

on: pull_request
name: CI
jobs:
  dump:
    name: Dump
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: technote-space/get-diff-action@v6
        with:
          PATTERNS: '*.ts'
          RELATIVE: 'src/abc'
      - run: echo ${{ env.GIT_DIFF }}

If the files src/abc/test1.ts, src/abc/test2.ts, src/abc/test3.txt, and src/test4.ts exist, the result will be as follows:

> Run echo 'test1.ts' 'test2.ts'
test1.ts test2.ts

Author

GitHub (Technote)

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