Changed Lines

This GitHub action returns the file names and modified lines of each file in a pull request. This is useful if you're running a custom linter against your files and you want to compare log lines against modified lines in your PR.

Note

This action only works with pull requests. This action only works on Linux runners.

The action outputs a JSON formatted string. For example:

{"test_file_1.py": [13, 30, 39], "test_file_2.md": [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33], "test_file_3.txt": [14, 18, 19]}

Using Changed Lines

on: [ pull_request ]

jobs:
  find_changed_lines:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Find changed lines
        id: changed_lines
        uses: hestonhoffman/changed-lines@v1
      - name: Print changed lines
        run: echo ${{ steps.changed_lines.outputs.changed_lines }}

Return only a list of changed files

The outputs.changed_files output gives you only the changed filenames in a space-delimited list. For example:

test_file_1.py test_file_2.md test_file_3.txt

File delimiter

To change the delimiter, use the delimiter input. The following example outputs filenames separated by commas:

[...]
    steps:
      - uses: actions/checkout@v4
      - name: Find changed lines
        id: changed_lines
        uses: hestonhoffman/changed-lines@v1
      - name: Print changed files
        with:
          delimiter: ','
        run: echo ${{ steps.changed_lines.outputs.changed_files }}

Filter by file type

To return the output for only certain file types, use the file_filter input and specify a comma-separated list of file extensions. The following example only returns markdown and text files:

[...]
    steps:
      - uses: actions/checkout@v4
      - name: Find changed lines
        id: changed_lines
        uses: hestonhoffman/changed-lines@v1
      - name: Print changed files
        with:
          file_filter: '.md, .txt'
        run: echo ${{ steps.changed_lines.outputs.changed_files }}

Thanks to Jacob Tomlinson for a helpful tutorial.