Pulldozer

Pulldozer is a simple CLI tool for batch editing multiple GitHub repos.

You give Pulldozer a transformation script and it spits out pull requests. Duolingo has used Pulldozer to create well over 9000 PRs to date!

Usage

Clone this repo onto any Unix machine that has curl and jq. Set your GITHUB_TOKEN environment variable to an access token with repo scope and SSO enabled. To perform a batch edit (a.k.a. codemod):

1. Create a script file that defines a COMMIT_MESSAGE string, transform function, and REPOS list.

   Click here to see a Shell example

   COMMIT_MESSAGE='Fix "langauge" typos'
   
   transform() {
     # Write your transformation logic inside this function. GitHub org name
     # and repo name are passed into this `transform` function as vars $1 and
     # $2, respectively.
     echo "Hello world from $1/$2" > README.md
   
     # Pulldozer provides a `replace_all` helper function for replacing text
     # across all repo files. It's basically glorified sed.
     replace_all 'langauge' 'language'
   
     # Advanced `replace_all` example: regex, capture grouping, multi-line
     # matching, and file path filtering
     replace_all '(\nprotobuf==)\S+' '\13.19.4' 'requirements\.(in|txt)$'
   }
   
   REPOS='
   artnc/dotfiles
   duolingo/halflife-regression
   duolingo/rtl-viewpager
   '
   
   # Optional but recommended: Markdown to include in pull request descriptions
   DESCRIPTION='[Correct spelling](https://en.wiktionary.org/wiki/language)'
   # Optional: Markdown that will be posted as a comment on PRs
   COMMENT='This is a pull request comment'
   # Optional: Declare this variable to enable GitHub auto-merge on PRs
   AUTOMERGE=1

   By default, Pulldozer will interpret your script as POSIX shell. If you want to use Bash instead, just run bash ./pulldozer instead of ./pulldozer during step 2 below.

   Click here to see a JavaScript example

   const COMMIT_MESSAGE = 'Fix "langauge" typos';
   
   // Write your transformation logic inside this function. GitHub org name and
   // repo name are passed in as parameters.
   const transform = async (org, repo) => {
     const { writeFile } = require("fs").promises;
     await writeFile("README.md", `Hello world from ${org}/${repo}`);
   
     // Pulldozer provides a `replace_all` helper function (no need to import)
     // for replacing text across all repo files. This helper is easier than
     // traversing the repo yourself, and it also respects .gitignore.
     await replace_all("langauge", "language");
   
     // Advanced `replace_all` example: regex, capture grouping, multiline
     // matching, editing only a subset of repo files (optional third param)
     await replace_all(
       /(\nprotobuf==)\S+/,
       "$13.19.4",
       /requirements\.(in|txt)$/,
     );
   };
   
   const REPOS = [
     "artnc/dotfiles",
     "duolingo/halflife-regression",
     "duolingo/rtl-viewpager",
   ];
   
   // Optional but recommended: Markdown to include in pull request descriptions
   const DESCRIPTION =
     "[Correct spelling](https://en.wiktionary.org/wiki/language)";
   // Optional: Markdown that will be posted as a comment on PRs
   const COMMENT = "This is a pull request comment";
   // Optional: Declare this variable to enable GitHub auto-merge on PRs
   const AUTOMERGE = 1;

   Click here to see a Python example

   COMMIT_MESSAGE = 'Fix "langauge" typos'
   
   # Write your transformation logic inside this function. GitHub org name and
   # repo name are passed in as parameters.
   def transform(org, repo):
       with open("README.md", "w") as f:
           f.write(f"Hello world from {org}/{repo}")
   
       # Pulldozer provides a `replace_all` helper function (no need to import)
       # for replacing text across all repo files. This helper is easier than
       # using `os.walk` and `re.sub`, and it also respects .gitignore.
       replace_all("langauge", "language")
   
       # Advanced `replace_all` example: regex, capture grouping, multiline
       # matching, editing only a subset of repo files (optional third param)
       replace_all(r"(\nprotobuf==)\S+", r"\13.19.4", r"requirements\.(in|txt)$")
   
   REPOS = [
       "artnc/dotfiles",
       "duolingo/halflife-regression",
       "duolingo/rtl-viewpager",
   ]
   
   # Optional but recommended: Markdown to include in pull request descriptions
   DESCRIPTION = "[Correct spelling](https://en.wiktionary.org/wiki/language)"
   # Optional: Markdown that will be posted as a comment on PRs
   COMMENT = "This is a pull request comment"
   # Optional: Declare this variable to enable GitHub auto-merge on PRs
   AUTOMERGE = 1

2. Run ./pulldozer /path/to/your/script. Pulldozer will generate a preview diff and ask for confirmation before creating PRs.

Demo video

Duolingo is hiring! Apply at https://www.duolingo.com/careers