splice-bot: split part of a PR into a separate PR

This action automates the creation of a single‑file pull request when a reviewer writes a PR review comment with a line starting with splice-bot.

The typical use case is as follows.

A reviewer comments on a diff line with something like: splice-bot.

The workflow then

• checks out the base and head of the PR;
• extracts only the file on which the review comment was made;
• creates a new branch containing only that file change;
• opens a pull request with that single-file change;
• comments back in the original PR with a link to the new PR.

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Usage

To use this workflow from another repository, create a workflow such as:

name: splice-bot

on:
  pull_request_review_comment:
    types: [created]

jobs:
  call-splice-bot:
    uses: leanprover-community/SpliceBot/.github/workflows/splice.yaml@master
    permissions:
      contents: write
      pull-requests: write
    with:
      # optional branch to which the PR will point — defaults to "master"
      base_ref: master
    secrets: inherit

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Inputs

Name	Type	Required	Default	Description
base_ref	string	No	master	The base branch to which the single‑file PR points.

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Permissions

The caller workflow must grant the job permissions:

permissions:
  contents: write
  pull-requests: write

These propagate to the reusable workflow and are required for:

• checking out code
• committing a file
• creating a PR
• commenting on the original PR

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Example

In a PR review, comment on a specific file line:

The changes to this file look great, let's create a separate PR for them!

splice-bot

Thanks!

From the perspective of the action, the only important feature is that one of the lines starts with splice-bot. Whether or not there is further text after that, is irrelevant.

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File Structure

Your repository should contain the reusable workflow in:

.github/workflows/splice.yaml

where the .yaml file can be called whatever you want.

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