extract-rust-version.yml

# Find the nightly Rust version and required components in `rust-toolchain.toml` using
# <https://taplo.tamasfe.dev>. The output of this workflow can then be used in
# `@dtolnay/rust-toolchain` to install Rust.

name: Extract Rust Version

on:
  workflow_call:
    outputs:
      channel:
        description: The Rustup channel extracted from `rust-toolchain.toml`.
        value: ${{ jobs.extract-rust-version.outputs.channel }}
      components:
        description: A comma-separated list of Rustup components extracted from `rust-toolchain.toml`.
        value: ${{ jobs.extract-rust-version.outputs.components }}

jobs:
  extract-rust-version:
    name: Extract Rust version
    runs-on: ubuntu-latest
    outputs:
      channel: ${{ steps.toolchain.outputs.channel }}
      components: ${{ steps.toolchain.outputs.components }}
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Install Taplo
        run: |
          curl -fsSL /~https://github.com/tamasfe/taplo/releases/latest/download/taplo-linux-x86_64.gz \
            | gzip -d - | install -m 755 /dev/stdin /usr/local/bin/taplo

      - name: Extract toolchain
        id: toolchain
        run: |
          CHANNEL=$(taplo get -f='rust-toolchain.toml' 'toolchain.channel')
          COMPONENTS=$(taplo get -f='rust-toolchain.toml' --separator=', ' 'toolchain.components')

          echo channel=$CHANNEL >> $GITHUB_OUTPUT
          echo components=$COMPONENTS >> $GITHUB_OUTPUT