Awesome

github-actions-dhall

This is a demonstration using Dhall to generate YAML for github actions.

github-actions-dhall is self-hosting.

Example

Haskell

Store the following in example.dhall:

let haskellCi = https://raw.githubusercontent.com/vmchale/github-actions-dhall/master/haskell-ci.dhall

in    haskellCi.generalCi
        haskellCi.matrixSteps
        ( Some
            { ghc =
              [ haskellCi.GHC.GHC8101
              , haskellCi.GHC.GHC883
              , haskellCi.GHC.GHC865
              ]
            , cabal = [ haskellCi.Cabal.Cabal32 ]
            }
        )
    : haskellCi.CI.Type

Then, generate YAML with dhall-to-yaml --file example.dhall

jobs:
  build:
    runs-on: ubuntu-18.04
    steps:
      - uses: "actions/checkout@v1"
      - id: setup-haskell-cabal
        uses: "actions/setup-haskell@v1.1"
        with:
          cabal-version: "${{ matrix.cabal }}"
          ghc-version: "${{ matrix.ghc }}"
      - uses: "actions/cache@v1"
        with:
          key: "${{ runner.os }}-${{ matrix.ghc }}-cabal"
          path: "${{ steps.setup-haskell-cabal.outputs.cabal-store }}"
      - name: Install dependencies
        run: |
          cabal update
          cabal build --enable-tests --enable-benchmarks --only-dependencies
      - name: build
        run: cabal build --enable-tests --enable-benchmarks
      - name: test
        run: cabal test
      - name: haddock
        run: cabal haddock
    strategy:
      matrix:
        cabal:
          - '3.2'
        ghc:
          - '8.10.1'
          - '8.8.3'
          - '8.6.5'
name: Haskell CI
on:
  - push

Have a look at hlint-lib for a more "organic" example.