GitHub action to show generated diff preview (#778)

name: codegen diff preview

# This job will generate a branch containing exclusively codegen output and push it to GitHub

# once the branch is deployed, it will comment on GitHub with a link where you can see the generated diff.

on:

  push:

    branches:

    # this is a load-bearing branch filter: if this isn't here, you may

    # end up generating diffs for __generated-* branches which would lead to infinite recursion...

    - main

  pull_request:

    types:

    - opened

    - reopened

    - closed

    - synchronize

env:

  java_version: 11

jobs:

  cleanup-branch:

    if: ${{ github.event.action == 'closed' }}

    runs-on: ubuntu-latest

    name: cleanup generated code branch

    steps:

    - name: gen branch output

      run: echo "::set-output name=branchname::${GITHUB_HEAD_REF##*/}"

      id: branch_output

    - uses: actions/github-script@v5

      with:

        script: |

          console.log("deleting the generated code branch");

          await github.rest.git.deleteRef({

            owner: context.repo.owner,

            repo: context.repo.repo,

            ref: "heads/__generated-${{ steps.branch_output.outputs.branchname }}"

          })

  push-generated-code:

    runs-on: ubuntu-latest

    name: Push generated code to a branch

    if: ${{ github.event.action != 'closed' }}

    steps:

    # this is not technically necessary because of the branch filter above, but better to check

    # twice than have an infinitely recursing PR job

    - name: Assert we aren't already on a generated branch

      run: |

        [[ ${GITHUB_HEAD_REF:-$GITHUB_REF} != "*__generated*" ]]

    - uses: actions/checkout@v2

    - uses: actions/cache@v2

      name: Gradle Cache

      with:

        path: |

          ~/.gradle/caches

          ~/.gradle/wrapper

        key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*') }}

        restore-keys: |

          ${{ runner.os }}-gradle-

    - name: Set up JDK

      uses: actions/setup-java@v1

      with:

        java-version: ${{ env.java_version }}

    - name: mk-generated

      run: ./tools/mk-generated.sh

    - name: push generated branch

      run: |

        git remote set-url origin https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/${{ github.repository }}

        git push -f origin "$(git rev-parse --abbrev-ref HEAD)"

    - name: finalize

      run: echo "generated output pushed to $(git rev-parse --abbrev-ref HEAD)"

    - name: gen branch output

      run: echo "::set-output name=branchname::$(git rev-parse --abbrev-ref HEAD)"

      id: branch_output

    - uses: actions/github-script@v5

      # NOTE: if comments on each commit become bothersome, add a check that github.event.pull_request.action == "opened"

      if: ${{ env.GITHUB_HEAD_REF }} != null

      with:

        script: |

          await github.rest.issues.createComment({

            issue_number: context.issue.number,

            owner: context.repo.owner,

            repo: context.repo.repo,

            body: `A new generated diff is ready to view: https://github.com/${context.repo.owner}/${context.repo.repo}/compare/__generated-main...${{ steps.branch_output.outputs.branchname }}`

          })

#!/bin/bash

#

# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.

# SPDX-License-Identifier: Apache-2.0.

#

# Create a branch containing exclusively generated code

#

# This script creates a new branch `__generated-$current_branch` that contains the results of the smoke-test codegen

# This script outputs the name of the new branch to stdout

set -e

# Redirect stdout to stderr for all the code in `{ .. }`

{

	git diff --quiet || (echo 'working tree not clean, aborting' && exit 1)

	gh_branch=${GITHUB_HEAD_REF##*/}

	echo "Loaded branch from GitHub: $gh_branch ($GITHUB_HEAD_REF)"

	current_branch="${gh_branch:-$(git rev-parse --abbrev-ref HEAD)}"

	echo "Current branch resolved to: $current_branch"

	gen_branch="__generated-$current_branch"

	git branch -D "$gen_branch" || echo "no branch named $gen_branch yet"

	repo_root=$(git rev-parse --show-toplevel)

	cd "$repo_root" && ./gradlew :aws:sdk:assemble

	target="$(mktemp -d)"

	mv "$repo_root"/aws/sdk/build/aws-sdk "$target"

	git checkout --orphan "$gen_branch"

	cd "$repo_root" && git rm -rf .

	rm -rf "$repo_root/aws-sdk"

	mv "$target"/aws-sdk "$repo_root"/.

	git add "$repo_root"/aws-sdk

	PRE_COMMIT_ALLOW_NO_CONFIG=1 git -c "user.name=GitHub Action (generated code preview)" -c "user.email=generated-code-action@github.com" commit -m "Generated code for $current_branch"

} >&2