WIP: Remove force push to Pantheon by preparing local history

.github/testing_fixtures/dtp-nearly-empty-site/index.php

@@ -1,5 +1,4 @@
 <?php
 
-echo "Hello World<br>";
-echo "Hello World";
+echo "Hello world";
 header('Pragma: no-cache');

.github/testing_fixtures/dtp-nearly-empty-site/sample-files/test-pr-change.php

@@ -0,0 +1,4 @@
+<?php
+echo "Hello world";
+echo "In bats testing, this file will be copied to replace the root index.php file";
+echo "this is a commit on test-pr";

.github/workflows/deploy-pr.yml

@@ -13,7 +13,7 @@ jobs:
     permissions:
       deployments: write
       contents: read
-      pull-requests: read   
+      pull-requests: read
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
@@ -30,3 +30,17 @@ jobs:
         git_commit_message: "This is an automated commit message from GitHub Actions."
         delete_old_environments: true
         clone_content: true
+
+  unit-tests:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Setup Bats and bats libs
+      id: setup-bats
+      uses: bats-core/bats-action@3.0.0
+    - name: Test bash scripts with bats
+      shell: bash
+      # env:
+      # BATS_LIB_PATH: ${{ steps.setup-bats.outputs.lib-path }}
+      # TERM: xterm
+      run: bats tests/

action.yml

@@ -54,19 +54,24 @@ inputs:
     required: false
     default: ""
 
-  # todo checkout_repo:
-  #   description: "A boolean for whether or not this composite step should checkout the git repo. Set to false if a checkout has already been perf"
-
 runs:
     using: 'composite'
     steps:
+      # Setting this environment variable at the first step makes it cleaner
+      # for later steps to run inside with working-directory: ${{ env.SITE_ROOT }}
+      # Not all consumers of this Action have a Git root on GitHub that matches
+      # the site root on Pantheon. For those projects, we need to set this variable.
+      - name: Create SITE_ROOT variable
+        shell: bash
+        run: echo "SITE_ROOT=${{ inputs.relative_site_root != '' && inputs.relative_site_root || '.' }}" >> $GITHUB_ENV
 
       - name: Set target_env
         id: set_target_env
         shell: bash
         env:
           PR_NUM: ${{ github.event.pull_request.number }}
           INPUT_TARGET_ENV: ${{ inputs.target_env }}
+        # todo, move this to a bats-testable bash script.
         run: |
           # Set target_env
           set +e
@@ -123,10 +128,13 @@ runs:
 
       - name: Install Terminus Plugin
         shell: bash
-        run: |
-          # Install Terminus Plugin
-          set +e
-          terminus self:plugin:install terminus-build-tools-plugin
+        run: terminus self:plugin:install "pantheon-systems/terminus-build-tools-plugin:3.x-dev"
+
+      - name: Set PANTHEON_REPO_LOCATION
+        shell: bash
+        env:
+          PANTHEON_SITE: ${{ inputs.site }}
+        run: echo "PANTHEON_REPO_LOCATION=$(terminus connection:info ${PANTHEON_SITE}.dev  --field=git_url)" >> $GITHUB_ENV
 
       - name: Configure Git User
         shell: bash
@@ -139,43 +147,44 @@ runs:
           git config --global user.email "${PANTHEON_GIT_USER_EMAIL}"
           git config --global user.name "${PANTHEON_GIT_USER_NAME}"
 
-      - name: Prepare site root
+      # This change is necessary to fetch from Pantheon's Git server.
+      - name: Turn off strict host checking
+        shell: bash
+        run: mkdir -p $HOME/.ssh && echo "StrictHostKeyChecking no" >> "$HOME/.ssh/config"
+
+      - name: Create local Git repo (only when relative_site_root is set)
         shell: bash
+        if: ${{ inputs.relative_site_root != '' }}
+        working-directory: ${{ env.SITE_ROOT }}
         env:
           SITE_ROOT: ${{ inputs.relative_site_root }}
         run: |
-          # Prepare site root
+          # Create local Git repo (only when relative_site_root is set)
           set +e
-          if [ -n "$SITE_ROOT" ]; then
-            cd ${SITE_ROOT}
-            git init -b main
-            echo "this origin setting is a hack to get past the 'inferring' of a git provider in build tools"
-            git remote add origin https://github.com/${{ github.repository }}
-          else
-            git fetch --unshallow origin
-          fi
+          git init -b main
+          echo "this origin setting is a hack to get past the 'inferring' of a Git provider in Build Tools"
+          git remote add origin https://github.com/${{ github.repository }}
+
+      - name: Prepare site root's Git History
+        shell: bash
+        working-directory: ${{ env.SITE_ROOT }}
+        env:
+          PANTHEON_SITE: ${{ inputs.site }}
+        run: bash ${{ github.action_path }}/scripts/prepare-repo.sh
 
       - name: Deployment Processing
         shell: bash
         id: deploy_to_pantheon
+        working-directory: ${{ env.SITE_ROOT }}
         env:
           PANTHEON_SITE: ${{ inputs.site }}
           PANTHEON_SOURCE_ENV: ${{ inputs.source_env }}
-          SITE_ROOT: ${{ inputs.relative_site_root }}
           PANTHEON_COMMIT_MESSAGE: ${{ inputs.git_commit_message }}
           # todo, might need to make this configurable too.
           # the default in build tools is 180. But that's regularly failing
           # on a small personal site.
           TERMINUS_BUILD_TOOLS_WORKFLOW_TIMEOUT: 300
-        run: |
-          # Push to Pantheon
-          set +e
-
-          if [ -n "$SITE_ROOT" ]; then
-            cd ${SITE_ROOT}
-          fi
-
-          terminus -n build:env:create ${PANTHEON_SITE}.${PANTHEON_SOURCE_ENV} ${PANTHEON_TARGET_ENV} --yes --message="${PANTHEON_COMMIT_MESSAGE}" ${PANTHEON_CLONE_CONTENT_FLAG}
+        run: terminus -n build:env:create ${PANTHEON_SITE}.${PANTHEON_SOURCE_ENV} ${PANTHEON_TARGET_ENV} --yes --message="${PANTHEON_COMMIT_MESSAGE}" ${PANTHEON_CLONE_CONTENT_FLAG} --no-git-force
 
       - name: Update deployment status
         uses: bobheadxi/deployments@v1
@@ -189,19 +198,13 @@ runs:
           deployment_id: ${{ steps.deployment.outputs.deployment_id }}
           env: ${{ env.PANTHEON_TARGET_ENV }}-${{ inputs.site }}
           env_url: https://${{ env.PANTHEON_TARGET_ENV }}-${{ inputs.site }}.pantheonsite.io
+
       - name: Deleting old multidevs
         if: ${{ inputs.delete_old_environments == 'true' && steps.deploy_to_pantheon.outcome == 'success' }}
+        working-directory: ${{ env.SITE_ROOT }}
         shell: bash
         env:
           PANTHEON_SITE: ${{ inputs.site }}
           GITHUB_TOKEN: ${{ github.token }}
           SITE_ROOT: ${{ inputs.relative_site_root }}
-        run: |
-          # Delete old multidevs
-          set +e
-
-          if [ -n "$SITE_ROOT" ]; then
-            cd ${SITE_ROOT}
-          fi
-
-          terminus build:env:delete:pr $PANTHEON_SITE --yes
+        run: terminus build:env:delete:pr $PANTHEON_SITE --yes

scripts/prepare-repo.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+
+# This script prepares the local repository in a CI environment for pushing to Pantheon.
+# To avoid force pushing, it brings in a history from Pantheon so that in a later step
+# we can commit on top of it and push to Pantheon.
+
+# Exit on error, undefined variables, and pipe failures
+set -euo pipefail
+
+# todo exit with errors if needed env vars are missing.
+if [[ -z "${PANTHEON_REPO_LOCATION:-}" ]]; then
+  echo "Error: PANTHEON_REPO_LOCATION is not set. It should be set to the Pantheon repository URL."
+  exit 1
+fi
+if [[ -z "${PANTHEON_TARGET_ENV:-}" ]]; then
+  echo "Error: PANTHEON_TARGET_ENV is not set."
+  exit 1
+fi
+
+# When runnning on the "main" branch, the target environment is "dev" but the
+# associated git branch on Pantheon is "master". So that is the branch we need to
+# fetch and reset to.
+if [[ "$PANTHEON_TARGET_ENV" == "dev" ]]; then
+  PANTHEON_TARGET_ENV="master"
+fi
+
+git remote add pantheon $PANTHEON_REPO_LOCATION
+
+if git ls-remote --exit-code --heads pantheon "$PANTHEON_TARGET_ENV" > /dev/null; then
+    echo "the branch already exists in the remote"
+else
+  git fetch pantheon master
+  git push pantheon FETCH_HEAD:refs/heads/$PANTHEON_TARGET_ENV
+fi
+git fetch pantheon $PANTHEON_TARGET_ENV
+
+# Reset your working directory to match the remote branch
+git reset --hard pantheon/$PANTHEON_TARGET_ENV
+# Create and switch to a local branch tracking the remote one
+# todo, name the branch based on some variable.
+git checkout -B temp-build-branch

scripts/readme.md

@@ -0,0 +1,5 @@
+# Bash scripts
+
+This directory contains bash scripts that are invoked from the `action.yml` at the root of the repository.
+
+Breaking these operations out into separate scripts allows for easier testing and debugging of each individual step.

tests/push-to-pantheon.bats

@@ -0,0 +1,82 @@
+#!/usr/bin/env bats
+
+# Source the setup script
+load "./test_helper/setup_mock_repos"
+
+setup() {
+
+    ROOT_OF_TESTS_INVOCATION="$(pwd)"
+    # Create temporary directories for testing
+    GITHUB_DIR="$(mktemp -d)"
+    PANTHEON_DIR="$(mktemp -d)"
+    CI_DIR="$(mktemp -d)"
+
+    # Set up mock repositories
+    setup_mock_repos "$GITHUB_DIR" "$PANTHEON_DIR" "$CI_DIR"
+}
+
+@test "simulate a push to pantheon job when Pantheon does not have the target branch" {
+
+    export PANTHEON_REPO_LOCATION=$PANTHEON_DIR
+    export PANTHEON_TARGET_ENV=pr-123
+
+    run mock_ci_build_process "$CI_DIR"
+    [ "$status" -eq 0 ]
+
+    run cat "test.css"
+    [[ "${output}" =~ "background-color: #FF0000" ]]
+
+    run $ROOT_OF_TESTS_INVOCATION/scripts/prepare-repo.sh
+    echo ${output}
+    [ "$status" -eq 0 ]
+
+    git add .
+    # todo use a variable for the commit message.
+    git commit -m 'build process for pr-123'
+    git push pantheon temp-build-branch:$PANTHEON_TARGET_ENV
+
+    echo "checkout that the pantheon repo contains the built CSS"
+    cd $PANTHEON_DIR
+    run git show pr-123:test.css
+    echo ${output}
+    [[ "${output}" =~ "background-color: #FF0000" ]]
+}
+
+@test "simulate a push to pantheon job when Pantheon already does have the target branch" {
+
+    export PANTHEON_REPO_LOCATION=$PANTHEON_DIR
+    export PANTHEON_TARGET_ENV=pr-123
+
+    cd $PANTHEON_DIR
+    git checkout -b $PANTHEON_TARGET_ENV
+    echo "hello world" > test.txt
+    git add .
+    git commit -m 'adding test.txt'
+    git checkout master
+
+    run git show $PANTHEON_TARGET_ENV:test.txt
+    echo ${output}
+    [[ "${output}" =~ "hello world" ]]
+
+    cd $CI_DIR
+    run mock_ci_build_process "$CI_DIR"
+    [ "$status" -eq 0 ]
+
+    run cat "test.css"
+    [[ "${output}" =~ "background-color: #FF0000" ]]
+
+    run $ROOT_OF_TESTS_INVOCATION/scripts/prepare-repo.sh
+    echo ${output}
+    [ "$status" -eq 0 ]
+
+    git add .
+    # todo use a variable for the commit message.
+    git commit -m 'build process for pr-123'
+    git push pantheon temp-build-branch:$PANTHEON_TARGET_ENV
+
+    echo "checkout that the pantheon repo contains the built CSS"
+    cd $PANTHEON_DIR
+    run git show pr-123:test.css
+    echo ${output}
+    [[ "${output}" =~ "background-color: #FF0000" ]]
+}