ci: add a workflow to detect and check dependencies for blocked pull requests

Signed-off-by: Rachel Powers <508861+Ryex@users.noreply.github.com>

.github/workflows/blocked_prs.yml

@@ -0,0 +1,236 @@
+name: Blocked/Stacked Pull Requests Automation
+
+on:
+  pull_request_target:
+    types:
+      - opened
+      - edited
+  workflow_dispatch:
+    inputs:
+      pr_id:
+        description: Local Pull Request number to work on
+        required: true
+        type: number
+
+jobs:
+  block_status:
+    name: Check Blocked Status
+    runs-on: ubuntu-latest
+    steps:
+      - name: Setup From Pull Request Vent
+        if: ${{ github.event_name != 'workflow_dispatch' }}
+        id: pr_event_setup
+        env:
+          REPO_L: ${{ github.event.pull_request.base.repo.name }}
+          OWNER_L: ${{ github.event.pull_request.base.repo.owner.login }}
+          REPO_URL_L: $ {{ github.event.pull_request.base.repo.html_url }}
+          PR_HEAD_SHA_L: ${{ github.event.pull_request.head.sha }}
+          PR_NUMBER_L: ${{ github.event.pull_request.number }}
+          PR_HEAD_LABEL_L: ${{ github.event.pull_request.head.label }}
+          PR_BODY_L: ${{ github.event.pull_request.body }}
+          PR_LABLES_L: ${{ github.event.pull_request.labels }}
+        run: |
+          # setup env for the rest of the workflow
+          {
+            echo "REPO=$REPO_L"
+            echo "OWNER=$OWNER_L"
+            echo "REPO_URL=$REPO_URL_L"
+            echo "PR_NUMBER=$PR_NUMBER_L"
+            echo "PR_HEAD_SHA=$PR_HEAD_SHA_L"
+            echo "PR_HEAD_LABEL=$PR_HEAD_LABEL_L"
+            echo "PR_BODY=$PR_BODY_L"
+            echo "PR_LABELS=$(jq 'reduce .[].name as $l ([]; . + [$l])' <<< "$PR_LABELS_L" )"
+          } >> "$GITHUB_ENV"
+
+      - name: Setup From Dispatch Event
+        if: ${{ github.event_name == 'workflow_dispatch' }}
+        id: dispatch_event_setup
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          OWNER_REPO_L: ${{ github.repository }}
+          OWNER_L: ${{ github.repository_owner }}
+          REPO_URL_L: $ {{ github.repositoryUrl }}
+          PR_NUMBER_L: ${{ inputs.pr_id }}
+        run: |
+          # setup env for the rest of the workflow
+          owner_prefix="$OWNER_L/"
+          REPO_L="${OWNER_REPO_L#"$owner_prefix"}"
+          PR_L=$(
+            gh api \
+              -H "Accept: application/vnd.github.raw+json" \
+              -H "X-GitHub-Api-Version: 2022-11-28" \
+              "/repos/$OWNER_L/$REPO_L/pulls/$PR_NUMBER_L"
+          )
+          PR_HEAD_SHA_L=$(jq -r '.head.sha' <<< "$PR_L")
+          PR_HEAD_LABEL_L=$(jq -r '.head.label' <<< "$PR_L")
+          PR_BODY_L=$(jq -r '.body' <<< "$PR_L")
+          PR_LABELS_L=$(jq '.labels' <<< "$PR_L")
+          {
+            echo "REPO=$REPO_L"
+            echo "OWNER=$OWNER_L"
+            echo "REPO_URL=$REPO_URL_L"
+            echo "PR_NUMBER=$PR_NUMBER_L"
+            echo "PR_HEAD_SHA=$PR_HEAD_SHA_L"
+            echo "PR_HEAD_LABEL=$PR_HEAD_LABEL_L"
+            echo "PR_BODY=$PR_BODY_L"
+            echo "PR_LABELS=$(jq 'reduce .[].name as $l ([]; . + [$l])' <<< "$PR_LABELS_L" )"
+          } >> "$GITHUB_ENV"
+
+
+      - name: Find Blocked/Stacked PRs in body
+        id: pr_ids
+        run: |
+          PRS=$(
+            jq '
+              . as $body 
+                | (
+                    $body | scan("blocked (?by)|(?on):? #(?<num>[0-9]+)") 
+                      | map({
+                        "type": "Blocked on",
+                        "number": ( . | tonumber )
+                      })
+                  ) as $bprs
+                | (
+                    $body | scan("stacked on:? #(?<num>[0-9]+)")
+                      | map({
+                        "type": "Stacked on",
+                        "number": ( . | tonumber )
+                      })
+                  ) as $sprs
+                | ($bprs + $sprs) as $prs 
+                | { 
+                    "blocking": $prs,
+                    "numBlocking": ( $prs | length),
+                  }
+              ' <<< "$PR_BODY"
+          )
+          echo "prs=$PRS" >> "$GITHUB_OUPUT"
+
+      - name: Collect Blocked PR Data
+        id: blocked_data
+        if: ${{ fromJSON(steps.pr_ids.outputs.prs).numBlocking > 0 }}
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          BLOCKED_PR_DATA=$(
+            while read -r PR ; do
+              gh api \
+                -H "Accept: application/vnd.github.raw+json" \
+                -H "X-GitHub-Api-Version: 2022-11-28" \
+                "/repos/$OWNER/$REPO/pulls/$(jq -r '.number' <<< "$PR")" \
+                | jq --arg type "$(jq -r '.type' <<< "$PR")" \
+                  '
+                    . | {
+                      "type": $type,
+                      "number": .number,
+                      "merged": .merged,
+                      "labels": (reduce .labels[].name as $l ([]; . + [$l])), 
+                      "basePrUrl": .html_url,
+                      "baseRepoName": .head.repo.name,
+                      "baseRepoOwner": .head.repo.owner.login,
+                      "baseRepoUrl": .head.repo.html_url,
+                      "baseSha": .head.sha,
+                      "baseRefName": .head.ref,
+                    }
+                  '
+            done < <(jq -c '.blocking[]' <<< "${{steps.pr_ids.outputs.prs}}") | jq -s
+          )
+          echo "state=$BLOCKED_PR_DATA" >> "$GITHUB_OUPUT"
+          echo "all_merged=$(jq 'all(.[].merged; .)' <<< "$BLOCKED_PR_DATA")"
+
+      - name: Apply Blocked Label if Missing
+        id: label_blocked
+        if: ${{ fromJSON(steps.pr_ids.outputs.prs).numBlocking > 0 && !contains(fromJSON(env.PR_LABELS), 'blocked') && !fromJSON(steps.blocked_data.outputs.all_merged) }}
+        continue-on-error: true
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          gh api \
+            --method POST \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            "/repos/$OWNER/$REPO/issues/$PR_NUMBER/labels" \
+            -f "labels[]=blocked"
+
+      - name: Remove 'blocked' Label if All Dependencies Are Merged
+        id: unlabel_blocked
+        if: ${{ fromJSON(steps.pr_ids.outputs.prs).numBlocking > 0 && fromJSON(steps.blocked_data.outputs.all_merged) }}
+        continue-on-error: true
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          gh api \
+            --method DELETE \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            "/repos/$OWNER/$REPO/issues/$PR_NUMBER/labels/blocked"
+
+      - name: Apply 'blocking' Label to Dependencies if Missing
+        id: label_blocking
+        if: ${{ fromJSON(steps.pr_ids.outputs.prs).numBlocking > 0 }}
+        continue-on-error: true
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          # label pr dependencies with 'blocking' if not already
+          while read -r PR_DATA ; do
+            if jq -e 'all(.labels[]; . != "blocking")' <<< "$PR_DATA" > /dev/null ; then
+              PR=$(jq -r '.number' <<< "$PR_DATA")
+              gh api \
+                --method POST \
+                -H "Accept: application/vnd.github+json" \
+                -H "X-GitHub-Api-Version: 2022-11-28" \
+                "/repos/$OWNER/$REPO/issues/$PR/labels" \
+                -f "labels[]=blocking"
+            fi
+          done < <(jq -c '.[]' <<< "${{steps.blocked_data.outputs.state}}")
+
+      - name: Apply Blocking PR Status Check
+        id: blocked_check
+        if: ${{ fromJSON(steps.pr_ids.outputs.prs).numBlocking > 0 }}
+        continue-on-error: true
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          # create commit Status, overwrites previous identical context
+          while read -r PR_DATA ; do
+            DESC=$(
+              jq -r ' "Blocking PR #" + (.number | tostring) + " is " + (if .merged then "" else "not yet " end) + "merged"' <<< "$PR_DATA"
+            )
+            gh api \
+              --method POST \
+              -H "Accept: application/vnd.github+json" \
+              -H "X-GitHub-Api-Version: 2022-11-28" \
+              "/repos/${OWNER}/${REPO}/statuses/${PR_HEAD_SHA}" \
+              -f "state=$(jq -r 'if .merged then "success" else "failure" end' <<< "$PR_DATA")" \
+              -f "target_url=$(jq -r '.basePrUrl' <<< "$PR_DATA" )" \
+              -f "description=$DESC" \
+              -f "context=continuous-integration/blocked-pr-check:$(jq '.number' <<< "$PR_DATA")"
+          done < <(jq -c '.[]' <<< "${{steps.blocked_data.outputs.state}}")
+
+      - name: Context Comment
+        id: blocked_comment
+        if: ${{ fromJSON(steps.pr_ids.outputs.prs).numBlocking > 0 }}
+        continue-on-error: true
+        run: |
+          COMMENT_PATH="$(pwd)/temp_comment_file.txt"
+          touch "$COMMENT_PATH"
+          echo "" > "$COMMENT_PATH"
+          while read -r PR_DATA ; do
+            BASE_PR=$(jq '.number' <<< "$PR_DATA")
+            BASE_REF_NAME=$(jq '.baseRefName' <<< "$PR_DATA")
+            COMPARE_URL="$REPO_URL/compare/$BASE_REF_NAME...$PR_HEAD_LABEL"
+            STATUS=$(jq 'if .merged then ":heavy_check_mark: Merged" else ":x: Not Merged" end' <<< "$PR_DATA")
+            TYPE=$(jq -r '.type' <<< "$PR_DATA")
+            echo "  - $TYPE #$BASE_PR $STATUS [(compare)]($COMPARE_URL)" >> "$COMMENT_PATH"
+          done < <(jq -c '.[]'  <<< "${{steps.blocked_data.outputs.state}}")
+          echo "file_path=${COMMENT_PATH}" >> "$GITHUB_OUTPUT"
+
+      - name: 💬 PR Comment
+        if: ${{ fromJSON(steps.pr_ids.outputs.prs).numBlocking > 0 }}
+        continue-on-error: true
+        uses: spicyparrot/pr-comment-action@v1.0.0
+        with:
+          comment: "### PR Dependencies :pushpin:"
+          comment_path: ${{ steps.blocked_comment.outputs.file_path }}
+          comment_id: "block_pr_dependencies"