ci: add reviewers if labels are manually added after PR creation

2 files changed, 99 insertions, 90 deletions

diff --git a/.github/workflows/labeler.yml b/.github/workflows/labeler.yml
index 4940d6bb58..3de0c453a5 100644
--- a/.github/workflows/labeler.yml
+++ b/.github/workflows/labeler.yml
@@ -32,93 +32,3 @@ jobs:
     - name: "Extract commit scope and add as label"
       continue-on-error: true
       run: gh pr edit "$PR_NUMBER" --add-label "$(echo "$PR_TITLE" | sed -E 's|[[:alpha:]]+\((.+)\)!?:.*|\1|')"
-
-  add-reviewer:
-    runs-on: ubuntu-latest
-    needs: ["triage", "type-scope"]
-    permissions:
-      pull-requests: write
-    steps:
-      - uses: actions/github-script@v5
-        with:
-          script: |
-            const reviewers = []
-
-            const { data: { labels } } = await github.rest.pulls.get({
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              pull_number: context.issue.number
-            })
-            const label_names = labels.map(label => label.name)
-
-            if (label_names.includes('api')) {
-              reviewers.push("bfredl")
-              reviewers.push("gpanders")
-              reviewers.push("muniter")
-            }
-
-            if (label_names.includes('ci')) {
-              reviewers.push("jamessan")
-            }
-
-            if (label_names.includes('diagnostic')) {
-              reviewers.push("gpanders")
-            }
-
-            if (label_names.includes('distribution')) {
-              reviewers.push("jamessan")
-            }
-
-            if (label_names.includes('documentation')) {
-              reviewers.push("clason")
-            }
-
-            if (label_names.includes('extmarks')) {
-              reviewers.push("bfredl")
-            }
-
-            if (label_names.includes('filetype')) {
-              reviewers.push("clason")
-              reviewers.push("gpanders")
-            }
-
-            if (label_names.includes('gui')) {
-              reviewers.push("glacambre")
-              reviewers.push("smolck")
-            }
-
-            if (label_names.includes('lsp')) {
-              reviewers.push("mfussenegger")
-              reviewers.push("mjlbach")
-            }
-
-            if (label_names.includes('treesitter')) {
-              reviewers.push("bfredl")
-              reviewers.push("vigoux")
-            }
-
-            if (label_names.includes('typo')) {
-              reviewers.push("dundargoc")
-            }
-
-            if (label_names.includes('ui')) {
-              reviewers.push("bfredl")
-            }
-
-            if (label_names.includes('vim-patch')) {
-              reviewers.push("janlazo")
-              reviewers.push("seandewar")
-              reviewers.push("zeertzjq")
-            }
-
-            const index = reviewers.indexOf(context.actor);
-            if (index > -1) {
-              reviewers.splice(index, 1);
-            }
-
-            github.rest.pulls.requestReviewers({
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              pull_number: context.issue.number,
-              reviewers: reviewers
-            });
diff --git a/.github/workflows/reviews.yml b/.github/workflows/reviews.yml
new file mode 100644
index 0000000000..1491482b98
--- /dev/null
+++ b/.github/workflows/reviews.yml
@@ -0,0 +1,99 @@
+name: "Request reviews"
+on:
+  pull_request_target:
+    types: [labeled]
+  workflow_run:
+    workflows: [Pull Request Labeler]
+    types: [completed]
+jobs:
+  request-reviewer:
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+    steps:
+      - uses: actions/github-script@v5
+        with:
+          script: |
+            // The number of the pull request that triggered this run. If label
+            // was added manually by a person the number will be stored in current
+            // context, otherwise the number will be stored in the payload.
+            const pr_number = context.issue.number || context.payload.workflow_run.pull_requests[0].number
+
+            const pr_data = await github.rest.pulls.get({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: pr_number
+            })
+            const labels = pr_data.data.labels.map(e => e.name)
+
+            const reviewers = new Set()
+            if (labels.includes('api')) {
+              reviewers.add("bfredl")
+              reviewers.add("gpanders")
+              reviewers.add("muniter")
+            }
+
+            if (labels.includes('ci')) {
+              reviewers.add("jamessan")
+            }
+
+            if (labels.includes('diagnostic')) {
+              reviewers.add("gpanders")
+            }
+
+            if (labels.includes('distribution')) {
+              reviewers.add("jamessan")
+            }
+
+            if (labels.includes('documentation')) {
+              reviewers.add("clason")
+            }
+
+            if (labels.includes('extmarks')) {
+              reviewers.add("bfredl")
+            }
+
+            if (labels.includes('filetype')) {
+              reviewers.add("clason")
+              reviewers.add("gpanders")
+            }
+
+            if (labels.includes('gui')) {
+              reviewers.add("glacambre")
+              reviewers.add("smolck")
+            }
+
+            if (labels.includes('lsp')) {
+              reviewers.add("mfussenegger")
+              reviewers.add("mjlbach")
+            }
+
+            if (labels.includes('treesitter')) {
+              reviewers.add("bfredl")
+              reviewers.add("vigoux")
+            }
+
+            if (labels.includes('typo')) {
+              reviewers.add("dundargoc")
+            }
+
+            if (labels.includes('ui')) {
+              reviewers.add("bfredl")
+            }
+
+            if (labels.includes('vim-patch')) {
+              reviewers.add("janlazo")
+              reviewers.add("seandewar")
+              reviewers.add("zeertzjq")
+            }
+
+            // Remove person that opened the PR since they can't review themselves
+            const pr_opener = pr_data.data.user.login
+            reviewers.delete(pr_opener)
+
+            github.rest.pulls.requestReviewers({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: pr_number,
+              reviewers: Array.from(reviewers)
+            });