docs: add beta blocker contributor guidance (#55199)

* docs: add beta blocker contributor guidance

* fix: tighten beta blocker labeling and flaky config test

.github/workflows/labeler.yml

@@ -2,9 +2,9 @@ name: Labeler
 
 on:
   pull_request_target: # zizmor: ignore[dangerous-triggers] maintainer-owned triage workflow; no untrusted checkout or PR code execution
-    types: [opened, synchronize, reopened]
+    types: [opened, synchronize, reopened, edited]
   issues:
-    types: [opened]
+    types: [opened, edited]
   workflow_dispatch:
     inputs:
       max_prs:
@@ -209,6 +209,59 @@ jobs:
             //     labels: [trustedLabel],
             //   });
             // }
+      - name: Apply beta-blocker title label
+        uses: actions/github-script@v8
+        with:
+          github-token: ${{ steps.app-token.outputs.token || steps.app-token-fallback.outputs.token }}
+          script: |
+            const pullRequest = context.payload.pull_request;
+            if (!pullRequest) {
+              return;
+            }
+
+            const labelName = "beta-blocker";
+            const matchesBetaBlocker = /\bbeta blocker\b/i.test(pullRequest.title ?? "");
+
+            try {
+              await github.rest.issues.getLabel({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                name: labelName,
+              });
+            } catch (error) {
+              if (error?.status !== 404) {
+                throw error;
+              }
+              core.info(`Skipping ${labelName} labeling because the label does not exist in the repository.`);
+              return;
+            }
+
+            const currentLabels = await github.paginate(github.rest.issues.listLabelsOnIssue, {
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: pullRequest.number,
+              per_page: 100,
+            });
+            const hasLabel = currentLabels.some((label) => label.name === labelName);
+
+            if (matchesBetaBlocker && !hasLabel) {
+              await github.rest.issues.addLabels({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: pullRequest.number,
+                labels: [labelName],
+              });
+              return;
+            }
+
+            if (!matchesBetaBlocker && hasLabel) {
+              await github.rest.issues.removeLabel({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: pullRequest.number,
+                name: labelName,
+              });
+            }
       - name: Apply too-many-prs label
         uses: actions/github-script@v8
         with:
@@ -419,6 +472,7 @@ jobs:
             const maxCount = processAll ? Number.POSITIVE_INFINITY : Math.max(1, maxPrs);
 
             const sizeLabels = ["size: XS", "size: S", "size: M", "size: L", "size: XL"];
+            const betaBlockerLabel = "beta-blocker";
             const labelColor = "b76e79";
             // const trustedLabel = "trusted-contributor";
             // const experiencedLabel = "experienced-contributor";
@@ -449,6 +503,22 @@ jobs:
               }
             }
 
+            async function hasBetaBlockerLabel() {
+              try {
+                await github.rest.issues.getLabel({
+                  owner,
+                  repo,
+                  name: betaBlockerLabel,
+                });
+                return true;
+              } catch (error) {
+                if (error?.status !== 404) {
+                  throw error;
+                }
+                return false;
+              }
+            }
+
             async function resolveContributorLabel(login) {
               if (contributorCache.has(login)) {
                 return contributorCache.get(login);
@@ -580,7 +650,37 @@ jobs:
               labelNames.add(label);
             }
 
+            async function applyBetaBlockerTitleLabel(pullRequest, labelNames) {
+              const matchesBetaBlocker = /\bbeta blocker\b/i.test(pullRequest.title ?? "");
+
+              if (matchesBetaBlocker) {
+                if (!labelNames.has(betaBlockerLabel)) {
+                  await github.rest.issues.addLabels({
+                    owner,
+                    repo,
+                    issue_number: pullRequest.number,
+                    labels: [betaBlockerLabel],
+                  });
+                  labelNames.add(betaBlockerLabel);
+                }
+                return;
+              }
+
+              if (!labelNames.has(betaBlockerLabel)) {
+                return;
+              }
+
+              await github.rest.issues.removeLabel({
+                owner,
+                repo,
+                issue_number: pullRequest.number,
+                name: betaBlockerLabel,
+              });
+              labelNames.delete(betaBlockerLabel);
+            }
+
             await ensureSizeLabels();
+            const betaBlockerLabelExists = await hasBetaBlockerLabel();
 
             let page = 1;
             let processed = 0;
@@ -618,6 +718,9 @@ jobs:
 
                 await applySizeLabel(pullRequest, currentLabels, labelNames);
                 await applyContributorLabel(pullRequest, labelNames);
+                if (betaBlockerLabelExists) {
+                  await applyBetaBlockerTitleLabel(pullRequest, labelNames);
+                }
 
                 processed += 1;
               }
@@ -719,3 +822,56 @@ jobs:
             //     labels: [trustedLabel],
             //   });
             // }
+      - name: Apply beta-blocker title label
+        uses: actions/github-script@v8
+        with:
+          github-token: ${{ steps.app-token.outputs.token || steps.app-token-fallback.outputs.token }}
+          script: |
+            const issue = context.payload.issue;
+            if (!issue || issue.pull_request) {
+              return;
+            }
+
+            const labelName = "beta-blocker";
+            const matchesBetaBlocker = /^beta blocker:/i.test(issue.title ?? "");
+
+            try {
+              await github.rest.issues.getLabel({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                name: labelName,
+              });
+            } catch (error) {
+              if (error?.status !== 404) {
+                throw error;
+              }
+              core.info(`Skipping ${labelName} labeling because the label does not exist in the repository.`);
+              return;
+            }
+
+            const currentLabels = await github.paginate(github.rest.issues.listLabelsOnIssue, {
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: issue.number,
+              per_page: 100,
+            });
+            const hasLabel = currentLabels.some((label) => label.name === labelName);
+
+            if (matchesBetaBlocker && !hasLabel) {
+              await github.rest.issues.addLabels({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: issue.number,
+                labels: [labelName],
+              });
+              return;
+            }
+
+            if (!matchesBetaBlocker && hasLabel) {
+              await github.rest.issues.removeLabel({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: issue.number,
+                name: labelName,
+              });
+            }