Introduce LABEL_NOTICE for PR bot

.agent/skills/contributing/SKILL.md

@@ -17,7 +17,7 @@
 # under the License.
 
 name: contributing
-description: Guides the contribution workflow for Apache Beam, including creating PRs, issue management, code review process, and release cycles. Use when contributing code, creating PRs, or understanding the contribution process.
+description: Guides the contribution workflow for Apache Beam, including creating PRs, issue management, code review process, release cycles, and rigorous evaluation rules for high-risk core component changes. Use when contributing code, creating PRs, or modifying core Beam components.
 ---
 
 # Contributing to Apache Beam
@@ -71,6 +71,10 @@ description: Guides the contribution workflow for Apache Beam, including creatin
   - Implementation details belong in inline code comments.
 - Use descriptive commit messages
 
+#### Working on Core Components (High Risk — Heightened Scrutiny)
+
+> **AGENT DIRECTIVE**: modification to **Core Components** carries an inherently elevated risk of silent regression across distributed runners. Refer to `.github/autolabeler.yml` under the `"core"` label for the authoritative list of core component paths (including `sdks/java/core`, `runners/core-*`, `model`, `sdks/python/apache_beam/transforms|coders`, `sdks/go/pkg/beam/core`, `FileIO`, and `GCS`). If you are an AI agent modifying files matched by these paths, **evaluate your changes with scrutiny.**
+
 ### 5. Create Pull Request
 - Link to the issue in PR description
 - Pre-commit tests run automatically
@@ -91,6 +95,7 @@ description: Guides the contribution workflow for Apache Beam, including creatin
 
 ### For Reviewers
 - PRs can only be merged by [Beam committers](https://home.apache.org/phonebook.html?pmc=beam)
+- PRs with the `core` label touch foundational Beam semantics or common code paths; review with extra scrutiny for non-obvious failure modes, edge case, and performance regressions
 
 ## Testing Workflows
 

.github/autolabeler.yml

@@ -17,6 +17,26 @@
 
 # Please keep the entries sorted lexicographically in each category.
 
+# All core components
+"core": # This label instructs review with scrutiny 
+  - "model/**/*"
+  - "runners/core-java/**/*"
+  - "runners/java-fn-execution/**/*"
+  - "sdks/go/pkg/beam/*.go"
+  - "sdks/go/pkg/beam/core/**/*"
+  - "sdks/go/pkg/beam/io/fileio/**/*"
+  - "sdks/go/pkg/beam/io/filesystem/**/*"
+  - "sdks/go/pkg/beam/transforms/**/*"
+  - "sdks/java/core/**/*"
+  - "sdks/java/extensions/google-cloud-platform-core/**/*"
+  - "sdks/java/harness/**/*"
+  - "sdks/python/apache_beam/*.py"
+  - "sdks/python/apache_beam/coders/**/*"
+  - "sdks/python/apache_beam/io/file*"
+  - "sdks/python/apache_beam/io/gcp/gcs*"
+  - "sdks/python/apache_beam/transforms/**/*"
+  - "sdks/python/apache_beam/typehints/**/*"
+
 # General
 build: ["assembly.xml", "buildSrc/**/*", ".gitattributes", ".github/workflows/*", ".gitignore", "gradle/**/*", ".mailmap", "release/**/*", "sdks/java/build-tools/**/*"]
 docker: ["runners/flink/job-server-container/**/*", "runners/spark/job-server/container/**/*", "sdks/go/container/**/*", "sdks/java/container/**/*", "sdks/python/container/**/*"]
@@ -80,7 +100,6 @@ io:  ["sdks/go/pkg/beam/io/**/*", "sdks/java/io/**/*", "sdks/python/apache_beam/
 
 # Runners
 "runners": ["runners/**/*", "sdks/go/pkg/beam/runners/**/*", "sdks/python/apache_beam/runners/**/*", "sdks/typescript/src/apache_beam/runners/**/*"]
-"core": ["runners/core-java/**/*"]
 "dataflow": ["runners/google-cloud-dataflow-java/**/*", "sdks/go/pkg/beam/runners/dataflow/**/*", "sdks/python/runners/dataflow/**/*"]
 "direct": ["runners/direct-java/**/*", "sdks/go/pkg/beam/runners/direct/**/*", "sdks/python/runners/direct/**/*"]
 "flink": ["runners/flink/**/*", "sdks/go/pkg/beam/runners/flink/**/*"]

scripts/ci/pr-bot/findPrsNeedingAttention.ts

@@ -128,7 +128,9 @@ async function assignToNewReviewers(
   console.log(`Assigning new reviewers for pr ${pull.number}`);
   await github.addPrComment(
     pull.number,
-    commentStrings.assignNewReviewer(prState.reviewersAssignedForLabels)
+    commentStrings.assignNewReviewer(prState.reviewersAssignedForLabels, {
+      labels: pull.labels,
+    })
   );
 
   await stateClient.writePrState(pull.number, prState);

scripts/ci/pr-bot/processNewPrs.ts

@@ -341,7 +341,9 @@ async function processPull(
   console.log(`Assigning reviewers for PR ${pull.number}`);
   await github.addPrComment(
     pull.number,
-    commentStrings.assignReviewer(prState.reviewersAssignedForLabels)
+    commentStrings.assignReviewer(prState.reviewersAssignedForLabels, {
+      labels: pull.labels,
+    })
   );
 
   github.nextActionReviewers(pull.number, pull.labels);

scripts/ci/pr-bot/shared/commentStrings.ts

@@ -16,8 +16,37 @@
  * limitations under the License.
  */
 
+import { Label } from "./githubUtils";
 const { NO_MATCHING_LABEL } = require("./constants");
 
+export interface AssignReviewerOptions {
+  labels?: (string | Label)[];
+  notices?: string[];
+}
+
+// Custom notices for specific labels
+const LABEL_NOTICES: Record<string, string> = {
+  core: "This pull request likely touches a core component (\"core\" label). Please review with scrutiny.",
+};
+
+function formatNotices(
+  labelToReviewerMapping: any,
+  options?: AssignReviewerOptions
+): string {
+  const notices = [...(options?.notices || [])];
+  const labels = [
+    ...(options?.labels || []),
+    ...Object.keys(labelToReviewerMapping),
+  ];
+  for (const label of labels) {
+    const name = (typeof label === "string" ? label : label.name).toLowerCase();
+    if (LABEL_NOTICES[name] && !notices.includes(LABEL_NOTICES[name])) {
+      notices.push(LABEL_NOTICES[name]);
+    }
+  }
+  return notices.length ? `\n${notices.join("\n\n")}\n` : "";
+}
+
 export function allChecksPassed(reviewersToNotify: string[]): string {
   return `All checks have passed: @${reviewersToNotify.join(" ")}`;
 }
@@ -26,7 +55,10 @@ export function assignCommitter(committer: string): string {
   return `R: @${committer} for final approval`;
 }
 
-export function assignReviewer(labelToReviewerMapping: any): string {
+export function assignReviewer(
+  labelToReviewerMapping: any,
+  options?: AssignReviewerOptions
+): string {
   let commentString =
     "Assigning reviewers:\n\n";
 
@@ -39,6 +71,8 @@ export function assignReviewer(labelToReviewerMapping: any): string {
     }
   }
 
+  commentString += formatNotices(labelToReviewerMapping, options);
+
   commentString += `
 
 Note: If you would like to opt out of this review, comment \`assign to next reviewer\`.
@@ -114,9 +148,12 @@ Users are removed if they haven't reviewed or completed a PR in the last 3 month
   return commentString;
 }
 
-export function assignNewReviewer(labelToReviewerMapping: {
-  [label: string]: string;
-}): string {
+export function assignNewReviewer(
+  labelToReviewerMapping: {
+    [label: string]: string;
+  },
+  options?: AssignReviewerOptions
+): string {
   let commentString =
     "Assigning new set of reviewers because Pr has gone too long without review. If you would like to opt out of this review, comment `assign to next reviewer`:\n\n";
 
@@ -129,6 +166,8 @@ export function assignNewReviewer(labelToReviewerMapping: {
     }
   }
 
+  commentString += formatNotices(labelToReviewerMapping, options);
+
   commentString += `
 Available commands:
 - \`stop reviewer notifications\` - opt out of the automated review tooling

scripts/ci/pr-bot/shared/userCommand.ts

@@ -101,14 +101,16 @@ async function assignToNextReviewer(
 
     // Comment assigning reviewer
     console.log(`Assigning ${chosenReviewer}`);
+    const existingLabels =
+      payload.issue?.labels || payload.pull_request?.labels;
     await github.addPrComment(
       pullNumber,
-      commentStrings.assignReviewer(prState.reviewersAssignedForLabels)
+      commentStrings.assignReviewer(prState.reviewersAssignedForLabels, {
+        labels: existingLabels,
+      })
     );
 
     // Set next action to reviewer
-    const existingLabels =
-      payload.issue?.labels || payload.pull_request?.labels;
     await github.nextActionReviewers(pullNumber, existingLabels);
     prState.nextAction = "Reviewers";
 
@@ -227,7 +229,9 @@ async function assignReviewerSet(
   console.log(`Assigning reviewers for pr ${pullNumber}`);
   await github.addPrComment(
     pullNumber,
-    commentStrings.assignReviewer(prState.reviewersAssignedForLabels)
+    commentStrings.assignReviewer(prState.reviewersAssignedForLabels, {
+      labels: existingLabels,
+    })
   );
 
   github.nextActionReviewers(pullNumber, existingLabels);

scripts/ci/pr-bot/test/commentStringsTest.ts

@@ -0,0 +1,45 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+var assert = require("assert");
+const commentStrings = require("../shared/commentStrings");
+
+describe("commentStrings", function () {
+  describe("assignReviewer()", function () {
+    it("should not include scrutiny statement when core label is not present", function () {
+      const comment = commentStrings.assignReviewer(
+        { Java: "reviewer1" },
+        { labels: [{ name: "Java" }] }
+      );
+      assert(!comment.includes("review with scrutiny"));
+    });
+
+    it("should include scrutiny statement when core label is present in options.labels", function () {
+      const comment = commentStrings.assignReviewer(
+        { Java: "reviewer1" },
+        { labels: [{ name: "core" }] }
+      );
+      assert(comment.includes("review with scrutiny"));
+    });
+
+    it("should include scrutiny statement when core label is in mapping keys", function () {
+      const comment = commentStrings.assignReviewer({ core: "reviewer1" });
+      assert(comment.includes("review with scrutiny"));
+    });
+  });
+});