feat(core): warn when a PR adds more than one new integration

src/github/manifests/home-assistant-core/index.ts

@@ -35,6 +35,7 @@ import { issueLinks } from "./rules/issue-links.js";
 import { newIntegrationValidation } from "./rules/new-integration-validation.js";
 import { platinumApproval } from "./rules/platinum-approval.js";
 import { qualityScale } from "./rules/quality-scale.js";
+import { singleNewIntegration } from "./rules/single-new-integration.js";
 import { singleNewPlatform } from "./rules/single-new-platform.js";
 
 const componentCodeowners = (domain: string) => `homeassistant/components/${domain}/*`;
@@ -60,6 +61,7 @@ export const homeAssistantCore: RepoManifest = {
     qualityScale,
     newIntegrationValidation,
     singleNewPlatform,
+    singleNewIntegration,
     forbiddenFiles({ base: "dev", files: coreForbiddenFiles }),
     integrationTransport,
     mentionCodeOwners({ pathPattern: componentCodeowners, domains: itemIntegrationDomains }),

src/github/manifests/home-assistant-core/rules/single-new-integration.ts

@@ -0,0 +1,64 @@
+import { EventType } from "../../../engine/event.js";
+import type { RuleContext } from "../../../engine/model/rule-context.js";
+import { type CheckOutcome, check } from "../../../engine/rule.js";
+import { parseFiles } from "../helpers/parse-path.js";
+import { isReleasePR } from "../helpers/release-pr.js";
+
+const REVIEW_PROCESS_URL =
+  "https://developers.home-assistant.io/docs/review-process/#home-assistant-core";
+
+type HandledEvent =
+  | EventType.PULL_REQUEST_OPENED
+  | EventType.PULL_REQUEST_REOPENED
+  | EventType.PULL_REQUEST_SYNCHRONIZE
+  | EventType.ON_DEMAND;
+
+async function evaluate(ctx: RuleContext<HandledEvent>): Promise<CheckOutcome | undefined> {
+  if (await isReleasePR(ctx.target)) {
+    return { status: "skip", message: "Not checked on release PRs." };
+  }
+
+  const parsed = await parseFiles(ctx, await ctx.target.files());
+
+  // Every integration, virtual ones included, has a manifest.json, while a
+  // virtual integration has no __init__.py: count added manifests.
+  const added = [
+    ...new Set(
+      parsed
+        .filter(
+          (p) =>
+            p.type === "component" &&
+            p.status === "added" &&
+            p.path === `homeassistant/components/${p.component}/manifest.json`,
+        )
+        .map((p) => `\`${p.component}\``),
+    ),
+  ].sort();
+
+  if (added.length === 0) {
+    return { status: "skip", message: "No new integrations added." };
+  }
+  if (added.length === 1) {
+    return { status: "pass", message: `Adds a single new integration: ${added[0]}.` };
+  }
+  return {
+    status: "warn",
+    message:
+      `This PR adds ${added.length} new integrations (${added.join(", ")}). ` +
+      "Add one integration per PR, virtual integrations included, and split the " +
+      `others into separate PRs. See the [review process](${REVIEW_PROCESS_URL}).`,
+  };
+}
+
+export const singleNewIntegration = check({
+  id: "single-new-integration",
+  title: "Single new integration",
+  description: "Warns on PRs that add more than one new integration, virtual ones included",
+  events: [
+    EventType.PULL_REQUEST_OPENED,
+    EventType.PULL_REQUEST_REOPENED,
+    EventType.PULL_REQUEST_SYNCHRONIZE,
+    EventType.ON_DEMAND,
+  ],
+  evaluate,
+});

tests/github/manifests/home-assistant-core/rules/single-new-integration.test.ts

@@ -0,0 +1,106 @@
+import { describe, expect, it } from "vitest";
+import { EventType } from "../../../../../src/github/engine/event.js";
+import { singleNewIntegration } from "../../../../../src/github/manifests/home-assistant-core/rules/single-new-integration.js";
+import { createMockContext, mockPRFiles, runRule } from "../../../helpers/mock-context.js";
+
+function makeFile(filename: string, status = "added") {
+  return {
+    filename,
+    status,
+    additions: 10,
+    deletions: 0,
+    changes: 10,
+    sha: "abc",
+    blob_url: "",
+    raw_url: "",
+    contents_url: "",
+  };
+}
+
+function prContext() {
+  return createMockContext({
+    eventType: EventType.ON_DEMAND,
+    payload: { pull_request: { head: { sha: "abc123" }, labels: [] } },
+  });
+}
+
+describe("single-new-integration", () => {
+  it("skips when no integration is added", async () => {
+    const context = prContext();
+    mockPRFiles(context, [
+      makeFile("homeassistant/components/hue/manifest.json", "modified"),
+      makeFile("homeassistant/components/hue/sensor.py"),
+    ]);
+
+    const result = await runRule(singleNewIntegration, context);
+    expect(result?.section).toMatchObject({ id: "single-new-integration", status: "skip" });
+  });
+
+  it("passes when a single integration is added", async () => {
+    const context = prContext();
+    mockPRFiles(context, [
+      makeFile("homeassistant/components/awesome/__init__.py"),
+      makeFile("homeassistant/components/awesome/manifest.json"),
+      makeFile("tests/components/awesome/__init__.py"),
+    ]);
+
+    const result = await runRule(singleNewIntegration, context);
+    expect(result?.section).toMatchObject({ id: "single-new-integration", status: "pass" });
+    expect(result?.section?.message).toContain("`awesome`");
+  });
+
+  it("warns when multiple virtual integrations are added", async () => {
+    const context = prContext();
+    mockPRFiles(context, [
+      makeFile("homeassistant/components/brand_a/manifest.json"),
+      makeFile("homeassistant/components/brand_b/manifest.json"),
+      makeFile("homeassistant/generated/integrations.json", "modified"),
+    ]);
+
+    const result = await runRule(singleNewIntegration, context);
+    expect(result?.section?.status).toBe("warn");
+    expect(result?.section?.message).toContain("2 new integrations");
+    expect(result?.section?.message).toContain("`brand_a`");
+    expect(result?.section?.message).toContain("`brand_b`");
+  });
+
+  it("warns when a regular and a virtual integration are added together", async () => {
+    const context = prContext();
+    mockPRFiles(context, [
+      makeFile("homeassistant/components/awesome/__init__.py"),
+      makeFile("homeassistant/components/awesome/manifest.json"),
+      makeFile("homeassistant/components/awesome_brand/manifest.json"),
+    ]);
+
+    const result = await runRule(singleNewIntegration, context);
+    expect(result?.section?.status).toBe("warn");
+  });
+
+  it("ignores manifest fixtures in tests", async () => {
+    const context = prContext();
+    mockPRFiles(context, [
+      makeFile("homeassistant/components/awesome/manifest.json"),
+      makeFile("tests/components/awesome/fixtures/manifest.json"),
+      makeFile("tests/testing_config/custom_components/test/manifest.json"),
+    ]);
+
+    const result = await runRule(singleNewIntegration, context);
+    expect(result?.section?.status).toBe("pass");
+  });
+
+  it("skips release PRs", async () => {
+    const context = createMockContext({
+      eventType: EventType.ON_DEMAND,
+      payload: {
+        pull_request: { head: { sha: "abc123", ref: "rc" }, base: { ref: "master" }, labels: [] },
+      },
+    });
+    mockPRFiles(context, [
+      makeFile("homeassistant/components/brand_a/manifest.json"),
+      makeFile("homeassistant/components/brand_b/manifest.json"),
+    ]);
+
+    const result = await runRule(singleNewIntegration, context);
+    expect(result?.section).toMatchObject({ id: "single-new-integration", status: "skip" });
+  });
+});

tests/github/manifests/snapshots/home-assistant-core/pull_request.opened.all-change-types.yaml

@@ -7,6 +7,10 @@ statuses:
     title: Single new platform
     status: skip
     message: New-integration PRs are checked by new integration validation.
+  - id: single-new-integration
+    title: Single new integration
+    status: pass
+    message: "Adds a single new integration: `awesome`."
   - id: forbidden-files
     title: Forbidden files
     status: pass

tests/github/manifests/snapshots/home-assistant-core/pull_request.opened.bugfix-single-integration.yaml

@@ -7,6 +7,10 @@ statuses:
     title: Single new platform
     status: skip
     message: No new platforms added.
+  - id: single-new-integration
+    title: Single new integration
+    status: skip
+    message: No new integrations added.
   - id: forbidden-files
     title: Forbidden files
     status: pass

tests/github/manifests/snapshots/home-assistant-core/pull_request.opened.dependency-bump.yaml

@@ -7,6 +7,10 @@ statuses:
     title: Single new platform
     status: skip
     message: No new platforms added.
+  - id: single-new-integration
+    title: Single new integration
+    status: skip
+    message: No new integrations added.
   - id: forbidden-files
     title: Forbidden files
     status: pass

tests/github/manifests/snapshots/home-assistant-core/pull_request.opened.new-integration-no-docs.yaml

@@ -7,6 +7,10 @@ statuses:
     title: Single new platform
     status: skip
     message: New-integration PRs are checked by new integration validation.
+  - id: single-new-integration
+    title: Single new integration
+    status: pass
+    message: "Adds a single new integration: `awesome`."
   - id: forbidden-files
     title: Forbidden files
     status: pass

tests/github/manifests/snapshots/home-assistant-core/pull_request.opened.new-integration-transports.yaml

@@ -7,6 +7,10 @@ statuses:
     title: Single new platform
     status: skip
     message: New-integration PRs are checked by new integration validation.
+  - id: single-new-integration
+    title: Single new integration
+    status: pass
+    message: "Adds a single new integration: `awesome`."
   - id: forbidden-files
     title: Forbidden files
     status: pass

tests/github/manifests/snapshots/home-assistant-core/pull_request.opened.release.yaml

@@ -7,6 +7,10 @@ statuses:
     title: Single new platform
     status: skip
     message: Not checked on release PRs.
+  - id: single-new-integration
+    title: Single new integration
+    status: skip
+    message: Not checked on release PRs.
   - id: forbidden-files
     title: Forbidden files
     status: skip

tests/github/manifests/snapshots/home-assistant-core/pull_request.reopened.yaml

@@ -7,6 +7,10 @@ statuses:
     title: Single new platform
     status: skip
     message: No new platforms added.
+  - id: single-new-integration
+    title: Single new integration
+    status: skip
+    message: No new integrations added.
   - id: forbidden-files
     title: Forbidden files
     status: pass

tests/github/manifests/snapshots/home-assistant-core/pull_request.synchronize.merge-conflict.yaml

@@ -7,6 +7,10 @@ statuses:
     title: Single new platform
     status: skip
     message: No new platforms added.
+  - id: single-new-integration
+    title: Single new integration
+    status: skip
+    message: No new integrations added.
   - id: forbidden-files
     title: Forbidden files
     status: pass