PR checks: Run slowest macOS checks on larger runners

.github/workflows/codeql.yml

@@ -77,7 +77,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-22.04,ubuntu-24.04,windows-2022,windows-2025,macos-14,macos-15]
+        os: [ubuntu-22.04,ubuntu-24.04,windows-2022,windows-2025,macos-14-xlarge,macos-15-xlarge]
         tools: ${{ fromJson(needs.check-codeql-versions.outputs.versions) }}
     runs-on: ${{ matrix.os }}
 

package.json

@@ -12,7 +12,8 @@
     "ava": "npm run transpile && ava --verbose",
     "test": "npm run ava -- src/",
     "test-debug": "npm run test -- --timeout=20m",
-    "transpile": "tsc --build --verbose tsconfig.json"
+    "transpile": "tsc --build --verbose tsconfig.json",
+    "update-pr-checks": "./pr-checks/sync.sh"
   },
   "license": "MIT",
   "workspaces": [

pr-checks/checks/multi-language-autodetect.yml

@@ -2,7 +2,8 @@ name: "Multi-language repository"
 description: "An end-to-end integration test of a multi-language repository using automatic language detection"
 operatingSystems:
   - ubuntu
-  - macos
+  - os: macos
+    runner-image: macos-latest-xlarge
 env:
   CODEQL_ACTION_RESOLVE_SUPPORTED_LANGUAGES_USING_CLI: true
 installGo: true

pr-checks/checks/swift-autobuild.yml

@@ -3,7 +3,8 @@ description: "Tests creation of a Swift database using autobuild"
 versions:
   - nightly-latest
 operatingSystems:
-  - macos
+  - os: macos
+    runner-image: macos-latest-xlarge
 steps:
   - uses: ./../action/init
     id: init

pr-checks/sync.ts

@@ -28,6 +28,24 @@ interface WorkflowInput {
 /** A partial mapping from known input names to input definitions. */
 type WorkflowInputs = Partial<Record<KnownInputName, WorkflowInput>>;
 
+/** An operating system identifier. */
+type OperatingSystemIdentifier = "ubuntu" | "macos" | "windows";
+
+/**
+ * Represents an operating system matrix entry for a generated PR check workflow.
+ *
+ * Either a string containing the OS identifier or an object containing the OS identifier and an
+ * optional runner image label.
+ */
+type OperatingSystem =
+  | OperatingSystemIdentifier
+  | {
+      /** OS identifier. */
+      os: OperatingSystemIdentifier;
+      /** Optional runner image label. */
+      "runner-image"?: string;
+    };
+
 /**
  * Represents PR check specifications.
  */
@@ -36,8 +54,8 @@ interface Specification extends JobSpecification {
   inputs?: Record<string, WorkflowInput>;
   /** CodeQL bundle versions to test against. Defaults to `DEFAULT_TEST_VERSIONS`. */
   versions?: string[];
-  /** Operating system prefixes used to select runner images (e.g. `["ubuntu", "macos"]`). */
-  operatingSystems?: string[];
+  /** Operating system prefixes, either as strings or with explicit runner image labels. */
+  operatingSystems?: OperatingSystem[];
   /** Per-OS version overrides. If specified for an OS, only those versions are tested on that OS. */
   osCodeQlVersions?: Record<string, string[]>;
   /** Whether to use the all-platform CodeQL bundle. */
@@ -311,20 +329,33 @@ function generateJobMatrix(
       );
     }
 
-    const runnerImages = ["ubuntu-latest", "macos-latest", "windows-latest"];
+    const defaultRunnerImages = [
+      "ubuntu-latest",
+      "macos-latest",
+      "windows-latest",
+    ];
     const operatingSystems = checkSpecification.operatingSystems ?? ["ubuntu"];
 
-    for (const operatingSystem of operatingSystems) {
+    for (const operatingSystemConfig of operatingSystems) {
+      const operatingSystem =
+        typeof operatingSystemConfig === "string"
+          ? operatingSystemConfig
+          : operatingSystemConfig.os;
+
       // If osCodeQlVersions is set for this OS, only include the specified CodeQL versions.
       const allowedVersions =
         checkSpecification.osCodeQlVersions?.[operatingSystem];
       if (allowedVersions && !allowedVersions.includes(version)) {
         continue;
       }
 
-      const runnerImagesForOs = runnerImages.filter((image) =>
-        image.startsWith(operatingSystem),
-      );
+      const runnerImagesForOs =
+        typeof operatingSystemConfig === "string" ||
+        operatingSystemConfig["runner-image"] === undefined
+          ? defaultRunnerImages.filter((image) =>
+              image.startsWith(operatingSystem),
+            )
+          : [operatingSystemConfig["runner-image"]];
 
       for (const runnerImage of runnerImagesForOs) {
         matrix.push({