[EngSys][rush-runner] refactor for test-ability (#32148)

- Extract several helpers into helpers.js so that it is easier to add
tests for them.
- update jsdoc to support TypeScript checks
- add some tests of expetations (currently failing)

eng/tools/rush-runner/helpers.js

@@ -0,0 +1,147 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+// @ts-check
+
+import * as fs from "node:fs";
+import * as path from "node:path";
+
+/** @type {Record<"core"|"test-utils"|"identity", string[]>} */
+export const reducedDependencyTestMatrix = {
+  core: [
+    "@azure-rest/synapse-access-control",
+    "@azure/arm-resources",
+    "@azure/identity",
+    "@azure/service-bus",
+    "@azure/template",
+  ],
+  "test-utils": [
+    "@azure-tests/perf-storage-blob",
+    "@azure/arm-eventgrid",
+    "@azure/ai-text-analytics",
+    "@azure/identity",
+    "@azure/template",
+  ],
+  identity: [
+    "@azure-tests/perf-storage-blob",
+    "@azure/ai-text-analytics",
+    "@azure/arm-resources",
+    "@azure/identity-cache-persistence",
+    "@azure/identity-vscode",
+    "@azure/storage-blob",
+    "@azure/template",
+  ],
+};
+
+/** @type {string[]} */
+const restrictedToPackages = [
+  "@azure/abort-controller",
+  "@azure/core-amqp",
+  "@azure/core-auth",
+  "@azure/core-client",
+  "@azure/core-http-compat",
+  "@azure/core-lro",
+  "@azure/core-paging",
+  "@azure/core-rest-pipeline",
+  "@azure/core-sse",
+  "@azure/core-tracing",
+  "@azure/core-util",
+  "@azure/core-xml",
+  "@azure/logger",
+  "@azure-rest/core-client",
+  "@typespec/ts-http-runtime",
+  "@azure/identity",
+  "@azure/arm-resources",
+  "@azure-tools/test-perf",
+  "@azure-tools/test-recorder",
+  "@azure-tools/test-credential",
+  "@azure-tools/test-utils",
+  "@azure-tools/test-utils-vitest",
+];
+
+/**
+ * Helper function that determines the rush command flag to use based on each individual package name for the 'build' check.
+ *
+ * If the targeted package is one of the restricted packages with a ton of dependents, we only want to run that package
+ * and not all of its dependents.
+ * @param {string[]} packageNames - An array of strings containing the packages names to run the action on.
+ * @param {string[]} actionComponents - An array of strings containing the packages names to run the action on.
+ */
+export const getDirectionMappedPackages = (packageNames, actionComponents) => {
+  const mappedPackages = [];
+
+  for (const packageName of packageNames) {
+    // Build command without any additional option should build the project and downstream
+    // If service is configured to run only a set of downstream projects then build all projects leading to them to support testing
+    // If the package is a core package, azure-identity or arm-resources then build only the package,
+    // otherwise build the package and all its dependents
+    var rushCommandFlag = "--impacted-by";
+
+    if (restrictedToPackages.includes(packageName)) {
+      // if this is one of our restricted packages with a ton of deps, make it targeted
+      // as including all dependents will be too much
+      rushCommandFlag = "--to";
+    } else if (actionComponents.length == 1) {
+      // else we are building the project and its dependents
+      rushCommandFlag = "--from";
+    }
+
+    mappedPackages.push([rushCommandFlag, packageName]);
+  }
+
+  return mappedPackages;
+};
+
+/**
+ * Returns an array of full paths to package.json files under a directory
+ *
+ * @param {string} searchDir - directory to search
+ */
+const getPackageJSONs = (searchDir) => {
+  // This gets all the directories with package.json at the `sdk/<service>/<service-sdk>` level excluding "arm-" packages
+  const sdkDirectories = fs
+    .readdirSync(searchDir)
+    .map((f) => path.join(searchDir, f, "package.json")); // turn potential directory names into package.json paths
+
+  // This gets all the directories with package.json at the `sdk/<service>/<service-sdk>/perf-tests` level excluding "-track-1" perf test packages
+  let perfTestDirectories = [];
+  const searchPerfTestDir = path.join(searchDir, "perf-tests");
+  if (fs.existsSync(searchPerfTestDir)) {
+    perfTestDirectories = fs
+      .readdirSync(searchPerfTestDir)
+      .filter((f) => !f.endsWith("-track-1")) // exclude libraries ending with "-track-1" (perf test projects)
+      .map((f) => path.join(searchPerfTestDir, f, "package.json")); // turn potential directory names into package.json paths
+  }
+
+  return sdkDirectories.concat(perfTestDirectories).filter((f) => fs.existsSync(f)); // only keep paths for files that actually exist
+};
+
+/**
+ * Returns package names and package dirs arrays
+ *
+ * @param {string} baseDir -
+ * @param {string[]} serviceDirs -
+ * @param {string} artifactNames -
+ */
+export const getServicePackages = (baseDir, serviceDirs, artifactNames) => {
+  const packageNames = [];
+  const packageDirs = [];
+  let validSdkTypes = ["client", "mgmt", "perf-test", "utility"]; // valid "sdk-type"s that we are looking for, to be able to apply rush-runner jobs on
+  const artifacts = artifactNames.split(",");
+  for (const serviceDir of serviceDirs) {
+    const searchDir = path.resolve(path.join(baseDir, "sdk", serviceDir));
+    const packageJSONs = getPackageJSONs(searchDir);
+    for (const filePath of packageJSONs) {
+      const contents = JSON.parse(fs.readFileSync(filePath, "utf8"));
+      const artifactName = contents.name.replace("@", "").replace("/", "-");
+      if (
+        validSdkTypes.includes(contents["sdk-type"]) &&
+        (artifactNames.length === 0 || artifacts.includes(artifactName))
+      ) {
+        packageNames.push(contents.name);
+        packageDirs.push(path.dirname(filePath));
+      }
+    }
+  }
+  return {packageNames, packageDirs};
+};