re-generation, the metadata files should be update

packages/rlc-common/src/metadata/buildPackageFile.ts

@@ -91,15 +91,17 @@ export function buildPackageFile(
 export function updatePackageFile(
   model: RLCModel,
   existingFilePathOrContent: string | Record<string, any>,
-  { exports }: PackageFileOptions = {}
+  { exports, clientContextPaths }: PackageFileOptions = {}
 ) {
   const hasLro = hasPollingOperations(model);
   const isAzure = isAzurePackage(model);
   const needsLroUpdate = isAzure && hasLro;
   const needsExportsUpdate = exports;
+  const needsConstantPathsUpdate =
+    clientContextPaths && clientContextPaths.length > 0;
 
   // Early return if nothing needs to be updated
-  if (!needsLroUpdate && !needsExportsUpdate) {
+  if (!needsLroUpdate && !needsExportsUpdate && !needsConstantPathsUpdate) {
     return;
   }
 
@@ -136,6 +138,21 @@ export function updatePackageFile(
     };
   }
 
+  // Update constantPaths metadata for Azure packages
+  if (needsConstantPathsUpdate && isAzure && packageInfo["//metadata"]) {
+    const metadata = packageInfo["//metadata"];
+    // Filter out existing userAgentInfo entries
+    const nonUserAgentPaths = (metadata.constantPaths || []).filter(
+      (item: any) => item.prefix !== "userAgentInfo"
+    );
+    // Add new userAgentInfo entries from clientContextPaths
+    const newUserAgentPaths = clientContextPaths!.map((path) => ({
+      path: path,
+      prefix: "userAgentInfo"
+    }));
+    metadata.constantPaths = [...nonUserAgentPaths, ...newUserAgentPaths];
+  }
+
   return {
     path: "package.json",
     content: JSON.stringify(packageInfo, null, 2)

packages/rlc-common/src/metadata/buildReadmeFile.ts

@@ -370,20 +370,38 @@ export function updateReadmeFile(
   try {
     const existingContent = readFileSync(existingReadmeFilePath, "utf8");
     const metadata = createMetadata(model) ?? {};
+    const newClientName = getClientName(model);
 
+    let updatedContent = existingContent;
+
+    // Update API reference link
     const newApiRefLink = hbs
       .compile(apiReferenceTemplate, { noEscape: true })(metadata)
       .trim();
 
-    if (!newApiRefLink) {
-      return { path: "README.md", content: existingContent };
+    if (newApiRefLink) {
+      const apiRefRegex =
+        /^- \[API reference documentation\]\(https:\/\/learn\.microsoft\.com\/javascript\/api\/[^)]+\)$/m;
+      updatedContent = updatedContent.replace(apiRefRegex, (match) =>
+        match ? newApiRefLink : match
+      );
     }
 
-    const apiRefRegex =
-      /^- \[API reference documentation\]\(https:\/\/learn\.microsoft\.com\/javascript\/api\/[^)]+\)$/m;
-    const updatedContent = existingContent.replace(apiRefRegex, (match) =>
-      match ? newApiRefLink : match
+    // Extract old client name from existing README import statements
+    const importMatch = existingContent.match(
+      /import\s*\{\s*([A-Za-z0-9_]+)\s*\}\s*from\s*["'][^"']*["']/
     );
+    const oldClientName = importMatch?.[1];
+
+    // Only update client name if we found an old name and it's different from the new one
+    if (oldClientName && newClientName && oldClientName !== newClientName) {
+      // Create a regex that matches the old client name as a whole word
+      const oldClientNameRegex = new RegExp(`\\b${oldClientName}\\b`, "g");
+      updatedContent = updatedContent.replace(
+        oldClientNameRegex,
+        newClientName
+      );
+    }
 
     return { path: "README.md", content: updatedContent };
   } catch {

packages/rlc-common/test/integration/packageJson.spec.ts

@@ -815,6 +815,114 @@ describe("Package file generation", () => {
       );
       expect(packageFile).to.not.have.property("tshy");
     });
+
+    it("should update constantPaths when clientContextPaths option is provided for Azure packages", () => {
+      const model = createMockModel({
+        moduleKind: "esm",
+        flavor: "azure",
+        isMonorepo: true,
+        hasLro: false
+      });
+
+      const initialPackageInfo = {
+        name: "@azure/test-package",
+        version: "1.0.0",
+        dependencies: {
+          "@azure/core-client": "^1.0.0"
+        },
+        "//metadata": {
+          constantPaths: [
+            { path: "src/old-path.ts", prefix: "userAgentInfo" },
+            { path: "src/other-file.ts", prefix: "packageDetails" }
+          ]
+        }
+      };
+
+      const packageFileContent = updatePackageFile(model, initialPackageInfo, {
+        clientContextPaths: [
+          "src/api/newContext.ts",
+          "src/api/anotherContext.ts"
+        ]
+      });
+      const packageFile = JSON.parse(packageFileContent?.content ?? "{}");
+
+      expect(packageFile["//metadata"]).to.have.property("constantPaths");
+      const constantPaths = packageFile["//metadata"]["constantPaths"];
+
+      // Should keep non-userAgentInfo entries
+      expect(constantPaths).to.deep.include({
+        path: "src/other-file.ts",
+        prefix: "packageDetails"
+      });
+
+      // Should replace old userAgentInfo entries with new ones
+      expect(constantPaths).to.deep.include({
+        path: "src/api/newContext.ts",
+        prefix: "userAgentInfo"
+      });
+      expect(constantPaths).to.deep.include({
+        path: "src/api/anotherContext.ts",
+        prefix: "userAgentInfo"
+      });
+
+      // Should not include old userAgentInfo entry
+      expect(constantPaths).to.not.deep.include({
+        path: "src/old-path.ts",
+        prefix: "userAgentInfo"
+      });
+    });
+
+    it("should not update constantPaths when clientContextPaths is empty", () => {
+      const model = createMockModel({
+        moduleKind: "esm",
+        flavor: "azure",
+        isMonorepo: true,
+        hasLro: false
+      });
+
+      const initialPackageInfo = {
+        name: "@azure/test-package",
+        version: "1.0.0",
+        "//metadata": {
+          constantPaths: [{ path: "src/old-path.ts", prefix: "userAgentInfo" }]
+        }
+      };
+
+      const packageFileContent = updatePackageFile(model, initialPackageInfo, {
+        clientContextPaths: []
+      });
+
+      // Should return undefined when nothing needs to be updated
+      expect(packageFileContent).to.be.undefined;
+    });
+
+    it("should not update constantPaths for non-Azure packages", () => {
+      const model = createMockModel({
+        moduleKind: "esm",
+        flavor: undefined,
+        isMonorepo: true,
+        hasLro: false
+      });
+
+      const initialPackageInfo = {
+        name: "@test/test-package",
+        version: "1.0.0",
+        "//metadata": {
+          constantPaths: [{ path: "src/old-path.ts", prefix: "userAgentInfo" }]
+        }
+      };
+
+      const packageFileContent = updatePackageFile(model, initialPackageInfo, {
+        clientContextPaths: ["src/api/newContext.ts"]
+      });
+
+      // Should return package.json but without updating constantPaths for non-Azure packages
+      expect(packageFileContent).to.not.be.undefined;
+      const packageFile = JSON.parse(packageFileContent?.content ?? "{}");
+      expect(packageFile["//metadata"]["constantPaths"]).to.deep.equal([
+        { path: "src/old-path.ts", prefix: "userAgentInfo" }
+      ]);
+    });
   });
 
   describe("Flavorless lib", () => {

packages/typespec-ts/src/index.ts

@@ -557,7 +557,11 @@ export async function $onEmit(context: EmitContext) {
       let modularPackageInfo = {};
       if (option.isModularLibrary) {
         modularPackageInfo = {
-          exports: getModuleExports(context, modularEmitterOptions)
+          exports: getModuleExports(context, modularEmitterOptions),
+          clientContextPaths: getRelativeContextPaths(
+            context,
+            modularEmitterOptions
+          )
         };
       }
       await emitContentByBuilder(
@@ -577,6 +581,19 @@ export async function $onEmit(context: EmitContext) {
           dpgContext.generationPathDetail?.metadataDir
         );
       }
+
+      // Regenerate snippets.spec.ts for documentation
+      if (option.azureSdkForJs) {
+        for (const subClient of dpgContext.sdkPackage.clients) {
+          await emitContentByBuilder(
+            program,
+            (model) =>
+              buildSnippets(model, subClient.name, option.azureSdkForJs),
+            rlcClient,
+            dpgContext.generationPathDetail?.metadataDir
+          );
+        }
+      }
     }
     if (isAzureFlavor) {
       await emitContentByBuilder(