[typespec-metadata] Apply correct Java namespace prefix based on service type and flavor

.chronus/changes/typespec-metadata-java-namespace-prefix-2026-03-23.md

@@ -0,0 +1,11 @@
+---
+changeKind: feature
+packages:
+  - "@azure-tools/typespec-metadata"
+---
+
+Update Java namespace to apply the correct Azure prefix based on service type and flavor:
+- `com.azure.` for current data plane services
+- `com.azure.resourcemanager.` for current ARM/management services
+- `com.azure.v2.` for next-gen data plane services (flavor: `azurev2`)
+- `com.azure.resourcemanager.v2.` for next-gen ARM services (flavor: `azurev2`)

packages/typespec-metadata/src/collector.ts

@@ -64,6 +64,59 @@ interface EmitterRegistration {
   parser: LanguageParser;
 }
 
+/**
+ * Known Azure Java namespace prefixes in order of specificity.
+ * Used to strip and replace prefixes based on service type and flavor.
+ */
+const JAVA_AZURE_PREFIXES = [
+  "com.azure.resourcemanager.v2.",
+  "com.azure.v2.",
+  "com.azure.resourcemanager.",
+  "com.azure.",
+] as const;
+
+/**
+ * Determines the correct Java namespace prefix based on service type and flavor.
+ * - com.azure.            : current data plane
+ * - com.azure.resourcemanager. : current ARM/management
+ * - com.azure.v2.         : next-gen data plane (flavor: azurev2)
+ * - com.azure.resourcemanager.v2. : next-gen ARM (flavor: azurev2)
+ */
+function getJavaNamespacePrefix(isManagement: boolean, isAzureV2: boolean): string {
+  if (isManagement) {
+    return isAzureV2 ? "com.azure.resourcemanager.v2." : "com.azure.resourcemanager.";
+  }
+  return isAzureV2 ? "com.azure.v2." : "com.azure.";
+}
+
+/**
+ * Applies the correct Java namespace prefix based on service type and flavor.
+ * If the namespace already has a known Azure prefix, it is replaced with the correct one.
+ * If the namespace does not start with a known Azure prefix, the correct prefix is prepended.
+ */
+function applyJavaNamespacePrefix(
+  namespace: string,
+  isManagement: boolean,
+  isAzureV2: boolean,
+): string {
+  const targetPrefix = getJavaNamespacePrefix(isManagement, isAzureV2);
+
+  // If namespace already has the correct prefix, no change needed
+  if (namespace.startsWith(targetPrefix)) {
+    return namespace;
+  }
+
+  // Strip any existing Azure prefix and replace with the correct one
+  for (const prefix of JAVA_AZURE_PREFIXES) {
+    if (namespace.startsWith(prefix)) {
+      return targetPrefix + namespace.substring(prefix.length);
+    }
+  }
+
+  // No known Azure prefix found — prepend the correct prefix
+  return targetPrefix + namespace;
+}
+
 const EMITTER_REGISTRY: Record<string, EmitterRegistration> = {
   "@azure-tools/typespec-csharp": { language: "csharp", parser: parseCSharp },
   "@azure-tools/typespec-java": { language: "java", parser: parseJava },
@@ -86,6 +139,7 @@ interface LanguageParserResult {
 type LanguageParser = (
   options: Record<string, unknown>,
   params: Record<string, unknown>,
+  typespecType?: "data" | "management",
 ) => LanguageParserResult;
 
 /**
@@ -120,19 +174,32 @@ function parsePython(
 
 /**
  * Java-specific metadata parser.
- * Strips 'com.' prefix from namespace if present for package name derivation.
+ * Applies the correct Azure Java namespace prefix based on service type and flavor:
+ * - com.azure.            : current data plane
+ * - com.azure.resourcemanager. : current ARM/management
+ * - com.azure.v2.         : next-gen data plane (flavor: azurev2)
+ * - com.azure.resourcemanager.v2. : next-gen ARM (flavor: azurev2)
  */
 function parseJava(
   options: Record<string, unknown>,
   params: Record<string, unknown>,
+  typespecType?: "data" | "management",
 ): LanguageParserResult {
   let packageName = options["package-name"] ?? options["package_name"];
-  const namespace = options["namespace"];
+  const rawNamespace = options["namespace"];
 
-  if (namespace && !packageName) {
-    const ns = String(namespace);
-    const stripped = ns.startsWith("com.") ? ns.substring(4) : ns;
-    packageName = stripped.replace(/\./g, "-");
+  const flavor = options["flavor"];
+  const isAzureV2 = flavor === "azurev2";
+  const isManagement = typespecType === "management";
+
+  let namespace: string | undefined;
+  if (rawNamespace) {
+    namespace = applyJavaNamespacePrefix(String(rawNamespace), isManagement, isAzureV2);
+
+    if (!packageName) {
+      const stripped = namespace.startsWith("com.") ? namespace.substring(4) : namespace;
+      packageName = stripped.replace(/\./g, "-");
+    }
   }
 
   return {
@@ -257,6 +324,7 @@ export interface LanguageCollectionResult {
 export async function collectLanguagePackages(
   program: Program,
   baseOutputDir: string,
+  typespecType?: "data" | "management",
 ): Promise<LanguageCollectionResult> {
   const optionMap = program.compilerOptions.options ?? {};
   const params = extractParameters(optionMap);
@@ -272,7 +340,7 @@ export async function collectLanguagePackages(
   }
 
   return {
-    languages: buildLanguageMetadata(optionMap, params, baseOutputDir, defaultServiceDir),
+    languages: buildLanguageMetadata(optionMap, params, baseOutputDir, defaultServiceDir, typespecType),
     sourceConfigPath: program.compilerOptions.config,
   };
 }
@@ -419,6 +487,7 @@ export function buildLanguageMetadata(
   params: Record<string, unknown>,
   baseOutputDir: string,
   defaultServiceDir?: string,
+  typespecType?: "data" | "management",
 ): Record<string, LanguagePackageMetadata> {
   const languagesDict: Record<string, LanguagePackageMetadata> = {};
 
@@ -429,6 +498,7 @@ export function buildLanguageMetadata(
       params,
       baseOutputDir,
       defaultServiceDir,
+      typespecType,
     );
     const language = inferLanguageFromEmitterName(emitterName);
     languagesDict[language] = metadata;
@@ -443,6 +513,7 @@ function createLanguageMetadata(
   params: Record<string, unknown>,
   baseOutputDir: string,
   defaultServiceDir?: string,
+  typespecType?: "data" | "management",
 ): LanguagePackageMetadata {
   const normalizedOptions = normalizeOptionsObject(emitterOptions);
 
@@ -463,7 +534,7 @@ function createLanguageMetadata(
   const registration = EMITTER_REGISTRY[normalizedEmitterName];
 
   if (registration) {
-    const result = registration.parser(normalizedOptions, params);
+    const result = registration.parser(normalizedOptions, params, typespecType);
     packageName = result.packageName;
     namespace = result.namespace;
   } else {

packages/typespec-metadata/src/emitter.ts

@@ -18,7 +18,7 @@ export async function $onEmit(context: EmitContext<MetadataEmitterOptions>): Pro
   // Get the common tsp-output directory (parent of this emitter's output dir)
   const commonOutputDir = getDirectoryPath(getDirectoryPath(context.emitterOutputDir));
 
-  const languageResult = await collectLanguagePackages(context.program, commonOutputDir);
+  const languageResult = await collectLanguagePackages(context.program, commonOutputDir, typespecMetadata.type);
 
   const snapshot: MetadataSnapshot = {
     emitterVersion: SNAPSHOT_VERSION,

packages/typespec-metadata/test/collector.test.ts

@@ -183,6 +183,131 @@ describe("language-specific parsers", () => {
   });
 });
 
+describe("Java namespace prefix handling", () => {
+  it("should keep data-plane namespace with com.azure. prefix unchanged when no flavor", () => {
+    const optionMap: Record<string, Record<string, unknown>> = {
+      "@azure-tools/typespec-java": {
+        namespace: "com.azure.security.keyvault.secrets",
+      },
+    };
+
+    const result = buildLanguageMetadata(optionMap, {}, "/output", undefined, "data");
+    expect(result["java"].namespace).toBe("com.azure.security.keyvault.secrets");
+    expect(result["java"].packageName).toBe("azure-security-keyvault-secrets");
+  });
+
+  it("should keep management-plane namespace with com.azure.resourcemanager. prefix unchanged when no flavor", () => {
+    const optionMap: Record<string, Record<string, unknown>> = {
+      "@azure-tools/typespec-java": {
+        namespace: "com.azure.resourcemanager.contoso",
+      },
+    };
+
+    const result = buildLanguageMetadata(optionMap, {}, "/output", undefined, "management");
+    expect(result["java"].namespace).toBe("com.azure.resourcemanager.contoso");
+    expect(result["java"].packageName).toBe("azure-resourcemanager-contoso");
+  });
+
+  it("should update data-plane namespace to com.azure.v2. when flavor is azurev2", () => {
+    const optionMap: Record<string, Record<string, unknown>> = {
+      "@azure-tools/typespec-java": {
+        namespace: "com.azure.security.keyvault.secrets",
+        flavor: "azurev2",
+      },
+    };
+
+    const result = buildLanguageMetadata(optionMap, {}, "/output", undefined, "data");
+    expect(result["java"].namespace).toBe("com.azure.v2.security.keyvault.secrets");
+    expect(result["java"].packageName).toBe("azure-v2-security-keyvault-secrets");
+  });
+
+  it("should update management-plane namespace to com.azure.resourcemanager.v2. when flavor is azurev2", () => {
+    const optionMap: Record<string, Record<string, unknown>> = {
+      "@azure-tools/typespec-java": {
+        namespace: "com.azure.resourcemanager.contoso",
+        flavor: "azurev2",
+      },
+    };
+
+    const result = buildLanguageMetadata(optionMap, {}, "/output", undefined, "management");
+    expect(result["java"].namespace).toBe("com.azure.resourcemanager.v2.contoso");
+    expect(result["java"].packageName).toBe("azure-resourcemanager-v2-contoso");
+  });
+
+  it("should update data-plane namespace to com.azure.resourcemanager. when typespecType is management", () => {
+    const optionMap: Record<string, Record<string, unknown>> = {
+      "@azure-tools/typespec-java": {
+        namespace: "com.azure.contoso",
+      },
+    };
+
+    const result = buildLanguageMetadata(optionMap, {}, "/output", undefined, "management");
+    expect(result["java"].namespace).toBe("com.azure.resourcemanager.contoso");
+  });
+
+  it("should not change namespace if it already has the correct v2 prefix", () => {
+    const optionMap: Record<string, Record<string, unknown>> = {
+      "@azure-tools/typespec-java": {
+        namespace: "com.azure.v2.security.keyvault.secrets",
+        flavor: "azurev2",
+      },
+    };
+
+    const result = buildLanguageMetadata(optionMap, {}, "/output", undefined, "data");
+    expect(result["java"].namespace).toBe("com.azure.v2.security.keyvault.secrets");
+  });
+
+  it("should not change namespace if it already has the correct resourcemanager.v2 prefix", () => {
+    const optionMap: Record<string, Record<string, unknown>> = {
+      "@azure-tools/typespec-java": {
+        namespace: "com.azure.resourcemanager.v2.contoso",
+        flavor: "azurev2",
+      },
+    };
+
+    const result = buildLanguageMetadata(optionMap, {}, "/output", undefined, "management");
+    expect(result["java"].namespace).toBe("com.azure.resourcemanager.v2.contoso");
+  });
+
+  it("should prepend correct prefix to namespace without any Azure prefix (data plane)", () => {
+    const optionMap: Record<string, Record<string, unknown>> = {
+      "@azure-tools/typespec-java": {
+        namespace: "security.keyvault.secrets",
+      },
+    };
+
+    const result = buildLanguageMetadata(optionMap, {}, "/output", undefined, "data");
+    expect(result["java"].namespace).toBe("com.azure.security.keyvault.secrets");
+  });
+
+  it("should prepend correct prefix to namespace without any Azure prefix (management plane, azurev2)", () => {
+    const optionMap: Record<string, Record<string, unknown>> = {
+      "@azure-tools/typespec-java": {
+        namespace: "contoso",
+        flavor: "azurev2",
+      },
+    };
+
+    const result = buildLanguageMetadata(optionMap, {}, "/output", undefined, "management");
+    expect(result["java"].namespace).toBe("com.azure.resourcemanager.v2.contoso");
+  });
+
+  it("should preserve explicit package-name when namespace is updated", () => {
+    const optionMap: Record<string, Record<string, unknown>> = {
+      "@azure-tools/typespec-java": {
+        "package-name": "azure-security-keyvault-secrets",
+        namespace: "com.azure.security.keyvault.secrets",
+        flavor: "azurev2",
+      },
+    };
+
+    const result = buildLanguageMetadata(optionMap, {}, "/output", undefined, "data");
+    expect(result["java"].namespace).toBe("com.azure.v2.security.keyvault.secrets");
+    // Explicit package-name should be preserved
+    expect(result["java"].packageName).toBe("azure-security-keyvault-secrets");
+  });
+});
+
 describe("service-dir handling", () => {
   it("should use language-specific service-dir if present", () => {
     const languageServiceDir = "sdk/security/keyvault";