Specific scope decorator should always override all-scopes decorator (#2390)

Resolves #1961

Author: live1206

.chronus/changes/decorator-override-2025-2-14-15-58-44.md

@@ -0,0 +1,7 @@
+---
+changeKind: feature
+packages:
+  - "@azure-tools/typespec-client-generator-core"
+---
+
+Specific scope decorator should always override all-scopes decorator

packages/typespec-client-generator-core/src/decorators.ts

@@ -107,13 +107,20 @@ function setScopedDecoratorData(
   value: unknown,
   scope?: LanguageScopes,
 ) {
+  const targetEntry = context.program.stateMap(key).get(target);
   // if no scope specified, then set with the new value
   if (!scope) {
-    context.program.stateMap(key).set(target, Object.fromEntries([[AllScopes, value]]));
+    if (targetEntry && targetEntry[AllScopes]) {
+      targetEntry[AllScopes] = value;
+    } else {
+      const newObject = Object.fromEntries([[AllScopes, value]]);
+      context.program
+        .stateMap(key)
+        .set(target, !targetEntry ? newObject : { ...targetEntry, ...newObject });
+    }
     return;
   }
 
-  const targetEntry = context.program.stateMap(key).get(target);
   const [negationScopes, scopes] = parseScopes(context, scope);
   if (negationScopes !== undefined && negationScopes.length > 0) {
     // override the previous value for negation scopes

packages/typespec-client-generator-core/test/decorators/scope.test.ts

@@ -158,7 +158,7 @@ it("first scoped decorator then non-scoped decorator", async () => {
     emitterName: "@azure-tools/typespec-csharp",
   });
   const { func: funcCsharp } = (await runnerWithCsharp.compile(code)) as { func: Operation };
-  strictEqual(getAccess(runnerWithCsharp.context, funcCsharp), "internal");
+  strictEqual(getAccess(runnerWithCsharp.context, funcCsharp), "public");
 });
 
 it("first non-scoped augmented decorator then scoped augmented decorator", async () => {
@@ -202,10 +202,10 @@ it("first scoped augmented decorator then non-scoped augmented decorator", async
     emitterName: "@azure-tools/typespec-csharp",
   });
   const { func: funcCsharp } = (await runnerWithCsharp.compile(code)) as { func: Operation };
-  strictEqual(getAccess(runnerWithCsharp.context, funcCsharp), "public");
+  strictEqual(getAccess(runnerWithCsharp.context, funcCsharp), "internal");
 });
 
-it("two scoped decorator", async () => {
+it("two scoped decorators", async () => {
   const code = `
     @test
     @access(Access.internal, "csharp")
@@ -226,6 +226,27 @@ it("two scoped decorator", async () => {
   strictEqual(getAccess(runnerWithCsharp.context, funcCsharp), "internal");
 });
 
+it("two non-scoped decorators", async () => {
+  const code = `
+    @test
+    @access(Access.internal)
+    @access(Access.public)
+    op func(
+      @query("createdAt")
+      createdAt: utcDateTime;
+    ): void;
+  `;
+
+  const { func } = (await runner.compile(code)) as { func: Operation };
+  strictEqual(getAccess(runner.context, func), "internal");
+
+  const runnerWithCsharp = await createSdkTestRunner({
+    emitterName: "@azure-tools/typespec-csharp",
+  });
+  const { func: funcCsharp } = (await runnerWithCsharp.compile(code)) as { func: Operation };
+  strictEqual(getAccess(runnerWithCsharp.context, funcCsharp), "internal");
+});
+
 it("csv scope list", async () => {
   function getCodeTemplate(language: string) {
     return `