Fix crash when Traits builders gets passed non model (Azure#694)

fix [Azure#577](Azure#577)
fix [Azure#332](Azure#332)

.chronus/changes/fix-trait-crash-unreferencable-2024-3-18-16-38-1.md

@@ -0,0 +1,8 @@
+---
+# Change versionKind to one of: internal, fix, dependencies, feature, deprecation, breaking
+changeKind: fix
+packages:
+  - "@azure-tools/typespec-azure-core"
+---
+
+Fix crash when `Traits` builders gets passed non model

packages/typespec-azure-core/lib/operations.tsp

@@ -90,7 +90,7 @@ alias ExpectedResourceOperationTraits = [
  */
 @ensureTraitsPresent(InterfaceTraits, ExpectedResourceOperationTraits)
 interface ResourceOperations<
-  InterfaceTraits,
+  InterfaceTraits extends TypeSpec.Reflection.Model,
   ErrorResponse = Azure.Core.Foundations.ErrorResponse
 > {
   /**

packages/typespec-azure-core/lib/traits.tsp

@@ -65,7 +65,7 @@ model TraitOverride<Trait> {}
 @trait
 @added(Azure.Core.Versions.v1_0_Preview_2)
 @Private.ensureAllQueryParams(Parameters)
-model QueryParametersTrait<Parameters, Contexts = unknown> {
+model QueryParametersTrait<Parameters extends Model, Contexts = unknown> {
   @traitContext(Contexts)
   queryParams: {
     @traitLocation(TraitLocation.Parameters)
@@ -79,7 +79,8 @@ model QueryParametersTrait<Parameters, Contexts = unknown> {
  */
 @trait
 @added(Azure.Core.Versions.v1_0_Preview_2)
-model ListQueryParametersTrait<Parameters> is QueryParametersTrait<Parameters, TraitContext.List>;
+model ListQueryParametersTrait<Parameters extends Model>
+  is QueryParametersTrait<Parameters, TraitContext.List>;
 
 /**
  * Declares a trait that is applied as a request header parameter.
@@ -89,7 +90,7 @@ model ListQueryParametersTrait<Parameters> is QueryParametersTrait<Parameters, T
 @trait
 @added(Azure.Core.Versions.v1_0_Preview_2)
 @Private.ensureAllHeaderParams(Headers)
-model RequestHeadersTrait<Headers, Contexts = unknown> {
+model RequestHeadersTrait<Headers extends Model, Contexts = unknown> {
   @traitContext(Contexts)
   requestHeaders: {
     @traitLocation(TraitLocation.Parameters)
@@ -105,7 +106,7 @@ model RequestHeadersTrait<Headers, Contexts = unknown> {
 @trait
 @added(Azure.Core.Versions.v1_0_Preview_2)
 @Private.ensureAllHeaderParams(Headers)
-model ResponseHeadersTrait<Headers, Contexts = unknown> {
+model ResponseHeadersTrait<Headers extends Model, Contexts = unknown> {
   @traitContext(Contexts)
   responseHeaders: {
     @traitLocation(TraitLocation.Response)
@@ -311,7 +312,7 @@ namespace Azure {
          */
         extern dec ensureTraitsPresent(
           target: Interface | TypeSpec.Reflection.Operation,
-          traitModel: unknown,
+          traitModel: Model,
           expectedTraits: ExpectedTrait[]
         );
 
@@ -322,7 +323,7 @@ namespace Azure {
          * @param target The model type where this check will be established.
          * @param paramModel The actual model type to check for query parameters.
          */
-        extern dec ensureAllQueryParams(target: unknown, paramModel: unknown);
+        extern dec ensureAllQueryParams(target: unknown, paramModel: Model);
 
         /**
          * `@ensureAllHeaderParams` checks the properties of `paramModel` to ensure they all are marked
@@ -331,7 +332,7 @@ namespace Azure {
          * @param target The model type where this check will be established.
          * @param paramModel The actual model type to check for header properties.
          */
-        extern dec ensureAllHeaderParams(target: unknown, paramModel: unknown);
+        extern dec ensureAllHeaderParams(target: unknown, paramModel: Model);
       }
     }
   }

packages/typespec-azure-core/test/operations.test.ts

@@ -2897,4 +2897,23 @@ describe("typespec-azure-core: operation templates", () => {
       ]);
     });
   });
+
+  // Regression test for https://github.com/Azure/typespec-azure/issues/332
+  it("doesn't crash when passing non model to ServiceTraits", async () => {
+    const [_, diagnostics] = await getOperations(`
+      alias Operations = Azure.Core.ResourceOperations<abc>;
+    `);
+    expectDiagnostics(
+      diagnostics.filter((x) => x.severity === "error"),
+      [
+        {
+          code: "unknown-identifier",
+          message: "Unknown identifier abc",
+        },
+        {
+          code: "unassignable",
+        },
+      ]
+    );
+  });
 });

packages/typespec-azure-core/test/traits.test.ts

@@ -264,7 +264,7 @@ describe("typespec-azure-core: service traits", () => {
           { trait: "MissingTrait", diagnostic: "conditional-requests-trait-missing" },
           { trait: "AnotherMissingTrait", diagnostic: "repeatable-requests-trait-missing" }
         ])
-        interface Operations<Traits> {}
+        interface Operations<Traits extends Reflection.Model> {}
 
         interface Usage extends Operations<ContextTrait & NoContextTrait> {}
         `);
@@ -302,6 +302,16 @@ describe("typespec-azure-core: service traits", () => {
         },
       ]);
     });
+
+    it("emits a diagnostic when using non model", async () => {
+      const diagnostics = await runner.diagnose(`
+        alias Test = Azure.Core.Traits.QueryParametersTrait<"abc">;
+      `);
+
+      expectDiagnostics(diagnostics, {
+        code: "unassignable",
+      });
+    });
   });
 
   describe("@ensureAllHeaderParams", () => {
@@ -326,5 +336,14 @@ describe("typespec-azure-core: service traits", () => {
         },
       ]);
     });
+    it("emits a diagnostic when using non model", async () => {
+      const diagnostics = await runner.diagnose(`
+        alias Test = Azure.Core.Traits.RequestHeadersTrait<"abc">;
+      `);
+
+      expectDiagnostics(diagnostics, {
+        code: "unassignable",
+      });
+    });
   });
 });