Add sourceModel and sourceOperation

common/changes/@typespec/compiler/feature-source-model-operation_2023-04-19-20-35.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@typespec/compiler",
+      "comment": "Api: Added `sourceModel` and `sourceOperation` on `Model` and `Operation` respectively.",
+      "type": "none"
+    }
+  ],
+  "packageName": "@typespec/compiler"
+}

common/changes/@typespec/html-program-viewer/feature-source-model-operation_2023-04-19-20-35.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@typespec/html-program-viewer",
+      "comment": "Update to show new `sourceModel` and `sourceOperation`",
+      "type": "none"
+    }
+  ],
+  "packageName": "@typespec/html-program-viewer"
+}

packages/compiler/core/checker.ts

@@ -1602,14 +1602,14 @@ export function createChecker(program: Program): Checker {
     let decorators: DecoratorApplication[] = [];
 
     // Is this a definition or reference?
-    let parameters: Model, returnType: Type;
+    let parameters: Model, returnType: Type, sourceOperation: Operation | undefined;
     if (node.signature.kind === SyntaxKind.OperationSignatureReference) {
       // Attempt to resolve the operation
       const baseOperation = checkOperationIs(node, node.signature.baseOperation, mapper);
       if (!baseOperation) {
         return errorType;
       }
-
+      sourceOperation = baseOperation;
       // Reference the same return type and create the parameters type
       parameters = cloneType(baseOperation.parameters);
       returnType = baseOperation.returnType;
@@ -1629,6 +1629,7 @@ export function createChecker(program: Program): Checker {
       parameters,
       returnType,
       decorators,
+      sourceOperation,
       interface: parentInterface,
     });
 
@@ -2328,6 +2329,7 @@ export function createChecker(program: Program): Checker {
     const isBase = checkModelIs(node, node.is, mapper);
 
     if (isBase) {
+      type.sourceModel = isBase;
       checkDeprecated(isBase, node.is!);
       // copy decorators
       decorators.push(...isBase.decorators);

packages/compiler/core/projector.ts

@@ -278,6 +278,9 @@ export function createProjector(
     if (model.baseModel) {
       projectedModel.baseModel = projectType(model.baseModel) as Model;
     }
+    if (model.sourceModel) {
+      projectedModel.sourceModel = projectType(model.sourceModel) as Model;
+    }
 
     if (model.indexer) {
       projectedModel.indexer = {
@@ -406,6 +409,10 @@ export function createProjector(
       projectedOp.templateArguments = mutate(projectedOp.templateMapper.args);
     }
 
+    if (op.sourceOperation) {
+      projectedOp.sourceOperation = projectType(op.sourceOperation) as Operation;
+    }
+
     if (op.namespace) {
       projectedOp.namespace = projectedNamespaceScope();
     }

packages/compiler/core/types.ts

@@ -226,6 +226,11 @@ export interface Model extends BaseType, DecoratedType, TemplatedTypeBase {
    */
   derivedModels: Model[];
 
+  /**
+   * The model that is referenced via `model is`.
+   */
+  sourceModel?: Model;
+
   /**
    * Late-bound symbol of this model type.
    * @internal
@@ -344,6 +349,11 @@ export interface Operation extends BaseType, DecoratedType, TemplatedTypeBase {
   interface?: Interface;
   parameters: Model;
   returnType: Type;
+
+  /**
+   * The operation that is referenced via `op is`.
+   */
+  sourceOperation?: Operation;
 }
 
 export interface Namespace extends BaseType, DecoratedType {

packages/compiler/test/checker/model.test.ts

@@ -563,6 +563,19 @@ describe("compiler: models", () => {
       });
     });
 
+    it("keeps reference to source model", async () => {
+      testHost.addTypeSpecFile(
+        "main.tsp",
+        `
+        import "./dec.js";
+        @test model A { }
+        @test  model B is A { };
+        `
+      );
+      const { A, B } = (await testHost.compile("main.tsp")) as { A: Model; B: Model };
+      strictEqual(B.sourceModel, A);
+    });
+
     it("copies decorators", async () => {
       testHost.addTypeSpecFile(
         "main.tsp",

packages/compiler/test/checker/operations.test.ts

@@ -22,6 +22,18 @@ describe("compiler: operations", () => {
     strictEqual((foo.returnType as IntrinsicType).name, "void");
   });
 
+  it("keeps reference to source operation", async () => {
+    testHost.addTypeSpecFile(
+      "main.tsp",
+      `
+      @test op a(): void;
+      @test op b is a;
+      `
+    );
+    const { a, b } = (await testHost.compile("main.tsp")) as { a: Operation; b: Operation };
+    strictEqual(b.sourceOperation, a);
+  });
+
   it("can be templated and referenced to define other operations", async () => {
     testHost.addTypeSpecFile(
       "main.tsp",

packages/html-program-viewer/src/ui.tsx

@@ -225,6 +225,7 @@ const OperationUI: FunctionComponent<{ type: Operation }> = ({ type }) => {
         interface: "skip",
         parameters: "nested",
         returnType: "ref",
+        sourceOperation: "ref",
       }}
     />
   );
@@ -247,6 +248,7 @@ const ModelUI: FunctionComponent<{ type: Model }> = ({ type }) => {
         baseModel: "ref",
         derivedModels: "ref",
         properties: "nested",
+        sourceModel: "ref",
       }}
     />
   );