Handle using properties called $ref (#3922)

common/changes/@autorest/core/fix-using-ref-as-prop_2021-02-23-21-57.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "@autorest/core",
+      "comment": "**Fix** issue when using properties with `$ref` as name where it would try to resolve a reference.",
+      "type": "patch"
+    }
+  ],
+  "packageName": "@autorest/core",
+  "email": "tiguerin@microsoft.com"
+}

packages/extensions/core/src/app.ts

@@ -3,7 +3,7 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 /* eslint-disable no-console */
-
+import "source-map-support/register";
 import { omit } from "lodash";
 
 // https://github.com/uxitten/polyfill/blob/master/string.polyfill.js

packages/extensions/core/src/lib/pipeline/plugins/components-cleaner.ts

@@ -28,7 +28,7 @@ import { PipelinePlugin } from "../common";
  *
  */
 
-type componentType =
+type ComponentType =
   | "schemas"
   | "responses"
   | "parameters"
@@ -165,10 +165,10 @@ export class ComponentsCleaner extends Transformer<any, oai.Model> {
       if (key === "x-ms-examples") {
         continue;
       }
-      if (key === "$ref") {
+      if (key === "$ref" && typeof value === "string") {
         const refParts = value.split("/");
-        const componentUid = refParts.pop();
-        const t: componentType = refParts.pop();
+        const componentUid = refParts.pop() as string;
+        const t: ComponentType = refParts.pop() as ComponentType;
         if (!this.visitedComponents[t].has(componentUid)) {
           this.visitedComponents[t].add(componentUid);
           this.componentsToKeep[t].add(componentUid);

packages/extensions/core/src/lib/pipeline/plugins/merger.ts

@@ -206,7 +206,7 @@ export class MultiAPIMerger extends Transformer<any, oai.Model> {
     for (const { value } of visit(node)) {
       if (value && typeof value === "object") {
         const ref = value.$ref;
-        if (ref && ref.startsWith("#")) {
+        if (ref && typeof ref === "string" && ref.startsWith("#")) {
           const fullRef = `${(<DataHandle>this.currentInput).originalFullPath}${ref}`;
           // change local refs to full ref
           value.$ref = fullRef;
@@ -275,7 +275,7 @@ export class MultiAPIMerger extends Transformer<any, oai.Model> {
       }
       if (value && typeof value === "object") {
         const ref = value.$ref;
-        if (ref) {
+        if (ref && typeof ref === "string") {
           // see if this object has a $ref
           const newRef = this.refs[ref];
           if (newRef) {

packages/extensions/core/src/lib/pipeline/plugins/ref-crawling.ts

@@ -95,6 +95,7 @@ class RefProcessor extends Transformer<any, any> {
 
   constructor(originalFile: DataHandle, private inputScope: DataSource) {
     super(originalFile);
+
     this.originalFileLocation = ResolveUri(originalFile.originalDirectory, originalFile.identity[0]);
   }
 
@@ -129,7 +130,8 @@ class RefProcessor extends Transformer<any, any> {
         this.promises.push(this.processXMSExamples(targetParent, value));
         continue;
       }
-      if (key === "$ref") {
+      // If the key is $ref and the value is a string then it should be a json reference. Otherwise it might be a property called $ref if it is another type.
+      if (key === "$ref" && typeof value === "string") {
         const refFileName = value.indexOf("#") === -1 ? value : value.split("#")[0];
         const refPointer = value.indexOf("#") === -1 ? undefined : value.split("#")[1];
         const newRefFileName = ResolveUri(this.originalFileLocation, refFileName);

packages/extensions/core/test/plugins/components-cleaner/components-cleaner.test.ts

@@ -54,4 +54,9 @@ describe("ComponentCleaner", () => {
   it("secondary-file components not referenced by something in a primary-file.", async () => {
     await expectScenarioToMatchSnapshot("some-unused-secondary-components");
   });
+
+  it("ignores schema properties called $ref", async () => {
+    const { input, output } = await runComponentCleaner("schema-with-$ref-property");
+    expect(output).toEqual(input);
+  });
 });

packages/extensions/core/test/plugins/components-cleaner/inputs/schema-with-$ref-property.json

@@ -0,0 +1,22 @@
+{
+  "openapi": "3.0.0",
+  "info": {
+    "description": "This is a simple openapi spec where a component has a property called $ref. This should be handled gracefully.",
+    "version": "1.0.0",
+    "title": "Swagger Petstore"
+  },
+  "paths": {},
+  "components": {
+    "schemas": {
+      "MyComponent": {
+        "x-ms-metadata": {
+          "apiVersions": ["1.0.0"],
+          "x-ms-secondary-file": false
+        },
+        "properties": {
+          "$ref": { "type": "string" }
+        }
+      }
+    }
+  }
+}