[spec-model] Add cache in ctor, to re-use objects for the same path

.github/shared/src/spec-model.js

@@ -1,3 +1,3 @@
 // @ts-check
 
 import { readdir } from "fs/promises";
@@ -5,6 +5,9 @@
 import { flatMapAsync, mapAsync } from "./array.js";
 import { Readme } from "./readme.js";
 
+/** @type {Map<string, SpecModel>} */
+const specModelCache = new Map();
+
 /**
  * @typedef {Object} ToJSONOptions
  * @prop {boolean} [includeRefs]
@@ -16,6 +19,7 @@
 
 export class SpecModel {
   /** @type {string} absolute path */
+  // @ts-ignore Ignore error that value may not be set in ctor (since we may returned cached value)
   #folder;
 
   /** @type {import('./logger.js').ILogger | undefined} */
@@ -30,8 +34,17 @@
    * @param {import('./logger.js').ILogger} [options.logger]
    */
   constructor(folder, options) {
-    this.#folder = resolve(folder);
+    const resolvedFolder = resolve(folder);
+
+    const cachedSpecModel = specModelCache.get(resolvedFolder);
+    if (cachedSpecModel !== undefined) {
+      return cachedSpecModel;
+    }
+
+    this.#folder = resolvedFolder;
     this.#logger = options?.logger;
+
+    specModelCache.set(resolvedFolder, this);
   }
 
   /**

.github/shared/test/spec-model.test.js

@@ -1,5 +1,6 @@
 // @ts-check
 
+import { randomUUID } from "crypto";
 import { readdir } from "fs/promises";
 import { dirname, isAbsolute, join, resolve } from "path";
 import { describe, expect, it } from "vitest";
@@ -18,6 +19,15 @@
     await expect(specModel.getReadmes()).rejects.toThrowError(/no such file or directory/i);
   });
 
+  it("returns cached spec model", async () => {
+    const path = randomUUID();
+
+    const specModel1 = new SpecModel(path);
+    const specModel2 = new SpecModel(path);
+
+    expect(specModel1).toBe(specModel2);
+  });
+
   it("returns spec model", async () => {
     const folder = resolve(
       __dirname,

.github/shared/test/swagger.test.js

@@ -1,14 +1,14 @@
 // @ts-check
 
-import { dirname, resolve, join } from "path";
+import { dirname, join, resolve } from "path";
 import { describe, expect, it } from "vitest";
 import { Swagger } from "../src/swagger.js";
 
 import { fileURLToPath } from "url";
+import { ConsoleLogger } from "../src/logger.js";
 import { Readme } from "../src/readme.js";
-import { Tag } from "../src/tag.js";
 import { SpecModel } from "../src/spec-model.js";
-import { ConsoleLogger } from "../src/logger.js";
+import { Tag } from "../src/tag.js";
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
 
@@ -51,6 +51,26 @@
     );
   });
 
+  it("returns examples", async () => {
+    const swagger = new Swagger(resolve(__dirname, "fixtures/swagger/ignoreExamples/swagger.json"));
+    const examples = await swagger.getExamples();
+
+    const expectedExamplePath = resolve(
+      __dirname,
+      "fixtures/swagger/ignoreExamples/examples/example.json",
+    );
+    expect(examples).toMatchObject(
+      new Map([
+        [
+          expectedExamplePath,
+          expect.objectContaining({
+            path: expect.stringContaining(expectedExamplePath),
+          }),
+        ],
+      ]),
+    );
+  });
+
   describe("getOperations", () => {
     it("should return normal operations", async () => {
       const testFixturePath = join(__dirname, "fixtures", "swagger", "specification");