[.github/shared] Add tests for 100% codecov (Azure#36459)

- Fix swagger.versionKind on windows

Author: mikeharder

.github/shared/src/github.js

@@ -1,3 +1,5 @@
+/* v8 ignore start */
+
 // @ts-check
 
 export const PER_PAGE_MAX = 100;

.github/shared/src/swagger.js

@@ -5,6 +5,7 @@ import { readFile } from "fs/promises";
 import { dirname, relative, resolve } from "path";
 import { mapAsync } from "./array.js";
 import { example } from "./changed-files.js";
+import { includesFolder } from "./path.js";
 import { SpecModelError } from "./spec-model-error.js";
 
 /**
@@ -191,7 +192,7 @@ export class Swagger {
    * @returns {string} version kind (stable or preview)
    */
   get versionKind() {
-    return dirname(this.#path).includes("/preview/")
+    return includesFolder(this.#path, "preview")
       ? API_VERSION_LIFECYCLE_STAGES.PREVIEW
       : API_VERSION_LIFECYCLE_STAGES.STABLE;
   }

.github/shared/test/changed-files.test.js

@@ -41,6 +41,20 @@ describe("changedFiles", () => {
     vi.mocked(simpleGit.simpleGit().diff).mockResolvedValue(files.join("\n"));
 
     await expect(getChangedFiles(options)).resolves.toEqual(files);
+    expect(simpleGit.simpleGit().diff).toHaveBeenCalledWith(["--name-only", "HEAD^", "HEAD"]);
+
+    const specFiles = files.filter((f) => f.startsWith("specification"));
+    vi.mocked(simpleGit.simpleGit().diff).mockResolvedValue(specFiles.join("\n"));
+    await expect(getChangedFiles({ ...options, paths: ["specification"] })).resolves.toEqual(
+      specFiles,
+    );
+    expect(simpleGit.simpleGit().diff).toHaveBeenCalledWith([
+      "--name-only",
+      "HEAD^",
+      "HEAD",
+      "--",
+      "specification",
+    ]);
   });
 
   const files = [
@@ -174,6 +188,7 @@ describe("changedFiles", () => {
       "should categorize files correctly with all types of changes (%o)",
       async (options) => {
         const gitOutput = [
+          "M\t.github/src/changed-files.js",
           "A\tspecification/new-service/readme.md",
           "M\tspecification/existing-service/main.tsp",
           "D\tspecification/old-service/contoso.json",
@@ -183,7 +198,31 @@ describe("changedFiles", () => {
         ].join("\n");
 
         vi.mocked(simpleGit.simpleGit().diff).mockResolvedValue(gitOutput);
-        const result = await getChangedFilesStatuses(options);
+        let result = await getChangedFilesStatuses(options);
+        expect(result).toEqual({
+          additions: ["specification/new-service/readme.md", "specification/service/derived.json"],
+          modifications: [
+            ".github/src/changed-files.js",
+            "specification/existing-service/main.tsp",
+            "specification/service/type-changed.json",
+          ],
+          deletions: ["specification/old-service/contoso.json"],
+          renames: [
+            {
+              from: "specification/service/old-name.json",
+              to: "specification/service/new-name.json",
+            },
+          ],
+          total: 7,
+        });
+        expect(simpleGit.simpleGit().diff).toHaveBeenCalledWith(["--name-status", "HEAD^", "HEAD"]);
+
+        const specGitOutput = gitOutput
+          .split("\n")
+          .filter((f) => f.includes("specification/"))
+          .join("\n");
+        vi.mocked(simpleGit.simpleGit().diff).mockResolvedValue(specGitOutput);
+        result = await getChangedFilesStatuses({ ...options, paths: ["specification"] });
         expect(result).toEqual({
           additions: ["specification/new-service/readme.md", "specification/service/derived.json"],
           modifications: [
@@ -199,6 +238,13 @@ describe("changedFiles", () => {
           ],
           total: 6,
         });
+        expect(simpleGit.simpleGit().diff).toHaveBeenCalledWith([
+          "--name-status",
+          "HEAD^",
+          "HEAD",
+          "--",
+          "specification",
+        ]);
       },
     );
 

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

@@ -2,7 +2,7 @@
 
 import { dirname, join, resolve } from "path";
 import { describe, expect, it } from "vitest";
-import { Swagger } from "../src/swagger.js";
+import { API_VERSION_LIFECYCLE_STAGES, Swagger } from "../src/swagger.js";
 
 import { fileURLToPath } from "url";
 import { ConsoleLogger } from "../src/logger.js";
@@ -71,6 +71,14 @@ describe("Swagger", () => {
     );
   });
 
+  it("computes versionKind from path", () => {
+    let swagger = new Swagger(resolve("foo/preview/2025-01-01-preview/foo.json"));
+    expect(swagger.versionKind).toEqual(API_VERSION_LIFECYCLE_STAGES.PREVIEW);
+
+    swagger = new Swagger(resolve("foo/stable/2025-01-01/foo.json"));
+    expect(swagger.versionKind).toEqual(API_VERSION_LIFECYCLE_STAGES.STABLE);
+  });
+
   describe("getOperations", () => {
     it("should return normal operations", async () => {
       const testFixturePath = join(__dirname, "fixtures", "swagger", "specification");