[ARMIncrementalTsp] Reduce checkout time (#32695)

.github/package.json

@@ -5,7 +5,6 @@
     "@types/github-script": "github:actions/github-script",
     "@octokit/webhooks-types": "^7.5.1",
     "@vitest/coverage-v8": "^3.0.5",
-    "memfs": "^4.17.0",
     "prettier": "^3.3.3",
     "vitest": "^3.0.5"
   },

.github/workflows/arm-incremental-typespec-preview.yaml

@@ -24,6 +24,10 @@ jobs:
         with:
           # Required to detect changed files in PR
           fetch-depth: 2
+          # Check only needs to view contents of changed files as a string, so can use
+          # "git show" on specific files instead of cloning whole repo
+          sparse-checkout: |
+            .github
 
       # Output is "true" if PR contains only incremental changes to an existing TypeSpec RP
       - id: incremental-typespec

.github/workflows/src/arm-incremental-typespec-preview.js

@@ -1,7 +1,6 @@
 // @ts-check
 
-import { readFile } from "fs/promises";
-import { dirname, join } from "path";
+import { dirname } from "path";
 import { getChangedResourceManagerSwaggerFiles } from "./changed-files.js";
 import { lsTree, show } from "./git.js";
 
@@ -26,10 +25,7 @@ export default async function incrementalTypeSpec({ github, context, core }) {
 
   // If any changed file is not typespec-generated, return false
   for (const file of changedRmSwaggerFiles) {
-    const swagger = await readFile(
-      join(process.env.GITHUB_WORKSPACE || "", file),
-      { encoding: "utf8" },
-    );
+    const swagger = await show("HEAD", file, core);
 
     const swaggerObj = JSON.parse(swagger);
 

.github/workflows/src/changed-files.js

@@ -15,10 +15,20 @@ export async function getChangedFiles(
   headCommitish = "HEAD",
   diffFilter = "d",
 ) {
-  return await getChangedFilesImpl(
-    `Get-ChangedFiles ${baseCommitish} ${headCommitish} ${diffFilter}"`,
+  const result = await execRoot(
+    `git -c core.quotepath=off diff --name-only --diff-filter=${diffFilter} ${baseCommitish} ${headCommitish}`,
     core,
   );
+
+  const files = result.trim().split("\n");
+
+  core.info("Changed Files:");
+  for (const file of files) {
+    core.info(`  ${file}`);
+  }
+  core.info("");
+
+  return files;
 }
 
 /**
@@ -34,10 +44,9 @@ export async function getChangedSwaggerFiles(
   headCommitish = "HEAD",
   diffFilter = "d",
 ) {
-  return await getChangedFilesImpl(
-    `Get-ChangedSwaggerFiles(Get-ChangedFiles ${baseCommitish} ${headCommitish} ${diffFilter})`,
-    core,
-  );
+  return (
+    await getChangedFiles(core, baseCommitish, headCommitish, diffFilter)
+  ).filter((f) => f.endsWith(".json"));
 }
 
 /**
@@ -55,9 +64,9 @@ export async function getChangedResourceManagerSwaggerFiles(
 ) {
   const changedSwaggerFiles = await getChangedSwaggerFiles(
     core,
-    "HEAD^",
-    "HEAD",
-    "",
+    baseCommitish,
+    headCommitish,
+    diffFilter,
   );
   const changedResourceManagerSwaggerFiles = changedSwaggerFiles.filter(
     (f) => f.includes("/resource-manager/") && !f.includes("/examples/"),
@@ -67,25 +76,3 @@ export async function getChangedResourceManagerSwaggerFiles(
   );
   return changedResourceManagerSwaggerFiles;
 }
-
-/**
- * @param {string} command
- * @param {import('github-script').AsyncFunctionArguments['core']} core
- * @returns {Promise<string[]>}
- */
-async function getChangedFilesImpl(command, core) {
-  const result = await execRoot(
-    `pwsh -command ". ./eng/scripts/ChangedFiles-Functions.ps1; ${command}"`,
-    core,
-  );
-
-  const files = result.trim().split("\n");
-
-  core.info("Changed Files:");
-  for (const file of files) {
-    core.info(`  ${file}`);
-  }
-  core.info("");
-
-  return files;
-}

.github/workflows/test/arm-incremental-typespec-preview.test.js

@@ -1,18 +1,9 @@
-import { vol } from "memfs";
-import { join } from "path";
-import { beforeEach, describe, expect, it, vi } from "vitest";
+import { describe, expect, it, vi } from "vitest";
 import { createMockCore } from "../../test/mocks.js";
 import incrementalTypeSpec from "../src/arm-incremental-typespec-preview.js";
 import * as changedFiles from "../src/changed-files.js";
 import * as git from "../src/git.js";
 
-vi.mock("fs/promises", async () => {
-  const memfs = await import("memfs");
-  return {
-    ...memfs.fs.promises,
-  };
-});
-
 const core = createMockCore();
 
 const swaggerTypeSpecGenerated = JSON.stringify({
@@ -22,11 +13,6 @@ const swaggerTypeSpecGenerated = JSON.stringify({
 });
 
 describe("incrementalTypeSpec", () => {
-  beforeEach(() => {
-    // TODO: Reset other global mocks like "core"
-    vol.reset();
-  });
-
   it("rejects if inputs null", async () => {
     await expect(incrementalTypeSpec({})).rejects.toThrow();
   });
@@ -49,9 +35,7 @@ describe("incrementalTypeSpec", () => {
       "getChangedResourceManagerSwaggerFiles",
     ).mockResolvedValue([swaggerPath]);
 
-    vol.fromJSON({
-      [join(process.env.GITHUB_WORKSPACE || "", swaggerPath)]: '"foo"',
-    });
+    vi.spyOn(git, "show").mockResolvedValue('"foo"');
 
     await expect(incrementalTypeSpec({ core })).resolves.toBe(false);
   });
@@ -65,10 +49,7 @@ describe("incrementalTypeSpec", () => {
       "getChangedResourceManagerSwaggerFiles",
     ).mockResolvedValue([swaggerPath]);
 
-    vol.fromJSON({
-      [join(process.env.GITHUB_WORKSPACE || "", swaggerPath)]:
-        swaggerTypeSpecGenerated,
-    });
+    vi.spyOn(git, "show").mockResolvedValue(swaggerTypeSpecGenerated);
 
     // "git ls-tree" returns "" if the spec folder doesn't exist in the base branch
     vi.spyOn(git, "lsTree").mockResolvedValue("");
@@ -85,10 +66,7 @@ describe("incrementalTypeSpec", () => {
       "getChangedResourceManagerSwaggerFiles",
     ).mockResolvedValue([swaggerPath]);
 
-    vol.fromJSON({
-      [join(process.env.GITHUB_WORKSPACE || "", swaggerPath)]:
-        swaggerTypeSpecGenerated,
-    });
+    vi.spyOn(git, "show").mockResolvedValue(swaggerTypeSpecGenerated);
 
     vi.spyOn(git, "lsTree").mockImplementation(
       async (_treeIsh, _path, _core, options) => {
@@ -98,10 +76,6 @@ describe("incrementalTypeSpec", () => {
       },
     );
 
-    vi.spyOn(git, "show").mockImplementation(async (_treeIsh, _path, _core) => {
-      return swaggerTypeSpecGenerated;
-    });
-
     await expect(incrementalTypeSpec({ core })).resolves.toBe(true);
   });
 });