Switch to ESM for source and test, use CommonJS for dist (#806)

__tests__/download/download-version.test.ts

@@ -1,9 +1,10 @@
 import { beforeEach, describe, expect, it, jest } from "@jest/globals";
+import * as semver from "semver";
 
 const mockInfo = jest.fn();
 const mockWarning = jest.fn();
 
-jest.mock("@actions/core", () => ({
+jest.unstable_mockModule("@actions/core", () => ({
   debug: jest.fn(),
   info: mockInfo,
   warning: mockWarning,
@@ -18,20 +19,17 @@ const mockExtractZip = jest.fn<any>();
 // biome-ignore lint/suspicious/noExplicitAny: Mock requires flexible typing in tests.
 const mockCacheDir = jest.fn<any>();
 
-jest.mock("@actions/tool-cache", () => {
-  const actual = jest.requireActual("@actions/tool-cache") as Record<
-    string,
-    unknown
-  >;
-
-  return {
-    ...actual,
-    cacheDir: mockCacheDir,
-    downloadTool: mockDownloadTool,
-    extractTar: mockExtractTar,
-    extractZip: mockExtractZip,
-  };
-});
+jest.unstable_mockModule("@actions/tool-cache", () => ({
+  cacheDir: mockCacheDir,
+  downloadTool: mockDownloadTool,
+  evaluateVersions: (versions: string[], range: string) =>
+    semver.maxSatisfying(versions, range) ?? "",
+  extractTar: mockExtractTar,
+  extractZip: mockExtractZip,
+  find: () => "",
+  findAllVersions: () => [],
+  isExplicitVersion: (version: string) => semver.valid(version) !== null,
+}));
 
 // biome-ignore lint/suspicious/noExplicitAny: Mock requires flexible typing in tests.
 const mockGetLatestVersionFromNdjson = jest.fn<any>();
@@ -40,7 +38,7 @@ const mockGetAllVersionsFromNdjson = jest.fn<any>();
 // biome-ignore lint/suspicious/noExplicitAny: Mock requires flexible typing in tests.
 const mockGetArtifactFromNdjson = jest.fn<any>();
 
-jest.mock("../../src/download/versions-client", () => ({
+jest.unstable_mockModule("../../src/download/versions-client", () => ({
   getAllVersions: mockGetAllVersionsFromNdjson,
   getArtifact: mockGetArtifactFromNdjson,
   getLatestVersion: mockGetLatestVersionFromNdjson,
@@ -53,7 +51,7 @@ const mockGetLatestVersionInManifest = jest.fn<any>();
 // biome-ignore lint/suspicious/noExplicitAny: Mock requires flexible typing in tests.
 const mockGetManifestArtifact = jest.fn<any>();
 
-jest.mock("../../src/download/version-manifest", () => ({
+jest.unstable_mockModule("../../src/download/version-manifest", () => ({
   getAllVersions: mockGetAllManifestVersions,
   getLatestKnownVersion: mockGetLatestVersionInManifest,
   getManifestArtifact: mockGetManifestArtifact,
@@ -62,15 +60,15 @@ jest.mock("../../src/download/version-manifest", () => ({
 // biome-ignore lint/suspicious/noExplicitAny: Mock requires flexible typing in tests.
 const mockValidateChecksum = jest.fn<any>();
 
-jest.mock("../../src/download/checksum/checksum", () => ({
+jest.unstable_mockModule("../../src/download/checksum/checksum", () => ({
   validateChecksum: mockValidateChecksum,
 }));
 
-import {
+const {
   downloadVersionFromManifest,
   downloadVersionFromNdjson,
   resolveVersion,
-} from "../../src/download/download-version";
+} = await import("../../src/download/download-version");
 
 describe("download-version", () => {
   beforeEach(() => {

__tests__/download/version-manifest.test.ts

@@ -2,7 +2,7 @@ import { beforeEach, describe, expect, it, jest } from "@jest/globals";
 
 const mockWarning = jest.fn();
 
-jest.mock("@actions/core", () => ({
+jest.unstable_mockModule("@actions/core", () => ({
   debug: jest.fn(),
   info: jest.fn(),
   warning: mockWarning,
@@ -10,16 +10,16 @@ jest.mock("@actions/core", () => ({
 
 // biome-ignore lint/suspicious/noExplicitAny: Mock requires flexible typing in tests.
 const mockFetch = jest.fn<any>();
-jest.mock("../../src/utils/fetch", () => ({
+jest.unstable_mockModule("../../src/utils/fetch", () => ({
   fetch: mockFetch,
 }));
 
-import {
+const {
   clearManifestCache,
   getAllVersions,
   getLatestKnownVersion,
   getManifestArtifact,
-} from "../../src/download/version-manifest";
+} = await import("../../src/download/version-manifest");
 
 const legacyManifestResponse = JSON.stringify([
   {

__tests__/download/versions-client.test.ts

@@ -2,18 +2,19 @@ import { beforeEach, describe, expect, it, jest } from "@jest/globals";
 
 // biome-ignore lint/suspicious/noExplicitAny: Mock requires flexible typing in tests.
 const mockFetch = jest.fn<any>();
-jest.mock("../../src/utils/fetch", () => ({
+
+jest.unstable_mockModule("../../src/utils/fetch", () => ({
   fetch: mockFetch,
 }));
 
-import {
+const {
   clearCache,
   fetchVersionData,
   getAllVersions,
   getArtifact,
   getLatestVersion,
   parseVersionData,
-} from "../../src/download/versions-client";
+} = await import("../../src/download/versions-client");
 
 const sampleNdjsonResponse = `{"version":"0.9.26","artifacts":[{"platform":"aarch64-apple-darwin","variant":"default","url":"https://github.com/astral-sh/uv/releases/download/0.9.26/uv-aarch64-apple-darwin.tar.gz","archive_format":"tar.gz","sha256":"fcf0a9ea6599c6ae28a4c854ac6da76f2c889354d7c36ce136ef071f7ab9721f"},{"platform":"x86_64-pc-windows-msvc","variant":"default","url":"https://github.com/astral-sh/uv/releases/download/0.9.26/uv-x86_64-pc-windows-msvc.zip","archive_format":"zip","sha256":"eb02fd95d8e0eed462b4a67ecdd320d865b38c560bffcda9a0b87ec944bdf036"}]}
 {"version":"0.9.25","artifacts":[{"platform":"aarch64-apple-darwin","variant":"default","url":"https://github.com/astral-sh/uv/releases/download/0.9.25/uv-aarch64-apple-darwin.tar.gz","archive_format":"tar.gz","sha256":"606b3c6949d971709f2526fa0d9f0fd23ccf60e09f117999b406b424af18a6a6"}]}`;