fix: migrate to esm module

In order to use dependencies that are esm modules (which `@actions/*`
just did), we have to be an esm module ourselves.

Note that this doesn't work yet; esm modules break jest's mocking.
This'll be addressed in future commits.

Author: pbrisbin

jest.config.js

@@ -0,0 +1,23 @@
+import { createDefaultPreset } from "ts-jest";
+
+const presetConfig = createDefaultPreset();
+
+const jestConfig = {
+  ...presetConfig,
+  resetMocks: true,
+  testEnvironment: "node",
+  extensionsToTreatAsEsm: [".ts"],
+  moduleNameMapper: {
+    "^(\\.{1,2}/.*)\\.js$": "$1",
+  },
+  transform: {
+    "^.+\\.ts$": [
+      "ts-jest",
+      {
+        useESM: true,
+      },
+    ],
+  },
+};
+
+export default jestConfig;

jest.config.ts

@@ -1,13 +1,14 @@
 {
   "name": "stack-action",
   "version": "0.0.0",
+  "type": "module",
   "description": "Build and test stack-based Haskell projects",
   "main": "lib/main.js",
   "scripts": {
     "build": "tsc && ncc build lib/main.js && sed -i 's/\\x0D$//' ./dist/index.js",
     "format": "prettier --write \"**/*.ts\"",
     "format-check": "prettier --check \"**/*.ts\"",
-    "test": "jest",
+    "test": "NODE_OPTIONS='--experimental-vm-modules' jest",
     "readme": "npx action-docs -u && prettier --write README.md"
   },
   "repository": {

package.json

@@ -1,4 +1,6 @@
-import { parseGitStatus, isInterestingFile } from "./dirty-files";
+import { jest } from "@jest/globals";
+
+import { parseGitStatus, isInterestingFile } from "./dirty-files.js";
 
 describe("parseGitStatus", () => {
   test("parse file name, and filters untracked", () => {

src/dirty-files.test.ts

@@ -1,4 +1,6 @@
-import { envsubst } from "./envsubst";
+import { jest } from "@jest/globals";
+
+import { envsubst } from "./envsubst.js";
 
 const HOME = process.env.HOME;
 

src/envsubst.test.ts

@@ -1,4 +1,6 @@
-import { getCacheKeys } from "./get-cache-keys";
+import { jest } from "@jest/globals";
+
+import { getCacheKeys } from "./get-cache-keys.js";
 
 test("getCacheKeys", () => {
   const keys = getCacheKeys(["prefix-os-compiler", "package", "source"]);

src/get-cache-keys.test.ts

@@ -1,7 +1,7 @@
 import * as fs from "fs";
 import * as core from "@actions/core";
 
-import { StackCLI } from "./stack-cli";
+import { StackCLI } from "./stack-cli.js"
 
 export const HIE_YAML: string = "hie.yaml";
 

src/hie.ts

@@ -1,7 +1,7 @@
 import * as core from "@actions/core";
 import * as Shellwords from "shellwords-ts";
-import { envsubst } from "./envsubst";
-import { type OnDirtyFiles, parseOnDirtyFiles } from "./dirty-files";
+import { envsubst } from "./envsubst.js"
+import { type OnDirtyFiles, parseOnDirtyFiles } from "./dirty-files.js"
 
 export type Inputs = {
   workingDirectory: string | null;

src/inputs.ts

@@ -1,13 +1,13 @@
 import * as core from "@actions/core";
 
-import { checkDirtyFiles } from "./dirty-files";
-import { StackCLI } from "./stack-cli";
-import { getCacheKeys } from "./get-cache-keys";
-import { hashProject } from "./hash-project";
-import { getInputs } from "./inputs";
-import { readStackYamlSync, getStackDirectories } from "./stack-yaml";
-import { DEFAULT_CACHE_OPTIONS, withCache } from "./with-cache";
-import { GenHIE } from "./hie";
+import { checkDirtyFiles } from "./dirty-files.js"
+import { StackCLI } from "./stack-cli.js"
+import { getCacheKeys } from "./get-cache-keys.js"
+import { hashProject } from "./hash-project.js"
+import { getInputs } from "./inputs.js"
+import { readStackYamlSync, getStackDirectories } from "./stack-yaml.js"
+import { DEFAULT_CACHE_OPTIONS, withCache } from "./with-cache.js"
+import { GenHIE } from "./hie.js"
 
 async function run() {
   try {

src/main.ts

@@ -1,4 +1,6 @@
-import { parseStackPath } from "./parse-stack-path";
+import { jest } from "@jest/globals";
+
+import { parseStackPath } from "./parse-stack-path.js";
 
 const EXAMPLE = [
   "snapshot-doc-root: /home/patrick/.stack/snapshots/x86_64-linux-tinfo6/0dd02c1d8a380045321779c4567c2aa8873910743eac342f72d56f3d26881028/9.2.7/doc",