fix: Use .default to access CJS module for dynamic imports (#202)

.github/workflows/ci.yml

@@ -11,6 +11,7 @@ env:
   TEST_ROOT_DATABASE_URL: postgres://postgres:postgres@127.0.0.1:5432/postgres
   TEST_DATABASE_URL: postgres://someone:something@127.0.0.1:5432/graphile_migrate_test
   PGVERSION: 10
+  NODE_OPTIONS: "--experimental-vm-modules"
 
 jobs:
   test:

__tests__/settings.test.ts

@@ -3,7 +3,12 @@ import "./helpers"; // Side effects - must come first
 import mockFs from "mock-fs";
 import * as path from "path";
 
-import { DEFAULT_GMRC_PATH, getSettings } from "../src/commands/_common";
+import {
+  DEFAULT_GMRC_COMMONJS_PATH,
+  DEFAULT_GMRC_PATH,
+  DEFAULT_GMRCJS_PATH,
+  getSettings,
+} from "../src/commands/_common";
 import {
   makeRootDatabaseConnectionString,
   ParsedSettings,
@@ -342,3 +347,48 @@ describe("gmrc path", () => {
     mockFs.restore();
   });
 });
+
+describe("gmrc from JS", () => {
+  const nodeMajor = parseInt(process.versions.node.split(".")[0], 10);
+  // Only test these on Node20+
+  const node20PlusIt = nodeMajor >= 20 ? it : it.skip.bind(it);
+  node20PlusIt("supports .gmrc.js", async () => {
+    mockFs.restore();
+    // The warmups force all the parts of Node import to be exercised before we
+    // try and import something from our mocked filesystem.
+    // @ts-ignore
+    await Promise.all([import("./warmup.js"), import("./warmup.cjs")]);
+
+    mockFs({
+      [DEFAULT_GMRCJS_PATH]: /* JavaScript */ `\
+module.exports = {
+  connectionString: "postgres://appuser:apppassword@host:5432/gmrcjs_test",
+};`,
+    });
+    const settings = await getSettings();
+    expect(settings.connectionString).toEqual(
+      "postgres://appuser:apppassword@host:5432/gmrcjs_test",
+    );
+    mockFs.restore();
+  });
+
+  node20PlusIt("supports .gmrc.cjs", async () => {
+    mockFs.restore();
+    // The warmups force all the parts of Node import to be exercised before we
+    // try and import something from our mocked filesystem.
+    // @ts-ignore
+    await Promise.all([import("./warmup.js"), import("./warmup.cjs")]);
+
+    mockFs({
+      [DEFAULT_GMRC_COMMONJS_PATH]: /* JavaScript */ `\
+module.exports = {
+  connectionString: "postgres://appuser:apppassword@host:5432/gmrc_commonjs_test",
+};`,
+    });
+    const settings = await getSettings();
+    expect(settings.connectionString).toEqual(
+      "postgres://appuser:apppassword@host:5432/gmrc_commonjs_test",
+    );
+    mockFs.restore();
+  });
+});

__tests__/warmup.cjs

@@ -0,0 +1 @@
+module.exports = {};

__tests__/warmup.js

@@ -0,0 +1 @@
+module.exports = {};

package.json

@@ -12,7 +12,7 @@
     "prepack": "npm run tsc && chmod +x dist/cli.js",
     "clean": "rm -Rf dist",
     "test": "yarn lint && yarn run lint:deps && FORCE_COLOR=1 yarn run test:only --ci",
-    "test:only": "jest -i",
+    "test:only": "NODE_OPTIONS=\"--experimental-vm-modules\" jest -i",
     "version": "yarn prepack && ./scripts/update-docs.js && node ./scripts/version.mjs && git add README.md src/version.ts",
     "watch": "mkdir -p dist && touch dist/cli.js && chmod +x dist/cli.js && npm run tsc --watch"
   },

src/commands/_common.ts

@@ -77,7 +77,8 @@ export async function getSettings(options: Options = {}): Promise<Settings> {
     const relativePath = pathToFileURL(resolve(process.cwd(), path)).href;
 
     try {
-      return (await import(relativePath)) as Settings;
+      const module = (await import(relativePath)) as Record<string, unknown>;
+      return (module.default ?? module) as Settings;
     } catch (e) {
       throw new Error(
         `Failed to import '${relativePath}'; error:\n    ${