From e0f460e34e1cf4150264b8cafe3310a682c3570b Mon Sep 17 00:00:00 2001
From: James Addison <jay@jp-hosting.net>
Date: Fri, 9 Jul 2021 05:30:37 +0100
Subject: [PATCH] Test coverage: moduleType overrides during ts-node loader
 usage (#1376)

* Test coverage: add test case to confirm that moduleType overrides are applied for ts-node in loader mode

* Ensure that a default export exists for the esm-exception module

* Re-order tsconfig.json glob rules, and use implicit globbing

* lint fixup: apply prettier

* Add 'experimental-specifier-resolution' flag to NPM options in ESM module override test

* Ensure that a default export exists for the cjs-subdir module

* Revert "Ensure that a default export exists for the cjs-subdir module"

This reverts commit c64cf928787b476911dc86657dde7d4289a277a4.

* Revert "Add 'experimental-specifier-resolution' flag to NPM options in ESM module override test"

This reverts commit 1093df80dcf7782910a00c8c292f3bd2a6a8a5a7.

* Specify tsconfig project using TS_NODE_PROJECT environment variable

* Use full file paths in preference to directory-default module imports

This avoids ERR_UNSUPPORTED_DIR_IMPORT, without having to provide the 'experimental-specifier-resolution' flag to ts-node

* Update index.ts

* Update index.ts

* Update tsconfig.json

* Extract execModuleTypeOverride function

* Add expected failure cases for Node 12.15, 14.13

Co-authored-by: Andrew Bradley <cspotcode@gmail.com>
---
 src/test/index.spec.ts                        | 33 +++++++++++++++++++
 .../src/cjs-subdir/esm-exception/index.ts     |  6 ++++
 tests/module-types/src/cjs-subdir/index.ts    |  3 ++
 tests/module-types/test.esm.js                |  7 ++++
 tests/module-types/tsconfig.json              |  3 +-
 5 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 tests/module-types/src/cjs-subdir/esm-exception/index.ts
 create mode 100644 tests/module-types/test.esm.js

diff --git a/src/test/index.spec.ts b/src/test/index.spec.ts
index 5fda4567e..773dc61af 100644
--- a/src/test/index.spec.ts
+++ b/src/test/index.spec.ts
@@ -1888,5 +1888,38 @@ test.suite('ts-node', (test) => {
         expect(stdout).to.contain('CommonJS');
       });
     }
+
+    async function execModuleTypeOverride() {
+      return exec(`${cmd} ./module-types/test.esm.js`, {
+        env: {
+          ...process.env,
+          TS_NODE_PROJECT: './module-types/tsconfig.json',
+        },
+      });
+    }
+
+    // TODO: are 12.15 and 14.13 precisely the version ranges for which overrides cause errors?
+    if (semver.satisfies(process.version, '14.13.0')) {
+      test('[expected failure] moduleTypes can override module type to CJS in an ESM loader project', async () => {
+        const { err, stderr, stdout } = await execModuleTypeOverride();
+        expect(err).to.not.equal(null);
+        expect(stderr).to.contain(
+          'Error: Unexpected export statement in CJS module.'
+        );
+      });
+    } else if (semver.satisfies(process.version, '12.15.0')) {
+      test('[expected failure] moduleTypes can override module type to CJS in an ESM loader project', async () => {
+        const { err, stderr, stdout } = await execModuleTypeOverride();
+        expect(err).to.not.equal(null);
+        expect(stderr).to.contain(
+          'TypeError [ERR_INVALID_RETURN_PROPERTY_VALUE]: Expected string to be returned for the "format" from the "loader resolve" function but got type undefined.'
+        );
+      });
+    } else {
+      test('moduleTypes can override module type to CJS in an ESM loader project', async () => {
+        const { err, stderr, stdout } = await execModuleTypeOverride();
+        expect(err).to.equal(null);
+      });
+    }
   });
 });
diff --git a/tests/module-types/src/cjs-subdir/esm-exception/index.ts b/tests/module-types/src/cjs-subdir/esm-exception/index.ts
new file mode 100644
index 000000000..d90eb38f6
--- /dev/null
+++ b/tests/module-types/src/cjs-subdir/esm-exception/index.ts
@@ -0,0 +1,6 @@
+export const cjs: boolean = true;
+
+declare const require: any;
+const requireType = typeof require;
+
+export default { requireType };
diff --git a/tests/module-types/src/cjs-subdir/index.ts b/tests/module-types/src/cjs-subdir/index.ts
index a9a1650ec..8bb71bcd4 100644
--- a/tests/module-types/src/cjs-subdir/index.ts
+++ b/tests/module-types/src/cjs-subdir/index.ts
@@ -1 +1,4 @@
 export const cjs: boolean = true;
+
+declare const require: any;
+export const requireType = typeof require;
diff --git a/tests/module-types/test.esm.js b/tests/module-types/test.esm.js
new file mode 100644
index 000000000..df09a1f96
--- /dev/null
+++ b/tests/module-types/test.esm.js
@@ -0,0 +1,7 @@
+import assert from 'assert';
+
+import cjsSubdirCJS from './src/cjs-subdir/index.ts';
+import cjsSubdirESM from './src/cjs-subdir/esm-exception/index.ts';
+
+assert(cjsSubdirCJS.requireType === 'function');
+assert(cjsSubdirESM.requireType === 'undefined');
diff --git a/tests/module-types/tsconfig.json b/tests/module-types/tsconfig.json
index e71261266..9655d689a 100644
--- a/tests/module-types/tsconfig.json
+++ b/tests/module-types/tsconfig.json
@@ -5,7 +5,8 @@
       "webpack.config.ts": "cjs",
       // Test that subsequent patterns override earlier ones
       "src/cjs-subdir/**/*": "esm",
-      "src/cjs-subdir": "cjs"
+      "src/cjs-subdir": "cjs",
+      "src/cjs-subdir/esm-exception": "esm"
     }
   },
   "compilerOptions": {