Add moduleType option to override module type on certain files. (#1371)

* Add moduleType option to override module type on certain files.  Also
refactor resolverFunctions into their own file; should break this into
2x PRs later.

* lint fix

* add test

* remove unnecessary exports from ts-internals; mark exports as @internal

* add docs

* strip optionBasePaths from showConfig output

* proper path normalization to support windows

* lint-fix

* use es2015 instead of es2020 in test tsconfig to support ts2.7

* add missing path normalization when calling classifyModule

* 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 c64cf92.

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

This reverts commit 1093df8.

* 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>

* Update tests

* fix

* fix

* fix for TS2.7

* fix

* fix

* reword

* update docs

* address todos

* fix

Co-authored-by: James Addison <jay@jp-hosting.net>

Author: cspotcode

dist-raw/node-cjs-loader-utils.js

@@ -5,17 +5,28 @@
 const path = require('path');
 const packageJsonReader = require('./node-package-json-reader');
 const {JSONParse} = require('./node-primordials');
+const {normalizeSlashes} = require('../dist/util');
 
 module.exports.assertScriptCanLoadAsCJSImpl = assertScriptCanLoadAsCJSImpl;
 
-// copied from Module._extensions['.js']
-// https://github.com/nodejs/node/blob/v15.3.0/lib/internal/modules/cjs/loader.js#L1113-L1120
-function assertScriptCanLoadAsCJSImpl(filename) {
+/**
+ * copied from Module._extensions['.js']
+ * https://github.com/nodejs/node/blob/v15.3.0/lib/internal/modules/cjs/loader.js#L1113-L1120
+ * @param {import('../src/index').Service} service
+ * @param {NodeJS.Module} module
+ * @param {string} filename
+ */
+function assertScriptCanLoadAsCJSImpl(service, module, filename) {
   const pkg = readPackageScope(filename);
+
+  // ts-node modification: allow our configuration to override
+  const tsNodeClassification = service.moduleTypeClassifier.classifyModule(normalizeSlashes(filename));
+  if(tsNodeClassification.moduleType === 'cjs') return;
+
   // Function require shouldn't be used in ES modules.
-  if (pkg && pkg.data && pkg.data.type === 'module') {
+  if (tsNodeClassification.moduleType === 'esm' || (pkg && pkg.data && pkg.data.type === 'module')) {
     const parentPath = module.parent && module.parent.filename;
-    const packageJsonPath = path.resolve(pkg.path, 'package.json');
+    const packageJsonPath = pkg ? path.resolve(pkg.path, 'package.json') : null;
     throw createErrRequireEsm(filename, parentPath, packageJsonPath);
   }
 }

src/bin.ts

@@ -296,6 +296,7 @@ export function main(
     const json = {
       ['ts-node']: {
         ...service.options,
+        optionBasePaths: undefined,
         experimentalEsmLoader: undefined,
         compilerOptions: undefined,
         project: service.configFilePath ?? service.options.project,

src/configuration.ts

@@ -1,6 +1,12 @@
 import { resolve, dirname } from 'path';
 import type * as _ts from 'typescript';
-import { CreateOptions, DEFAULTS, TSCommon, TsConfigOptions } from './index';
+import {
+  CreateOptions,
+  DEFAULTS,
+  OptionBasePaths,
+  TSCommon,
+  TsConfigOptions,
+} from './index';
 import type { TSInternal } from './ts-compiler-types';
 import { createTsInternals } from './ts-internals';
 import { getDefaultTsconfigJsonForNodeVersion } from './tsconfigs';
@@ -70,6 +76,7 @@ export function readConfig(
    * this function.
    */
   tsNodeOptionsFromTsconfig: TsConfigOptions;
+  optionBasePaths: OptionBasePaths;
 } {
   // Ordered [a, b, c] where config a extends b extends c
   const configChain: Array<{
@@ -110,6 +117,7 @@ export function readConfig(
             configFilePath,
             config: { errors: [result.error], fileNames: [], options: {} },
             tsNodeOptionsFromTsconfig: {},
+            optionBasePaths: {},
           };
         }
 
@@ -140,6 +148,7 @@ export function readConfig(
             configFilePath,
             config: { errors, fileNames: [], options: {} },
             tsNodeOptionsFromTsconfig: {},
+            optionBasePaths: {},
           };
         }
         if (resolvedExtendedConfigPath == null) break;
@@ -152,6 +161,7 @@ export function readConfig(
 
   // Merge and fix ts-node options that come from tsconfig.json(s)
   const tsNodeOptionsFromTsconfig: TsConfigOptions = {};
+  const optionBasePaths: OptionBasePaths = {};
   for (let i = configChain.length - 1; i >= 0; i--) {
     const { config, basePath, configPath } = configChain[i];
     const options = filterRecognizedTsConfigTsNodeOptions(config['ts-node'])
@@ -169,6 +179,11 @@ export function readConfig(
       options.scopeDir = resolve(basePath, options.scopeDir!);
     }
 
+    // Downstream code uses the basePath; we do not do that here.
+    if (options.moduleTypes) {
+      optionBasePaths.moduleTypes = basePath;
+    }
+
     assign(tsNodeOptionsFromTsconfig, options);
   }
 
@@ -222,7 +237,12 @@ export function readConfig(
     )
   );
 
-  return { configFilePath, config: fixedConfig, tsNodeOptionsFromTsconfig };
+  return {
+    configFilePath,
+    config: fixedConfig,
+    tsNodeOptionsFromTsconfig,
+    optionBasePaths,
+  };
 }
 
 /**
@@ -251,6 +271,7 @@ function filterRecognizedTsConfigTsNodeOptions(
     transpiler,
     scope,
     scopeDir,
+    moduleTypes,
     ...unrecognized
   } = jsonObject as TsConfigOptions;
   const filteredTsConfigOptions = {
@@ -271,6 +292,7 @@ function filterRecognizedTsConfigTsNodeOptions(
     transpiler,
     scope,
     scopeDir,
+    moduleTypes,
   };
   // Use the typechecker to make sure this implementation has the correct set of properties
   const catchExtraneousProps: keyof TsConfigOptions = (null as any) as keyof typeof filteredTsConfigOptions;

src/esm.ts

@@ -8,6 +8,7 @@ import {
 } from 'url';
 import { extname } from 'path';
 import * as assert from 'assert';
+import { normalizeSlashes } from './util';
 const {
   createResolve,
 } = require('../dist-raw/node-esm-resolve-implementation');
@@ -96,11 +97,27 @@ export function registerAndCreateEsmHooks(opts?: RegisterOptions) {
 
     // If file has .ts, .tsx, or .jsx extension, then ask node how it would treat this file if it were .js
     const ext = extname(nativePath);
+    let nodeSays: { format: Format };
     if (ext !== '.js' && !tsNodeInstance.ignored(nativePath)) {
-      return defer(formatUrl(pathToFileURL(nativePath + '.js')));
+      nodeSays = await defer(formatUrl(pathToFileURL(nativePath + '.js')));
+    } else {
+      nodeSays = await defer();
     }
-
-    return defer();
+    // For files compiled by ts-node that node believes are either CJS or ESM, check if we should override that classification
+    if (
+      !tsNodeInstance.ignored(nativePath) &&
+      (nodeSays.format === 'commonjs' || nodeSays.format === 'module')
+    ) {
+      const { moduleType } = tsNodeInstance.moduleTypeClassifier.classifyModule(
+        normalizeSlashes(nativePath)
+      );
+      if (moduleType === 'cjs') {
+        return { format: 'commonjs' };
+      } else if (moduleType === 'esm') {
+        return { format: 'module' };
+      }
+    }
+    return nodeSays;
   }
 
   async function transformSource(