fix #1662 and add tests

src/configuration.ts

@@ -100,7 +100,10 @@ export function findAndReadConfig(rawOptions: CreateOptions) {
       rawOptions.project,
       cwd
     );
-    ({ compiler } = resolveCompiler(options.compiler, projectLocalResolveDir));
+    ({ compiler } = resolveCompiler(
+      options.compiler,
+      optionBasePaths.compiler ?? projectLocalResolveDir
+    ));
   }
 
   return {
@@ -258,6 +261,9 @@ export function readConfig(
     if (options.compiler != null) {
       optionBasePaths.compiler = basePath;
     }
+    if (options.swc != null) {
+      optionBasePaths.swc = basePath;
+    }
 
     assign(tsNodeOptionsFromTsconfig, options);
   }
@@ -329,19 +335,16 @@ export function resolveAndLoadCompiler(
   name: string | undefined,
   relativeToPath: string
 ) {
-  const { compiler, projectLocalResolveHelper } = resolveCompiler(
-    name,
-    relativeToPath
-  );
+  const { compiler } = resolveCompiler(name, relativeToPath);
   const ts = loadCompiler(compiler);
-  return { compiler, ts, projectLocalResolveHelper };
+  return { compiler, ts };
 }
 
 function resolveCompiler(name: string | undefined, relativeToPath: string) {
   const projectLocalResolveHelper =
     createProjectLocalResolveHelper(relativeToPath);
   const compiler = projectLocalResolveHelper(name || 'typescript', true);
-  return { projectLocalResolveHelper, compiler };
+  return { compiler };
 }
 
 /** @internal */

src/index.ts

@@ -387,6 +387,7 @@ export interface OptionBasePaths {
   moduleTypes?: string;
   transpiler?: string;
   compiler?: string;
+  swc?: string;
 }
 
 /**
@@ -658,11 +659,15 @@ export function createFromPreloadedConfig(
   const transpileOnly =
     (options.transpileOnly === true || options.swc === true) &&
     options.typeCheck !== true;
-  const transpiler = options.transpiler
-    ? options.transpiler
-    : options.swc
-    ? require.resolve('./transpilers/swc.js')
-    : undefined;
+  let transpiler: RegisterOptions['transpiler'] | undefined = undefined;
+  let transpilerBasePath: string | undefined = undefined;
+  if (options.transpiler) {
+    transpiler = options.transpiler;
+    transpilerBasePath = optionBasePaths.transpiler;
+  } else if (options.swc) {
+    transpiler = require.resolve('./transpilers/swc.js');
+    transpilerBasePath = optionBasePaths.swc;
+  }
   const transformers = options.transformers || undefined;
   const diagnosticFilters: Array<DiagnosticFilter> = [
     {
@@ -729,8 +734,8 @@ export function createFromPreloadedConfig(
       typeof transpiler === 'string' ? transpiler : transpiler[0];
     const transpilerOptions =
       typeof transpiler === 'string' ? {} : transpiler[1] ?? {};
-    const transpilerConfigLocalResolveHelper = optionBasePaths.transpiler
-      ? createProjectLocalResolveHelper(optionBasePaths.transpiler!)
+    const transpilerConfigLocalResolveHelper = transpilerBasePath
+      ? createProjectLocalResolveHelper(transpilerBasePath)
       : projectLocalResolveHelper;
     const transpilerPath = transpilerConfigLocalResolveHelper(
       transpilerName,

src/test/pluggable-dep-resolution.spec.ts

@@ -0,0 +1,59 @@
+import { context } from './testlib';
+import { contextTsNodeUnderTest, resetNodeEnvironment } from './helpers';
+import * as expect from 'expect';
+import { resolve } from 'path';
+
+const test = context(contextTsNodeUnderTest);
+
+test.suite(
+  'Pluggable dependency (compiler, transpiler, swc backend) is require()d relative to the tsconfig file that declares it',
+  (test) => {
+    test.runSerially();
+
+    // The use-case we want to support:
+    //
+    // User shares their tsconfig across multiple projects as an npm module named "shared-config", similar to @tsconfig/bases
+    // In their npm module
+    //     They have tsconfig.json with `swc: true` or `compiler: "ts-patch"` or something like that
+    //     The module declares a dependency on a known working version of @swc/core, or ts-patch, or something like that.
+    // They use this reusable config via `npm install shared-config` and `"extends": "shared-config/tsconfig.json"`
+    //
+    // ts-node should resolve ts-patch or @swc/core relative to the extended tsconfig
+    // to ensure we use the known working versions.
+
+    macro('tsconfig-custom-compiler.json', 'root custom compiler');
+    macro('tsconfig-custom-transpiler.json', 'root custom transpiler');
+    macro('tsconfig-swc-custom-backend.json', 'root custom swc backend');
+    macro('tsconfig-swc-core.json', 'root @swc/core');
+    macro('tsconfig-swc-wasm.json', 'root @swc/wasm');
+    macro('tsconfig-swc.json', 'root @swc/core');
+
+    macro('node_modules/shared-config/tsconfig-custom-compiler.json', 'shared-config custom compiler');
+    macro('node_modules/shared-config/tsconfig-custom-transpiler.json', 'shared-config custom transpiler');
+    macro('node_modules/shared-config/tsconfig-swc-custom-backend.json', 'shared-config custom swc backend');
+    macro('node_modules/shared-config/tsconfig-swc-core.json', 'shared-config @swc/core');
+    macro('node_modules/shared-config/tsconfig-swc-wasm.json', 'shared-config @swc/wasm');
+    macro('node_modules/shared-config/tsconfig-swc.json', 'shared-config @swc/core');
+
+    macro('tsconfig-extend-custom-compiler.json', 'shared-config custom compiler');
+    macro('tsconfig-extend-custom-transpiler.json', 'shared-config custom transpiler');
+    macro('tsconfig-extend-swc-custom-backend.json', 'shared-config custom swc backend');
+    macro('tsconfig-extend-swc-core.json', 'shared-config @swc/core');
+    macro('tsconfig-extend-swc-wasm.json', 'shared-config @swc/wasm');
+    macro('tsconfig-extend-swc.json', 'shared-config @swc/core');
+
+    function macro(config: string, expected: string) {
+      test(`${config} uses ${expected}`, async (t) => {
+        t.teardown(resetNodeEnvironment);
+
+        const output = t.context.tsNodeUnderTest
+          .create({
+            project: resolve('tests/pluggable-dep-resolution', config),
+          })
+          .compile('', 'index.ts');
+
+        expect(output).toContain(`emit from ${expected}\n`);
+      });
+    }
+  }
+);

src/transpilers/swc.ts

@@ -29,10 +29,10 @@ export function create(createOptions: SwcTranspilerOptions): Transpiler {
   } else if (swc == null) {
     let swcResolved;
     try {
-      swcResolved = projectLocalResolveHelper('@swc/core', true);
+      swcResolved = transpilerConfigLocalResolveHelper('@swc/core', true);
     } catch (e) {
       try {
-        swcResolved = projectLocalResolveHelper('@swc/wasm', true);
+        swcResolved = transpilerConfigLocalResolveHelper('@swc/wasm', true);
       } catch (e) {
         throw new Error(
           'swc compiler requires either @swc/core or @swc/wasm to be installed as a dependency.  See https://typestrong.org/ts-node/docs/transpilers'

tests/pluggable-dep-resolution/tsconfig-custom-compiler.json

@@ -0,0 +1 @@
+{ "ts-node": { "transpileOnly": true, "compiler": "custom-compiler" } }

tests/pluggable-dep-resolution/tsconfig-custom-transpiler.json

@@ -0,0 +1 @@
+{ "ts-node": { "transpileOnly": true, "transpiler": "custom-transpiler" } }

tests/pluggable-dep-resolution/tsconfig-extend-custom-compiler.json

@@ -0,0 +1 @@
+{ "extends": "shared-config/tsconfig-custom-compiler.json" }

tests/pluggable-dep-resolution/tsconfig-extend-custom-transpiler.json

@@ -0,0 +1 @@
+{ "extends": "shared-config/tsconfig-custom-transpiler.json" }

tests/pluggable-dep-resolution/tsconfig-extend-swc-core.json

@@ -0,0 +1 @@
+{ "extends": "shared-config/tsconfig-swc-core.json" }

tests/pluggable-dep-resolution/tsconfig-extend-swc-custom-backend.json

@@ -0,0 +1 @@
+{ "extends": "shared-config/tsconfig-swc-custom-backend.json" }

tests/pluggable-dep-resolution/tsconfig-extend-swc-wasm.json

@@ -0,0 +1 @@
+{ "extends": "shared-config/tsconfig-swc-wasm.json" }

tests/pluggable-dep-resolution/tsconfig-extend-swc.json

@@ -0,0 +1 @@
+{ "extends": "shared-config/tsconfig-swc.json" }

tests/pluggable-dep-resolution/tsconfig-swc-core.json

@@ -0,0 +1,6 @@
+{
+  "ts-node": {
+    "transpileOnly": true,
+    "transpiler": ["ts-node/transpilers/swc", { "swc": "@swc/core" }]
+  }
+}

tests/pluggable-dep-resolution/tsconfig-swc-custom-backend.json

@@ -0,0 +1,6 @@
+{
+  "ts-node": {
+    "transpileOnly": true,
+    "transpiler": ["ts-node/transpilers/swc", { "swc": "custom-swc" }]
+  }
+}

tests/pluggable-dep-resolution/tsconfig-swc-wasm.json

@@ -0,0 +1,6 @@
+{
+  "ts-node": {
+    "transpileOnly": true,
+    "transpiler": ["ts-node/transpilers/swc", { "swc": "@swc/wasm" }]
+  }
+}

tests/pluggable-dep-resolution/tsconfig-swc.json

@@ -0,0 +1 @@
+{ "ts-node": { "swc": true } }