fix: rewrite type imports. also preserve comments

stainless-em · stainless-em · commit d316d1ae3fe8 · 2025-12-05T16:08:09.000-05:00
diff --git a/integration/__file_snapshots__/project-references/multiple-targets/main/dist/index.mjs b/integration/__file_snapshots__/project-references/multiple-targets/main/dist/index.mjs
@@ -1,3 +1,4 @@
+// eslint-disable-next-line node/no-missing-import
 import print from "../../print/dist/index.mjs";
 print("TypeScript");
 //# sourceMappingURL=index.mjs.map
diff --git a/integration/__file_snapshots__/project-references/multiple-targets/main/dist/index.mjs.map b/integration/__file_snapshots__/project-references/multiple-targets/main/dist/index.mjs.map
diff --git a/integration/__file_snapshots__/project-references/only-esnext/main/dist/index.js b/integration/__file_snapshots__/project-references/only-esnext/main/dist/index.js
diff --git a/integration/__file_snapshots__/project-references/only-esnext/main/dist/index.js.map b/integration/__file_snapshots__/project-references/only-esnext/main/dist/index.js.map
diff --git a/integration/__file_snapshots__/single-project/multiple-targets/dist/index.mjs.map b/integration/__file_snapshots__/single-project/multiple-targets/dist/index.mjs.map
diff --git a/integration/__file_snapshots__/single-project/only-esnext/dist/index.js.map b/integration/__file_snapshots__/single-project/only-esnext/dist/index.js.map
diff --git a/integration/__file_snapshots__/type-import/.files b/integration/__file_snapshots__/type-import/.files
@@ -0,0 +1,8 @@
+dist/index.cjs
+dist/index.d.cts
+dist/index.d.mts
+dist/index.mjs
+dist/print.cjs
+dist/print.d.cts
+dist/print.d.mts
+dist/print.mjs
diff --git a/integration/__file_snapshots__/type-import/dist/index.cjs b/integration/__file_snapshots__/type-import/dist/index.cjs
@@ -0,0 +1,7 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.inferred = exports.x = void 0;
+const print_1 = require("./print.cjs");
+exports.x = "Type";
+exports.inferred = (0, print_1.print)(exports.x);
+// const inferred: import("./print").PrintResult;
diff --git a/integration/__file_snapshots__/type-import/dist/index.d.cts b/integration/__file_snapshots__/type-import/dist/index.d.cts
@@ -0,0 +1,2 @@
+export declare const x: import("./print.cjs").Printable;
+export declare const inferred: import("./print.cjs").PrintResult;
diff --git a/integration/__file_snapshots__/type-import/dist/index.d.mts b/integration/__file_snapshots__/type-import/dist/index.d.mts
@@ -0,0 +1,2 @@
+export declare const x: import("./print.mjs").Printable;
+export declare const inferred: import("./print.mjs").PrintResult;
diff --git a/integration/__file_snapshots__/type-import/dist/index.mjs b/integration/__file_snapshots__/type-import/dist/index.mjs
@@ -0,0 +1,4 @@
+import { print } from "./print.mjs";
+export const x = "Type";
+export const inferred = print(x);
+// const inferred: import("./print").PrintResult;
diff --git a/integration/__file_snapshots__/type-import/dist/print.cjs b/integration/__file_snapshots__/type-import/dist/print.cjs
@@ -0,0 +1,9 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.print = print;
+function print(name) {
+    console.log(`Hello ${name}`);
+    return {
+        uwu: 1,
+    };
+}
diff --git a/integration/__file_snapshots__/type-import/dist/print.d.cts b/integration/__file_snapshots__/type-import/dist/print.d.cts
@@ -0,0 +1,5 @@
+export type Printable = string;
+export interface PrintResult {
+    uwu: 1;
+}
+export declare function print(name: Printable): PrintResult;
diff --git a/integration/__file_snapshots__/type-import/dist/print.d.mts b/integration/__file_snapshots__/type-import/dist/print.d.mts
@@ -0,0 +1,5 @@
+export type Printable = string;
+export interface PrintResult {
+    uwu: 1;
+}
+export declare function print(name: Printable): PrintResult;
diff --git a/integration/__file_snapshots__/type-import/dist/print.mjs b/integration/__file_snapshots__/type-import/dist/print.mjs
@@ -0,0 +1,6 @@
+export function print(name) {
+    console.log(`Hello ${name}`);
+    return {
+        uwu: 1,
+    };
+}
diff --git a/integration/__fixtures__/type-import/src/index.ts b/integration/__fixtures__/type-import/src/index.ts
@@ -0,0 +1,5 @@
+import { print } from "./print";
+
+export const x: import("./print").Printable = "Type";
+export const inferred = print(x);
+// const inferred: import("./print").PrintResult;
diff --git a/integration/__fixtures__/type-import/src/print.ts b/integration/__fixtures__/type-import/src/print.ts
@@ -0,0 +1,10 @@
+export type Printable = string;
+export interface PrintResult {
+  uwu: 1;
+}
+export function print(name: Printable): PrintResult {
+  console.log(`Hello ${name}`);
+  return {
+    uwu: 1,
+  };
+}
diff --git a/integration/__fixtures__/type-import/tsconfig.json b/integration/__fixtures__/type-import/tsconfig.json
@@ -0,0 +1,9 @@
+{
+  "extends": "@tsconfig/node10/tsconfig.json",
+  "compilerOptions": {
+    "outDir": "dist",
+    "moduleResolution": "node",
+    "importHelpers": true,
+    "declaration": true
+  }
+}
diff --git a/integration/build.test.ts b/integration/build.test.ts
@@ -822,6 +822,34 @@ describe("dynamic import", () => {
   });
 });
 
+describe("type import", () => {
+  beforeEach(async () => {
+    await copyInputFixture("type-import");
+  });
+
+  test("success", async () => {
+    await writeConfig({
+      targets: [
+        { extname: ".cjs", module: "commonjs" },
+        { extname: ".mjs", module: "esnext" },
+      ],
+    });
+
+    const { exitCode } = await runCLI();
+    expect(exitCode).toEqual(0);
+
+    await matchOutputFiles("type-import");
+
+    // Check if the output files are executable
+    const cjsResult = await runCJSModule("dist/index.cjs");
+    expect(cjsResult.stdout).toEqual("Hello Type");
+
+    const esmResult = await runCJSModule("dist/index.mjs");
+    // eslint-disable-next-line jest/no-conditional-expect
+    expect(esmResult.stdout).toEqual("Hello Type");
+  });
+});
+
 describe("transpile only", () => {
   beforeEach(async () => {
     await copyInputFixture("transpile-only");
diff --git a/package.json b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "tsc-multi",
-  "version": "1.1.9",
+  "version": "1.1.10",
   "description": "Compile multiple TypeScript projects into multiple targets.",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
@@ -13,7 +13,7 @@
     "lint": "eslint . --ext .js,.ts,.jsx,.tsx",
     "clean": "rm -rf dist",
     "test": "npm-run-all test:*",
-    "test:integration": "jest --runInBand --config integration/jest.config.js"
+    "test:integration": "jest --config integration/jest.config.js"
   },
   "repository": {
     "type": "git",
diff --git a/src/transformer.ts b/src/transformer.ts
@@ -47,6 +47,8 @@ export function createTransformer<T extends ts.SourceFile | ts.Bundle>(
     isExportDeclaration,
     isVariableStatement,
     isSourceFile,
+    isImportTypeNode,
+    isLiteralTypeNode,
   } = options.ts;
 
   function isDirectory(sourceFile: ts.SourceFile, path: string): boolean {
@@ -63,11 +65,11 @@ export function createTransformer<T extends ts.SourceFile | ts.Bundle>(
     return sys.fileExists(fullPath);
   }
 
-  function updateModuleSpecifier(
+  function updateModuleSpecifier<T extends ts.Node>(
     ctx: ts.TransformationContext,
     sourceFile: ts.SourceFile,
-    node: ts.Expression
-  ): ts.Expression {
+    node: T
+  ): ts.LiteralExpression | T {
     if (!isStringLiteral(node) || !isRelativePath(node.text)) return node;
 
     const ext = extname(node.text);
@@ -160,9 +162,11 @@ export function createTransformer<T extends ts.SourceFile | ts.Bundle>(
           }
         }
       }
+
       // ESM import
       if (isImportDeclaration(node)) {
-        return factory.createImportDeclaration(
+        return factory.updateImportDeclaration(
+          node,
           node.modifiers,
           node.importClause,
           updateModuleSpecifier(ctx, sourceFile, node.moduleSpecifier),
@@ -174,7 +178,8 @@ export function createTransformer<T extends ts.SourceFile | ts.Bundle>(
       if (isExportDeclaration(node)) {
         if (!node.moduleSpecifier) return node;
 
-        return factory.createExportDeclaration(
+        return factory.updateExportDeclaration(
+          node,
           node.modifiers,
           node.isTypeOnly,
           node.exportClause,
@@ -191,7 +196,8 @@ export function createTransformer<T extends ts.SourceFile | ts.Bundle>(
         const [firstArg, ...restArg] = node.arguments;
         if (!firstArg) return node;
 
-        return factory.createCallExpression(
+        return factory.updateCallExpression(
+          node,
           node.expression,
           node.typeArguments,
           [updateModuleSpecifier(ctx, sourceFile, firstArg), ...restArg]
@@ -207,7 +213,8 @@ export function createTransformer<T extends ts.SourceFile | ts.Bundle>(
         const [firstArg, ...restArgs] = node.arguments;
         if (!firstArg) return node;
 
-        return factory.createCallExpression(
+        return factory.updateCallExpression(
+          node,
           node.expression,
           node.typeArguments,
           [
@@ -221,6 +228,19 @@ export function createTransformer<T extends ts.SourceFile | ts.Bundle>(
         );
       }
 
+      if (isImportTypeNode(node) && isLiteralTypeNode(node.argument)) {
+        return factory.updateImportTypeNode(
+          node,
+          factory.createLiteralTypeNode(
+            updateModuleSpecifier(ctx, sourceFile, node.argument.literal)
+          ),
+          node.attributes,
+          node.qualifier,
+          node.typeArguments,
+          node.isTypeOf
+        );
+      }
+
       return visitEachChild(node, visitor, ctx);
     };
 

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+export declare const x: import("./print.cjs").Printable;`
	`2`	`+export declare const inferred: import("./print.cjs").PrintResult;`