fix: respect moduleResolution setting in emitDts (#2845)

see #2837 for more info

---------

Co-authored-by: Mattias Granlund <[email protected]>

Author: dummdidumm

.changeset/witty-kiwis-divide.md

@@ -0,0 +1,5 @@
+---
+'svelte2tsx': patch
+---
+
+fix: respect moduleResolution setting in emitDts

.gitignore

@@ -33,7 +33,7 @@ bower_components
 build/Release
 
 # Dependency directories
-node_modules/
+/node_modules/
 jspm_packages/
 
 # TypeScript v1 declaration files

packages/svelte2tsx/.gitignore

@@ -1,5 +1,6 @@
 .DS_Store
-node_modules
+/node_modules
+/test/emitDts/samples/cross-package-generic-types/node_modules/.svelte2tsx-language-server-files
 /index.js
 /index.js.map
 /index.mjs

packages/svelte2tsx/src/emitDts.ts

@@ -112,8 +112,11 @@ function loadTsconfig(config: EmitDtsConfig, svelteMap: SvelteMap) {
             ...options,
             noEmit: false, // Set to true in case of jsconfig, force false, else nothing is emitted
             moduleResolution:
-                // NodeJS: up to 4.9, Node10: since 5.0
-                (ts.ModuleResolutionKind as any).NodeJs ?? ts.ModuleResolutionKind.Node10, // Classic if not set, which gives wrong results
+                options.moduleResolution &&
+                options.moduleResolution !== ts.ModuleResolutionKind.Classic
+                    ? options.moduleResolution
+                    : // NodeJS: up to 4.9, Node10: since 5.0
+                      ((ts.ModuleResolutionKind as any).NodeJs ?? ts.ModuleResolutionKind.Node10), // Classic if not set, which gives wrong results
             declaration: true, // Needed for d.ts file generation
             emitDeclarationOnly: true, // We only want d.ts file generation
             declarationDir: config.declarationDir, // Where to put the declarations

packages/svelte2tsx/test/emitDts/samples/cross-package-generic-types/expected/consumer.d.ts

@@ -0,0 +1,13 @@
+import { GenericToken } from 'test-package';
+export declare class MyService {
+    private name;
+    constructor(name: string);
+    getName(): string;
+}
+export declare const SERVICE_TOKEN: GenericToken<MyService>;
+export declare const ANNOTATED_TOKEN: GenericToken<MyService>;
+export declare const ASSERTION_TOKEN: GenericToken<MyService>;
+export declare class AnotherService {
+    value: number;
+}
+export declare const ANOTHER_TOKEN: GenericToken<AnotherService>;

packages/svelte2tsx/test/emitDts/samples/cross-package-generic-types/expected/index.d.ts

@@ -0,0 +1 @@
+export * from './consumer.js';

packages/svelte2tsx/test/emitDts/samples/cross-package-generic-types/node_modules/test-package/not-at-root/index.d.ts

@@ -0,0 +1,8 @@
+{
+	"name": "test-cross-package-generics",
+	"version": "0.0.1",
+	"type": "module",
+	"dependencies": {
+		"test-package": "1.0.0"
+	}
+}

packages/svelte2tsx/test/emitDts/samples/cross-package-generic-types/node_modules/test-package/package.json

@@ -0,0 +1,21 @@
+import { GenericToken } from 'test-package';
+
+export class MyService {
+	constructor(private name: string) {}
+	getName() { return this.name; }
+}
+
+// This should preserve the generic type as GenericToken<MyService>
+// Before the fix, this would be compiled as 'any' due to module resolution issues
+export const SERVICE_TOKEN = new GenericToken<MyService>('MyService');
+
+// These explicit annotations should work regardless
+export const ANNOTATED_TOKEN: GenericToken<MyService> = new GenericToken<MyService>('MyService');
+export const ASSERTION_TOKEN = new GenericToken<MyService>('MyService') as GenericToken<MyService>;
+
+// Test with different generic types
+export class AnotherService {
+	value = 42;
+}
+
+export const ANOTHER_TOKEN = new GenericToken<AnotherService>('AnotherService');