fix(typescript): avoid resolving definition files with arbitrary extensions

packages/typescript/package.json

@@ -74,7 +74,7 @@
     "@types/resolve": "^1.20.2",
     "buble": "^0.20.0",
     "rollup": "^4.0.0-24",
-    "typescript": "^4.8.3"
+    "typescript": "^5.9.3"
   },
   "types": "./types/index.d.ts"
 }

packages/typescript/src/index.ts

@@ -224,7 +224,6 @@ export default function typescript(options: RollupTypescriptOptions = {}): Plugi
       const mode =
         typeof ts.getImpliedNodeFormatForFile === 'function'
           ? ts.getImpliedNodeFormatForFile(
-              // @ts-expect-error
               containingFile,
               undefined, // eslint-disable-line no-undefined
               { ...ts.sys, ...formatHost },
@@ -236,7 +235,7 @@ export default function typescript(options: RollupTypescriptOptions = {}): Plugi
       const resolved = resolveModule(importee, containingFile, undefined, mode);
 
       if (resolved) {
-        if (/\.d\.[cm]?ts/.test(resolved.extension)) return null;
+        if (isDeclarationOutputFile(resolved.extension)) return null;
         if (!filter(resolved.resolvedFileName)) return null;
         return path.normalize(resolved.resolvedFileName);
       }

packages/typescript/src/options/tsconfig.ts

@@ -122,7 +122,7 @@ function setModuleResolutionKind(parsedConfig: ParsedCommandLine): ParsedCommand
   };
 }
 
-const configCache = new Map() as typescript.ESMap<string, ExtendedConfigCacheEntry>;
+const configCache = new Map() as Map<string, ExtendedConfigCacheEntry>;
 
 /**
  * Parse the Typescript config to use with the plugin.

packages/typescript/src/outputFile.ts

@@ -38,7 +38,7 @@ export function isTypeScriptMapOutputFile(name: string): boolean {
  * Checks if the given OutputFile represents some declaration
  */
 export function isDeclarationOutputFile(name: string): boolean {
-  return /\.d\.[cm]?ts$/.test(name);
+  return /\.d(\..+)?\.[cm]?ts$/.test(name);
 }
 
 /**

packages/typescript/src/watchProgram.ts

@@ -210,12 +210,12 @@ function createWatchHost(
       containingFile,
       _reusedNames,
       redirectedReference,
-      _optionsOnlyWithNewerTsVersions,
+      compilerOptions,
       containingSourceFile
     ) {
       return moduleNames.map((moduleName, i) => {
         const mode = containingSourceFile
-          ? ts.getModeForResolutionAtIndex?.(containingSourceFile, i)
+          ? ts.getModeForResolutionAtIndex?.(containingSourceFile, i, compilerOptions)
           : undefined; // eslint-disable-line no-undefined
 
         return resolveModule(moduleName, containingFile, redirectedReference, mode);

packages/typescript/test/fixtures/arbitrary-dts/main.ts

@@ -0,0 +1,3 @@
+import module from './module.custom';
+
+export default module.x;

packages/typescript/test/fixtures/arbitrary-dts/module.custom

@@ -0,0 +1,3 @@
+export default {
+    x: 5,
+};

packages/typescript/test/fixtures/arbitrary-dts/module.d.custom.ts

@@ -0,0 +1,4 @@
+declare const CustomModule: {
+    x: Number;
+}
+export default CustomModule;

packages/typescript/test/fixtures/arbitrary-dts/tsconfig.json

@@ -0,0 +1,5 @@
+{
+    "compilerOptions": {
+        "allowArbitraryExtensions": true
+    },
+}

packages/typescript/test/test.js

@@ -316,7 +316,7 @@ test.serial('warns for invalid module types', async (t) => {
       code: 'PLUGIN_WARNING',
       plugin: 'typescript',
       pluginCode: 'TS6046',
-      message: `@rollup/plugin-typescript TS6046: Argument for '--module' option must be: 'none', 'commonjs', 'amd', 'system', 'umd', 'es6', 'es2015', 'es2020', 'es2022', 'esnext', 'node16', 'nodenext'.`
+      message: `@rollup/plugin-typescript TS6046: Argument for '--module' option must be: 'none', 'commonjs', 'amd', 'system', 'umd', 'es6', 'es2015', 'es2020', 'es2022', 'esnext', 'node16', 'node18', 'node20', 'nodenext', 'preserve'.`
     }
   ]);
 });
@@ -496,6 +496,18 @@ test.serial('should not resolve .d.ts files', async (t) => {
   t.deepEqual(imports, ['an-import']);
 });
 
+test.serial('should not resolve arbitrary .d.<ext>.ts files', async (t) => {
+  const bundle = await rollup({
+    input: 'fixtures/arbitrary-dts/main.ts',
+    plugins: [typescript({ tsconfig: 'fixtures/arbitrary-dts/tsconfig.json' })],
+    onwarn
+  });
+  const arbitraryDeclarationModules = bundle.cache.modules.filter((module) =>
+    module.id.includes('.d.custom.ts')
+  );
+  t.is(arbitraryDeclarationModules.length, 0);
+});
+
 test.serial('should transpile JSX if enabled', async (t) => {
   process.chdir('fixtures/jsx');
 
@@ -1538,8 +1550,9 @@ test.serial('correctly resolves types with nodenext moduleResolution', async (t)
   const code = await getCode(bundle, outputOptions);
 
   t.true(code.includes('var bar = foo'), code);
-  t.is(warnings.length, 1);
-  t.is(warnings[0].code, 'UNRESOLVED_IMPORT');
+  t.is(warnings.length, 2);
+  t.is(warnings[0].pluginCode, 'TS5110');
+  t.is(warnings[1].code, 'UNRESOLVED_IMPORT');
 });
 
 test.serial('noForceEmit option defers to tsconfig.json for emitDeclarationOnly', async (t) => {