feat(typescript): reuse module resolution cache from host (#294)

Author: serkodev

packages/typescript/lib/node/decorateLanguageServiceHost.ts

@@ -48,14 +48,7 @@ export function decorateLanguageServiceHost(
 			language.plugins,
 			fileName => language.scripts.get(fileName),
 		);
-		const getCanonicalFileName = languageServiceHost.useCaseSensitiveFileNames?.()
-			? (fileName: string) => fileName
-			: (fileName: string) => fileName.toLowerCase();
-		const moduleResolutionCache = ts.createModuleResolutionCache(
-			languageServiceHost.getCurrentDirectory(),
-			getCanonicalFileName,
-			languageServiceHost.getCompilationSettings(),
-		);
+		const moduleResolutionCache = languageServiceHost.getModuleResolutionCache?.();
 
 		if (resolveModuleNameLiterals) {
 			languageServiceHost.resolveModuleNameLiterals = (
@@ -70,7 +63,7 @@ export function decorateLanguageServiceHost(
 					ts,
 					pluginExtensions,
 					containingSourceFile,
-					moduleResolutionCache.getPackageJsonInfoCache(),
+					moduleResolutionCache?.getPackageJsonInfoCache(),
 					languageServiceHost,
 					options,
 				);

packages/typescript/lib/node/utils.ts

@@ -39,7 +39,7 @@ export function fixupImpliedNodeFormatForFile(
 	ts: typeof import('typescript'),
 	pluginExtensions: string[],
 	sourceFile: ts.SourceFile,
-	packageJsonInfoCache: ts.PackageJsonInfoCache,
+	packageJsonInfoCache: ts.PackageJsonInfoCache | undefined,
 	host: ts.ModuleResolutionHost,
 	options: ts.CompilerOptions,
 ) {