[FIX] Linting empty files should not cause errors

Author: matz3

packages/ui5-linter/src/detectors/typeChecker/host.ts

@@ -66,10 +66,11 @@ export async function createVirtualCompilerHost(
 		}
 	}
 
-	function getFile(fileName: string) {
-		const vFile = files.get(fileName);
-		if (vFile) {
-			return vFile;
+	function getFile(fileName: string) : string | undefined {
+		// NOTE: This function should be kept in sync with "fileExists"
+
+		if (files.has(fileName)) {
+			return files.get(fileName);
 		}
 		if (fileName.startsWith("/types/")) {
 			const fsPath = mapToTypePath(fileName);
@@ -106,8 +107,18 @@ export async function createVirtualCompilerHost(
 			return false;
 		},
 		fileExists: (fileName) => {
-			// console.log(`${fileName}: ${files.has(fileName)}`);
-			return !!getFile(fileName);
+			// NOTE: This function should be kept in sync with "getFile"
+
+			if (files.has(fileName)) {
+				return true;
+			}
+			if (fileName.startsWith("/types/")) {
+				const fsPath = mapToTypePath(fileName);
+				if (fsPath) {
+					return ts.sys.fileExists(fsPath);
+				}
+			}
+			return false;
 		},
 		getCurrentDirectory: () => options.rootDir || "/",
 		// eslint-disable-next-line @typescript-eslint/no-unused-vars
@@ -138,7 +149,7 @@ export async function createVirtualCompilerHost(
 				return sourceFileCache.get(fileName);
 			}
 			const sourceText = getFile(fileName);
-			if (!sourceText) {
+			if (sourceText === undefined) {
 				throw new Error(`File not found: ${fileName}`);
 			}
 

packages/ui5-linter/test/fixtures/linter/projects/com.ui5.troublesome.app/webapp/emptyFile.js

@@ -334,6 +334,14 @@ Generated by [AVA](https://avajs.dev).
         messages: [],
         warningCount: 0,
       },
+      {
+        coverageInfo: [],
+        errorCount: 0,
+        fatalErrorCount: 0,
+        filePath: 'webapp/emptyFile.js',
+        messages: [],
+        warningCount: 0,
+      },
       {
         coverageInfo: [],
         errorCount: 0,