[@typescript/vfs] Fix the exception when file content is empty.

microsoft · Mar 2, 2024 · 2fa00c5 · 2fa00c5
1 parent 2ca478b
commit 2fa00c5
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Showing 2 changed files with 15 additions and 1 deletion.
diff --git a/packages/typescript-vfs/src/index.ts b/packages/typescript-vfs/src/index.ts
@@ -440,7 +440,7 @@ export function createSystem(files: Map<string, string>): System {
     getDirectories: () => [],
     getExecutingFilePath: () => notImplemented("getExecutingFilePath"),
     readDirectory: audit("readDirectory", directory => (directory === "/" ? Array.from(files.keys()) : [])),
-    readFile: audit("readFile", fileName => files.get(fileName) || files.get(libize(fileName))),
+    readFile: audit("readFile", fileName => files.get(fileName) ?? files.get(libize(fileName))),
     resolvePath: path => path,
     newLine: "\n",
     useCaseSensitiveFileNames: true,

diff --git a/packages/typescript-vfs/test/index.test.ts b/packages/typescript-vfs/test/index.test.ts
@@ -214,3 +214,17 @@ it("grabs lib dts files from node_modules", async () => {
   const fsMap = createDefaultMapFromNodeModules({})
   expect(fsMap.get("/lib.es2015.collection.d.ts")).toBeDefined()
 })
+
+it("empty file content", async () => {
+  const options = { target: ts.ScriptTarget.ES2020 }
+  const fsMap = createDefaultMapFromNodeModules(options, ts)
+  fsMap.set("index.ts", "")
+  const system = createSystem(fsMap)
+  const host = createVirtualCompilerHost(system, options, ts)
+  ts.createProgram({
+    rootNames: ["index.ts"],
+    options,
+    host: host.compilerHost,
+  })
+})
+