Fix an expired todo test (#6665)

* Fix a expired todo test

* only check TypeError

* Throw a specific TypeError

* fix async expect

* use return

src/common/get-file-info.js

@@ -19,6 +19,14 @@ const path = require("path");
  * internally by the method wrapper. See withPlugins() in index.js.
  */
 function getFileInfo(filePath, opts) {
+  if (typeof filePath !== "string") {
+    return Promise.reject(
+      new TypeError(
+        `expect \`filePath\` to be a string, got \`${typeof filePath}\``
+      )
+    );
+  }
+
   return createIgnorer(opts.ignorePath, opts.withNodeModules).then(ignorer =>
     _getFileInfo(
       ignorer,
@@ -34,6 +42,12 @@ function getFileInfo(filePath, opts) {
  * @returns {FileInfoResult}
  */
 getFileInfo.sync = function(filePath, opts) {
+  if (typeof filePath !== "string") {
+    throw new TypeError(
+      `expect \`filePath\` to be a string, got \`${typeof filePath}\``
+    );
+  }
+
   const ignorer = createIgnorer.sync(opts.ignorePath, opts.withNodeModules);
   return _getFileInfo(
     ignorer,

tests_integration/__tests__/file-info.js

@@ -106,16 +106,15 @@ describe("extracts file-info with inferredParser=foo when a plugin is hand-picke
 });
 
 test("API getFileInfo with no args", () => {
-  // TODO: change this to `rejects.toThrow()` when we upgrade to Jest >= 22
-  // https://github.com/facebook/jest/issues/3601
-  expect.assertions(1);
-  return prettier.getFileInfo().catch(err => {
-    expect(err).toBeDefined();
-  });
+  return expect(prettier.getFileInfo()).rejects.toThrow(
+    new TypeError("expect `filePath` to be a string, got `undefined`")
+  );
 });
 
 test("API getFileInfo.sync with no args", () => {
-  expect(() => prettier.getFileInfo.sync()).toThrow();
+  expect(() => prettier.getFileInfo.sync()).toThrow(
+    new TypeError("expect `filePath` to be a string, got `undefined`")
+  );
 });
 
 test("API getFileInfo with filepath only", () => {