fix($formatOnSave): Fix error when no .eslintignore is found

We were not properly handling the case where no `.eslintignore` was found when attempting to
determine whether to run `formatOnSave`. Now, if no `.eslintignore` is found, we short circuit and
assume the file is not ignored.

Fixes #67 (again)

dist/helpers.js

@@ -37,9 +37,13 @@ var getNearestEslintignorePath = function getNearestEslintignorePath(filePath) {
 };
 
 var getFilePathRelativeToEslintignore = function getFilePathRelativeToEslintignore(filePath) {
-  return flow(getNearestEslintignorePath, getDirFromFilePath, function (eslintignoreDir) {
-    return path.relative(eslintignoreDir, filePath);
-  })(filePath);
+  var nearestEslintignorePath = getNearestEslintignorePath(filePath);
+
+  if (!nearestEslintignorePath) return undefined;
+
+  var eslintignoreDir = getDirFromFilePath(nearestEslintignorePath);
+
+  return path.relative(eslintignoreDir, filePath);
 };
 
 var getLinesFromFilePath = function getLinesFromFilePath(filePath) {
@@ -94,7 +98,11 @@ var shouldUseEslint = function shouldUseEslint() {
 };
 
 var isFilePathEslintignored = function isFilePathEslintignored(filePath) {
-  return someGlobsMatchFilePath(getIgnoredGlobsFromNearestEslintIgnore(filePath), getFilePathRelativeToEslintignore(filePath));
+  var filePathRelativeToEslintignore = getFilePathRelativeToEslintignore(filePath);
+
+  if (!filePathRelativeToEslintignore) return false;
+
+  return someGlobsMatchFilePath(getIgnoredGlobsFromNearestEslintIgnore(filePath), filePathRelativeToEslintignore);
 };
 
 var isFormatOnSaveEnabled = function isFormatOnSaveEnabled() {

src/helpers.js

@@ -21,9 +21,15 @@ const getDirFromFilePath = (filePath: FilePath): FilePath => path.parse(filePath
 const getNearestEslintignorePath = (filePath: FilePath): ?FilePath =>
   findCached(getDirFromFilePath(filePath), '.eslintignore');
 
-const getFilePathRelativeToEslintignore = (filePath: FilePath): FilePath =>
-  flow(getNearestEslintignorePath, getDirFromFilePath, eslintignoreDir =>
-    path.relative(eslintignoreDir, filePath))(filePath);
+const getFilePathRelativeToEslintignore = (filePath: FilePath): ?FilePath => {
+  const nearestEslintignorePath = getNearestEslintignorePath(filePath);
+
+  if (!nearestEslintignorePath) return undefined;
+
+  const eslintignoreDir = getDirFromFilePath(nearestEslintignorePath);
+
+  return path.relative(eslintignoreDir, filePath);
+};
 
 const getLinesFromFilePath = (filePath: FilePath) =>
   fs.readFileSync(filePath, 'utf8').split(LINE_SEPERATOR_REGEX);
@@ -58,11 +64,16 @@ const isCurrentScopeEmbeddedScope = (editor: TextEditor) => EMBEDDED_SCOPES.incl
 
 const shouldUseEslint = () => getConfigOption('useEslint');
 
-const isFilePathEslintignored = (filePath: FilePath) =>
-  someGlobsMatchFilePath(
+const isFilePathEslintignored = (filePath: FilePath) => {
+  const filePathRelativeToEslintignore = getFilePathRelativeToEslintignore(filePath);
+
+  if (!filePathRelativeToEslintignore) return false;
+
+  return someGlobsMatchFilePath(
     getIgnoredGlobsFromNearestEslintIgnore(filePath),
-    getFilePathRelativeToEslintignore(filePath),
+    filePathRelativeToEslintignore,
   );
+};
 
 const isFormatOnSaveEnabled = () => getConfigOption('formatOnSaveOptions.enabled');
 

src/helpers.test.js

@@ -1,5 +1,6 @@
 // @flow
 const path = require('path');
+const atomLinter = require('atom-linter');
 
 const textEditor = require('../tests/mocks/textEditor');
 const {
@@ -15,6 +16,8 @@ const {
   getPrettierOptions,
 } = require('./helpers');
 
+jest.mock('atom-linter');
+
 describe('getConfigOption', () => {
   test('retrieves a config option from the prettier-atom config', () => {
     const mockGet = jest.fn(() => 'foo');
@@ -132,21 +135,43 @@ describe('shouldUseEslint', () => {
 });
 
 describe('isFilePathEslintignored', () => {
+  test('is false if no .eslintignore file can be found', () => {
+    atomLinter.findCached.mockImplementation(() => null);
+    const filePath = path.join(__dirname, '..', 'tests', 'fixtures', 'matchesEslintignore.js');
+
+    const actual = isFilePathEslintignored(filePath);
+    const expected = false;
+
+    expect(actual).toBe(expected);
+  });
+
   test('is false if the filePath does not match a glob in the nearest eslintignore', () => {
+    atomLinter.findCached.mockImplementation(() =>
+      path.join(__dirname, '..', 'tests', 'fixtures', '.eslintignore'));
     const filePath = path.join(__dirname, '..', 'tests', 'fixtures', 'doesNotMatchEslintignore.js');
 
     const actual = isFilePathEslintignored(filePath);
     const expected = false;
 
+    expect(atomLinter.findCached).toHaveBeenCalledWith(
+      path.join(__dirname, '..', 'tests', 'fixtures'),
+      '.eslintignore',
+    );
     expect(actual).toBe(expected);
   });
 
   test('is true if the filePath does match a glob in the nearest eslintignore', () => {
+    atomLinter.findCached.mockImplementation(() =>
+      path.join(__dirname, '..', 'tests', 'fixtures', '.eslintignore'));
     const filePath = path.join(__dirname, '..', 'tests', 'fixtures', 'matchesEslintignore.js');
 
     const actual = isFilePathEslintignored(filePath);
     const expected = true;
 
+    expect(atomLinter.findCached).toHaveBeenCalledWith(
+      path.join(__dirname, '..', 'tests', 'fixtures'),
+      '.eslintignore',
+    );
     expect(actual).toBe(expected);
   });
 });