fix: don't try to instantiate ESLint if it doesn't exist (old versions)

Author: savetheclocktower

lib/worker.js

@@ -108,7 +108,6 @@ function buildCommonConstructorOptions (config, cwd) {
 }
 
 function clearESLintCache () {
-  log(`Clearing cache!`);
   for (let key of PATHS_CACHE) {
     PATHS_CACHE.delete(key);
   }
@@ -160,30 +159,33 @@ function getESLint (filePath, config, { legacyPackagePresent, projectPath }) {
   let resolveDir = findCwd(filePath, projectPath);
 
   if (!useCache || !PATHS_CACHE.has(resolveDir)) {
-    PATHS_CACHE.set(resolveDir, resolveESLint(resolveDir));
+    PATHS_CACHE.set(resolveDir, resolveESLint(filePath));
   }
   let eslintPath = PATHS_CACHE.get(resolveDir);
 
   if (!useCache || !ESLINT_CACHE.has(resolveDir)) {
     log(`Creating new ESLint instance with cwd: ${resolveDir}`);
     const eslintRootPath = eslintPath.replace(/eslint([/\\]).*?$/, 'eslint$1');
     const packageMeta = require(Path.join(eslintRootPath, 'package.json'));
-
     const { ESLint } = createRequire(eslintPath)('eslint');
-    let commonOptions = buildCommonConstructorOptions(config, projectPath || resolveDir);
+    let bundle = {
+      cwd: resolveDir,
+      isBuiltIn: eslintPath === resolveBuiltInESLint(),
+      eslintPath: eslintRootPath,
+      eslintVersion: packageMeta.version
+    };
 
-    const eslintLint = new ESLint({ ...commonOptions, fix: false });
-    const eslintFix = new ESLint({ ...commonOptions });
+    // Older versions of ESLint won't have this API.
+    if (ESLint) {
+      let commonOptions = buildCommonConstructorOptions(config, projectPath || resolveDir);
 
-    ESLINT_CACHE.set(resolveDir, {
-      ESLint,
-      eslintLint,
-      eslintFix,
-      eslintPath: eslintRootPath,
-      eslintVersion: packageMeta.version,
-      isBuiltIn: eslintPath === resolveBuiltInESLint(),
-      cwd: resolveDir
-    });
+      const eslintLint = new ESLint({ ...commonOptions, fix: false });
+      const eslintFix = new ESLint({ ...commonOptions });
+
+      Object.assign(bundle, { ESLint, eslintLint, eslintFix });
+    }
+
+    ESLINT_CACHE.set(resolveDir, bundle);
   }
 
   let cached = ESLINT_CACHE.get(resolveDir);
@@ -250,8 +252,8 @@ function formatResults (files, rules, config, { isModified, key, isFixJob, lintM
       }
 
       let idTag = '';
-      if (showRuleIdInMessage && message.ruleId) {
-        idTag = ` (${message.ruleId})`;
+      if (showRuleIdInMessage) {
+        idTag = message.fatal ? ` (Fatal)` : ` (${message.ruleId})`;
       }
 
       let rule = rules[message.ruleId];
@@ -280,7 +282,7 @@ function formatResults (files, rules, config, { isModified, key, isFixJob, lintM
         severity: SEVERITIES[message.severity] || 'error',
         location: {
           file: filePath,
-          position,
+          position
         },
         fix: message.fix,
         excerpt: `${message.message}${idTag}`,