perf: split engine

Author: ricardogobbosouza

src/getCLIEngine.js

@@ -0,0 +1,30 @@
+export default function getCLIEngine(options, startCli = true) {
+  let { eslintPath, CLIEngine, cli } = options;
+
+  if (!eslintPath) {
+    eslintPath = 'eslint';
+
+    // eslint-disable-next-line no-param-reassign
+    options.eslintPath = eslintPath;
+  }
+
+  if (!CLIEngine) {
+    ({ CLIEngine } = require(eslintPath));
+
+    // eslint-disable-next-line no-param-reassign
+    options.CLIEngine = CLIEngine;
+  }
+
+  if (!cli && startCli) {
+    cli = new CLIEngine(options);
+
+    // eslint-disable-next-line no-param-reassign
+    options.cli = cli;
+  }
+
+  return {
+    eslintPath,
+    CLIEngine,
+    cli,
+  };
+}

src/getOptions.js

@@ -1,10 +1,10 @@
 import validateOptions from 'schema-utils';
 
 import schema from './options.json';
+import getCLIEngine from './getCLIEngine';
 
 export default function getOptions(pluginOptions) {
   const options = {
-    eslintPath: 'eslint',
     files: '.',
     ...pluginOptions,
   };
@@ -14,7 +14,7 @@ export default function getOptions(pluginOptions) {
     baseDataPath: 'options',
   });
 
-  const { CLIEngine } = require(options.eslintPath);
+  const { CLIEngine } = getCLIEngine(options, false);
 
   options.formatter = getFormatter(CLIEngine, options.formatter);
 

src/linter.js

@@ -3,11 +3,11 @@ import { isAbsolute, join } from 'path';
 import { writeFileSync, ensureFileSync } from 'fs-extra';
 
 import ESLintError from './ESLintError';
+import getCLIEngine from './getCLIEngine';
 
 export default function linter(options, compiler, callback) {
   try {
-    const { CLIEngine } = require(options.eslintPath);
-    const cli = new CLIEngine(options);
+    const { CLIEngine, cli } = getCLIEngine(options);
     const report = cli.executeOnFiles(options.files);
 
     // filter ignored files