fix: Fix linting

Use the blueprint to update .eslintignore to exclude the electron project's node_modules and our various built output directories

blueprints/ember-electron/index.js

@@ -1,7 +1,11 @@
 const Blueprint = require('ember-cli/lib/models/blueprint');
 const { api } = require('@electron-forge/core');
 const chalk = require('chalk');
-const { electronProjectPath } = require('../../lib/utils/build-paths');
+const {
+  electronProjectPath,
+  emberBuildDir,
+  emberTestBuildDir
+} = require('../../lib/utils/build-paths');
 const path = require('path');
 const denodeify = require('denodeify');
 const fs = require('fs');
@@ -47,6 +51,7 @@ module.exports = class EmberElectronBlueprint extends Blueprint {
 
   async afterInstall() {
     await this.updateTravisYml();
+    await this.updateEslintIgnore();
     await this.createElectronProject();
   }
 
@@ -102,6 +107,19 @@ module.exports = class EmberElectronBlueprint extends Blueprint {
     }
   }
 
+  async updateEslintIgnore() {
+    const toAppend = [
+      '',
+      '# ember-electron',
+      `/${electronProjectPath}/node_modules/`,
+      `/${electronProjectPath}/out/`,
+      `/${electronProjectPath}/${emberBuildDir}/`,
+      `/${electronProjectPath}/${emberTestBuildDir}/`
+    ].join('\n');
+
+    await this.insertIntoFile('.eslintignore', toAppend);
+  }
+
   async createElectronProject() {
     this.ui.writeLine(chalk.green(`Creating electron-forge project at './${electronProjectPath}'`));
 

node-tests/acceptance/end-to-end-test.js

@@ -148,6 +148,10 @@ describe('end-to-end', function() {
       });
     });
 
+    it('lints', async function() {
+      await expect(run('./node_modules/.bin/eslint', [ '.' ])).to.be.fulfilled;
+    });
+
     it('extra checks pass', () => {
       let fixturePath = path.resolve(__dirname, '..', 'fixtures', 'ember-test');