[new][dev] - Create script to easily scaffold new rules.

Author: Ethan Cohen

package.json

@@ -23,7 +23,8 @@
     "lint": "eslint  --config .eslintrc src tests",
     "lint:fix": "npm run lint -- --fix",
     "pretest": "npm run lint:fix",
-    "test": "jest --coverage"
+    "test": "jest --coverage",
+    "create": "node ./scripts/create-rule"
   },
   "devDependencies": {
     "babel-cli": "^6.14.0",
@@ -37,6 +38,7 @@
     "eslint-config-airbnb-base": "^11.0.0",
     "eslint-plugin-import": "^2.2.0",
     "jest": "^18.1.0",
+    "minimist": "^1.2.0",
     "rimraf": "^2.5.2",
     "to-ast": "^1.0.0"
   },

scripts/boilerplate/doc.js

@@ -0,0 +1,23 @@
+const docBoilerplateGenerator = name => `# ${name}
+
+Write a useful explanation here!
+
+#### References
+1.
+
+## Rule details
+
+This rule takes no arguments.
+
+### Succeed
+\`\`\`jsx
+<div />
+\`\`\`
+
+### Fail
+\`\`\`jsx
+
+\`\`\`
+`;
+
+module.exports = docBoilerplateGenerator;

scripts/boilerplate/rule.js

@@ -0,0 +1,33 @@
+const ruleBoilerplate = (author, description) => `/**
+ * @fileoverview ${description}
+ * @author ${author}
+ */
+
+// ----------------------------------------------------------------------------
+// Rule Definition
+// ----------------------------------------------------------------------------
+
+import { generateObjSchema } from '../util/schemas';
+
+const errorMessage = '';
+
+const schema = generateObjSchema();
+
+module.exports = {
+  meta: {
+    docs: {},
+    schema: [schema],
+  },
+
+  create: context => ({
+    JSXOpeningElement: (node) => {
+      context.report({
+        node,
+        message: errorMessage,
+      });
+    },
+  }),
+};
+`;
+
+module.exports = ruleBoilerplate;

scripts/boilerplate/test.js

@@ -0,0 +1,39 @@
+const testBoilerplate = (name, author, description) => `/**
+ * @fileoverview ${description}
+ * @author ${author}
+ */
+
+// -----------------------------------------------------------------------------
+// Requirements
+// -----------------------------------------------------------------------------
+
+import { RuleTester } from 'eslint';
+import rule from '../../../src/rules/${name}';
+
+const parserOptions = {
+  ecmaVersion: 6,
+  ecmaFeatures: {
+    jsx: true,
+  },
+};
+
+// -----------------------------------------------------------------------------
+// Tests
+// -----------------------------------------------------------------------------
+
+const ruleTester = new RuleTester();
+
+const expectedError = {
+  message: '',
+  type: 'JSXOpeningElement',
+};
+
+ruleTester.run('${name}', rule, {
+  valid: [
+    { code: '<div />;', parserOptions },
+  ],
+  invalid: [],
+});
+`;
+
+module.exports = testBoilerplate;

scripts/create-rule.js

@@ -0,0 +1,31 @@
+const path = require('path');
+const fs = require('fs');
+const argv = require('minimist')(process.argv.slice(2)); // eslint-disable-line import/no-extraneous-dependencies
+const ruleBoilerplateGenerator = require('./boilerplate/rule');
+const testBoilerplateGenerator = require('./boilerplate/test');
+const docBoilerplateGenerator = require('./boilerplate/doc');
+
+const ruleName = argv._[0];
+const author = argv.author || '$AUTHOR';
+const description = argv.description || '$DESCRIPTION';
+
+const rulePath = path.resolve(`src/rules/${ruleName}.js`);
+const testPath = path.resolve(`__tests__/src/rules/${ruleName}-test.js`);
+const docsPath = path.resolve(`docs/rules/${ruleName}.md`);
+
+// Validate
+if (!ruleName) {
+  throw new Error('Rule name is required');
+} else if (fs.existsSync(rulePath)) {
+  throw new Error('Rule already exists!');
+}
+
+// Generate file boilerplate
+const ruleBoilerplate = ruleBoilerplateGenerator(author, description);
+const testBoilerplate = testBoilerplateGenerator(ruleName, author, description);
+const docBoilerplate = docBoilerplateGenerator(ruleName);
+
+// Create new files
+fs.writeFileSync(rulePath, ruleBoilerplate);
+fs.writeFileSync(testPath, testBoilerplate);
+fs.writeFileSync(docsPath, docBoilerplate);

scripts/create-rule.md

@@ -0,0 +1,21 @@
+# Rule Generator
+
+```bash
+$ node scripts/create-rule.js rule-name --author="Your name" --description="Description of the rule"
+# OR with npm script alias
+$ npm run create -- rule-name --author="Your name" --description="Description of rule"
+```
+
+This script will generate three files with basic boilerplate for the given rule:
+1. src/rules/${rule-name}.js
+2. \__tests__/src/rules/${rule-name}-test.js
+3. docs/rules/${rule-name}.md
+
+If the rule already exists or is not specified in the correct format, an error will be thrown.
+
+If we wanted to scaffold a rule for `no-marquee`, we could run:
+```bash
+$ node scripts/create-rule.js no-marquee --author="Ethan Cohen <@evcohen>" --description="Enforce <marquee> elements are not used."
+# OR
+$ npm run create -- no-marquee --author="Ethan Cohen <@evcohen>" --description="Enforce <marquee> elements are not used."
+```