⚒ add 'npm run new' command

package.json

@@ -34,11 +34,12 @@
     "rimraf": "^2.6.3"
   },
   "scripts": {
-    "build": "node scripts/update.js",
+    "build": "node scripts/update",
     "clean": "rimraf .nyc_output coverage",
     "codecov": "nyc report --reporter text-lcov | codecov --pipe --disable=gcov -t $CODECOV_TOKEN",
     "coverage": "opener ./coverage/lcov-report/index.html",
     "lint": "eslint lib scripts tests/lib .eslintrc.js",
+    "new": "node scripts/new-rule",
     "pretest": "npm run -s lint",
     "test": "nyc npm run -s test:_mocha",
     "test:ci": "nyc npm run -s test:_mocha",

scripts/new-rule.js

@@ -0,0 +1,108 @@
+/**
+ * @author Toru Nagashima <https://github.com/mysticatea>
+ * See LICENSE file in root directory for full license.
+ */
+"use strict"
+
+const cp = require("child_process")
+const fs = require("fs")
+const path = require("path")
+const logger = console
+
+// main
+;(ruleId => {
+    if (ruleId == null) {
+        logger.error("Usage: npm run new <RuleID>")
+        process.exitCode = 1
+        return
+    }
+    if (!/^[\w-]+$/u.test(ruleId)) {
+        logger.error("Invalid RuleID '%s'.", ruleId)
+        process.exitCode = 1
+        return
+    }
+
+    const ruleFile = path.resolve(__dirname, `../lib/rules/${ruleId}.js`)
+    const testFile = path.resolve(__dirname, `../tests/lib/rules/${ruleId}.js`)
+    const docFile = path.resolve(__dirname, `../docs/rules/${ruleId}.md`)
+
+    fs.writeFileSync(
+        ruleFile,
+        `/**
+ * @author Toru Nagashima <https://github.com/mysticatea>
+ * See LICENSE file in root directory for full license.
+ */
+"use strict"
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "",
+            category: "",
+            recommended: false,
+            url: "",
+        },
+        fixable: null,
+        messages: {
+        },
+        schema: [],
+        type: "problem",
+    },
+    create(context) {
+        return {}
+    },
+}
+`
+    )
+    fs.writeFileSync(
+        testFile,
+        `/**
+ * @author Toru Nagashima <https://github.com/mysticatea>
+ * See LICENSE file in root directory for full license.
+ */
+"use strict"
+const { RuleTester } = require("eslint")
+const rule = require("../../../lib/rules/${ruleId}.js")
+
+new RuleTester().run("${ruleId}", rule, {
+    valid: [],
+    invalid: [],
+})
+`
+    )
+    fs.writeFileSync(
+        docFile,
+        `#  (es/${ruleId})
+
+(TODO: Why this rule is useful.)
+
+## 📖 Rule Details
+
+(TODO: How this rule will report code.)
+
+👍 Examples of **correct** code for this rule:
+
+\`\`\`js
+/*eslint node/${ruleId}: error */
+\`\`\`
+
+👎 Examples of **incorrect** code for this rule:
+
+\`\`\`js
+/*eslint node/${ruleId}: error */
+\`\`\`
+
+## ⚙ Options
+
+\`\`\`json
+{
+    "node/${ruleId}": ["error", ...]
+}
+\`\`\`
+`
+    )
+
+    cp.execSync(`code "${ruleFile}"`)
+    cp.execSync(`code "${testFile}"`)
+    cp.execSync(`code "${docFile}"`)
+})(process.argv[2])