From 838cfb841087ddba4f4fd91bb24000673d22e338 Mon Sep 17 00:00:00 2001
From: Christopher Quadflieg <chrissi92@hotmail.de>
Date: Fri, 10 Jul 2020 19:04:06 +0200
Subject: [PATCH] feat: use recommended as default

---
 src/core/configuration.ts | 39 +++++++++++++++++++++++++++++++++++++++
 src/core/core.ts          | 12 +++++++++++-
 test/core.spec.js         | 30 ++++++++++++++++++++++++++++--
 3 files changed, 78 insertions(+), 3 deletions(-)
 create mode 100644 src/core/configuration.ts

diff --git a/src/core/configuration.ts b/src/core/configuration.ts
new file mode 100644
index 000000000..e56853cbe
--- /dev/null
+++ b/src/core/configuration.ts
@@ -0,0 +1,39 @@
+import { Configuration } from './types'
+
+export function isConfiguration(value: unknown): value is Configuration {
+  // Config must be an object
+  if (typeof value !== 'object') {
+    return false
+  }
+
+  // Config must not be null
+  if (value === null) {
+    return false
+  }
+
+  // This helps to get better support for TypeScript
+  const config = value as Record<string, unknown>
+
+  // If extends is defined, it must be an array
+  if (config.extends !== undefined) {
+    if (!Array.isArray(config.extends)) {
+      return false
+    }
+
+    // Any value within extens must be a string
+    for (const extension of config.extends) {
+      if (typeof extension !== 'string') {
+        return false
+      }
+    }
+  }
+
+  // If extends is defined, it must be an object
+  if (config.rules !== undefined) {
+    if (typeof config.rules !== 'object' && config.rules !== null) {
+      return false
+    }
+  }
+
+  return true
+}
diff --git a/src/core/core.ts b/src/core/core.ts
index 0909be7da..9b09aa231 100644
--- a/src/core/core.ts
+++ b/src/core/core.ts
@@ -1,3 +1,4 @@
+import { isConfiguration } from './configuration'
 import HTMLParser from './htmlparser'
 import Reporter, { ReportMessageCallback } from './reporter'
 import * as HTMLRules from './rules'
@@ -59,10 +60,19 @@ class HTMLHintCore {
 
   public verify(
     html: string,
-    config: Configuration = { extends: [HTMLHINT_LEGACY] }
+    config: Configuration = { extends: [HTMLHINT_RECOMMENDED] }
   ) {
+    if (!isConfiguration(config)) {
+      throw new Error('The HTMLHint configuration is invalid')
+    }
+
     let ruleset: Ruleset = {}
 
+    // If an empty configuration is passed, use the recommended ruleset
+    if (config.extends === undefined && config.rules === undefined) {
+      config.extends = [HTMLHINT_RECOMMENDED]
+    }
+
     // Iterate through extensions and merge rulesets into ruleset
     for (const extend of config.extends ?? []) {
       if (typeof extend === 'string') {
diff --git a/test/core.spec.js b/test/core.spec.js
index d9792c233..c719911fa 100644
--- a/test/core.spec.js
+++ b/test/core.spec.js
@@ -1,22 +1,48 @@
 const expect = require('expect.js')
 
+/** @type import('../src/core/core').HTMLHint */
 const HTMLHint = require('../dist/htmlhint.js').HTMLHint
 
 describe('Core', () => {
   describe('Defaults', () => {
-    it('Not load default ruleset when use undefined ruleset should result in an error', () => {
+    it('Should use the recommended ruleset, if configuration is not defined', () => {
       const code =
         '<P ATTR=\'1\' id="a">><div id="a"><img src="" a="1" a="2"/></div>'
       const messages = HTMLHint.verify(code)
       expect(messages.length).to.be(9)
     })
 
-    it('Not load default ruleset when use empty ruleset should result in an error', () => {
+    it('Should use the recommended ruleset, if empty configuration is passed', () => {
       const code =
         '<P ATTR=\'1\' id="a">><div id="a"><img src="" a="1" a="2"/></div>'
       const messages = HTMLHint.verify(code, {})
       expect(messages.length).to.be(9)
     })
+
+    it('Should use the legacy ruleset, if it is passed', () => {
+      const code =
+        '<P ATTR=\'1\' id="a">><div id="a"><img src="" a="1" a="2"/></div>'
+      const messages = HTMLHint.verify(code, {
+        extends: ['htmlhint:legacy'],
+      })
+      expect(messages.length).to.be(9)
+    })
+
+    it('Should use the recommended ruleset, if it is passed', () => {
+      const code =
+        '<P ATTR=\'1\' id="a">><div id="a"><img src="" a="1" a="2"/></div>'
+      const messages = HTMLHint.verify(code, {
+        extends: ['htmlhint:recommended'],
+      })
+      expect(messages.length).to.be(9)
+    })
+
+    it('Should use no ruleset, if extends is not defined and empty ruleset is passed', () => {
+      const code =
+        '<P ATTR=\'1\' id="a">><div id="a"><img src="" a="1" a="2"/></div>'
+      const messages = HTMLHint.verify(code, { rules: {} })
+      expect(messages.length).to.be(0)
+    })
   })
 
   describe('Customization', () => {