Improve validation

src/config/normalize/lib/main.js

@@ -6,6 +6,7 @@ import { cleanObject } from '../../../utils/clean.js'
 import { getInfo } from './info.js'
 import { applyKeywords } from './keywords/main.js'
 import { normalizeRules } from './normalize.js'
+import { normalizeOpts } from './options.js'
 import { logWarnings } from './warn.js'
 
 // Validate and normalize a library's inputs.
@@ -20,7 +21,7 @@ import { logWarnings } from './warn.js'
 //  - Makes it clear to users what the order is
 // TODO: abstract this function to its own library
 export const normalizeInputs = async function (inputs, rules, opts) {
-  const { soft, all } = normalizeOpts(opts)
+  const { soft, all } = normalizeOpts(rules, opts)
   const rulesA = normalizeRules(rules, all)
 
   try {
@@ -38,10 +39,6 @@ export const normalizeInputs = async function (inputs, rules, opts) {
   }
 }
 
-const normalizeOpts = function ({ soft = false, all } = {}) {
-  return { soft, all }
-}
-
 const applyRuleDeep = async function ({ inputs, moves, warnings }, rule) {
   const entries = list(inputs, rule.name, {
     childFirst: true,

src/config/normalize/lib/options.js

@@ -0,0 +1,20 @@
+import isPlainObj from 'is-plain-obj'
+
+export const normalizeOpts = function (rules, { soft = false, all } = {}) {
+  validateRules(rules)
+  return { soft, all }
+}
+
+const validateRules = function (rules) {
+  if (!Array.isArray(rules)) {
+    throw new TypeError(`Rules must be an array: ${rules}`)
+  }
+
+  rules.forEach(validateRule)
+}
+
+const validateRule = function (rule) {
+  if (!isPlainObj(rule)) {
+    throw new TypeError(`Rules must be plain objects: ${rule}`)
+  }
+}