fix: ensure complex object keys are quoted

Fix chaijs#45

lib/helpers.js

@@ -154,9 +154,21 @@ export function inspectList(list, options, inspectItem, separator = ', ') {
   return `${output}${truncated}`
 }
 
+function quoteComplexKey(key) {
+  if (key.match(/^[a-zA-Z_][a-zA-Z_0-9]*$/)) {
+    return key
+  }
+  return JSON.stringify(key)
+    .replace(/'/g, "\\'")
+    .replace(/\\"/g, '"')
+    .replace(/(^"|"$)/g, "'")
+}
+
 export function inspectProperty([key, value], options) {
   options.truncate -= 2
-  if (typeof key !== 'string' && typeof key !== 'number') {
+  if (typeof key === 'string') {
+    key = quoteComplexKey(key)
+  }else if (typeof key !== 'number') {
     key = `[${options.inspect(key, options)}]`
   }
   options.truncate -= key.length

test/objects.js

@@ -10,6 +10,23 @@ for (const [suite, inspect] of Object.entries({
       expect(inspect({})).to.equal('{}')
     })
 
+    it('quotes a key if it contains special chars', () => {
+      expect(inspect({ 'a.b': 1 })).to.equal("{ 'a.b': 1 }")
+      expect(inspect({ 'a b': 1 })).to.equal("{ 'a b': 1 }")
+    })
+
+    it('quotes a key if it is empty', () => {
+      expect(inspect({ '': 1 })).to.equal("{ '': 1 }")
+    })
+
+    it('quotes a key if it contains a single quote', () => {
+      expect(inspect({ "'": 1 })).to.equal("{ '\\'': 1 }")
+    })
+
+    it('quotes a key if it contains a double quote', () => {
+      expect(inspect({ '"': 1 })).to.equal("{ '\"': 1 }")
+    })
+
     describe('truncate', () => {
       it('returns the full representation when truncate is over string length', () => {
         expect(inspect({ a: 1, b: 2, c: 3 }, { truncate: 20 })).to.equal('{ a: 1, b: 2, c: 3 }')