Add object contains property string

README.md

@@ -258,6 +258,7 @@ expect([ 1, 2, 3 ]).toExclude(4)
 Asserts the given `object` contains all keys and values in `value`, recursively. The `comparator` function, if given, should compare two objects and either `return false` or `throw` if they are not equal. It defaults to `assert.deepEqual`.
 
 ```js
+expect({ a: 1, b: 2 }).toInclude('a')
 expect({ a: 1, b: 2 }).toInclude({ b: 2 })
 expect({ a: 1, b: 2, c: { d: 3 } }).toInclude({ b: 2, c: { d: 3 } })
 ```

modules/TestUtils.js

@@ -82,11 +82,17 @@ export const arrayContains = (array, value, compareValues) => {
  * Returns true if the given object contains the value, false
  * otherwise. The compareValues function must return false to
  * indicate a non-match.
+ *
+ * If the value is a string returns true if a value exists on
+ * the object for the string property.
  */
 export const objectContains = (object, value, compareValues) => {
   if (compareValues == null)
     compareValues = isEqual
 
+  if (typeof value === 'string')
+    return object.hasOwnProperty(value)
+
   return Object.keys(value).every(k => {
     if (isObject(object[k])) {
       return objectContains(object[k], value[k], compareValues)

modules/__tests__/toInclude-test.js

@@ -20,6 +20,18 @@ describe('toInclude', () => {
     }).toNotThrow()
   })
 
+  it('does not throw when an object contains an expected key', () => {
+    expect(() => {
+      expect({ a: 1 }).toInclude('a')
+    }).toNotThrow()
+  })
+
+  it('throws when an object contains an unexpected key', () => {
+    expect(() => {
+      expect({ a: 1 }).toInclude('b')
+    }).toThrow(/to include/)
+  })
+
   it('does not throw when an object contains an expected object', () => {
     expect(() => {
       expect({ a: 1, b: 2, c: 3 }).toInclude({ b: 2 })