Added tests

.size-snapshot.json

@@ -1,25 +1,25 @@
 {
   "dist/index.umd.js": {
-    "bundled": 66802,
-    "minified": 23724,
-    "gzipped": 7169
+    "bundled": 67132,
+    "minified": 23802,
+    "gzipped": 7191
   },
   "dist/index.umd.min.js": {
-    "bundled": 31438,
-    "minified": 12846,
-    "gzipped": 4182
+    "bundled": 31768,
+    "minified": 12924,
+    "gzipped": 4205
   },
   "dist/index.esm.js": {
-    "bundled": 12271,
-    "minified": 7288,
-    "gzipped": 2066,
+    "bundled": 12577,
+    "minified": 7364,
+    "gzipped": 2096,
     "treeshaked": {
       "rollup": {
-        "code": 3754,
+        "code": 3832,
         "import_statements": 137
       },
       "webpack": {
-        "code": 4860
+        "code": 4938
       }
     }
   }

package.json

@@ -84,9 +84,9 @@
     "babel-jest": "^24.0.0",
     "cross-env": "^5.1.4",
     "emotion": "^9.1.1",
-    "enzyme": "^3.3.0",
-    "enzyme-adapter-react-16": "^1.1.1",
-    "enzyme-to-json": "^3.3.3",
+    "enzyme": "^3.10.0",
+    "enzyme-adapter-react-16": "^1.14.0",
+    "enzyme-to-json": "^3.4.0",
     "eslint": "^4.19.1",
     "eslint-config-prettier": "^2.9.0",
     "eslint-plugin-flowtype": "^2.46.1",

src/Popper.test.js

@@ -86,6 +86,40 @@ describe('Popper component', () => {
     ).not.toThrow();
   });
 
+  it('accepts a ref function', () => {
+    const myRef = jest.fn();
+    const referenceElement = document.createElement('div');
+    mount(
+      <InnerPopper referenceElement={referenceElement} innerRef={myRef}>
+        {({ ref, style, placement}) => (
+          <div
+            ref={ref}
+            style={style}
+            data-placement={placement}
+          />
+        )}
+      </InnerPopper>
+    )
+    expect(myRef).toBeCalled();
+  });
+
+  it('accepts a ref object', () => {
+    const myRef = (React: any).createRef();
+    const referenceElement = document.createElement('div');
+    mount(
+      <InnerPopper referenceElement={referenceElement} innerRef={myRef}>
+        {({ ref, style, placement}) => (
+          <div
+            ref={ref}
+            style={style}
+            data-placement={placement}
+          />
+        )}
+      </InnerPopper>
+    )
+    expect(myRef.current).toBeDefined();
+  });
+
   it('accepts a `referenceElement` property', () => {
     class VirtualReference {
       getBoundingClientRect() {