[Fix] shallow: Share child context logic between shallow and dive

Author: Matthew Howard

packages/enzyme-test-suite/test/ShallowWrapper-spec.jsx

@@ -604,6 +604,67 @@ describe('shallow', () => {
           expect(consumer.text()).to.equal('howdy!');
         });
       });
+
+      describe('shallow() on Provider and Consumer', () => {
+        let Provider;
+        let Consumer;
+
+        beforeEach(() => {
+          ({ Provider, Consumer } = React.createContext('howdy!'));
+        });
+
+        class Consumes extends React.Component {
+          render() {
+            return (
+              <span>
+                <Consumer>{(value) => <span>{value}</span>}</Consumer>
+              </span>
+            );
+          }
+        }
+
+        class Provides extends React.Component {
+          render() {
+            const { children } = this.props;
+
+            return (
+              <Provider value="foo"><div><div />{children}</div></Provider>
+            );
+          }
+        }
+
+        class MyComponent extends React.Component {
+          render() {
+            return (
+              <Provides><Consumes /></Provides>
+            );
+          }
+        }
+
+        it('works on a Provider', () => {
+          const wrapper = shallow(<MyComponent />);
+          const provides = wrapper.find(Provides).dive();
+          const provider = provides.find(Provider).shallow();
+          expect(provider.text()).to.equal('<Consumes />');
+        });
+
+        it('always gives the default provider value if shallow() rendering a <Consumer /> directly', () => {
+          // Diving directly on a consumer will give you the default value
+          const wrapper = shallow(<MyComponent />);
+          const consumes = wrapper.find(Consumes).shallow();
+          const consumer = consumes.find(Consumer).shallow();
+          expect(consumer.text()).to.equal('howdy!');
+        });
+
+        it('gives the actual <Provider /> value if one dive()s it', () => {
+          const wrapper = shallow(<MyComponent />);
+          const provides = wrapper.find(Provides).shallow();
+          const provider = provides.find(Provider).shallow();
+          const consumes = provider.find(Consumes).shallow();
+          const consumer = consumes.find(Consumer).shallow();
+          expect(consumer.text()).to.equal('foo');
+        });
+      });
     });
 
     describeIf(is('> 0.13'), 'stateless function components (SFCs)', () => {

packages/enzyme/src/ShallowWrapper.js

@@ -369,6 +369,20 @@ function makeShallowOptions(nodes, root, passedOptions, wrapper) {
 }
 
 
+function makeInheritedChildOptions(wrapper, options = {}) {
+  const childOptions = {
+    ...wrapper[OPTIONS],
+    ...options,
+    context: options.context || {
+      ...wrapper[OPTIONS].context,
+      ...wrapper[ROOT][CHILD_CONTEXT],
+    },
+  };
+  privateSet(childOptions, PROVIDER_VALUES, wrapper[ROOT][PROVIDER_VALUES]);
+  return childOptions;
+}
+
+
 /**
  * @class ShallowWrapper
  */
@@ -1280,10 +1294,11 @@ class ShallowWrapper {
    * @param {Object} options
    * @returns {ShallowWrapper}
    */
-  shallow(options) {
-    return this.single('shallow', (n) => (
-      this.wrap(getAdapter(this[OPTIONS]).nodeToElement(n), null, options)
-    ));
+  shallow(options = {}) {
+    return this.single('shallow', (n) => {
+      const childOptions = makeInheritedChildOptions(this, options);
+      return this.wrap(getAdapter(this[OPTIONS]).nodeToElement(n), null, childOptions);
+    });
   }
 
   /**
@@ -1694,15 +1709,7 @@ class ShallowWrapper {
       if (!isCustomComponentElement(el, adapter)) {
         throw new TypeError(`ShallowWrapper::${name}() can only be called on components`);
       }
-      const childOptions = {
-        ...this[OPTIONS],
-        ...options,
-        context: options.context || {
-          ...this[OPTIONS].context,
-          ...this[ROOT][CHILD_CONTEXT],
-        },
-      };
-      privateSet(childOptions, PROVIDER_VALUES, this[ROOT][PROVIDER_VALUES]);
+      const childOptions = makeInheritedChildOptions(this, options);
       return this.wrap(el, null, childOptions);
     });
   }