fix: forcely update Context Provider, fixes #1207

src/reconciler/componentComparator.js

@@ -153,10 +153,14 @@ const compareComponents = (oldType, newType, setNewType, baseType) => {
   }
 
   if (isLazyType({ type: oldType })) {
+    // no need to update
+    // setNewType(newType);
     return defaultResult;
   }
 
   if (isContextType({ type: oldType })) {
+    // update provider
+    setNewType(newType);
     return defaultResult;
   }
 

test/hot/react-dom.integration.spec.js

@@ -101,6 +101,64 @@ describe(`🔥-dom`, () => {
       expect(unmount).toHaveBeenCalled();
     });
 
+    it('should reload context', async () => {
+      const mount = jest.fn();
+      const unmount = jest.fn();
+
+      const genApp = contextValue => {
+        const context = React.createContext(contextValue);
+
+        const RenderContext = () => {
+          const v = React.useContext(context);
+
+          return <span>contextValue={v}</span>;
+        };
+
+        const MountCheck = () => {
+          React.useEffect(() => {
+            mount('test1');
+            return unmount;
+          }, []);
+          return 'fun1';
+        };
+
+        const App = () => (
+          <div>
+            <RenderContext />
+            <context.Provider value={`~${contextValue}~`}>
+              <RenderContext />
+              <MountCheck />
+            </context.Provider>
+          </div>
+        );
+
+        ReactHotLoader.register(context, 'context', 'test');
+
+        return App;
+      };
+
+      const el = document.createElement('div');
+      const App1 = genApp('1-test-1');
+      ReactDom.render(<App1 />, el);
+
+      expect(el.innerHTML).toMatch(/1-test-1/);
+      expect(el.innerHTML).toMatch(/~1-test-1~/);
+
+      incrementHotGeneration();
+      {
+        const App1 = genApp('2-hot-2');
+        ReactDom.render(<App1 />, el);
+      }
+
+      await tick();
+
+      expect(el.innerHTML).toMatch(/2-hot-2/);
+      expect(el.innerHTML).toMatch(/~2-hot-2~/);
+
+      expect(mount).toHaveBeenCalledTimes(1);
+      expect(unmount).toHaveBeenCalledTimes(0);
+    });
+
     it('should reload hook effect', async () => {
       const mount = jest.fn();
       const unmount = jest.fn();

yarn.lock

@@ -4594,11 +4594,6 @@ lodash@^4.0.0, lodash@^4.13.1, lodash@^4.14.0, lodash@^4.15.0, lodash@^4.17.4, l
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.4.tgz#78203a4d1c328ae1d86dca6460e369b57f4055ae"
   integrity sha1-eCA6TRwyiuHYbcpkYONptX9AVa4=
 
-lodash@^4.17.11:
-  version "4.17.11"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.11.tgz#b39ea6229ef607ecd89e2c8df12536891cac9b8d"
-  integrity sha512-cQKh8igo5QUhZ7lg38DYWAxMvjSAKG0A8wGSVimP07SIUEK2UO+arSRKbRZWtelMtN5V0Hkwh5ryOto/SshYIg==
-
 lodash@^4.17.5:
   version "4.17.5"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.5.tgz#99a92d65c0272debe8c96b6057bc8fbfa3bed511"