Mock SCU if gDSFP defined in shallow renderer rerender

enzymejs · Feb 28, 2019 · 9e2b05e · 9e2b05e
1 parent 6fda886
commit 9e2b05e
Showing 1 changed file with 22 additions and 0 deletions.
diff --git a/packages/enzyme/src/ShallowWrapper.js b/packages/enzyme/src/ShallowWrapper.js
@@ -243,6 +243,26 @@ function privateSetChildContext(adapter, wrapper, instance, renderedNode, getChi
   }
 }
 
+function mockSCUIfgDSFPReturnNonNull(node, state) {
+  const { getDerivedStateFromProps } = node.type;
+  const { instance } = node;
+  if (typeof getDerivedStateFromProps === 'function') {
+    // we try to fix a React shallow renderer bug here.
+    // (facebook/react#14607, which has been fixed in react 16.8):
+    // when gDSFP return derived state, it will set instance state in shallow renderer before SCU,
+    // this will cause `this.state` in sCU be the updated state, which is wrong behavior.
+    // so we have to wrap sCU to pass the old state to original sCU.
+    const originalSCU = instance.shouldComponentUpdate;
+    instance.shouldComponentUpdate = (...args) => {
+      instance.state = state;
+      const sCUResult = originalSCU.apply(instance, args);
+      const nextState = args[1];
+      instance.state = nextState;
+      instance.shouldComponentUpdate = originalSCU;
+      return sCUResult;
+    };
+  }
+}
 
 /**
  * @class ShallowWrapper
@@ -452,6 +472,7 @@ class ShallowWrapper {
             && instance
           ) {
             if (typeof instance.shouldComponentUpdate === 'function') {
+              mockSCUIfgDSFPReturnNonNull(node, state);
               shouldComponentUpdateSpy = spyMethod(instance, 'shouldComponentUpdate');
             }
             if (
@@ -601,6 +622,7 @@ class ShallowWrapper {
             && lifecycles.componentDidUpdate.onSetState
             && typeof instance.shouldComponentUpdate === 'function'
           ) {
+            mockSCUIfgDSFPReturnNonNull(node, state);
             shouldComponentUpdateSpy = spyMethod(instance, 'shouldComponentUpdate');
           }
           if (