Merge pull request #21 from oslabs-beta/rydang/snapshotrefactor

middleware for componentWillUnmount

Author: mylee1995

package/index.js

@@ -3,6 +3,7 @@ const mode = { jumping: false };
 
 const linkState = require('./linkState')(snapShot, mode);
 const timeJump = require('./timeJump')(snapShot, mode);
+const unlinkState = require('./unlinkState')(snapShot);
 
 const getShot = () => snapShot.map(({ component }) => component.state);
 
@@ -16,6 +17,7 @@ window.addEventListener('message', ({ data: { action, payload } }) => {
 
 module.exports = {
   linkState,
+  unlinkState,
   timeJump,
   getShot,
 };

package/linkState.js

@@ -2,6 +2,8 @@
 // changes the setState method to also update our snapshot
 
 module.exports = (snapShot, mode) => {
+  const unlinkState = require('./unlinkState')(snapShot);
+
   // send message to window containing component states
   // unless library is currently jumping through time
   function sendSnapShot() {
@@ -45,15 +47,13 @@ module.exports = (snapShot, mode) => {
   }
 
   function changeComponentWillUnmount(component) {
+    let oldComponentWillUnmount = () => { };
+    // if componentWillUnmount is defined, then create copy by value
+    if (typeof component.componentWillUnmount === 'function') oldComponentWillUnmount = component.componentWillUnmount.bind(component);
+    // replace componentWillUnmount
     component.componentWillUnmount = () => {
-      let snapShotIndex = snapShot.length;
-      for (let i = 0; i < snapShot.length; i += 1) {
-        const { component: comp } = snapShot[i];
-        if (component === comp) {
-          snapShotIndex = i;
-        }
-      }
-      snapShot.splice(snapShotIndex, 1);
+      oldComponentWillUnmount();
+      unlinkState(component);
     };
   }
 

package/unlinkState.js

@@ -0,0 +1,12 @@
+module.exports = (snapShot) => {
+  return (component) => {
+    let snapShotIndex = snapShot.length;
+    for (let i = 0; i < snapShot.length; i += 1) {
+      const { component: comp } = snapShot[i];
+      if (component === comp) {
+        snapShotIndex = i;
+      }
+    }
+    snapShot.splice(snapShotIndex, 1);
+  };
+};