history persistor: follow the recommended HOC guidelines.

src/Journal/JournalCalendar.tsx

@@ -36,7 +36,7 @@ class JournalCalendar extends React.PureComponent {
   }
 
   render() {
-    const PersistCalendar = historyPersistor(Calendar, 'Calendar');
+    const PersistCalendar = historyPersistor('Calendar')(Calendar);
     let items = this.props.entries;
 
     return (

src/Pim/PimMain.tsx

@@ -77,7 +77,7 @@ class PimMain extends React.PureComponent {
       } as any,
     };
 
-    const PersistCalendar = historyPersistor(Calendar, 'Calendar');
+    const PersistCalendar = historyPersistor('Calendar')(Calendar);
 
     return (
       <React.Fragment>
@@ -114,4 +114,4 @@ class PimMain extends React.PureComponent {
   }
 }
 
-export default historyPersistor(PimMain, 'PimMain');
+export default historyPersistor('PimMain')(PimMain);

src/persist-state-history.tsx

@@ -6,26 +6,28 @@ let stateCache = {};
 
 type Constructor<T> = new(...args: any[]) => T;
 
-export function historyPersistor<T extends Constructor<React.Component>>(Base: T, tag: string) {
-  return withRouter(class extends Base {
-    constructor(...rest: any[]) {
-      const props = rest[0];
-      super(...rest);
-      const tagName = this.getKeyForTag(props, tag);
-      if (tagName in stateCache) {
-        this.state = stateCache[tagName];
+export function historyPersistor(tag: string) {
+  return function<T extends Constructor<React.Component>>(Base: T) {
+    return withRouter(class extends Base {
+      constructor(...rest: any[]) {
+        const props = rest[0];
+        super(...rest);
+        const tagName = this.getKeyForTag(props, tag);
+        if (tagName in stateCache) {
+          this.state = stateCache[tagName];
+        }
       }
-    }
 
-    componentWillUnmount() {
-      if (super.componentWillUnmount) {
-        super.componentWillUnmount();
+      componentWillUnmount() {
+        if (super.componentWillUnmount) {
+          super.componentWillUnmount();
+        }
+        stateCache[this.getKeyForTag(this.props, tag)] = this.state;
       }
-      stateCache[this.getKeyForTag(this.props, tag)] = this.state;
-    }
 
-    getKeyForTag(props: any, tagName: string) {
-      return props.location.pathname + ':' + tagName;
-    }
-  });
+      getKeyForTag(props: any, tagName: string) {
+        return props.location.pathname + ':' + tagName;
+      }
+    });
+  };
 }