From 95766fd68a58d44d14a65ba60227057a4bb711d9 Mon Sep 17 00:00:00 2001
From: Paul Kaplan <pkaplan@media.mit.edu>
Date: Mon, 10 May 2021 10:22:18 -0400
Subject: [PATCH] Add clear to infinite list, fixup tests

---
 src/redux/infinite-list.js            | 10 ++++++----
 test/unit/redux/infinite-list.test.js | 15 ++++++++++++++-
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/src/redux/infinite-list.js b/src/redux/infinite-list.js
index b09e10b12..90f664577 100644
--- a/src/redux/infinite-list.js
+++ b/src/redux/infinite-list.js
@@ -35,17 +35,16 @@
  */
 const InfiniteList = key => {
     
-    const initialState = {
+    const getInitialState = () => ({
         items: [],
-        offset: 0,
         error: null,
         loading: true,
         moreToLoad: false
-    };
+    });
 
     const reducer = (state, action) => {
         if (typeof state === 'undefined') {
-            state = initialState;
+            state = getInitialState();
         }
 
         switch (action.type) {
@@ -88,6 +87,8 @@ const InfiniteList = key => {
                 loading: false,
                 moreToLoad: false
             };
+        case `${key}_CLEAR`:
+            return getInitialState();
         default:
             return state;
         }
@@ -100,6 +101,7 @@ const InfiniteList = key => {
         error: error => ({type: `${key}_ERROR`, error}),
         loading: () => ({type: `${key}_LOADING`}),
         append: (items, moreToLoad) => ({type: `${key}_APPEND`, items, moreToLoad}),
+        clear: () => ({type: `${key}_CLEAR`}),
 
         /**
          * Load more action returns a thunk. It takes a function to call to get more items.
diff --git a/test/unit/redux/infinite-list.test.js b/test/unit/redux/infinite-list.test.js
index 9e9995a3d..991caa0ae 100644
--- a/test/unit/redux/infinite-list.test.js
+++ b/test/unit/redux/infinite-list.test.js
@@ -104,6 +104,19 @@ describe('Infinite List redux module', () => {
             });
         });
 
+        describe('CLEAR', () => {
+            test('resets everything back to the initial state', () => {
+                const state = {
+                    error: new Error(),
+                    items: [1, 2, 3],
+                    loading: 'something not initial',
+                    moreToLoad: 'something not initial'
+                };
+                const newState = module.reducer(state, module.actions.clear());
+                expect(newState).toEqual(initialState);
+            });
+        });
+
         describe('ERROR', () => {
             let action;
             let error = new Error();
@@ -167,7 +180,7 @@ describe('Infinite List redux module', () => {
     describe('selector', () => {
         test('will return the slice of state defined by the key', () => {
             const state = {
-                [module.key]: module.reducer(undefined, {}) // eslint-disable-line no-undefined
+                [module.key]: initialState
             };
             expect(module.selector(state)).toBe(initialState);
         });