Don't update 'byId' if no changes + add 'selectClaimWithId'

## Ticket
116 Claim store optimization ideas (reducing unnecessary renders)

## Changes
- Ignore things like `confirmations` so that already-fetched claims aren't invalidated and causes re-rendering. The `stringify` might look expensive, but the amount of avoided re-renders outweighs it. There might be faster ways to compare, though.

- With `byId[claimId]` references more stable now, memoized selectors can now use 'selectClaimWithId' to pick a specific claim to depend on, instead of 'byId' which changes on every update.

ui/redux/reducers/claims.js

@@ -130,6 +130,35 @@ function resolveDelta(original: any, delta: any) {
   }
 }
 
+function claimObjHasNewData(original, fresh) {
+  // Don't blow away 'is_my_output' just because the next query didn't ask for it.
+  const ignoreIsMyOutput = original.is_my_output !== undefined && fresh.is_my_output === undefined;
+
+  // Something is causing the tags to be re-ordered differently
+  // (https://github.com/OdyseeTeam/odysee-frontend/issues/116#issuecomment-962747147).
+  // Just do a length comparison for now, which covers 99% of cases while we
+  // figure out what's causing the order to change.
+  const ignoreTags =
+    original.value &&
+    fresh.value &&
+    original.value.tags &&
+    fresh.value.tags &&
+    original.value.tags.length !== fresh.value.tags.length;
+
+  const excludeKeys = (key, value) => {
+    if (key === 'confirmations' || (ignoreTags && key === 'tags') || (ignoreIsMyOutput && key === 'is_my_output')) {
+      return undefined;
+    }
+
+    return value;
+  };
+
+  const originalStringified = JSON.stringify(original, excludeKeys);
+  const freshStringified = JSON.stringify(fresh, excludeKeys);
+
+  return originalStringified !== freshStringified;
+}
+
 // ****************************************************************************
 // handleClaimAction
 // ****************************************************************************
@@ -138,7 +167,7 @@ function handleClaimAction(state: State, action: any): State {
   const { resolveInfo }: ClaimActionResolveInfo = action.data;
 
   const byUri = Object.assign({}, state.claimsByUri);
-  const byId = Object.assign({}, state.byId);
+  const byIdDelta = {};
   const channelClaimCounts = Object.assign({}, state.channelClaimCounts);
   const pendingById = state.pendingById;
   let newResolvingUrls = new Set(state.resolvingUris);
@@ -151,10 +180,13 @@ function handleClaimAction(state: State, action: any): State {
 
     if (stream) {
       if (pendingById[stream.claim_id]) {
-        byId[stream.claim_id] = mergeClaim(stream, byId[stream.claim_id]);
+        byIdDelta[stream.claim_id] = mergeClaim(stream, state.byId[stream.claim_id]);
       } else {
-        byId[stream.claim_id] = stream;
+        if (!state.byId[stream.claim_id] || claimObjHasNewData(state.byId[stream.claim_id], stream)) {
+          byIdDelta[stream.claim_id] = stream;
         }
+      }
+
       byUri[url] = stream.claim_id;
 
       // If url isn't a canonical_url, make sure that is added too
@@ -181,9 +213,9 @@ function handleClaimAction(state: State, action: any): State {
       }
 
       if (pendingById[channel.claim_id]) {
-        byId[channel.claim_id] = mergeClaim(channel, byId[channel.claim_id]);
+        byIdDelta[channel.claim_id] = mergeClaim(channel, state.byId[channel.claim_id]);
       } else {
-        byId[channel.claim_id] = channel;
+        byIdDelta[channel.claim_id] = channel;
       }
 
       byUri[channel.permanent_url] = channel.claim_id;
@@ -194,10 +226,11 @@ function handleClaimAction(state: State, action: any): State {
 
     if (collection) {
       if (pendingById[collection.claim_id]) {
-        byId[collection.claim_id] = mergeClaim(collection, byId[collection.claim_id]);
+        byIdDelta[collection.claim_id] = mergeClaim(collection, state.byId[collection.claim_id]);
       } else {
-        byId[collection.claim_id] = collection;
+        byIdDelta[collection.claim_id] = collection;
       }
+
       byUri[url] = collection.claim_id;
       byUri[collection.canonical_url] = collection.claim_id;
       byUri[collection.permanent_url] = collection.claim_id;
@@ -216,7 +249,7 @@ function handleClaimAction(state: State, action: any): State {
   });
 
   return Object.assign({}, state, {
-    byId,
+    byId: resolveDelta(state.byId, byIdDelta),
     claimsByUri: byUri,
     channelClaimCounts,
     resolvingUris: Array.from(newResolvingUrls),

ui/redux/selectors/claims.js

@@ -43,6 +43,21 @@ export const selectClaimsByUri = createSelector(selectClaimIdsByUri, selectClaim
   return claims;
 });
 
+/**
+ * Returns the claim with the specified ID. The claim could be undefined if does
+ * not exist or have not fetched. Take note of the second parameter, which means
+ * an inline function or helper would be required when used as an input to
+ * 'createSelector'.
+ *
+ * @param state
+ * @param claimId
+ * @returns {*}
+ */
+export const selectClaimWithId = (state: State, claimId: string) => {
+  const byId = selectClaimsById(state);
+  return byId[claimId];
+};
+
 export const selectAllClaimsByChannel = createSelector(selectState, (state) => state.paginatedClaimsByChannel || {});
 
 export const selectPendingIds = createSelector(selectState, (state) => Object.keys(state.pendingById) || []);