re-reselect proof of concept + fix Date selector as first example

`makeSelectDataForUri` always returns a new reference, so `ClaimPreview` was constantly being rendered. It's pretty expensive since `ClaimPreview`'s rendering checks against a huge blocklist, which is another issue on it's own.

- This commit tests the usage of `re-reselect` as the solution to the multi-instance memoization problem (https://github.com/toomuchdesign/re-reselect/blob/master/examples/1-join-selectors.md)

package.json

@@ -56,6 +56,7 @@
     "match-sorter": "^6.3.0",
     "parse-duration": "^1.0.0",
     "proxy-polyfill": "0.1.6",
+    "re-reselect": "^4.0.0",
     "react-datetime-picker": "^3.2.1",
     "react-plastic": "^1.1.1",
     "react-top-loading-bar": "^2.0.1",

ui/component/claimPreview/index.js

@@ -1,6 +1,6 @@
 import { connect } from 'react-redux';
 import {
-  makeSelectClaimForUri,
+  selectClaimForUri,
   makeSelectIsUriResolving,
   makeSelectClaimIsMine,
   makeSelectClaimIsPending,
@@ -8,7 +8,7 @@ import {
   makeSelectReflectingClaimForUri,
   makeSelectClaimWasPurchased,
   makeSelectTitleForUri,
-  makeSelectDateForUri,
+  selectDateForUri,
 } from 'redux/selectors/claims';
 import { makeSelectStreamingUrlForUri } from 'redux/selectors/file_info';
 import {
@@ -30,14 +30,14 @@ import ClaimPreview from './view';
 import formatMediaDuration from 'util/formatMediaDuration';
 
 const select = (state, props) => {
-  const claim = props.uri && makeSelectClaimForUri(props.uri)(state);
+  const claim = props.uri && selectClaimForUri(state, props.uri);
   const media = claim && claim.value && (claim.value.video || claim.value.audio);
   const mediaDuration = media && media.duration && formatMediaDuration(media.duration, { screenReader: true });
 
   return {
     claim,
     mediaDuration,
-    date: props.uri && makeSelectDateForUri(props.uri)(state),
+    date: props.uri && selectDateForUri(state, props.uri),
     title: props.uri && makeSelectTitleForUri(props.uri)(state),
     pending: props.uri && makeSelectClaimIsPending(props.uri)(state),
     reflectingProgress: props.uri && makeSelectReflectingClaimForUri(props.uri)(state),
@@ -45,7 +45,6 @@ const select = (state, props) => {
     claimIsMine: props.uri && makeSelectClaimIsMine(props.uri)(state),
     isResolvingUri: props.uri && makeSelectIsUriResolving(props.uri)(state),
     isResolvingRepost: props.uri && makeSelectIsUriResolving(props.repostUrl)(state),
-    repostClaim: props.uri && makeSelectClaimForUri(props.uri)(state),
     nsfw: props.uri && makeSelectClaimIsNsfw(props.uri)(state),
     blackListedOutpoints: selectBlackListedOutpoints(state),
     filteredOutpoints: selectFilteredOutpoints(state),

ui/component/claimPreviewTile/index.js

@@ -6,7 +6,7 @@ import {
   makeSelectTitleForUri,
   makeSelectChannelForClaimUri,
   makeSelectClaimIsNsfw,
-  makeSelectDateForUri,
+  selectDateForUri,
 } from 'redux/selectors/claims';
 import { doFileGet } from 'redux/actions/file';
 import { doResolveUri } from 'redux/actions/claims';
@@ -24,7 +24,7 @@ const select = (state, props) => {
   return {
     claim,
     mediaDuration,
-    date: props.uri && makeSelectDateForUri(props.uri)(state),
+    date: props.uri && selectDateForUri(state, props.uri),
     channel: props.uri && makeSelectChannelForClaimUri(props.uri)(state),
     isResolvingUri: props.uri && makeSelectIsUriResolving(props.uri)(state),
     thumbnail: props.uri && makeSelectThumbnailForUri(props.uri)(state),

ui/component/dateTime/index.js

@@ -1,11 +1,11 @@
 import { connect } from 'react-redux';
-import { makeSelectDateForUri } from 'redux/selectors/claims';
+import { selectDateForUri } from 'redux/selectors/claims';
 import * as SETTINGS from 'constants/settings';
 import { makeSelectClientSetting } from 'redux/selectors/settings';
 import DateTime from './view';
 
 const select = (state, props) => ({
-  date: props.date || makeSelectDateForUri(props.uri)(state),
+  date: props.date || selectDateForUri(state, props.uri),
   clock24h: makeSelectClientSetting(SETTINGS.CLOCK_24H)(state),
 });
 export default connect(select)(DateTime);

ui/redux/selectors/claims.js

@@ -2,20 +2,22 @@
 import { normalizeURI, parseURI, isURIValid } from 'util/lbryURI';
 import { selectSupportsByOutpoint } from 'redux/selectors/wallet';
 import { createSelector } from 'reselect';
+import { createCachedSelector } from 're-reselect';
 import { isClaimNsfw, filterClaims } from 'util/claim';
 import * as CLAIM from 'constants/claim';
 
+type State = { claims: any };
+
 const selectState = (state) => state.claims || {};
 
-export const selectById = createSelector(selectState, (state) => state.byId || {});
-
-export const selectPendingClaimsById = createSelector(selectState, (state) => state.pendingById || {});
+export const selectById = (state: State) => selectState(state).byId || {};
+export const selectPendingClaimsById = (state: State) => selectState(state).pendingById || {};
 
 export const selectClaimsById = createSelector(selectById, selectPendingClaimsById, (byId, pendingById) => {
   return Object.assign(byId, pendingById); // do I need merged to keep metadata?
 });
 
-export const selectClaimIdsByUri = createSelector(selectState, (state) => state.claimsByUri || {});
+export const selectClaimIdsByUri = (state: State) => selectState(state).claimsByUri || {};
 
 export const selectCurrentChannelPage = createSelector(selectState, (state) => state.currentChannelPage || 1);
 
@@ -74,6 +76,43 @@ export const selectReflectingById = createSelector(selectState, (state) => state
 
 export const makeSelectClaimForClaimId = (claimId: string) => createSelector(selectClaimsById, (byId) => byId[claimId]);
 
+export const selectClaimForUri = createCachedSelector(
+  selectClaimIdsByUri,
+  selectClaimsById,
+  (state, uri) => uri,
+  (state, uri, returnRepost = true) => returnRepost,
+  (byUri, byId, uri, returnRepost) => {
+    const validUri = isURIValid(uri);
+
+    if (validUri && byUri) {
+      const claimId = uri && byUri[normalizeURI(uri)];
+      const claim = byId[claimId];
+
+      // Make sure to return the claim as is so apps can check if it's been resolved before (null) or still needs to be resolved (undefined)
+      if (claimId === null) {
+        return null;
+      } else if (claimId === undefined) {
+        return undefined;
+      }
+
+      const repostedClaim = claim && claim.reposted_claim;
+      if (repostedClaim && returnRepost) {
+        const channelUrl =
+          claim.signing_channel && (claim.signing_channel.canonical_url || claim.signing_channel.permanent_url);
+
+        return {
+          ...repostedClaim,
+          repost_url: normalizeURI(uri),
+          repost_channel_url: channelUrl,
+          repost_bid_amount: claim && claim.meta && claim.meta.effective_amount,
+        };
+      } else {
+        return claim;
+      }
+    }
+  }
+)((state, uri, returnRepost = true) => `${uri}:${returnRepost ? '1' : '0'}`);
+
 export const makeSelectClaimForUri = (uri: string, returnRepost: boolean = true) =>
   createSelector(selectClaimIdsByUri, selectClaimsById, (byUri, byId) => {
     const validUri = isURIValid(uri);
@@ -242,8 +281,9 @@ export const makeSelectMetadataItemForUri = (uri: string, key: string) =>
 export const makeSelectTitleForUri = (uri: string) =>
   createSelector(makeSelectMetadataForUri(uri), (metadata) => metadata && metadata.title);
 
-export const makeSelectDateForUri = (uri: string) =>
-  createSelector(makeSelectClaimForUri(uri), (claim) => {
+export const selectDateForUri = createCachedSelector(
+  selectClaimForUri, // input: (state, uri, ?returnRepost)
+  (claim) => {
     const timestamp =
       claim &&
       claim.value &&
@@ -257,7 +297,8 @@ export const makeSelectDateForUri = (uri: string) =>
     }
     const dateObj = new Date(timestamp);
     return dateObj;
-  });
+  }
+)((state, uri) => uri);
 
 export const makeSelectAmountForUri = (uri: string) =>
   createSelector(makeSelectClaimForUri(uri), (claim) => {

yarn.lock

@@ -13179,6 +13179,11 @@ rc@^1.0.1, rc@^1.1.6, rc@^1.2.8:
     minimist "^1.2.0"
     strip-json-comments "~2.0.1"
 
+re-reselect@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/re-reselect/-/re-reselect-4.0.0.tgz#9ddec4c72c4d952f68caa5aa4b76a9ed38b75cac"
+  integrity sha512-wuygyq8TXUlSdVXv2kigXxQNOgdb9m7LbIjwfTNGSpaY1riLd5e+VeQjlQMyUtrk0oiyhi1AqIVynworl3qxHA==
+
 react-async-script@^1.1.1:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/react-async-script/-/react-async-script-1.1.1.tgz#f481c6c5f094bf4b94a9d52da0d0dda2e1a74bdf"