Add ability to filter individual posts (#18945)

* Add database table for status-specific filters

* Add REST endpoints, entities and attributes

* Show status filters in /filters interface

* Perform server-side filtering for individual posts filters

* Fix filtering on context mismatch

* Refactor `toServerSideType` by moving it to its own module

* Move loupe and delete icons to their own module

* Add ability to filter individual posts from WebUI

* Replace keyword list by warnings (expired, context mismatch)

* Refactor server-side filtering code

* Add tests

app/javascript/mastodon/reducers/filters.js

@@ -1,4 +1,5 @@
 import { FILTERS_IMPORT } from '../actions/importer';
+import { FILTERS_FETCH_SUCCESS, FILTERS_CREATE_SUCCESS } from '../actions/filters';
 import { Map as ImmutableMap, is, fromJS } from 'immutable';
 
 const normalizeFilter = (state, filter) => {
@@ -7,13 +8,17 @@ const normalizeFilter = (state, filter) => {
     title: filter.title,
     context: filter.context,
     filter_action: filter.filter_action,
+    keywords: filter.keywords,
     expires_at: filter.expires_at ? Date.parse(filter.expires_at) : null,
   });
 
   if (is(state.get(filter.id), normalizedFilter)) {
     return state;
   } else {
-    return state.set(filter.id, normalizedFilter);
+    // Do not overwrite keywords when receiving a partial filter
+    return state.update(filter.id, ImmutableMap(), (old) => (
+      old.mergeWith(((old_value, new_value) => (new_value === undefined ? old_value : new_value)), normalizedFilter)
+    ));
   }
 };
 
@@ -27,6 +32,10 @@ const normalizeFilters = (state, filters) => {
 
 export default function filters(state = ImmutableMap(), action) {
   switch(action.type) {
+  case FILTERS_CREATE_SUCCESS:
+    return normalizeFilter(state, action.filter);
+  case FILTERS_FETCH_SUCCESS:
+    //TODO: handle deleting obsolete filters
   case FILTERS_IMPORT:
     return normalizeFilters(state, action.filters);
   default: