From 931c33eca49972ba1d4012682db12ce47fb89c1e Mon Sep 17 00:00:00 2001
From: Juan <jm@guide42.com>
Date: Fri, 2 Aug 2024 07:30:16 -0300
Subject: [PATCH] Simplify array intersection

---
 src/components/EventsCompare.tsx | 33 ++++++++++++++++-------------
 src/models/in-common.ts          |  4 ++--
 src/utils/array.ts               | 36 +++++++++++++++++---------------
 3 files changed, 39 insertions(+), 34 deletions(-)

diff --git a/src/components/EventsCompare.tsx b/src/components/EventsCompare.tsx
index 0efc4c6..ed44f2c 100644
--- a/src/components/EventsCompare.tsx
+++ b/src/components/EventsCompare.tsx
@@ -40,17 +40,16 @@ function EventsCompare({
     () => eventIds.length < 2
       ? {}
       : Object.fromEntries(
-        intersection(
-          // @ts-ignore
-          ...eventIds.map((eventId) => inCommon[eventId])
-        )
-        .map(
-          (address) => [
-            address,
-            getColorForSeed(address),
-          ]
-        )
-      ),
+          intersection(
+            ...eventIds.map((eventId) => inCommon[eventId])
+          )
+          .map(
+            (address) => [
+              address,
+              getColorForSeed(address),
+            ]
+          )
+        ),
     [eventIds, inCommon]
   )
 
@@ -75,9 +74,11 @@ function EventsCompare({
   )
 
   function onOwnerEnter(ownerEventId: number, owner: string): void {
-    if (owner in adressesColors &&
+    if (
+      owner in adressesColors &&
       settings &&
-      settings.autoScrollCollectors) {
+      settings.autoScrollCollectors
+    ) {
       for (const eventId of eventIds) {
         if (eventId !== ownerEventId &&
           eventId && liRefs &&
@@ -89,9 +90,11 @@ function EventsCompare({
           })
         }
       }
-      if (ownerEventId in liRefs &&
+      if (
+        ownerEventId in liRefs &&
         owner in liRefs[ownerEventId] &&
-        liRefs[ownerEventId][owner].current) {
+        liRefs[ownerEventId][owner].current
+      ) {
         liRefs[ownerEventId][owner].current.scrollIntoView({
           behavior: 'smooth',
           block: 'center',
diff --git a/src/models/in-common.ts b/src/models/in-common.ts
index 4e52b14..7fdee0d 100644
--- a/src/models/in-common.ts
+++ b/src/models/in-common.ts
@@ -72,7 +72,7 @@ export function mergeAllInCommon(
  * Merges in-common collectors that belong to all events.
  */
 export function mergeAddressesInCommon(inCommon: InCommon): string[] {
-  let mergedAddresses = null
+  let mergedAddresses: string[] | null = null
   for (const [, addresses] of Object.entries(inCommon)) {
     if (mergedAddresses == null) {
       mergedAddresses = addresses
@@ -91,7 +91,7 @@ export function getAddressInCommonEventIds(
   inCommon: InCommon,
   address: string,
 ): number[] {
-  const eventIds = []
+  const eventIds: number[] = []
   for (const [rawEventId, addresses] of Object.entries(inCommon)) {
     if (addresses.indexOf(address) !== -1) {
       eventIds.push(parseInt(rawEventId))
diff --git a/src/utils/array.ts b/src/utils/array.ts
index 02fcfb8..d23bcfa 100644
--- a/src/utils/array.ts
+++ b/src/utils/array.ts
@@ -1,35 +1,35 @@
 /**
  * Returns elements found in all array arguments.
  */
-export function intersection<T>(array: T[], ...args: T[][]): T[] {
-  if (array == null) {
+export function intersection<T>(...args: T[][]): T[] {
+  if (args.length === 0 || args[0].length === 0) {
     return []
   }
-  const result = []
-  for (var i = 0, length = array.length; i < length; i++) {
-    const item = array[i]
-    if (result.indexOf(item) !== -1) {
-      continue
-    }
-    let j: number
-    for (j = 0; j < args.length; j++) {
-      if (args[j].indexOf(item) === -1) {
-        break
-      }
-    }
-    if (j === args.length - 1) {
-      result.push(item)
+
+  const all = new Set<T>()
+  const tail = args.slice(1)
+
+  for (const item of args[0]) {
+    if (tail.every((other) => other.includes(item))) {
+      all.add(item)
     }
   }
-  return result
+
+  return [...all]
 }
 
+/**
+ * Returns elements in all array arguments.
+ */
 export function union<T>(...args: T[][]): T[] {
   const all = new Set<T>()
+
   for (let i = 0; i < args.length; i++) {
     const arg = args[i]
+
     if (Array.isArray(arg)) {
       const array: T[] = [].concat(...arg)
+
       for (const item of array) {
         all.add(item)
       }
@@ -37,6 +37,7 @@ export function union<T>(...args: T[][]): T[] {
       all.add(arg)
     }
   }
+
   return [...all]
 }
 
@@ -69,6 +70,7 @@ export function equals(a: unknown[], b: unknown[]): boolean {
       return false
     }
   }
+
   return true
 }