memoize sequence item

Author: seveibar

src/components/Document/index.js

@@ -117,6 +117,7 @@ export default function Document({
           isHighlighted={highlightedItems.includes(i)}
           onRemoveLabel={onRemoveLabel}
           color={seq.color || colorLabelMap[seq.label]}
+          key={i}
         />
       ))}
       {firstSequenceItem && !secondSequenceItem && (

src/components/SequenceItem/index.js

@@ -1,4 +1,4 @@
-import React from "react"
+import React, { memo } from "react"
 import classNames from "classnames"
 import { styled, Tooltip } from "@material-ui/core"
 import stringToSequence from "../../string-to-sequence.js"
@@ -155,4 +155,4 @@ export const SequenceItem = ({
   )
 }
 
-export default SequenceItem
+export default memo(SequenceItem)