fix(body): relax stipulations for fetching next page

Previously, we were only fetching the next page if the scrollHeight was
exactly equal to the scrollTop + the offsetHeight. It looks like this
calculation was thrown off by style changes and the scroll-x bar. We now
include a 'buffer' into the calculation. If the scrollHeight is within
10px of the scrollTop + offsetHeight, we attempt to fetch (barring that
we have already `fetchedAll`)

app/components/BodyTable.tsx

@@ -34,6 +34,10 @@ const getNextPageNumber = (direction: 'up' | 'down', value: any[], pageSize: num
  return firstPage - 1
 }
 
+const shouldFetchNextPageDown = (scrollHeight: number, scrollTop: number, offsetHeight: number, buffer: number) => {
+ return Math.abs(scrollTop + offsetHeight - scrollHeight) < buffer
+}
+
 export default class BodyTable extends React.Component<BodyTableProps> {
  constructor (props: BodyTableProps) {
  super(props)
@@ -50,7 +54,8 @@ export default class BodyTable extends React.Component<BodyTableProps> {
  // grab the scrollable container from the BodyTable layout
  const scroller: any = document.getElementById('body-table-container')
  const { scrollHeight, scrollTop, offsetHeight } = scroller
- if (scrollHeight === parseInt(scrollTop) + parseInt(offsetHeight)) {
+
+ if (shouldFetchNextPageDown(scrollHeight, scrollTop, offsetHeight, 10)) {
  this.fetchNextPage('down')
  }