diff --git a/app/src/components/ChartPanel/index.tsx b/app/src/components/ChartPanel/index.tsx
index 826fc42..8253fdc 100644
--- a/app/src/components/ChartPanel/index.tsx
+++ b/app/src/components/ChartPanel/index.tsx
@@ -28,24 +28,6 @@ function spacingForChartCount(count: number): 4 | 6 | 12 {
   }
 }
 
-// function FadingChart(props: { chartParameters: ChartParameters; chartsInView: number; key: any }) {
-//   const { chartsInView, chartParameters } = props
-//   const [spacing, setSpacing] = React.useState(spacingForChartCount(chartsInView))
-
-//   // Update spacing after animations have completed
-//   React.useEffect(() => {
-//     const newSpacing = spacingForChartCount(chartsInView)
-//     if (spacing !== newSpacing) {
-//       setSpacing(newSpacing)
-//       // setTimeout(() => , 500)
-//     }
-//   })
-
-//   return (
-
-//   )
-// }
-
 function ChartPanel(props: Props) {
   const chartsInView = props.charts.count()
 
diff --git a/app/src/components/Sidebar/CodeDiff/Gutters.tsx b/app/src/components/Sidebar/CodeDiff/Gutters.tsx
index 129b10b..3b93247 100644
--- a/app/src/components/Sidebar/CodeDiff/Gutters.tsx
+++ b/app/src/components/Sidebar/CodeDiff/Gutters.tsx
@@ -4,10 +4,9 @@ import * as React from 'react'
 import Add from '@material-ui/icons/Add'
 import ChartPreview from './ChartPreview'
 import Remove from '@material-ui/icons/Remove'
-import ShowChart from '@material-ui/icons/ShowChart'
-import { Theme, Tooltip } from '@material-ui/core'
 import { JsonPropertyLocation } from '../../../../../backend/src/JsonAstParser'
 import { lineChangeStyle, trimNewlineRight } from './util'
+import { Theme } from '@material-ui/core'
 import { withStyles } from '@material-ui/styles'
 
 interface Props {
@@ -53,12 +52,14 @@ function tokensForLine(change: diff.Change, line: number, props: Props) {
   const { classes, literalPositions } = props
   const literal = literalPositions[line]
 
-  let chartPreview = null
-  if (literal) {
-    chartPreview = (
-      <ChartPreview treeNode={props.treeNode} classes={{ icon: props.classes.iconButton }} literal={literal} />
-    )
-  }
+  const chartPreview = Boolean(literal) ? (
+    <ChartPreview
+      key="chartPreview"
+      treeNode={props.treeNode}
+      classes={{ icon: props.classes.iconButton }}
+      literal={literal}
+    />
+  ) : null
 
   if (change.added) {
     return [chartPreview, <Add key="add" className={classes.icon} />]