Bug 1619645 - Improve wording for ProgressBar aria label (#6470)

Author: Tintinator

ui/shared/ProgressBar.jsx

@@ -4,34 +4,37 @@ import { Progress } from 'reactstrap';
 
 import SimpleTooltip from './SimpleTooltip';
 
-const ProgressBar = ({ magnitude, regression, color }) => (
-  <SimpleTooltip
-    text={
-      <Progress
-        multi
-        aria-label={`Magnitude of difference based on lower is better. Metric: ${
-          regression ? 100 - magnitude : magnitude
-        } % regressed`}
-      >
-        {/* the % of the bars that are colored and transparent is based on the newIsBetter metric,
-        which determines whether the colored bar for magnitude is displayed on the left or right */}
-        <div aria-hidden="true" className="progress w-100">
-          <Progress
-            bar
-            value={regression ? 100 - magnitude : magnitude}
-            color={regression ? 'transparent' : color}
-          />
-          <Progress
-            bar
-            value={regression ? magnitude : 100 - magnitude}
-            color={regression ? color : 'transparent'}
-          />
-        </div>
-      </Progress>
-    }
-    tooltipText="Relative magnitude of change (scale from 0 - 20%+)"
-  />
-);
+const ProgressBar = ({ magnitude, regression, color }) => {
+  const truncMag = regression
+    ? (Math.floor((100 - magnitude) * 100) / 100).toFixed(2)
+    : (Math.floor(magnitude * 100) / 100).toFixed(2);
+  return (
+    <SimpleTooltip
+      text={
+        <Progress
+          multi
+          aria-label={`Lower is better. Metric: ${truncMag} % regressed`}
+        >
+          {/* the % of the bars that are colored and transparent is based on the newIsBetter metric,
+          which determines whether the colored bar for magnitude is displayed on the left or right */}
+          <div aria-hidden="true" className="progress w-100">
+            <Progress
+              bar
+              value={regression ? 100 - magnitude : magnitude}
+              color={regression ? 'transparent' : color}
+            />
+            <Progress
+              bar
+              value={regression ? magnitude : 100 - magnitude}
+              color={regression ? color : 'transparent'}
+            />
+          </div>
+        </Progress>
+      }
+      tooltipText="Relative magnitude of change (scale from 0 - 20%+)"
+    />
+  );
+};
 
 ProgressBar.propTypes = {
   regression: PropTypes.bool.isRequired,