Export getRange to helper funciton

ui/src/shared/components/Dygraph.js

@@ -1,6 +1,7 @@
 /* eslint-disable no-magic-numbers */
 import React, {PropTypes} from 'react';
 import Dygraph from '../../external/dygraph';
+import getRange from 'src/shared/parsing/getRangeForDygraph';
 import _ from 'lodash';
 
 const {
@@ -179,60 +180,3 @@ export default React.createClass({
     );
   },
 });
-
-const PADDING_FACTOR = 0.1;
-
-function getRange(timeSeries, override, value = null, rangeValue = null) {
-  if (override) {
-    return override;
-  }
-
-  const subtractPadding = (val) => +val - val * PADDING_FACTOR;
-  const addPadding = (val) => +val + val * PADDING_FACTOR;
-
-  const pad = (val, side) => {
-    if (val === null || val === '') {
-      return null;
-    }
-
-    if (val < 0) {
-      return side === "top" ? subtractPadding(val) : addPadding(val);
-    }
-
-    return side === "top" ? addPadding(val) : subtractPadding(val);
-  };
-
-  const points = [
-    ...timeSeries,
-    [null, pad(value)],
-    [null, pad(rangeValue, "top")],
-  ];
-
-  const range = points.reduce(([min, max], series) => {
-    for (let i = 1; i < series.length; i++) {
-      const val = series[i];
-
-      if (max === null) {
-        max = val;
-      }
-
-      if (min === null) {
-        min = val;
-      }
-
-      if (typeof val === "number") {
-        min = Math.min(min, val);
-        max = Math.max(max, val);
-      }
-
-      return [min, max];
-    }
-  }, [null, null]);
-
-  // Dygraph will not reliably plot X / Y axis labels if min and max are both 0
-  if (range[0] === 0 && range[1] === 0) {
-    return [null, null];
-  }
-
-  return range;
-}

ui/src/shared/parsing/getRangeForDygraph.js

@@ -0,0 +1,56 @@
+const PADDING_FACTOR = 0.1;
+
+export default function getRange(timeSeries, override, value = null, rangeValue = null) {
+  if (override) {
+    return override;
+  }
+
+  const subtractPadding = (val) => +val - val * PADDING_FACTOR;
+  const addPadding = (val) => +val + val * PADDING_FACTOR;
+
+  const pad = (val, side) => {
+    if (val === null || val === '') {
+      return null;
+    }
+
+    if (val < 0) {
+      return side === "top" ? subtractPadding(val) : addPadding(val);
+    }
+
+    return side === "top" ? addPadding(val) : subtractPadding(val);
+  };
+
+  const points = [
+    ...timeSeries,
+    [null, pad(value)],
+    [null, pad(rangeValue, "top")],
+  ];
+
+  const range = points.reduce(([min, max], series) => {
+    for (let i = 1; i < series.length; i++) {
+      const val = series[i];
+
+      if (max === null) {
+        max = val;
+      }
+
+      if (min === null) {
+        min = val;
+      }
+
+      if (typeof val === "number") {
+        min = Math.min(min, val);
+        max = Math.max(max, val);
+      }
+    }
+
+    return [min, max];
+  }, [null, null]);
+
+  // If time series is such that min and max are equal use Dygraph defaults
+  if (range[0] === range[1]) {
+    return [null, null];
+  }
+
+  return range;
+}