diff --git a/services/test-validators.js b/services/test-validators.js
index c6804831c2..b6a30c2cb1 100644
--- a/services/test-validators.js
+++ b/services/test-validators.js
@@ -64,16 +64,24 @@ const isStarRating = withRegex(
 // Required to be > 0, because accepting zero masks many problems.
 const isMetric = withRegex(/^([1-9][0-9]*[kMGTPEZY]?|[1-9]\.[1-9][kMGTPEZY])$/)
 
-const isMetricOpenIssues = withRegex(
-  /^([1-9][0-9]*[kMGTPEZY]?|[1-9]\.[1-9][kMGTPEZY]) open$/
+/**
+ * @param {RegExp} nestedRegexp Pattern that must appear after the metric.
+ * @returns {Function} A function that returns a RegExp that matches a metric followed by another pattern.
+ */
+const isMetricWithPattern = nestedRegexp => {
+  const pattern = `^([1-9][0-9]*[kMGTPEZY]?|[1-9]\\.[1-9][kMGTPEZY])${nestedRegexp.source}$`
+  const regexp = new RegExp(pattern)
+  return withRegex(regexp)
+}
+
+const isMetricOpenIssues = isMetricWithPattern(/ open/)
+
+const isMetricOverMetric = isMetricWithPattern(
+  /\/([1-9][0-9]*[kMGTPEZY]?|[1-9]\.[1-9][kMGTPEZY])/
 )
 
-const isMetricOverMetric = withRegex(
-  /^([1-9][0-9]*[kMGTPEZY]?|[1-9]\.[1-9][kMGTPEZY])\/([1-9][0-9]*[kMGTPEZY]?|[1-9]\.[1-9][kMGTPEZY])$/
-)
-
-const isMetricOverTimePeriod = withRegex(
-  /^([1-9][0-9]*[kMGTPEZY]?|[1-9]\.[1-9][kMGTPEZY])\/(year|month|four weeks|quarter|week|day)$/
+const isMetricOverTimePeriod = isMetricWithPattern(
+  /\/(year|month|four weeks|quarter|week|day)/
 )
 
 const isZeroOverTimePeriod = withRegex(
@@ -151,6 +159,7 @@ module.exports = {
   isPhpVersionReduction,
   isStarRating,
   isMetric,
+  isMetricWithPattern,
   isMetricOpenIssues,
   isMetricOverMetric,
   isMetricOverTimePeriod,