1 files changed, 29 insertions, 0 deletions
diff --git a/spec/javascripts/monitoring/utils_spec.js b/spec/javascripts/monitoring/utils_spec.js
new file mode 100644
index 00000000000..e3c455d1686
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+++ b/spec/javascripts/monitoring/utils_spec.js
@@ -0,0 +1,29 @@
+import { getTimeDiff } from '~/monitoring/utils';
+import { timeWindows } from '~/monitoring/constants';
+
+describe('getTimeDiff', () => {
+  it('defaults to an 8 hour (28800s) difference', () => {
+    const params = getTimeDiff();
+
+    expect(params.end - params.start).toEqual(28800);
+  });
+
+  it('accepts time window as an argument', () => {
+    const params = getTimeDiff(timeWindows.thirtyMinutes);
+
+    expect(params.end - params.start).not.toEqual(28800);
+  });
+
+  it('returns a value for every defined time window', () => {
+    const nonDefaultWindows = Object.keys(timeWindows).filter(window => window !== 'eightHours');
+
+    nonDefaultWindows.forEach(window => {
+      const params = getTimeDiff(timeWindows[window]);
+      const diff = params.end - params.start;
+
+      // Ensure we're not returning the default, 28800 (the # of seconds in 8 hrs)
+      expect(diff).not.toEqual(28800);
+      expect(typeof diff).toEqual('number');
+    });
+  });
+});