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diff --git a/spec/frontend/analytics/usage_trends/utils_spec.js b/spec/frontend/analytics/usage_trends/utils_spec.js
new file mode 100644
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+++ b/spec/frontend/analytics/usage_trends/utils_spec.js
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+import {
+  getAverageByMonth,
+  getEarliestDate,
+  generateDataKeys,
+} from '~/analytics/usage_trends/utils';
+import {
+  mockCountsData1,
+  mockCountsData2,
+  countsMonthlyChartData1,
+  countsMonthlyChartData2,
+} from './mock_data';
+
+describe('getAverageByMonth', () => {
+  it('collects data into average by months', () => {
+    expect(getAverageByMonth(mockCountsData1)).toStrictEqual(countsMonthlyChartData1);
+    expect(getAverageByMonth(mockCountsData2)).toStrictEqual(countsMonthlyChartData2);
+  });
+
+  it('it transforms a data point to the first of the month', () => {
+    const item = mockCountsData1[0];
+    const firstOfTheMonth = item.recordedAt.replace(/-[0-9]{2}$/, '-01');
+    expect(getAverageByMonth([item])).toStrictEqual([[firstOfTheMonth, item.count]]);
+  });
+
+  it('it uses sane defaults', () => {
+    expect(getAverageByMonth()).toStrictEqual([]);
+  });
+
+  it('it errors when passing null', () => {
+    expect(() => {
+      getAverageByMonth(null);
+    }).toThrow();
+  });
+
+  describe('when shouldRound = true', () => {
+    const options = { shouldRound: true };
+
+    it('rounds the averages', () => {
+      const roundedData1 = countsMonthlyChartData1.map(([date, avg]) => [date, Math.round(avg)]);
+      const roundedData2 = countsMonthlyChartData2.map(([date, avg]) => [date, Math.round(avg)]);
+      expect(getAverageByMonth(mockCountsData1, options)).toStrictEqual(roundedData1);
+      expect(getAverageByMonth(mockCountsData2, options)).toStrictEqual(roundedData2);
+    });
+  });
+});
+
+describe('getEarliestDate', () => {
+  it('returns the date of the final item in the array', () => {
+    expect(getEarliestDate(mockCountsData1)).toBe('2020-06-12');
+  });
+
+  it('returns null for an empty array', () => {
+    expect(getEarliestDate([])).toBeNull();
+  });
+
+  it("returns null if the array has data but `recordedAt` isn't defined", () => {
+    expect(
+      getEarliestDate(mockCountsData1.map(({ recordedAt: date, ...rest }) => ({ date, ...rest }))),
+    ).toBeNull();
+  });
+});
+
+describe('generateDataKeys', () => {
+  const fakeQueries = [
+    { identifier: 'from' },
+    { identifier: 'first' },
+    { identifier: 'to' },
+    { identifier: 'last' },
+  ];
+
+  const defaultValue = 'default value';
+  const res = generateDataKeys(fakeQueries, defaultValue);
+
+  it('extracts each query identifier and sets them as object keys', () => {
+    expect(Object.keys(res)).toEqual(['from', 'first', 'to', 'last']);
+  });
+
+  it('sets every value to the `defaultValue` provided', () => {
+    expect(Object.values(res)).toEqual(Array(fakeQueries.length).fill(defaultValue));
+  });
+});