Add helper method to get a string representation of an AverageStatValue

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>

src/utils/webrtc/analyzers/AverageStatValue.js

@@ -55,6 +55,9 @@ const STAT_VALUE_TYPE = {
  * the raw value that was added or the relative one after the conversion (which,
  * for non cumulative values, will be the raw value too).
  *
+ * A string representation of the current relative values can be got by calling
+ * "toString()".
+ *
  * @param {int} count the number of instances to take into account.
  * @param {STAT_VALUE_TYPE} type whether the value is cumulative or relative.
  * @param {int} lastValueWeight the value to calculate the weights of all the
@@ -127,6 +130,22 @@ AverageStatValue.prototype = {
 		return weightedValues / weightsSum
 	},
 
+	toString() {
+		if (!this._relativeValues.length) {
+			return '[]'
+		}
+
+		let relativeValuesAsString = '[' + this._relativeValues[0]
+
+		for (let i = 1; i < this._relativeValues.length; i++) {
+			relativeValuesAsString += ', ' + this._relativeValues[i]
+		}
+
+		relativeValuesAsString += ']'
+
+		return relativeValuesAsString
+	},
+
 }
 
 export {

src/utils/webrtc/analyzers/AverageStatValue.spec.js

@@ -35,6 +35,43 @@ describe('AverageStatValue', () => {
 		})
 	})
 
+	describe('to string', () => {
+		test('no values', () => {
+			const stat = new AverageStatValue(3, STAT_VALUE_TYPE.CUMULATIVE, 3)
+			const stat2 = new AverageStatValue(3, STAT_VALUE_TYPE.RELATIVE, 3)
+
+			expect(stat.toString()).toBe('[]')
+			expect(stat2.toString()).toBe('[]')
+		})
+
+		test('single value', () => {
+			const stat = new AverageStatValue(3, STAT_VALUE_TYPE.CUMULATIVE, 3)
+			const stat2 = new AverageStatValue(3, STAT_VALUE_TYPE.RELATIVE, 3)
+
+			stat.add(42)
+			stat2.add(42)
+
+			// The first cumulative value is treated as 0 as it is the base from
+			// which the rest of the values will be calculated.
+			expect(stat.toString()).toBe('[0]')
+			expect(stat2.toString()).toBe('[42]')
+		})
+
+		test('several values', () => {
+			const testValues = [100, 200, 150, 123, 30, 50, 22, 33]
+			const stat = new AverageStatValue(3, STAT_VALUE_TYPE.CUMULATIVE, 3)
+			const stat2 = new AverageStatValue(3, STAT_VALUE_TYPE.RELATIVE, 3)
+
+			testValues.forEach((val, index) => {
+				stat.add(val)
+				stat2.add(val)
+			})
+
+			expect(stat.toString()).toBe('[20, -28, 11]')
+			expect(stat2.toString()).toBe('[50, 22, 33]')
+		})
+	})
+
 	describe('cumulative average', () => {
 		test('returns the last relative value', () => {
 			const testValues = [