Add summary function to init labels

index.d.ts

@@ -649,6 +649,20 @@ export class Summary<T extends string = string> {
  */
  labels(labels: LabelValues<T>): Summary.Internal<T>;
 
+ /**
+ * Initializes to 0 for given label values
+ * @param values Label values
+ * @return Configured summary with given labels
+ */
+ initLabels(...values: string[]): Summary.Internal<T>;
+
+ /**
+ * Initializes to 0 for given label values
+ * @param labels Object with label keys and values
+ * @return Configured counter with given labels
+ */
+ initLabels(labels: LabelValues<T>): Summary.Internal<T>;
+
  /**
  * Remove metrics for the given label values
  * @param values Label values

lib/summary.js

@@ -103,6 +103,22 @@ class Summary extends Metric {
  return startTimer.call(this, labels)();
  }
 
+ initLabels(...args) {
+ const labels = getLabels(this.labelNames, args);
+ validateLabel(this.labelNames, labels);
+ const hash = hashObject(labels, this.sortedLabelNames);
+ let summaryOfLabel = this.hashMap[hash];
+ if (!summaryOfLabel) {
+ summaryOfLabel = {
+ labels,
+ td: new timeWindowQuantiles(this.maxAgeSeconds, this.ageBuckets),
+ count: 0,
+ sum: 0,
+ };
+ this.hashMap[hash] = summaryOfLabel;
+ }
+ }
+
  labels(...args) {
  const labels = getLabels(this.labelNames, args);
  validateLabel(this.labelNames, labels);

test/summaryTest.js

@@ -307,6 +307,45 @@ describe.each([
  expect(value.labels.method).toBe('GET');
  });
  });
+
+ it.only('can init labels to 0', async () => {
+ instance.initLabels('GET', '/test');
+
+ const { values } = await instance.get();
+ expect(values).toHaveLength(3);
+ expect(values[0].labels.method).toEqual('GET');
+ expect(values[0].labels.endpoint).toEqual('/test');
+ expect(values[0].labels.quantile).toEqual(0.9);
+ expect(values[0].value).toEqual(0);
+
+ expect(values[1].metricName).toEqual('summary_test_sum');
+ expect(values[1].labels.method).toEqual('GET');
+ expect(values[1].labels.endpoint).toEqual('/test');
+ expect(values[1].value).toEqual(0);
+
+ expect(values[2].metricName).toEqual('summary_test_count');
+ expect(values[2].labels.method).toEqual('GET');
+ expect(values[2].labels.endpoint).toEqual('/test');
+ expect(values[2].value).toEqual(0);
+ });
+
+ it.only('can init labels passed as an object', async () => {
+ instance.initLabels({ method: 'GET' });
+
+ const { values } = await instance.get();
+ expect(values).toHaveLength(3);
+ expect(values[0].labels.method).toEqual('GET');
+ expect(values[0].labels.quantile).toEqual(0.9);
+ expect(values[0].value).toEqual(0);
+
+ expect(values[1].metricName).toEqual('summary_test_sum');
+ expect(values[1].labels.method).toEqual('GET');
+ expect(values[1].value).toEqual(0);
+
+ expect(values[2].metricName).toEqual('summary_test_count');
+ expect(values[2].labels.method).toEqual('GET');
+ expect(values[2].value).toEqual(0);
+ });
  });
 
  describe('remove', () => {