1 files changed, 207 insertions, 0 deletions
diff --git a/app/assets/javascripts/vue_merge_request_widget/components/extensions/telemetry.js b/app/assets/javascripts/vue_merge_request_widget/components/extensions/telemetry.js
new file mode 100644
index 00000000000..aec3a35f37c
--- /dev/null
+++ b/app/assets/javascripts/vue_merge_request_widget/components/extensions/telemetry.js
@@ -0,0 +1,207 @@
+import api from '~/api';
+import createEventHub from '~/helpers/event_hub_factory';
+import {
+  TELEMETRY_WIDGET_VIEWED,
+  TELEMETRY_WIDGET_EXPANDED,
+  TELEMETRY_WIDGET_FULL_REPORT_CLICKED,
+} from '../../constants';
+
+/*
+ * Additional events to send beyond the defaults for certain widget extensions
+ */
+const nonStandardEvents = {
+  codeQuality: {
+    uniqueUser: {
+      expand: ['i_testing_code_quality_widget_total'],
+    },
+    counter: {},
+  },
+  terraform: {
+    uniqueUser: {
+      expand: ['i_testing_terraform_widget_total'],
+    },
+    counter: {},
+  },
+  issues: {
+    uniqueUser: {
+      expand: ['i_testing_load_performance_widget_total'],
+    },
+    counter: {},
+  },
+  testReport: {
+    uniqueUser: {
+      expand: ['i_testing_summary_widget_total'],
+    },
+    counter: {},
+  },
+};
+
+function combineDeepArray(path, ...objects) {
+  const parts = path.split('.');
+  const allEntries = objects.reduce((entries, currentObject) => {
+    let expandedEntries = entries;
+    let traversed = currentObject;
+
+    parts.forEach((part) => {
+      traversed = traversed?.[part];
+    });
+
+    if (traversed) {
+      expandedEntries = [...entries, ...traversed];
+    }
+
+    return expandedEntries;
+  }, []);
+
+  return Array.from(new Set(allEntries));
+}
+
+function simplifyWidgetName(componentName) {
+  const noWidget = componentName.replace(/^Widget/, '');
+
+  return noWidget.charAt(0).toLowerCase() + noWidget.slice(1);
+}
+
+function baseRedisEventName(extensionName) {
+  const redisEventName = extensionName.replace(/([A-Z])/g, '_$1').toLowerCase();
+
+  return `i_merge_request_widget_${redisEventName}`;
+}
+
+function whenable(bus) {
+  return function when(event) {
+    return ({ execute, track, special }) => {
+      bus.$on(event, (busEvent) => {
+        track.forEach((redisEvent) => {
+          execute(redisEvent);
+        });
+
+        special?.({ event, execute, track, bus, busEvent });
+      });
+    };
+  };
+}
+
+function defaultBehaviorEvents({ bus, config }) {
+  const when = whenable(bus);
+  const isViewed = when(TELEMETRY_WIDGET_VIEWED);
+  const isExpanded = when(TELEMETRY_WIDGET_EXPANDED);
+  const fullReportIsClicked = when(TELEMETRY_WIDGET_FULL_REPORT_CLICKED);
+  const toHll = config?.uniqueUser || {};
+  const toCounts = config?.counter || {};
+  const user = api.trackRedisHllUserEvent.bind(api);
+  const count = api.trackRedisCounterEvent.bind(api);
+
+  if (toHll.view) {
+    isViewed({ execute: user, track: toHll.view });
+  }
+  if (toCounts.view) {
+    isViewed({ execute: count, track: toCounts.view });
+  }
+
+  if (toHll.expand) {
+    isExpanded({
+      execute: user,
+      track: toHll.expand,
+      special: ({ execute, track, busEvent }) => {
+        if (busEvent.type) {
+          track.forEach((event) => {
+            execute(`${event}_${busEvent.type}`);
+          });
+        }
+      },
+    });
+  }
+  if (toCounts.expand) {
+    isExpanded({
+      execute: count,
+      track: toCounts.expand,
+      special: ({ execute, track, busEvent }) => {
+        if (busEvent.type) {
+          track.forEach((event) => {
+            execute(`${event}_${busEvent.type}`);
+          });
+        }
+      },
+    });
+  }
+
+  if (toHll.clickFullReport) {
+    fullReportIsClicked({ execute: user, track: toHll.clickFullReport });
+  }
+  if (toCounts.clickFullReport) {
+    fullReportIsClicked({ execute: count, track: toCounts.clickFullReport });
+  }
+}
+
+function baseTelemetry(componentName) {
+  const simpleExtensionName = simplifyWidgetName(componentName);
+  const additionalNonStandard = nonStandardEvents[simpleExtensionName] || {};
+  /*
+   * Telemetry config format is:
+   *    {
+   *        TELEMETRY_TYPE: {
+   *            BEHAVIOR: [ EVENT_NAME, ... ]
+   *        }
+   *    }
+   *
+   * Right now, there are currently configurations for these telemetry types:
+   *     - uniqueUser is sent to RedisHLL
+   *     - counter is sent to a regular Redis counter
+   */
+  const defaultTelemetry = {
+    uniqueUser: {
+      view: [`${baseRedisEventName(simpleExtensionName)}_view`],
+      expand: [`${baseRedisEventName(simpleExtensionName)}_expand`],
+      clickFullReport: [`${baseRedisEventName(simpleExtensionName)}_click_full_report`],
+    },
+    counter: {
+      view: [`${baseRedisEventName(simpleExtensionName)}_count_view`],
+      expand: [`${baseRedisEventName(simpleExtensionName)}_count_expand`],
+      clickFullReport: [`${baseRedisEventName(simpleExtensionName)}_count_click_full_report`],
+    },
+  };
+
+  return {
+    uniqueUser: {
+      view: combineDeepArray('uniqueUser.view', defaultTelemetry, additionalNonStandard),
+      expand: combineDeepArray('uniqueUser.expand', defaultTelemetry, additionalNonStandard),
+      clickFullReport: combineDeepArray(
+        'uniqueUser.clickFullReport',
+        defaultTelemetry,
+        additionalNonStandard,
+      ),
+    },
+    counter: {
+      view: combineDeepArray('counter.view', defaultTelemetry, additionalNonStandard),
+      expand: combineDeepArray('counter.expand', defaultTelemetry, additionalNonStandard),
+      clickFullReport: combineDeepArray(
+        'counter.clickFullReport',
+        defaultTelemetry,
+        additionalNonStandard,
+      ),
+    },
+  };
+}
+
+export function createTelemetryHub(componentName) {
+  const bus = createEventHub();
+  const config = baseTelemetry(componentName);
+
+  defaultBehaviorEvents({ bus, config });
+
+  return {
+    viewed() {
+      bus.$emit(TELEMETRY_WIDGET_VIEWED);
+    },
+    expanded({ type }) {
+      bus.$emit(TELEMETRY_WIDGET_EXPANDED, { type });
+    },
+    fullReportClicked() {
+      bus.$emit(TELEMETRY_WIDGET_FULL_REPORT_CLICKED);
+    },
+    /* I want a Record here: #{ ...config } // and then the comment would be: This is for debugging only, changing your reference to it does nothing. 😘 */
+    config: Object.freeze({ ...config }), // This is *intended* to be for debugging only, but it's pretty mutable, and it has references to live data in child props
+    bus,
+  };
+}