Bug 1683057 - Implement the UUID metric type (#17)

Author: Beatriz Rizental

package-lock.json

@@ -32,6 +32,7 @@
     "@types/assert": "^1.5.2",
     "@types/mocha": "^8.0.3",
     "@types/selenium-webdriver": "^4.0.10",
+    "@types/uuid": "^8.3.0",
     "@typescript-eslint/eslint-plugin": "^4.6.1",
     "@typescript-eslint/parser": "^4.6.1",
     "eslint": "^7.12.1",
@@ -49,5 +50,8 @@
     "web-ext-types": "^3.2.1",
     "webpack": "^5.4.0",
     "webpack-cli": "^4.2.0"
+  },
+  "dependencies": {
+    "uuid": "^8.3.2"
   }
 }

package.json

@@ -55,7 +55,7 @@ class Glean {
    *
    * TODO: Only allow this function to be called on test mode (depends on Bug 1682771).
    */
-  static async resetGlean(): Promise<void> {
+  static async testRestGlean(): Promise<void> {
     // Reset upload enabled state, not to inerfere with other tests.
     Glean.uploadEnabled = true;
     // Clear the database.

src/glean.ts

@@ -35,7 +35,7 @@ class BooleanMetric extends Metric {
    *
    * @param value the value to set.
    */
-  async set(value: BooleanMetricPayload): Promise<void> {
+  async set(value: boolean): Promise<void> {
     if (!this.shouldRecord()) {
       return;
     }

src/metrics/boolean.ts

@@ -69,7 +69,7 @@ class CounterMetric extends Metric {
 
     if (amount <= 0) {
       // TODO: record error once Bug 1682574 is resolved.
-      console.warn(`Attempted to add an invalid amount ${amount}. `);
+      console.warn(`Attempted to add an invalid amount ${amount}. Ignoring.`);
       return;
     }
 

src/metrics/counter.ts

@@ -5,6 +5,7 @@
 import { BooleanMetricPayload, isBooleanMetricPayload } from "metrics/boolean";
 import { CounterMetricPayload, isCounterMetricPayload } from "metrics/counter";
 import { StringMetricPayload, isStringMetricPayload } from "metrics/string";
+import { UUIDMetricPayload, isUUIDMetricPayload } from "metrics/uuid";
 
 /**
  * Validates that a given value is the correct type of payload for a metric of a given type.
@@ -22,6 +23,8 @@ export function isMetricPayload<T>(type: string, v: unknown): v is T {
     return isCounterMetricPayload(v);
   case "string":
     return isStringMetricPayload(v);
+  case "uuid":
+    return isUUIDMetricPayload(v);
   default:
     return false;
   }
@@ -31,5 +34,6 @@ export function isMetricPayload<T>(type: string, v: unknown): v is T {
 export type MetricPayload =
   BooleanMetricPayload |
   CounterMetricPayload |
-  StringMetricPayload;
+  StringMetricPayload |
+  UUIDMetricPayload;
 

src/metrics/payload.ts

@@ -0,0 +1,98 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import { v4 as UUIDv4, validate as UUIDvalidate } from "uuid";
+
+import Metric, { CommonMetricData } from "metrics";
+import Glean from "glean";
+import { isString } from "utils";
+
+export type UUIDMetricPayload = string;
+
+/**
+ * Checks whether or not `v` is a valid UUID metric payload.
+ *
+ * @param v The value to verify.
+ *
+ * @returns A special Typescript value (which compiles down to a boolean)
+ *          stating whether `v` is a valid boolean metric payload.
+ */
+export function isUUIDMetricPayload(v: unknown): v is UUIDMetricPayload {
+  if (!isString(v)) {
+    return false;
+  }
+
+  return UUIDvalidate(v);
+}
+
+/**
+ *  An UUID metric.
+ *
+ * Stores UUID v4 (randomly generated) values.
+ */
+class UUIDMetric extends Metric {
+  constructor(meta: CommonMetricData) {
+    super("uuid", meta);
+  }
+
+  /**
+   * Sets to the specified value.
+   *
+   * @param value the value to set.
+   *
+   * @throws In case `value` is not a valid UUID.
+   */
+  async set(value: string): Promise<void> {
+    if (!this.shouldRecord()) {
+      return;
+    }
+
+    if (!value) {
+      value = UUIDv4();
+    }
+
+    if (!isUUIDMetricPayload(value)) {
+      // TODO: record error once Bug 1682574 is resolved.
+      console.warn(`"${value}" is not a valid UUID. Ignoring`);
+      return;
+    }
+
+    await Glean.db.record(this, value);
+  }
+
+  /**
+   * Generates a new random uuid and sets the metric to it.
+   *
+   * @returns The generated value or `undefined` in case this metric shouldn't be recorded.
+   */
+  async generateAndSet(): Promise<UUIDMetricPayload | undefined> {
+    if (!this.shouldRecord()) {
+      return;
+    }
+
+    const value = UUIDv4();
+    await this.set(value);
+
+    return value;
+  }
+ 
+  /**
+   * **Test-only API**
+   *
+   * Gets the currently stored value as a string.
+   *
+   * This doesn't clear the stored value.
+   *
+   * TODO: Only allow this function to be called on test mode (depends on Bug 1682771).
+   *
+   * @param ping the ping from which we want to retrieve this metrics value from.
+   *
+   * @returns The value found in storage or `undefined` if nothing was found.
+   */
+  async testGetValue(ping: string): Promise<UUIDMetricPayload | undefined> {
+    return Glean.db.getMetric(ping, this);
+  }
+}
+ 
+export default UUIDMetric;

src/metrics/uuid.ts

@@ -10,7 +10,7 @@ import { Lifetime } from "metrics";
 
 describe("BooleanMetric", function() {
   beforeEach(async function() {
-    await Glean.resetGlean();
+    await Glean.testRestGlean();
   });
 
   it("attemping to get the value of a metric that hasn't been recorded doesn't error", async function() {

tests/metrics/boolean.spec.ts

@@ -10,7 +10,7 @@ import { Lifetime } from "metrics";
 
 describe("CounterMetric", function() {
   beforeEach(async function() {
-    await Glean.resetGlean();
+    await Glean.testRestGlean();
   });
 
   it("attemping to get the value of a metric that hasn't been recorded doesn't error", async function() {

tests/metrics/counter.spec.ts

@@ -10,7 +10,7 @@ import { Lifetime } from "metrics";
 
 describe("StringMetric", function() {
   beforeEach(async function() {
-    await Glean.resetGlean();
+    await Glean.testRestGlean();
   });
 
   it("attemping to get the value of a metric that hasn't been recorded doesn't error", async function() {