Create telemetry shims (#797)

Author: jasonLaster

packages/devtools-modules/src/Services.js

@@ -498,6 +498,10 @@ PrefBranch.prototype = {
   },
 };
 
+window.telemetry = {}
+window.telemetry.histograms = {}
+window.telemetry.scalars = {}
+
 const Services = {
   _prefs: null,
 
@@ -563,15 +567,43 @@ const Services = {
   telemetry: {
     getHistogramById: function(name) {
       return {
-        add: () => {}
+        add: value => {
+          if (window.telemetry.histograms[name]) {
+            window.telemetry.histograms[name].push(value);
+          } else {
+            window.telemetry.histograms[name] = [value];
+          }
+        }
       };
     },
 
     getKeyedHistogramById: function(name) {
       return {
-        add: () => {}
+        add: (id, value) => {
+          if (!window.telemetry.histograms[name]) {
+            window.telemetry.histograms[name] = {};
+          }
+
+          if (!window.telemetry.histograms[name][id]) {
+            window.telemetry.histograms[name][id] = [];
+          }
+
+          window.telemetry.histograms[name][id].push(value);
+        }
       };
     },
+
+    scalarSet: function(scalarId, value) {
+      window.telemetry.scalars[scalarId] = value;
+    },
+
+    scalarAdd: function(scalarId, value) {
+      if (scalarId in window.telemetry.scalars) {
+        window.telemetry.scalars[scalarId] += value;
+      } else {
+        window.telemetry.scalars[scalarId] = value;
+      }
+    }
   },
 
   /**

packages/devtools-modules/src/tests/services-telemetry.js

@@ -0,0 +1,41 @@
+const Services = require("../Services");
+
+// const pref = Services;
+
+describe("services telemetry shim", () => {
+  beforeEach(() => {
+    telemetry.scalars = {};
+    telemetry.histograms = {};
+  });
+
+  it("getHistogramById", () => {
+    const hist = Services.telemetry.getHistogramById("foo");
+    hist.add(3);
+    expect(telemetry.histograms.foo).toEqual([3]);
+
+    hist.add(3);
+    expect(telemetry.histograms.foo).toEqual([3, 3]);
+  });
+
+  it("getKeyedHistogramById", () => {
+    const hist = Services.telemetry.getKeyedHistogramById("foo");
+    hist.add("a", 3);
+    expect(telemetry.histograms.foo.a).toEqual([3]);
+
+    hist.add("a", 3);
+    expect(telemetry.histograms.foo.a).toEqual([3, 3]);
+  });
+
+  it("scalarSet", () => {
+    Services.telemetry.scalarSet("foo", 3);
+    expect(telemetry.scalars.foo).toEqual(3);
+  });
+
+  it("scalarAdd", () => {
+    Services.telemetry.scalarAdd("foo", 3);
+    expect(telemetry.scalars.foo).toEqual(3);
+
+    Services.telemetry.scalarAdd("foo", 3);
+    expect(telemetry.scalars.foo).toEqual(6);
+  });
+});