feat(tests): add canvas mocks, needed for favico.js

ui/package-lock.json

@@ -6506,6 +6506,12 @@
         }
       }
     },
+    "jest-canvas-mock": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/jest-canvas-mock/-/jest-canvas-mock-1.1.0.tgz",
+      "integrity": "sha512-D2VoKl+L6r9VpqTPygXKvIOQ1aou7gz3PvstlWDZqPT7EVYcSz0Nj+yjJ9G+Y9EqJd2X95f3dzcmmXb2dvQ1DQ==",
+      "dev": true
+    },
     "jest-changed-files": {
       "version": "20.0.3",
       "resolved": "https://registry.npmjs.org/jest-changed-files/-/jest-changed-files-20.0.3.tgz",

ui/package.json

@@ -55,6 +55,7 @@
     "enzyme-adapter-react-16": "1.3.0",
     "enzyme-to-json": "3.3.4",
     "eslint-plugin-react": "7.11.1",
+    "jest-canvas-mock": "1.1.0",
     "jest-fetch-mock": "1.6.5",
     "jest-localstorage-mock": "2.2.0",
     "jest-mock-console": "0.4.0",

ui/src/setupTests.js

@@ -12,6 +12,9 @@ mockConsole(["error", "warn", "info", "log", "trace"]);
 // localStorage is used for Settings store
 require("jest-localstorage-mock");
 
+// favico.js needs canvas
+require("jest-canvas-mock");
+
 // fetch is used in multiple places to interact with Go backend
 // or upstream Alertmanager API
 global.fetch = require("jest-fetch-mock");