From f5a65ecef41cac7350b6377637025d412a715e2c Mon Sep 17 00:00:00 2001
From: Patrick Browne <pt.browne@gmail.com>
Date: Thu, 6 Feb 2020 13:10:28 +0100
Subject: [PATCH] feat: Expose only 1 method to initialize flags

---
 packages/cozy-flags/src/flag.js  | 50 ++++++++++++++++--
 packages/cozy-flags/src/tests.js | 91 ++++++++++++++++++--------------
 2 files changed, 96 insertions(+), 45 deletions(-)

diff --git a/packages/cozy-flags/src/flag.js b/packages/cozy-flags/src/flag.js
index c4810069a6..a4dd1ad01c 100644
--- a/packages/cozy-flags/src/flag.js
+++ b/packages/cozy-flags/src/flag.js
@@ -51,6 +51,13 @@ export const enable = flagsToEnable => {
   }
 }
 
+/**
+ * Initializes flags from the remote endpoint serving instance flags
+ *
+ * @private
+ * @see  https://docs.cozy.io/en/cozy-stack/settings/#get-settingsflags
+ * @param  {CozyClient} client
+ */
 export const initializeFromRemote = async client => {
   const {
     data: { attributes }
@@ -59,6 +66,9 @@ export const initializeFromRemote = async client => {
 }
 
 export const getTemplateData = attr => {
+  if (typeof document === 'undefined') {
+    return null
+  }
   const allDataNode = document.querySelector('[data-cozy]')
   const attrNode = document.querySelector(`[data-${attr}]`)
   try {
@@ -77,14 +87,43 @@ export const getTemplateData = attr => {
   }
 }
 
-export const initializeFromDOM = client => {
+/**
+ * Initialize from the template data injected by cozy-stack into the DOM
+ *
+ * @private
+ * @see https://docs.cozy.io/en/cozy-stack/client-app-dev/#good-practices-for-your-application
+ *
+ * @returns {Boolean} - False is DOM initialization could not be completed, true otherwise
+ */
+export const initializeFromDOM = async () => {
   const domData = getTemplateData('flags')
   if (!domData) {
-    console.warn('no dom daa')
-    return
+    return false
   }
-  for (const [flagName, flagValue] of Object.entries(domData)) {
-    flag(flagName, flagValue)
+  enable(domData)
+  return true
+}
+
+/**
+ * Initialize flags from DOM if possible, otherwise from remote endpoint
+ *
+ * @example
+ *
+ * Flags can be taken from the flags injected by the stack
+ * ```
+ * <div data-cozy="{{ .CozyData }}"></div>
+ *
+ * // not recommended but possible
+ * <div data-flags="{{ .Flags }}"></div>
+ * ````
+ *
+ * @param  {CozyClient} client - A CozyClient
+ * @return {Promise} Resolves when flags have been initialized
+ */
+export const initialize = async client => {
+  const domRes = await initializeFromDOM()
+  if (domRes == false) {
+    await initializeFromRemote(client)
   }
 }
 
@@ -94,5 +133,6 @@ flag.reset = resetFlags
 flag.enable = enable
 flag.initializeFromRemote = initializeFromRemote
 flag.initializeFromDOM = initializeFromDOM
+flag.initialize = initialize
 
 export default flag
diff --git a/packages/cozy-flags/src/tests.js b/packages/cozy-flags/src/tests.js
index cd67528960..bdc6d84093 100644
--- a/packages/cozy-flags/src/tests.js
+++ b/packages/cozy-flags/src/tests.js
@@ -56,52 +56,63 @@ export default function testFlagAPI(flag) {
     })
   })
 
-  if (typeof document !== 'undefined') {
-    describe('initializeFromDOM', () => {
-      it('should initialize from DOM', async () => {
-        const body = document.body
-        const div = document.createElement('div')
-        div.dataset.cozy = JSON.stringify({
-          flags: {
-            has_feature1: true,
-            has_feature2: false,
-            number_of_foos: 10,
-            bar_config: { qux: 'quux' }
-          }
-        })
-        body.appendChild(div)
+  describe('initialization', () => {
+    const remoteFlags = {
+      has_feature1: true,
+      has_feature2: false,
+      number_of_foos: 10,
+      bar_config: { qux: 'quux' },
+      from_remote: true
+    }
+    const flagRemoteResponse = {
+      data: {
+        type: 'io.cozy.settings',
+        id: 'io.cozy.settings.flags',
+        attributes: remoteFlags,
+        links: {
+          self: '/settings/flags'
+        }
+      }
+    }
 
-        await flag.initializeFromDOM()
-        expect(flag('has_feature1')).toBe(true)
-        expect(flag('has_feature2')).toBe(false)
-        expect(flag('number_of_foos')).toBe(10)
-        expect(flag('bar_config')).toEqual({ qux: 'quux' })
-      })
-    })
-  }
+    const domFlags = {
+      has_feature1: true,
+      has_feature2: false,
+      number_of_foos: 10,
+      bar_config: { qux: 'quux' },
+      from_remote: false
+    }
 
-  describe('initializeFromRemote', () => {
-    it('should initialize from the remote stack', async () => {
+    const setup = () => {
       const client = new CozyClient({})
-      const flagResponseFixture = {
-        data: {
-          type: 'io.cozy.settings',
-          id: 'io.cozy.settings.flags',
-          attributes: {
-            has_feature1: true,
-            has_feature2: false,
-            number_of_foos: 10,
-            bar_config: { qux: 'quux' }
-          },
-          links: {
-            self: '/settings/flags'
-          }
+      client.stackClient.fetchJSON = jest.fn(() => flagRemoteResponse)
+      return { client }
+    }
+
+    if (typeof document !== 'undefined') {
+      it('should initialize from DOM', async () => {
+        let div
+        try {
+          div = document.createElement('div')
+          div.dataset.cozy = JSON.stringify({ flags: domFlags })
+          document.body.appendChild(div)
+          await flag.initialize()
+          expect(flag('has_feature1')).toBe(true)
+          expect(flag('has_feature2')).toBe(false)
+          expect(flag('number_of_foos')).toBe(10)
+          expect(flag('bar_config')).toEqual({ qux: 'quux' })
+        } finally {
+          document.body.removeChild(div)
         }
-      }
-      client.stackClient.fetchJSON = jest.fn(() => flagResponseFixture)
-      await flag.initializeFromRemote(client)
+      })
+    }
+
+    it('should initialize from the remote stack', async () => {
+      const { client } = setup()
+      await flag.initialize(client)
       expect(flag('has_feature1')).toBe(true)
       expect(flag('has_feature2')).toBe(false)
+      expect(flag('from_remote')).toBe(true)
       expect(flag('number_of_foos')).toBe(10)
       expect(flag('bar_config')).toEqual({ qux: 'quux' })
     })