feat(stats): add useMaster scope to url_clicks model

opengovsg · Apr 13, 2021 · 48b98cb · 48b98cb
1 parent 3f7f559
commit 48b98cb
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Showing 3 changed files with 44 additions and 22 deletions.
diff --git a/src/server/models/statistics/clicks.ts b/src/server/models/statistics/clicks.ts
@@ -15,17 +15,36 @@ type UrlClicksTypeStatic = typeof Sequelize.Model & {
   new (values?: object, options?: Sequelize.BuildOptions): UrlClicksType
 }
 
-export const UrlClicks = <UrlClicksTypeStatic>sequelize.define('url_clicks', {
-  shortUrl: {
-    type: Sequelize.STRING,
-    primaryKey: true,
-    validate: {
-      is: SHORT_URL_REGEX,
+export const UrlClicks = <UrlClicksTypeStatic>sequelize.define(
+  'url_clicks',
+  {
+    shortUrl: {
+      type: Sequelize.STRING,
+      primaryKey: true,
+      validate: {
+        is: SHORT_URL_REGEX,
+      },
+    },
+    clicks: {
+      type: Sequelize.INTEGER,
+      defaultValue: 0,
+      allowNull: false,
     },
   },
-  clicks: {
-    type: Sequelize.INTEGER,
-    defaultValue: 0,
-    allowNull: false,
+  {
+    defaultScope: {
+      useMaster: true,
+    },
+    scopes: {
+      /**
+       * Use the master database for read queries. To be enabled
+       * when realtime data is needed.
+       */
+      useMasterDb() {
+        return {
+          useMaster: true,
+        }
+      },
+    },
   },
-})
+)
diff --git a/src/server/modules/statistics/repositories/StatisticsRepository.ts b/src/server/modules/statistics/repositories/StatisticsRepository.ts
@@ -27,18 +27,21 @@ export class StatisticsRepository implements interfaces.StatisticsRepository {
     )
 
     if (userCount == null) {
-      userCount = await User.scope('useMasterDb').count()
+      // Allow use of read replica
+      userCount = await User.unscoped().count()
       this.trySetCache(USER_COUNT_KEY, userCount.toString())
     }
 
     if (clickCount == null) {
       // Replace Nan with 0 if there is no data
-      clickCount = (await UrlClicks.sum('clicks')) || 0
+      // Allow use of read replica
+      clickCount = (await UrlClicks.unscoped().sum('clicks')) || 0
       this.trySetCache(CLICK_COUNT_KEY, clickCount.toString())
     }
 
     if (linkCount == null) {
-      linkCount = await Url.scope('useMasterDb').count()
+      // Allow use of read replica
+      linkCount = await Url.unscoped().count()
       this.trySetCache(LINK_COUNT_KEY, linkCount.toString())
     }
 

diff --git a/src/server/modules/statistics/repositories/__tests__/StatisticsRepository.test.ts b/src/server/modules/statistics/repositories/__tests__/StatisticsRepository.test.ts
@@ -63,15 +63,13 @@ describe('StatisticsRepository', () => {
   const userCount = 1
   const clickCount = 3
   const linkCount = 2
-  const { scope } = userModelMock
 
   beforeEach(async () => {
     await new Promise<void>((resolve) => {
       redisMockClient.flushall(() => resolve())
     })
     setSpy.mockClear()
     mgetSpy.mockClear()
-    scope.mockReset()
   })
 
   afterEach(async () => {
@@ -104,12 +102,14 @@ describe('StatisticsRepository', () => {
 
     // @ts-ignore
     mgetSpy.mockImplementation(raiseError)
-    scope.mockReturnValue({ count: () => userCount })
+    Object.assign(userModelMock, {
+      unscoped: () => ({ count: () => userCount }),
+    })
     Object.assign(urlModelMock, {
-      count: () => linkCount,
+      unscoped: () => ({ count: () => linkCount }),
     })
     Object.assign(urlClicksModelMock, {
-      sum: () => clickCount,
+      unscoped: () => ({ sum: () => clickCount }),
     })
 
     await expect(repository.getGlobalStatistics()).resolves.toStrictEqual({
@@ -119,7 +119,6 @@ describe('StatisticsRepository', () => {
     })
     expect(mgetSpy).toHaveBeenCalled()
     expect(setSpy).toHaveBeenCalledTimes(3)
-    expect(scope).toBeCalledWith('useMasterDb')
   })
 
   it('returns values from Sequelize even if Redis set fails', async () => {
@@ -133,7 +132,9 @@ describe('StatisticsRepository', () => {
       callback(new Error('error'))
     }
 
-    scope.mockReturnValue({ count: () => userCount })
+    Object.assign(urlModelMock, {
+      unscoped: () => ({ count: () => linkCount }),
+    })
     Object.assign(urlModelMock, {
       count: () => linkCount,
     })
@@ -151,6 +152,5 @@ describe('StatisticsRepository', () => {
     })
     expect(mgetSpy).toHaveBeenCalled()
     expect(setSpy).toHaveBeenCalledTimes(3)
-    expect(scope).toHaveBeenCalledWith('useMasterDb')
   })
 })