From 57ca5261bf130f96c521fcb20d2965e6883bf9b3 Mon Sep 17 00:00:00 2001
From: Rory Powell <rory.codes@gmail.com>
Date: Mon, 8 Aug 2022 16:12:38 +0100
Subject: [PATCH] Support per app events

---
 .../events/processors/posthog/rateLimiting.ts | 14 ++++-
 .../posthog/tests/PosthogProcessor.spec.ts    | 59 +++++++++++++++++--
 2 files changed, 65 insertions(+), 8 deletions(-)

diff --git a/packages/backend-core/src/events/processors/posthog/rateLimiting.ts b/packages/backend-core/src/events/processors/posthog/rateLimiting.ts
index f61d34d0a4..e2a02eb28e 100644
--- a/packages/backend-core/src/events/processors/posthog/rateLimiting.ts
+++ b/packages/backend-core/src/events/processors/posthog/rateLimiting.ts
@@ -1,6 +1,7 @@
 import { Event } from "@budibase/types"
 import { CacheKeys, TTL } from "../../../cache/generic"
 import * as cache from "../../../cache/generic"
+import * as context from "../../../context"
 
 type RateLimitedEvent =
   | Event.SERVED_BUILDER
@@ -15,6 +16,10 @@ const isRateLimited = (event: Event): event is RateLimitedEvent => {
   )
 }
 
+const isPerApp = (event: RateLimitedEvent) => {
+  return event === Event.SERVED_APP_PREVIEW || event === Event.SERVED_APP
+}
+
 interface EventProperties {
   timestamp: number
 }
@@ -69,7 +74,11 @@ export const limited = async (event: Event): Promise<boolean> => {
 }
 
 const eventKey = (event: RateLimitedEvent) => {
-  return `${CacheKeys.EVENTS_RATE_LIMIT}:${event}`
+  let key = `${CacheKeys.EVENTS_RATE_LIMIT}:${event}`
+  if (isPerApp(event)) {
+    key = key + context.getAppId()
+  }
+  return key
 }
 
 const readEvent = async (event: RateLimitedEvent) => {
@@ -81,8 +90,7 @@ const recordEvent = async (
   event: RateLimitedEvent,
   properties: EventProperties
 ) => {
-  const key = `${CacheKeys.EVENTS_RATE_LIMIT}:${event}`
-
+  const key = eventKey(event)
   const limit = RATE_LIMITS[event]
   let ttl
   switch (limit) {
diff --git a/packages/backend-core/src/events/processors/posthog/tests/PosthogProcessor.spec.ts b/packages/backend-core/src/events/processors/posthog/tests/PosthogProcessor.spec.ts
index 7ddee7279b..d14b697966 100644
--- a/packages/backend-core/src/events/processors/posthog/tests/PosthogProcessor.spec.ts
+++ b/packages/backend-core/src/events/processors/posthog/tests/PosthogProcessor.spec.ts
@@ -1,7 +1,10 @@
+import "../../../../../tests/utilities/TestConfiguration"
 import PosthogProcessor from "../PosthogProcessor"
 import { Event, IdentityType, Hosting } from "@budibase/types"
 const tk = require("timekeeper")
-import * as Cache from "../../../../cache/generic"
+import * as cache from "../../../../cache/generic"
+import { CacheKeys } from "../../../../cache/generic"
+import * as context from "../../../../context"
 
 const newIdentity = () => {
   return {
@@ -13,8 +16,11 @@ const newIdentity = () => {
 }
 
 describe("PosthogProcessor", () => {
-  beforeEach(() => {
+  beforeEach(async () => {
     jest.clearAllMocks()
+    await cache.bustCache(
+      `${CacheKeys.EVENTS_RATE_LIMIT}:${Event.SERVED_BUILDER}`
+    )
   })
 
   describe("processEvent", () => {
@@ -71,7 +77,7 @@ describe("PosthogProcessor", () => {
         tk.freeze(new Date(2022, 0, 3, 6, 0))
         await processor.processEvent(Event.SERVED_BUILDER, identity, properties)
 
-        expect(processor.posthog.capture).toHaveBeenCalledTimes(4)
+        expect(processor.posthog.capture).toHaveBeenCalledTimes(3)
       })
 
       it("sends event again after cache expires", async () => {
@@ -82,8 +88,8 @@ describe("PosthogProcessor", () => {
         tk.freeze(new Date(2022, 0, 1, 14, 0))
         await processor.processEvent(Event.SERVED_BUILDER, identity, properties)
 
-        await Cache.bustCache(
-          `${Cache.CacheKeys.EVENTS_RATE_LIMIT}:${Event.SERVED_BUILDER}`
+        await cache.bustCache(
+          `${CacheKeys.EVENTS_RATE_LIMIT}:${Event.SERVED_BUILDER}`
         )
 
         tk.freeze(new Date(2022, 0, 1, 14, 0))
@@ -91,6 +97,49 @@ describe("PosthogProcessor", () => {
 
         expect(processor.posthog.capture).toHaveBeenCalledTimes(2)
       })
+
+      it("sends per app events once per day per app", async () => {
+        const processor = new PosthogProcessor("test")
+        const identity = newIdentity()
+        const properties = {}
+
+        const runAppEvents = async (appId: string) => {
+          await context.doInAppContext(appId, async () => {
+            tk.freeze(new Date(2022, 0, 1, 14, 0))
+            await processor.processEvent(Event.SERVED_APP, identity, properties)
+            await processor.processEvent(
+              Event.SERVED_APP_PREVIEW,
+              identity,
+              properties
+            )
+
+            // go forward one hour - should be ignored
+            tk.freeze(new Date(2022, 0, 1, 15, 0))
+            await processor.processEvent(Event.SERVED_APP, identity, properties)
+            await processor.processEvent(
+              Event.SERVED_APP_PREVIEW,
+              identity,
+              properties
+            )
+
+            // go forward into next day
+            tk.freeze(new Date(2022, 0, 2, 9, 0))
+
+            await processor.processEvent(Event.SERVED_APP, identity, properties)
+            await processor.processEvent(
+              Event.SERVED_APP_PREVIEW,
+              identity,
+              properties
+            )
+          })
+        }
+
+        await runAppEvents("app_1")
+        expect(processor.posthog.capture).toHaveBeenCalledTimes(4)
+
+        await runAppEvents("app_2")
+        expect(processor.posthog.capture).toHaveBeenCalledTimes(8)
+      })
     })
   })
 })