From 065e74024e52c2e692f70834f053dadb675461b4 Mon Sep 17 00:00:00 2001
From: Dean <deanhannigan@gmail.com>
Date: Thu, 2 Feb 2023 11:38:10 +0000
Subject: [PATCH] Added new unit tests for feature flags

---
 .../backend-core/src/featureFlags/index.ts    | 30 ++++---
 .../featureFlags/tests/featureFlags.spec.ts   | 85 +++++++++++++++++++
 2 files changed, 101 insertions(+), 14 deletions(-)
 create mode 100644 packages/backend-core/src/featureFlags/tests/featureFlags.spec.ts

diff --git a/packages/backend-core/src/featureFlags/index.ts b/packages/backend-core/src/featureFlags/index.ts
index 6e8277ce13..34ee3599a5 100644
--- a/packages/backend-core/src/featureFlags/index.ts
+++ b/packages/backend-core/src/featureFlags/index.ts
@@ -6,7 +6,7 @@ import * as tenancy from "../tenancy"
  * The env var is formatted as:
  *  tenant1:feature1:feature2,tenant2:feature1
  */
-function getFeatureFlags() {
+export function buildFeatureFlags() {
   if (!env.TENANT_FEATURE_FLAGS) {
     return
   }
@@ -27,8 +27,6 @@ function getFeatureFlags() {
   return tenantFeatureFlags
 }
 
-const TENANT_FEATURE_FLAGS = getFeatureFlags()
-
 export function isEnabled(featureFlag: string) {
   const tenantId = tenancy.getTenantId()
   const flags = getTenantFeatureFlags(tenantId)
@@ -37,20 +35,23 @@ export function isEnabled(featureFlag: string) {
 
 export function getTenantFeatureFlags(tenantId: string) {
   let flags: string[] = []
-
-  if (TENANT_FEATURE_FLAGS) {
-    const globalFlags = TENANT_FEATURE_FLAGS["*"]
-    const tenantFlags = TENANT_FEATURE_FLAGS[tenantId] || []
+  const envFlags = buildFeatureFlags()
+  if (envFlags) {
+    const globalFlags = envFlags["*"]
+    const tenantFlags = envFlags[tenantId] || []
 
     // Explicitly exclude tenants from global features if required.
     // Prefix the tenant flag with '!'
-    const tenantOverrides = tenantFlags.reduce((acc: string[], flag) => {
-      if (flag.startsWith("!")) {
-        let stripped = flag.substring(1)
-        acc.push(stripped)
-      }
-      return acc
-    }, [])
+    const tenantOverrides = tenantFlags.reduce(
+      (acc: string[], flag: string) => {
+        if (flag.startsWith("!")) {
+          let stripped = flag.substring(1)
+          acc.push(stripped)
+        }
+        return acc
+      },
+      []
+    )
 
     if (globalFlags) {
       flags.push(...globalFlags)
@@ -72,4 +73,5 @@ export enum TenantFeatureFlag {
   LICENSING = "LICENSING",
   GOOGLE_SHEETS = "GOOGLE_SHEETS",
   USER_GROUPS = "USER_GROUPS",
+  ONBOARDING_TOUR = "ONBOARDING_TOUR",
 }
diff --git a/packages/backend-core/src/featureFlags/tests/featureFlags.spec.ts b/packages/backend-core/src/featureFlags/tests/featureFlags.spec.ts
new file mode 100644
index 0000000000..1b68959329
--- /dev/null
+++ b/packages/backend-core/src/featureFlags/tests/featureFlags.spec.ts
@@ -0,0 +1,85 @@
+import {
+  TenantFeatureFlag,
+  buildFeatureFlags,
+  getTenantFeatureFlags,
+} from "../"
+import env from "../../environment"
+
+const { ONBOARDING_TOUR, LICENSING, USER_GROUPS } = TenantFeatureFlag
+
+describe("featureFlags", () => {
+  beforeEach(() => {
+    env._set("TENANT_FEATURE_FLAGS", "")
+  })
+
+  it("Should return no flags when the TENANT_FEATURE_FLAG is empty", async () => {
+    let features = buildFeatureFlags()
+    expect(features).toBeUndefined()
+  })
+
+  it("Should generate a map of global and named tenant feature flags from the env value", async () => {
+    env._set(
+      "TENANT_FEATURE_FLAGS",
+      `*:${ONBOARDING_TOUR},tenant1:!${ONBOARDING_TOUR},tenant2:${USER_GROUPS},tenant1:${LICENSING}`
+    )
+
+    const parsedFlags: Record<string, string[]> = {
+      "*": [ONBOARDING_TOUR],
+      tenant1: [`!${ONBOARDING_TOUR}`, LICENSING],
+      tenant2: [USER_GROUPS],
+    }
+
+    let features = buildFeatureFlags()
+
+    expect(features).toBeDefined()
+    expect(features).toEqual(parsedFlags)
+  })
+
+  it("Should add feature flag flag only to explicitly configured tenant", async () => {
+    env._set(
+      "TENANT_FEATURE_FLAGS",
+      `*:${LICENSING},*:${USER_GROUPS},tenant1:${ONBOARDING_TOUR}`
+    )
+
+    let tenant1Flags = getTenantFeatureFlags("tenant1")
+    let tenant2Flags = getTenantFeatureFlags("tenant2")
+
+    expect(tenant1Flags).toBeDefined()
+    expect(tenant1Flags).toEqual([LICENSING, USER_GROUPS, ONBOARDING_TOUR])
+
+    expect(tenant2Flags).toBeDefined()
+    expect(tenant2Flags).toEqual([LICENSING, USER_GROUPS])
+  })
+})
+
+it("Should exclude tenant1 from global feature flag", async () => {
+  env._set(
+    "TENANT_FEATURE_FLAGS",
+    `*:${LICENSING},*:${ONBOARDING_TOUR},tenant1:!${ONBOARDING_TOUR}`
+  )
+
+  let tenant1Flags = getTenantFeatureFlags("tenant1")
+  let tenant2Flags = getTenantFeatureFlags("tenant2")
+
+  expect(tenant1Flags).toBeDefined()
+  expect(tenant1Flags).toEqual([LICENSING])
+
+  expect(tenant2Flags).toBeDefined()
+  expect(tenant2Flags).toEqual([LICENSING, ONBOARDING_TOUR])
+})
+
+it("Should explicitly add flags to configured tenants only", async () => {
+  env._set(
+    "TENANT_FEATURE_FLAGS",
+    `tenant1:${ONBOARDING_TOUR},tenant1:${LICENSING},tenant2:${LICENSING}`
+  )
+
+  let tenant1Flags = getTenantFeatureFlags("tenant1")
+  let tenant2Flags = getTenantFeatureFlags("tenant2")
+
+  expect(tenant1Flags).toBeDefined()
+  expect(tenant1Flags).toEqual([ONBOARDING_TOUR, LICENSING])
+
+  expect(tenant2Flags).toBeDefined()
+  expect(tenant2Flags).toEqual([LICENSING])
+})