Add some tests

src/__tests__/session-props.test.ts

@@ -0,0 +1,120 @@
+import { SessionPropsManager } from '../session-props'
+import { SessionIdManager } from '../sessionid'
+import { PostHogPersistence } from '../posthog-persistence'
+
+describe('Session Props Manager', () => {
+    const createSessionPropsManager = () => {
+        const onSessionId = jest.fn()
+        const generateProps = jest.fn()
+        const persistenceRegister = jest.fn()
+        const sessionIdManager = {
+            onSessionId,
+        } as unknown as SessionIdManager
+        const persistence = {
+            register: persistenceRegister,
+            props: {},
+        } as unknown as PostHogPersistence
+        const sessionPropsManager = new SessionPropsManager(sessionIdManager, persistence, generateProps)
+
+        return {
+            onSessionId,
+            sessionPropsManager,
+            persistence,
+            sessionIdManager,
+            generateProps,
+            persistenceRegister,
+        }
+    }
+
+    it('should register a callback with the session id manager', () => {
+        const { onSessionId } = createSessionPropsManager()
+        expect(onSessionId).toHaveBeenCalledTimes(1)
+    })
+
+    it('should update persistence with client session props', () => {
+        // arrange
+        const utmSource = 'some-utm-source'
+        const sessionId = 'session-id'
+        const { onSessionId, generateProps, persistenceRegister } = createSessionPropsManager()
+        generateProps.mockReturnValue({ utm_source: utmSource })
+        const callback = onSessionId.mock.calls[0][0]
+
+        // act
+        callback(sessionId)
+
+        //assert
+        expect(generateProps).toHaveBeenCalledTimes(1)
+
+        expect(persistenceRegister).toBeCalledWith({
+            $client_session_props: {
+                props: {
+                    utm_source: 'some-utm-source',
+                },
+                sessionId: 'session-id',
+            },
+        })
+    })
+
+    it('should not update client session props when session id stays the same', () => {
+        // arrange
+        const sessionId1 = 'session-id-1'
+        const { onSessionId, persistence, generateProps, persistenceRegister } = createSessionPropsManager()
+        persistence.props = {
+            $client_session_props: {
+                props: {},
+                sessionId: sessionId1,
+            },
+        }
+        const callback = onSessionId.mock.calls[0][0]
+
+        // act
+        callback(sessionId1)
+
+        //assert
+        expect(generateProps).toHaveBeenCalledTimes(0)
+        expect(persistenceRegister).toHaveBeenCalledTimes(0)
+    })
+
+    it('should update client session props when session id changes', () => {
+        // arrange
+        const sessionId1 = 'session-id-1'
+        const sessionId2 = 'session-id-2'
+
+        const { onSessionId, persistence, generateProps, persistenceRegister } = createSessionPropsManager()
+        persistence.props = {
+            $client_session_props: {
+                props: {},
+                sessionId: sessionId1,
+            },
+        }
+        const callback = onSessionId.mock.calls[0][0]
+
+        // act
+        callback(sessionId2)
+
+        //assert
+        expect(generateProps).toHaveBeenCalledTimes(1)
+        expect(persistenceRegister).toHaveBeenCalledTimes(1)
+    })
+
+    it('should return client session props', () => {
+        // arrange
+        const { persistence, sessionPropsManager } = createSessionPropsManager()
+        persistence.props = {
+            $client_session_props: {
+                props: {
+                    utm_source: 'some-utm-source',
+                },
+                sessionId: 'session-id',
+            },
+        }
+
+        // act
+        const properties = sessionPropsManager.getSessionProps()
+
+        //assert
+        expect(properties).toEqual({
+            $client_session_utm_source: 'some-utm-source',
+        })
+    })
+})