DCMAW-9802: Refactor session creation

backend-api/src/functions/asyncCredential/asyncCredentialHandler.test.ts

@@ -971,7 +971,7 @@ describe("Async Credential", () => {
             );
 
             expect(mockLogger.getLogMessages()[0].logMessage.sessionId).toEqual(
-              expect.any(String),
+              "mockSessionId",
             );
 
             expect(result).toStrictEqual({
@@ -1164,8 +1164,8 @@ class MockSessionServiceGetSessionBySubFailure
     return errorResponse("Mock failing DB call");
   };
 
-  createSession = async (): Promise<ErrorOrSuccess<null>> => {
-    return successResponse(null);
+  createSession = async (): Promise<ErrorOrSuccess<string>> => {
+    return successResponse("mockSessionId");
   };
 }
 
@@ -1183,8 +1183,8 @@ class MockSessionServiceNoActiveSession
     return successResponse(null);
   };
 
-  createSession = async (): Promise<ErrorOrSuccess<null>> => {
-    return successResponse(null);
+  createSession = async (): Promise<ErrorOrSuccess<string>> => {
+    return successResponse("mockSessionId");
   };
 }
 
@@ -1203,8 +1203,8 @@ class MockSessionServiceActiveSessionFound
     return successResponse("mockSessionId");
   };
 
-  createSession = async (): Promise<ErrorOrSuccess<null>> => {
-    return successResponse(null);
+  createSession = async (): Promise<ErrorOrSuccess<string>> => {
+    return successResponse("mockSessionId");
   };
 }
 
@@ -1223,7 +1223,7 @@ class MockSessionServiceFailToCreateSession
     return successResponse(null);
   };
 
-  createSession = async (): Promise<ErrorOrSuccess<null>> => {
+  createSession = async (): Promise<ErrorOrSuccess<string>> => {
     return errorResponse("Mock error");
   };
 }
@@ -1243,7 +1243,7 @@ class MockSessionServiceSessionCreated
     return successResponse(null);
   };
 
-  createSession = async (): Promise<ErrorOrSuccess<null>> => {
-    return successResponse(null);
+  createSession = async (): Promise<ErrorOrSuccess<string>> => {
+    return successResponse("mockSessionId");
   };
 }

backend-api/src/functions/asyncCredential/asyncCredentialHandler.ts

@@ -17,7 +17,6 @@ import {
   ICreateSession,
   IGetActiveSession,
 } from "./sessionService/sessionService";
-import { randomUUID } from "crypto";
 import { Logger } from "../services/logging/logger";
 import { MessageName } from "./registeredLogs";
 import { IGetClientCredentials } from "../asyncToken/ssmService/ssmService";
@@ -185,26 +184,12 @@ export async function lambdaHandler(
     return activeSessionFoundResponse(requestBody.sub);
   }
 
-  const { sub, client_id, govuk_signin_journey_id, redirect_uri, state } =
-    requestBody;
-  const { iss } = jwtPayload;
-
-  const sessionId = randomUUID();
-
-  const sessionConfig = {
-    sessionId,
-    state,
-    sub,
-    clientId: client_id,
-    govukSigninJourneyId: govuk_signin_journey_id,
-    redirectUri: redirect_uri,
-    issuer: iss,
-    issuedOn: Date.now().toString(),
-    sessionState: "ASYNC_AUTH_SESSION_CREATED",
-  };
+  const sessionServiceCreateSessionResult = await sessionService.createSession({
+    ...requestBody,
+    issuer: jwtPayload.iss,
+  });
 
-  const sessionServiceCreateSessionResult =
-    await sessionService.createSession(sessionConfig);
+  const sessionId = sessionServiceCreateSessionResult.value;
 
   const eventService = dependencies.eventService(config.SQS_QUEUE);
 
@@ -217,9 +202,9 @@ export async function lambdaHandler(
 
   const writeEventResult = await eventService.writeGenericEvent({
     eventName: "DCMAW_ASYNC_CRI_START",
-    sub,
+    sub: requestBody.sub,
     sessionId,
-    govukSigninJourneyId: govuk_signin_journey_id,
+    govukSigninJourneyId: requestBody.govuk_signin_journey_id,
     getNowInMilliseconds: Date.now,
     componentId: config.ISSUER,
   });

backend-api/src/functions/asyncCredential/sessionService/sessionService.test.ts

@@ -110,15 +110,12 @@ describe("Session Service", () => {
         dbMock.on(GetItemCommand).rejects("Mock DB Error");
 
         const result = await service.createSession({
-          sessionId: "137d5a4b-3046-456d-986a-147e0469cf62",
           state: "mockValidState",
           sub: "mockSub",
-          clientId: "mockClientId",
-          govukSigninJourneyId: "mockJourneyId",
-          redirectUri: "https://mockRedirectUri.com",
+          client_id: "mockClientId",
+          govuk_signin_journey_id: "mockJourneyId",
+          redirect_uri: "https://mockRedirectUri.com",
           issuer: "mockIssuer",
-          sessionState: "mockSessionState",
-          issuedOn: "mockIssuedOn",
         });
 
         expect(result.isError).toBe(true);
@@ -138,15 +135,12 @@ describe("Session Service", () => {
         });
 
         const result = await service.createSession({
-          sessionId: "137d5a4b-3046-456d-986a-147e0469cf62",
           state: "mockValidState",
           sub: "mockSub",
-          clientId: "mockClientId",
-          govukSigninJourneyId: "mockJourneyId",
-          redirectUri: "https://mockRedirectUri.com",
+          client_id: "mockClientId",
+          govuk_signin_journey_id: "mockJourneyId",
+          redirect_uri: "https://mockRedirectUri.com",
           issuer: "mockIssuer",
-          sessionState: "mockSessionState",
-          issuedOn: "mockIssuedOn",
         });
 
         expect(result.isError).toBe(true);
@@ -163,15 +157,12 @@ describe("Session Service", () => {
         dbMock.on(PutItemCommand).rejects("Mock DB Error");
 
         const result = await service.createSession({
-          sessionId: "137d5a4b-3046-456d-986a-147e0469cf62",
           state: "mockValidState",
           sub: "mockSub",
-          clientId: "mockClientId",
-          govukSigninJourneyId: "mockJourneyId",
-          redirectUri: "https://mockRedirectUri.com",
+          client_id: "mockClientId",
+          govuk_signin_journey_id: "mockJourneyId",
+          redirect_uri: "https://mockRedirectUri.com",
           issuer: "mockIssuer",
-          sessionState: "mockSessionState",
-          issuedOn: "mockIssuedOn",
         });
 
         expect(result.isError).toBe(true);
@@ -189,18 +180,15 @@ describe("Session Service", () => {
           dbMock.on(PutItemCommand).resolves({});
 
           const result = await service.createSession({
-            sessionId: "137d5a4b-3046-456d-986a-147e0469cf62",
             state: "mockValidState",
             sub: "mockSub",
-            clientId: "mockClientId",
-            govukSigninJourneyId: "mockJourneyId",
+            client_id: "mockClientId",
+            govuk_signin_journey_id: "mockJourneyId",
             issuer: "mockIssuer",
-            sessionState: "mockSessionState",
-            issuedOn: "mockIssuedOn",
           });
 
           expect(result.isError).toBe(false);
-          expect(result.value).toEqual(null);
+          expect(typeof result.value).toBe("string");
         });
       });
 
@@ -211,19 +199,16 @@ describe("Session Service", () => {
           dbMock.on(PutItemCommand).resolves({});
 
           const result = await service.createSession({
-            sessionId: "137d5a4b-3046-456d-986a-147e0469cf62",
             state: "mockValidState",
             sub: "mockSub",
-            clientId: "mockClientId",
-            govukSigninJourneyId: "mockJourneyId",
-            redirectUri: "https://mockRedirectUri.com",
+            client_id: "mockClientId",
+            govuk_signin_journey_id: "mockJourneyId",
+            redirect_uri: "https://mockRedirectUri.com",
             issuer: "mockIssuer",
-            sessionState: "mockSessionState",
-            issuedOn: "mockIssuedOn",
           });
 
           expect(result.isError).toBe(false);
-          expect(result.value).toEqual(null);
+          expect(typeof result.value).toBe("string");
         });
       });
     });

backend-api/src/functions/asyncCredential/sessionService/sessionService.ts

@@ -12,6 +12,7 @@ import {
   errorResponse,
   successResponse,
 } from "../../types/errorOrValue";
+import { randomUUID } from "crypto";
 
 export class SessionService implements IGetActiveSession, ICreateSession {
   readonly tableName: string;
@@ -72,31 +73,14 @@ export class SessionService implements IGetActiveSession, ICreateSession {
   }
 
   async createSession(
-    sessionConfig: IAuthSession,
-  ): Promise<ErrorOrSuccess<null>> {
-    const config: IPutAuthSessionConfig = {
-      TableName: this.tableName,
-      Item: {
-        sessionId: { S: sessionConfig.sessionId },
-        state: { S: sessionConfig.state },
-        sub: { S: sessionConfig.sub },
-        clientId: { S: sessionConfig.clientId },
-        govukSigninJourneyId: { S: sessionConfig.govukSigninJourneyId },
-        issuer: { S: sessionConfig.issuer },
-        sessionState: { S: sessionConfig.sessionState },
-        issuedOn: { S: sessionConfig.issuedOn },
-      },
-    };
-
-    if (sessionConfig.redirectUri) {
-      config.Item.redirectUri = { S: sessionConfig.redirectUri };
-    }
+    config: ICreateSessionConfig,
+  ): Promise<ErrorOrSuccess<string>> {
+    const sessionId = randomUUID();
+    const putSessionConfig = this.buildPutItemCommandInput(sessionId, config);
 
     let doesSessionExist;
     try {
-      doesSessionExist = await this.checkSessionsExists(
-        sessionConfig.sessionId,
-      );
+      doesSessionExist = await this.checkSessionsExists(sessionId);
     } catch (error) {
       return errorResponse(
         "Unexpected error when querying session table to check if sessionId exists",
@@ -108,14 +92,14 @@ export class SessionService implements IGetActiveSession, ICreateSession {
     }
 
     try {
-      await this.putSessionInDb(config);
+      await this.putSessionInDb(putSessionConfig);
     } catch (error) {
       return errorResponse(
         "Unexpected error when querying session table whilst creating a session",
       );
     }
 
-    return successResponse(null);
+    return successResponse(sessionId);
   }
 
   private hasValidSession(
@@ -129,6 +113,40 @@ export class SessionService implements IGetActiveSession, ICreateSession {
     );
   }
 
+  private buildPutItemCommandInput(
+    sessionId: string,
+    config: ICreateSessionConfig,
+  ) {
+    const {
+      state,
+      sub,
+      client_id,
+      govuk_signin_journey_id,
+      redirect_uri,
+      issuer,
+    } = config;
+
+    const putSessionConfig: IPutSessionConfig = {
+      TableName: this.tableName,
+      Item: {
+        sessionId: { S: sessionId },
+        state: { S: state },
+        sub: { S: sub },
+        clientId: { S: client_id },
+        govukSigninJourneyId: { S: govuk_signin_journey_id },
+        issuer: { S: issuer },
+        sessionState: { S: "ASYNC_AUTH_SESSION_CREATED" },
+        issuedOn: { S: Date.now().toString() },
+      },
+    };
+
+    if (redirect_uri) {
+      putSessionConfig.Item.redirectUri = { S: redirect_uri };
+    }
+
+    return putSessionConfig;
+  }
+
   private async checkSessionsExists(sessionId: string): Promise<boolean> {
     const output = await dbClient.send(
       new GetItemCommand({
@@ -142,24 +160,12 @@ export class SessionService implements IGetActiveSession, ICreateSession {
     return output.Item != null;
   }
 
-  private async putSessionInDb(config: IPutAuthSessionConfig) {
+  private async putSessionInDb(config: IPutSessionConfig) {
     await dbClient.send(new PutItemCommand(config));
   }
 }
 
-interface IAuthSession {
-  sessionId: string;
-  state: string;
-  sub: string;
-  clientId: string;
-  govukSigninJourneyId: string;
-  issuer: string;
-  sessionState: string;
-  issuedOn: string;
-  redirectUri?: string;
-}
-
-interface IPutAuthSessionConfig {
+interface IPutSessionConfig {
   TableName: string;
   Item: {
     sessionId: { S: string };
@@ -181,8 +187,19 @@ export interface IGetActiveSession {
   ) => Promise<ErrorOrSuccess<string | null>>;
 }
 
+interface ICreateSessionConfig {
+  state: string;
+  sub: string;
+  client_id: string;
+  govuk_signin_journey_id: string;
+  issuer: string;
+  redirect_uri?: string;
+}
+
 export interface ICreateSession {
-  createSession: (sessionConfig: IAuthSession) => Promise<ErrorOrSuccess<null>>;
+  createSession: (
+    config: ICreateSessionConfig,
+  ) => Promise<ErrorOrSuccess<string>>;
 }
 
 type IQueryCommandOutputType = {