refactor(loader): Unify session updates in one function

app/routes/shared/formular.server.ts

@@ -40,6 +40,7 @@ import {
 } from "~/services/session.server/arrayDeletion";
 import { interpolateDeep } from "~/util/fillTemplate";
 import { stepMeta } from "~/services/meta/formStepMeta";
+import { updateSessionInHeader } from "~/services/session.server/updateSessionInHeader";
 
 const structureCmsContent = (
   formPageContent: z.infer<CollectionSchemas["form-flow-pages"]>,
@@ -170,16 +171,12 @@ export const loader = async ({
     }),
   );
 
-  const { session, csrf } = await updateSessionWithCsrfToken(request);
-
-  // update session with last valid step
-  session.set(lastStepKey, { [flowId]: stepId });
-
-  // set session in header
-  const sessionContext = getSessionForContext("main");
-  const headers = { "Set-Cookie": await sessionContext.commitSession(session) };
+  const { headers, csrf } = await updateSessionInHeader({
+    request,
+    flowId,
+    stepId,
+  });
 
-  // get navigation destinations + labels
   const buttonNavigationProps = getButtonNavigationProps({
     flowController,
     stepId,

app/routes/shared/vorabcheck.server.ts

@@ -31,6 +31,7 @@ import { isStrapiHeadingComponent } from "~/services/cms/models/StrapiHeading";
 import { getButtonNavigationProps } from "~/util/buttonProps";
 import { stepMeta } from "~/services/meta/formStepMeta";
 import { getProgressProps } from "~/services/flow/server/progress";
+import { updateSessionInHeader } from "~/services/session.server/updateSessionInHeader";
 
 export const loader = async ({
   params,
@@ -98,14 +99,11 @@ export const loader = async ({
   const fieldNames = formElements.map((entry) => entry.name);
   const stepData = _.pick(userDataFromRedis, fieldNames);
 
-  const { session, csrf } = await updateSessionWithCsrfToken(request);
-
-  // update session with last valid step
-  session.set(lastStepKey, { [flowId]: stepId });
-
-  // set session in header
-  const sessionContext = getSessionForContext("main");
-  const headers = { "Set-Cookie": await sessionContext.commitSession(session) };
+  const { headers, csrf } = await updateSessionInHeader({
+    request,
+    flowId,
+    stepId,
+  });
 
   const buttonNavigationProps = getButtonNavigationProps({
     flowController,

app/services/session.server/updateSessionInHeader.ts

@@ -0,0 +1,24 @@
+import { updateSessionWithCsrfToken } from "~/services/security/csrf.server";
+import { lastStepKey } from "~/services/flow/constants";
+import { getSessionForContext } from "~/services/session.server/index";
+import type { FlowId } from "~/models/flows/contexts";
+
+export const updateSessionInHeader = async ({
+  request,
+  flowId,
+  stepId,
+}: {
+  request: Request;
+  flowId: FlowId;
+  stepId: string;
+}) => {
+  const { session, csrf } = await updateSessionWithCsrfToken(request);
+
+  // update session with last valid step
+  session.set(lastStepKey, { [flowId]: stepId });
+
+  const sessionContext = getSessionForContext("main");
+  const headers = { "Set-Cookie": await sessionContext.commitSession(session) };
+
+  return { headers, csrf };
+};