From 7c4ce131bf768f297d953ae82687174289cb5f6b Mon Sep 17 00:00:00 2001
From: robbond <rob@rdbsolutions.co.uk>
Date: Mon, 13 Apr 2026 10:07:58 +0100
Subject: [PATCH] refactor(newappeal): extract file merge and dedupe helpers
 (Slice 2b)

---
 components/newappeal/buildchecksection.js | 32 +++++++----------------
 components/newappeal/buildsection.js      | 11 ++++----
 context/refactor-tracker.md               |  4 +--
 lib/newappeal/fileListHelpers.js          | 28 ++++++++++++++++++++
 4 files changed, 45 insertions(+), 30 deletions(-)
 create mode 100644 lib/newappeal/fileListHelpers.js

diff --git a/components/newappeal/buildchecksection.js b/components/newappeal/buildchecksection.js
index d5672c35..679f0a34 100644
--- a/components/newappeal/buildchecksection.js
+++ b/components/newappeal/buildchecksection.js
@@ -21,6 +21,10 @@ import {
     updateLinks,
     getDocLink
 } from "../utils";
+import {
+    dedupeFilesListByName,
+    removeDuplicatesByKey
+} from "../../lib/newappeal/fileListHelpers";
 
 let BuildCheckSection = (props) => {
     useEffect(() => {
@@ -97,20 +101,10 @@ let BuildCheckSection = (props) => {
     });
     //console.log(buildAppealFilesArray);
 
-    function removeDuplicates(arr, key) {
-        const seen = new Set();
-        return arr.filter((item) => {
-            const value = item[key];
-            if (seen.has(value)) {
-                return false; // Duplicate found
-            } else {
-                seen.add(value); // Add value to the set
-                return true; // Keep the item
-            }
-        });
-    }
-
-    buildAppealFilesArray = removeDuplicates(buildAppealFilesArray, "name");
+    buildAppealFilesArray = removeDuplicatesByKey(
+        buildAppealFilesArray,
+        "name"
+    );
 
     let pdfObj = props.props.form.appealForm.values;
 
@@ -152,10 +146,7 @@ let BuildCheckSection = (props) => {
     const finaliseAppeal = async () => {
         //console.log("finalising appeal:", pdfObj);
 
-        const uniqueArray = pdfObj.filesList.filter(
-            (value, index, self) =>
-                index === self.findIndex((t) => t.name === value.name)
-        );
+        const uniqueArray = dedupeFilesListByName(pdfObj.filesList);
 
         pdfObj.filesList = uniqueArray;
         pdfObj.locale = locale;
@@ -197,10 +188,7 @@ let BuildCheckSection = (props) => {
         try {
             setDownloadInProgress(true);
 
-            const uniqueArray = pdfObj.filesList.filter(
-                (value, index, self) =>
-                    index === self.findIndex((t) => t.name === value.name)
-            );
+            const uniqueArray = dedupeFilesListByName(pdfObj.filesList);
 
             pdfObj.filesList = uniqueArray;
             pdfObj.locale = locale;
diff --git a/components/newappeal/buildsection.js b/components/newappeal/buildsection.js
index ea743e26..76435271 100644
--- a/components/newappeal/buildsection.js
+++ b/components/newappeal/buildsection.js
@@ -6,6 +6,7 @@ import { connect } from "react-redux";
 import { formValueSelector, reduxForm } from "redux-form";
 import { uploadFiles } from "../../actions/services/documentService";
 import { sendEmail } from "../../actions/services/notifyService";
+import { mergeWithExistingFilesList } from "../../lib/newappeal/fileListHelpers";
 import {
     normalizeYesNoBooleans,
     removeNullKeys,
@@ -166,12 +167,10 @@ let BuildSection = (props) => {
 
         //console.log(buildAppealFilesArray);
 
-        buildAppealFilesArray = values.hasOwnProperty("filesList")
-            ? (buildAppealFilesArray.concat(values.filesList),
-              buildAppealFilesArray.filter(function (item, idx) {
-                  return item.name;
-              }))
-            : buildAppealFilesArray;
+        buildAppealFilesArray = mergeWithExistingFilesList(
+            buildAppealFilesArray,
+            values
+        );
 
         Object.assign(values, { "filesList": buildAppealFilesArray });
 
diff --git a/context/refactor-tracker.md b/context/refactor-tracker.md
index c093d347..a4a5313d 100644
--- a/context/refactor-tracker.md
+++ b/context/refactor-tracker.md
@@ -4,7 +4,7 @@ Base branch for this tracker: `refactor`
 
 ## Status
 
-Current slice: Slice 2b — File Merge/Dedupe Helpers  
+Current slice: Slice 3 — Side Effect Facade  
 Status: READY TO START
 
 ---
@@ -32,7 +32,7 @@ Status: COMPLETE
 
 ### Slice 2b — File Merge/Dedupe Helpers
 
-Status: NOT STARTED
+Status: COMPLETE
 
 - Extract file list merge logic
 - Extract dedupe logic
diff --git a/lib/newappeal/fileListHelpers.js b/lib/newappeal/fileListHelpers.js
new file mode 100644
index 00000000..e13e6a9f
--- /dev/null
+++ b/lib/newappeal/fileListHelpers.js
@@ -0,0 +1,28 @@
+export const mergeWithExistingFilesList = (buildAppealFilesArray, values) => {
+    return values.hasOwnProperty("filesList")
+        ? (buildAppealFilesArray.concat(values.filesList),
+          buildAppealFilesArray.filter(function (item, idx) {
+              return item.name;
+          }))
+        : buildAppealFilesArray;
+};
+
+export const removeDuplicatesByKey = (arr, key) => {
+    const seen = new Set();
+    return arr.filter((item) => {
+        const value = item[key];
+        if (seen.has(value)) {
+            return false; // Duplicate found
+        } else {
+            seen.add(value); // Add value to the set
+            return true; // Keep the item
+        }
+    });
+};
+
+export const dedupeFilesListByName = (filesList) => {
+    return filesList.filter(
+        (value, index, self) =>
+            index === self.findIndex((t) => t.name === value.name)
+    );
+};