diff --git a/src-tauri/src/compress.rs b/src-tauri/src/compress.rs
index 502aa8b..db1a232 100644
--- a/src-tauri/src/compress.rs
+++ b/src-tauri/src/compress.rs
@@ -93,7 +93,20 @@ pub async fn compress_files(
 
         match run_gs(&app, args).await {
             Ok(()) => {
-                std::fs::rename(&tmp_path, &output_path).map_err(|e| e.to_string())?;
+                if let Err(e) = std::fs::rename(&tmp_path, &output_path) {
+                    let _ = std::fs::remove_file(&tmp_path);
+                    let _ = app.emit(
+                        "compress:progress",
+                        ProgressEvent {
+                            file: job.path.clone(),
+                            status: "error".into(),
+                            saved_bytes: None,
+                            compressed_size: None,
+                            error_msg: Some(e.to_string()),
+                        },
+                    );
+                    continue;
+                }
 
                 let compressed_size = std::fs::metadata(&output_path)
                     .map(|m| m.len() as i64)
diff --git a/src-tauri/src/lib.rs b/src-tauri/src/lib.rs
index 6e7a6b9..20a8bde 100644
--- a/src-tauri/src/lib.rs
+++ b/src-tauri/src/lib.rs
@@ -45,11 +45,6 @@ pub fn check_path_writable(path: String) -> bool {
     }
 }
 
-#[tauri::command]
-fn check_path_writable_cmd(path: String) -> bool {
-    check_path_writable(path)
-}
-
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
 pub fn run() {
     use crate::compress::compress_files;
@@ -89,7 +84,6 @@ pub fn run() {
             reveal_in_finder,
             get_file_meta,
             validate_pdf,
-            check_path_writable_cmd,
             set_menu_item_enabled,
             check_for_update,
         ])
diff --git a/src-tauri/src/menu.rs b/src-tauri/src/menu.rs
index e466a3e..d30a2ca 100644
--- a/src-tauri/src/menu.rs
+++ b/src-tauri/src/menu.rs
@@ -175,5 +175,50 @@ mod tests {
         assert!(ids.contains("clear-queue"));
         assert!(ids.contains("compress"));
         assert!(ids.contains("reset-selected"));
+        assert!(ids.contains("check-for-update"));
+    }
+
+    #[test]
+    fn menu_ids_sync_with_build_menu() {
+        // Note: build_menu requires AppHandle and cannot be called in unit tests.
+        // Instead we maintain a parallel list here that must be kept in sync with
+        // the map.insert calls in build_menu.
+        // Hardcoded list of IDs that are inserted in build_menu's HashMap
+        let build_menu_ids: &[&str] = &[
+            "add-files",
+            "reveal-in-finder",
+            "clear-queue",
+            "compress",
+            "reset-selected",
+            "check-for-update",
+        ];
+
+        // Assert length matches
+        assert_eq!(
+            MENU_IDS.len(),
+            build_menu_ids.len(),
+            "MENU_IDS and build_menu HashMap have different lengths"
+        );
+
+        // Assert all MENU_IDS appear in build_menu_ids
+        let build_menu_set: std::collections::HashSet<&str> =
+            build_menu_ids.iter().copied().collect();
+        for id in MENU_IDS {
+            assert!(
+                build_menu_set.contains(id),
+                "ID '{}' in MENU_IDS is not inserted in build_menu",
+                id
+            );
+        }
+
+        // Assert all build_menu_ids appear in MENU_IDS
+        let menu_ids_set: std::collections::HashSet<&str> = MENU_IDS.iter().copied().collect();
+        for id in build_menu_ids {
+            assert!(
+                menu_ids_set.contains(id),
+                "ID '{}' inserted in build_menu is not in MENU_IDS",
+                id
+            );
+        }
     }
 }
diff --git a/src-tauri/src/updater.rs b/src-tauri/src/updater.rs
index 37ae6ef..b3f4c6d 100644
--- a/src-tauri/src/updater.rs
+++ b/src-tauri/src/updater.rs
@@ -1,5 +1,9 @@
+fn strip_v(tag: &str) -> &str {
+    tag.strip_prefix('v').unwrap_or(tag)
+}
+
 pub fn parse_version(tag: &str) -> Option<(u64, u64, u64)> {
-    let s = tag.strip_prefix('v').unwrap_or(tag);
+    let s = strip_v(tag);
     let parts: Vec<&str> = s.split('.').collect();
     if parts.len() != 3 {
         return None;
@@ -40,13 +44,7 @@ pub async fn check_for_update() -> Option<String> {
         .ok()?;
 
     if is_newer(&release.tag_name, env!("CARGO_PKG_VERSION")) {
-        Some(
-            release
-                .tag_name
-                .strip_prefix('v')
-                .unwrap_or(&release.tag_name)
-                .to_string(),
-        )
+        Some(strip_v(&release.tag_name).to_string())
     } else {
         None
     }
diff --git a/src/lib/components/ActionBar.svelte b/src/lib/components/ActionBar.svelte
index 9b50aef..839e6c3 100644
--- a/src/lib/components/ActionBar.svelte
+++ b/src/lib/components/ActionBar.svelte
@@ -8,6 +8,7 @@
   import { selectedFileId } from "$lib/stores/selectionStore";
   import { settings } from "$lib/stores/settingsStore";
   import { toast } from "$lib/stores/toastStore";
+  import { basename } from "$lib/fileActions";
   import { buildNotificationBody } from "$lib/notification";
 
   const doneCount = derived(queue, ($q) => $q.filter((e) => e.status === "done").length);
@@ -59,7 +60,7 @@
         compressDone++;
       } else if (payload.status === "error") {
         queue.updateStatus(payload.file, "error", { errorMsg: payload.error_msg });
-        const name = payload.file.split("/").pop() ?? payload.file;
+        const name = basename(payload.file);
         toast.show(`${name}: ${payload.error_msg ?? "Compression failed"}`);
         compressDone++;
       } else {
diff --git a/src/lib/components/DetailPanel.svelte b/src/lib/components/DetailPanel.svelte
index 3b961bb..e2a6259 100644
--- a/src/lib/components/DetailPanel.svelte
+++ b/src/lib/components/DetailPanel.svelte
@@ -1,29 +1,20 @@
 <script lang="ts">
   import { derived } from "svelte/store";
-  import { invoke } from "@tauri-apps/api/core";
   import { open } from "@tauri-apps/plugin-dialog";
   import { queue, type Preset } from "$lib/stores/queueStore";
   import { selectedFileId } from "$lib/stores/selectionStore";
   import { settings } from "$lib/stores/settingsStore";
+  import { formatBytes } from "$lib/notification";
+  import { revealInFinder } from "$lib/fileActions";
 
   const selectedFile = derived([queue, selectedFileId], ([$q, $id]) => $q.find((e) => e.id === $id) ?? null);
 
   $: hasFiles = $queue.length > 0;
 
-  function formatSize(bytes: number): string {
-    if (bytes >= 1_000_000) return `${(bytes / 1_000_000).toFixed(1)} MB`;
-    if (bytes >= 1_000) return `${(bytes / 1_000).toFixed(0)} KB`;
-    return `${bytes} B`;
-  }
-
   function savingsPct(original: number, compressed: number): string {
     return `−${Math.round(((original - compressed) / original) * 100)}%`;
   }
 
-  function revealInFinder(path: string) {
-    invoke("reveal_in_finder", { path });
-  }
-
   function resetToCompress() {
     if (!$selectedFile) return;
     queue.resetFile($selectedFile.id);
@@ -85,13 +76,13 @@
       {/if}
 
       <div class="sizes">
-        <div class="size-row"><span class="label">Original</span><span>{formatSize($selectedFile.size)}</span></div>
+        <div class="size-row"><span class="label">Original</span><span>{formatBytes($selectedFile.size)}</span></div>
         {#if $selectedFile.status === "done" && $selectedFile.compressedSize !== undefined}
           <div class="result-block">
             <div class="savings-pct">{savingsPct($selectedFile.size, $selectedFile.compressedSize)}</div>
             <div class="size-story">
-              {formatSize($selectedFile.size)} → {formatSize($selectedFile.compressedSize)}
-              · saved {formatSize($selectedFile.size - $selectedFile.compressedSize)}
+              {formatBytes($selectedFile.size)} → {formatBytes($selectedFile.compressedSize)}
+              · saved {formatBytes($selectedFile.size - $selectedFile.compressedSize)}
             </div>
             <div class="result-actions">
               <button class="finder-btn" on:click={() => revealInFinder($selectedFile!.path)}>Show in Finder</button>
diff --git a/src/lib/fileActions.ts b/src/lib/fileActions.ts
index 49eeeed..e5cd844 100644
--- a/src/lib/fileActions.ts
+++ b/src/lib/fileActions.ts
@@ -2,8 +2,12 @@ import { invoke } from "@tauri-apps/api/core";
 import { open } from "@tauri-apps/plugin-dialog";
 import { queue } from "$lib/stores/queueStore";
 
+export function basename(path: string): string {
+  return path.split("/").pop() ?? path;
+}
+
 export async function addPath(path: string): Promise<void> {
-  const name = path.split("/").pop() ?? path;
+  const name = basename(path);
   try {
     const isPdf = await invoke<boolean>("validate_pdf", { path });
     if (!isPdf) {
@@ -24,3 +28,7 @@ export async function addFiles(): Promise<void> {
   const list = Array.isArray(paths) ? paths : [paths];
   for (const path of list) await addPath(path);
 }
+
+export function revealInFinder(path: string): void {
+  invoke("reveal_in_finder", { path }).catch(() => {});
+}
diff --git a/src/lib/notification.ts b/src/lib/notification.ts
index deba361..8609df5 100644
--- a/src/lib/notification.ts
+++ b/src/lib/notification.ts
@@ -1,4 +1,4 @@
-export function formatSavedBytes(bytes: number): string {
+export function formatBytes(bytes: number): string {
   if (bytes >= 1_000_000) return `${(bytes / 1_000_000).toFixed(1)} MB`;
   if (bytes >= 1_000) return `${Math.round(bytes / 1_000)} KB`;
   return `${bytes} B`;
@@ -11,7 +11,7 @@ export function buildNotificationBody(
 ): string {
   if (errorCount === 0) {
     const noun = doneCount === 1 ? "PDF" : "PDFs";
-    return `${doneCount} ${noun} compressed — saved ${formatSavedBytes(savedBytes)} total`;
+    return `${doneCount} ${noun} compressed — saved ${formatBytes(savedBytes)} total`;
   }
   const total = doneCount + errorCount;
   return `${doneCount} of ${total} PDFs compressed — ${errorCount} failed`;
diff --git a/src/routes/+page.svelte b/src/routes/+page.svelte
index 59b7cdb..d3f90be 100644
--- a/src/routes/+page.svelte
+++ b/src/routes/+page.svelte
@@ -10,7 +10,7 @@
   import { settings } from "$lib/stores/settingsStore";
   import { queue, pendingCount } from "$lib/stores/queueStore";
   import { selectedFileId } from "$lib/stores/selectionStore";
-  import { addFiles } from "$lib/fileActions";
+  import { addFiles, revealInFinder } from "$lib/fileActions";
   import { handleShortcut, type ShortcutState } from "$lib/shortcuts";
   import { openUrl } from "@tauri-apps/plugin-opener";
   import { toast } from "$lib/stores/toastStore";
@@ -22,7 +22,7 @@
 
   function revealSelected() {
     if (selectedFile?.status === "done") {
-      invoke("reveal_in_finder", { path: selectedFile.path });
+      revealInFinder(selectedFile.path);
     }
   }
 
@@ -87,6 +87,20 @@
     invoke("set_menu_item_enabled", { id, enabled }).catch(() => {});
   }
 
+  // ── update check helper ───────────────────────────────────────────────────
+
+  async function checkAndShowUpdateToast(showUpToDate = false) {
+    const version: string | null = await invoke("check_for_update");
+    if (version) {
+      toast.showPersistent(`v${version} is available`, {
+        label: "Download",
+        handler: () => openUrl("https://github.com/JBolanle/PDFCompressor/releases/latest"),
+      });
+    } else if (showUpToDate) {
+      toast.show("You're on the latest version");
+    }
+  }
+
   $: syncMenu("reveal-in-finder", selectedFile?.status === "done");
   $: syncMenu("clear-queue", $queue.length > 0);
   $: syncMenu("compress", $pendingCount > 0 && !isCompressing);
@@ -100,13 +114,7 @@
     settings.load();
     window.addEventListener("keydown", onKeyDown);
 
-    const version: string | null = await invoke("check_for_update");
-    if (version) {
-      toast.showPersistent(`v${version} is available`, {
-        label: "Download",
-        handler: () => openUrl("https://github.com/JBolanle/PDFCompressor/releases/latest"),
-      });
-    }
+    await checkAndShowUpdateToast();
 
     unlisteners = await Promise.all([
       listen("menu:add-files",        () => addFiles()),
@@ -114,17 +122,7 @@
       listen("menu:reveal-in-finder", () => revealSelected()),
       listen("menu:clear-queue",      () => clearAll()),
       listen("menu:reset-selected",   () => resetSelected()),
-      listen("menu:check-for-update", async () => {
-        const v: string | null = await invoke("check_for_update");
-        if (v) {
-          toast.showPersistent(`v${v} is available`, {
-            label: "Download",
-            handler: () => openUrl("https://github.com/JBolanle/PDFCompressor/releases/latest"),
-          });
-        } else {
-          toast.show("You're on the latest version");
-        }
-      }),
+      listen("menu:check-for-update", () => checkAndShowUpdateToast(true)),
     ]);
   });
 
diff --git a/src/test/notification.test.ts b/src/test/notification.test.ts
index 0042360..d5ba6ce 100644
--- a/src/test/notification.test.ts
+++ b/src/test/notification.test.ts
@@ -1,21 +1,21 @@
 import { describe, it, expect } from "vitest";
-import { buildNotificationBody, formatSavedBytes } from "$lib/notification";
+import { buildNotificationBody, formatBytes } from "$lib/notification";
 
-describe("formatSavedBytes", () => {
+describe("formatBytes", () => {
   it("formats bytes under 1 KB", () => {
-    expect(formatSavedBytes(500)).toBe("500 B");
+    expect(formatBytes(500)).toBe("500 B");
   });
 
   it("formats KB (rounds to nearest KB)", () => {
-    expect(formatSavedBytes(840_000)).toBe("840 KB");
+    expect(formatBytes(840_000)).toBe("840 KB");
   });
 
   it("formats MB to one decimal place", () => {
-    expect(formatSavedBytes(2_400_000)).toBe("2.4 MB");
+    expect(formatBytes(2_400_000)).toBe("2.4 MB");
   });
 
   it("formats exactly 1 MB", () => {
-    expect(formatSavedBytes(1_000_000)).toBe("1.0 MB");
+    expect(formatBytes(1_000_000)).toBe("1.0 MB");
   });
 });