Elaborate

web/packages/media/live-photo.ts

@@ -1,4 +1,4 @@
-import { nameAndExtension } from "@/next/file";
+import { fileNameFromComponents, nameAndExtension } from "@/next/file";
 import JSZip from "jszip";
 
 class LivePhoto {
@@ -8,18 +8,6 @@ class LivePhoto {
     videoNameTitle: string;
 }
 
-export function getFileNameWithoutExtension(filename: string) {
-    const lastDotPosition = filename.lastIndexOf(".");
-    if (lastDotPosition === -1) return filename;
-    else return filename.slice(0, lastDotPosition);
-}
-
-export function getFileExtensionWithDot(filename: string) {
-    const lastDotPosition = filename.lastIndexOf(".");
-    if (lastDotPosition === -1) return "";
-    else return filename.slice(lastDotPosition);
-}
-
 /**
  * Convert a binary serialized representation of a live photo to an in-memory
  * {@link LivePhoto}.
@@ -42,12 +30,12 @@ export const decodeLivePhoto = async (fileName: string, zipBlob: Blob) => {
     const livePhoto = new LivePhoto();
     for (const zipFileName in zip.files) {
         if (zipFileName.startsWith("image")) {
-            livePhoto.imageNameTitle =
-                name + getFileExtensionWithDot(zipFileName);
+            const [, imageExt] = nameAndExtension(zipFileName);
+            livePhoto.imageNameTitle = fileNameFromComponents([name, imageExt]);
             livePhoto.image = await zip.files[zipFileName].async("uint8array");
         } else if (zipFileName.startsWith("video")) {
-            livePhoto.videoNameTitle =
-                name + getFileExtensionWithDot(zipFileName);
+            const [, videoExt] = nameAndExtension(zipFileName);
+            livePhoto.videoNameTitle = fileNameFromComponents([name, videoExt]);
             livePhoto.video = await zip.files[zipFileName].async("uint8array");
         }
     }
@@ -69,7 +57,7 @@ export const encodeLivePhoto = async (livePhoto: LivePhoto) => {
     const [, videoExt] = nameAndExtension(livePhoto.videoNameTitle);
 
     const zip = new JSZip();
-    zip.file(["image", imageExt].filter((x) => !!x).join("."), livePhoto.image);
-    zip.file(["video", videoExt].filter((x) => !!x).join("."), livePhoto.video);
+    zip.file(fileNameFromComponents(["image", imageExt]), livePhoto.image);
+    zip.file(fileNameFromComponents(["video", videoExt]), livePhoto.video);
     return await zip.generateAsync({ type: "uint8array" });
 };

web/packages/next/file.ts

@@ -1,19 +1,34 @@
 import type { ElectronFile } from "./types/file";
 
+/**
+ * The two parts of a file name - the name itself, and an (optional) extension.
+ *
+ * The extension does not include the dot.
+ */
+type FileNameComponents = [name: string, extension: string | undefined];
+
 /**
  * Split a filename into its components - the name itself, and the extension (if
  * any) - returning both. The dot is not included in either.
  *
  * For example, `foo-bar.png` will be split into ["foo-bar", "png"].
+ *
+ * See {@link fileNameFromComponents} for the inverse operation.
  */
-export const nameAndExtension = (
-    fileName: string,
-): [string, string | undefined] => {
+export const nameAndExtension = (fileName: string): FileNameComponents => {
     const i = fileName.lastIndexOf(".");
     if (i == -1) return [fileName, undefined];
     else return [fileName.slice(0, i), fileName.slice(i + 1)];
 };
 
+/**
+ * Construct a file name from its components (name and extension).
+ *
+ * Inverse of {@link nameAndExtension}.
+ */
+export const fileNameFromComponents = (components: FileNameComponents) =>
+    components.filter((x) => !!x).join(".");
+
 export function getFileNameSize(file: File | ElectronFile) {
     return `${file.name}_${convertBytesToHumanReadable(file.size)}`;
 }