fix: crash when saving empty chords

src/lib/backup/backup.ts

@@ -72,22 +72,26 @@ export function createSettingsBackup(): CharaSettingsFile {
   };
 }
 
-export async function restoreBackup(event: Event) {
+export async function restoreBackup(
+  event: Event,
+  only?: "chords" | "layout" | "settings",
+) {
   const input = (event.target as HTMLInputElement).files![0];
   if (!input) return;
   const text = await input.text();
   if (input.name.endsWith(".json")) {
-    restoreFromFile(JSON.parse(text));
+    restoreFromFile(JSON.parse(text), only);
   } else if (isCsvLayout(text)) {
-    restoreFromFile(csvLayoutToJson(text));
+    restoreFromFile(csvLayoutToJson(text), only);
   } else if (isCsvChords(text)) {
-    restoreFromFile(csvChordsToJson(text));
+    restoreFromFile(csvChordsToJson(text), only);
   } else {
   }
 }
 
 export function restoreFromFile(
   file: CharaBackupFile | CharaSettingsFile | CharaLayoutFile | CharaChordFile,
+  only?: "chords" | "layout" | "settings",
 ) {
   if (file.charaVersion !== 1) throw new Error("Incompatible backup");
   switch (file.type) {
@@ -112,33 +116,45 @@ export function restoreFromFile(
 
       changes.update((changes) => {
         changes.push([
-          ...getChangesFromChordFile(recent[0]),
-          ...getChangesFromLayoutFile(recent[1]),
-          ...getChangesFromSettingsFile(recent[2]),
+          ...(!only || only === "chords"
+            ? getChangesFromChordFile(recent[0])
+            : []),
+          ...(!only || only === "layout"
+            ? getChangesFromLayoutFile(recent[1])
+            : []),
+          ...(!only || only === "settings"
+            ? getChangesFromSettingsFile(recent[2])
+            : []),
         ]);
         return changes;
       });
       break;
     }
     case "chords": {
-      changes.update((changes) => {
-        changes.push(getChangesFromChordFile(file));
-        return changes;
-      });
+      if (!only || only === "chords") {
+        changes.update((changes) => {
+          changes.push(getChangesFromChordFile(file));
+          return changes;
+        });
+      }
       break;
     }
     case "layout": {
-      changes.update((changes) => {
-        changes.push(getChangesFromLayoutFile(file));
-        return changes;
-      });
+      if (!only || only === "layout") {
+        changes.update((changes) => {
+          changes.push(getChangesFromLayoutFile(file));
+          return changes;
+        });
+      }
       break;
     }
     case "settings": {
-      changes.update((changes) => {
-        changes.push(getChangesFromSettingsFile(file));
-        return changes;
-      });
+      if (!only || only === "settings") {
+        changes.update((changes) => {
+          changes.push(getChangesFromSettingsFile(file));
+          return changes;
+        });
+      }
       break;
     }
     default: {

src/lib/components/Terminal.svelte

@@ -1,7 +1,12 @@
 <script lang="ts">
   import { serialLog, serialPort } from "$lib/serial/connection";
+  import { onMount } from "svelte";
   import { slide } from "svelte/transition";
 
+  onMount(() => {
+    io.scrollTo({ top: io.scrollHeight });
+  });
+
   function submit(event: Event) {
     event.preventDefault();
     $serialPort?.send(0, value.trim());

src/lib/serial/device.ts

@@ -342,23 +342,24 @@ export class CharaDevice {
         .join(" ")
         .replace(/[-[\]{}()*+?.,\\^$|#\s]/g, "\\$&");
       const readResult = await read(timeout);
-      if (readResult === undefined) {
+      return readResult
+        ?.replace(new RegExp(`^${commandString} `), "")
+        .split(" ");
+    }).then((it) => {
+      if (it === undefined) {
         console.error("No response");
         return Array(expectedLength).fill("NO_RESPONSE") as LengthArray<
           string,
           T
         >;
       }
-      const array = readResult
-        .replace(new RegExp(`^${commandString} `), "")
-        .split(" ");
-      if (array.length < expectedLength) {
+      if (it.length < expectedLength) {
         console.error("Response too short");
-        return array.concat(
-          Array(expectedLength - array.length).fill("TOO_SHORT"),
+        return it.concat(
+          Array(expectedLength - it.length).fill("TOO_SHORT"),
         ) as LengthArray<string, T>;
       }
-      return array as LengthArray<string, T>;
+      return it as LengthArray<string, T>;
     });
   }
 
@@ -401,7 +402,7 @@ export class CharaDevice {
       stringifyChordActions(chord.actions),
       stringifyPhrase(chord.phrase),
     ]);
-    if (status !== "0") console.error(`Failed with status ${status}`);
+    if (status !== "0") throw new Error(`Failed with status ${status}`);
   }
 
   async deleteChord(chord: Pick<Chord, "actions">) {

src/lib/undo-redo.ts

@@ -179,6 +179,22 @@ export const chords = derived(
   },
 );
 
+export const duplicateChords = derived(chords, (chords) => {
+  const duplicates = new Set<string>();
+  const seen = new Set<string>();
+
+  for (const chord of chords) {
+    const key = JSON.stringify(chord.actions);
+    if (seen.has(key)) {
+      duplicates.add(key);
+    } else {
+      seen.add(key);
+    }
+  }
+
+  return duplicates;
+});
+
 export const chordHashes = derived(
   chords,
   (chords) =>