Small further refactoring

products/jbrowse-desktop/public/electron.ts

@@ -15,7 +15,7 @@ const { unlink, readFile, copyFile, readdir, writeFile } = fs.promises
 
 const { app, ipcMain, shell, BrowserWindow, Menu } = electron
 
-interface Session {
+interface RecentSession {
   path: string
   updated: number
   name: string
@@ -25,7 +25,7 @@ function stringify(obj: unknown) {
   return JSON.stringify(obj, null, 2)
 }
 
-async function readSessions(): Promise<Session[]> {
+async function readRecentSessions(): Promise<RecentSession[]> {
   let data: string
   try {
     data = await readFile(recentSessionsPath, 'utf8')
@@ -38,6 +38,32 @@ async function readSessions(): Promise<Session[]> {
   }
 }
 
+async function readSession(sessionPath: string): Promise<any> {
+  let data: string
+  try {
+    data = await readFile(sessionPath, 'utf8')
+    return JSON.parse(data)
+  } catch (e) {
+    console.error(
+      `Failed to parse session at "${sessionPath}", data was ${data}`,
+    )
+    return e
+  }
+}
+
+async function readQuickstart(quickstartPath: string): Promise<any> {
+  let data: string
+  try {
+    data = await readFile(quickstartPath, 'utf8')
+    return JSON.parse(data)
+  } catch (e) {
+    console.error(
+      `Failed to parse quickstart at "${quickstartPath}", data was ${data}`,
+    )
+    return e
+  }
+}
+
 // manual auto-updates https://github.com/electron-userland/electron-builder/blob/docs/encapsulated%20manual%20update%20via%20menu.js
 autoUpdater.autoDownload = false
 
@@ -351,9 +377,7 @@ ipcMain.handle(
 ipcMain.handle(
   'listSessions',
   async (_event: unknown, showAutosaves: boolean) => {
-    const sessions = JSON.parse(await readFile(recentSessionsPath, 'utf8')) as {
-      path: string
-    }[]
+    const sessions = await readRecentSessions()
 
     if (!showAutosaves) {
       return sessions.filter(f => !f.path.startsWith(autosaveDir))
@@ -368,7 +392,7 @@ ipcMain.handle('loadExternalConfig', (_event: unknown, sessionPath) => {
 })
 
 ipcMain.handle('loadSession', async (_event: unknown, sessionPath: string) => {
-  const sessionSnapshot = JSON.parse(await readFile(sessionPath, 'utf8'))
+  const sessionSnapshot = await readSession(sessionPath)
   if (!sessionSnapshot.assemblies) {
     throw new Error(
       `File at ${sessionPath} does not appear to be a JBrowse session. It does not contain any assemblies.`,
@@ -407,7 +431,7 @@ ipcMain.handle(
 )
 
 ipcMain.handle('getQuickstart', async (_event: unknown, name: string) => {
-  return JSON.parse(await readFile(getQuickstartPath(name), 'utf8'))
+  return readQuickstart(getQuickstartPath(name))
 })
 
 ipcMain.handle(
@@ -443,7 +467,7 @@ ipcMain.handle(
 ipcMain.handle(
   'createInitialAutosaveFile',
   async (_event: unknown, snap: SessionSnap) => {
-    const rows = await readSessions()
+    const rows = await readRecentSessions()
     const idx = rows.findIndex(r => r.path === path)
     const path = getAutosavePath(`${+Date.now()}`)
     const entry = {
@@ -471,7 +495,7 @@ ipcMain.handle(
   async (_event: unknown, path: string, snap: SessionSnap) => {
     const [page, rows] = await Promise.all([
       mainWindow?.capturePage(),
-      readSessions(),
+      readRecentSessions(),
     ])
     const idx = rows.findIndex(r => r.path === path)
     const png = page?.resize({ width: 500 }).toDataURL()
@@ -525,15 +549,12 @@ ipcMain.handle('promptSessionSaveAs', async (_event: unknown) => {
 ipcMain.handle(
   'deleteSessions',
   async (_event: unknown, sessionPaths: string[]) => {
-    const sessions = await readSessions()
-    const indexes: number[] = []
-    sessions.forEach((row, idx) => {
-      if (sessionPaths.includes(row.path)) {
-        indexes.push(idx)
-      }
-    })
-    for (let i = indexes.length - 1; i >= 0; i--) {
-      sessions.splice(indexes[i], 1)
+    const sessions = await readRecentSessions()
+    const indices = sessions
+      .map((r, i) => (sessionPaths.includes(r.path) ? i : undefined))
+      .filter(f => f !== undefined)
+    for (let i = indices.length - 1; i >= 0; i--) {
+      sessions.splice(indices[i], 1)
     }
 
     await Promise.all([
@@ -551,7 +572,7 @@ ipcMain.handle(
 ipcMain.handle(
   'renameSession',
   async (_event: unknown, path: string, newName: string) => {
-    const sessions = await readSessions()
+    const sessions = await readRecentSessions()
     const session = JSON.parse(await readFile(path, 'utf8'))
     const idx = sessions.findIndex(row => row.path === path)
     if (idx !== -1) {