Strange error in Electron. Uncaught Exception: TypeError [ERR_INVALID_ARG_TYPE]: The “path”

Question

Hi I'm trying to follow a tutorial on Electron however I keep getting this error when trying to open a file from the menu i've made.

Uncaught Exception: TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be one of type string, Buffer, or URL. Received type undefined...

Here is my function.

function openFile() {
  // Opens file dialog looking for markdown
  const files = dialog.showOpenDialog(mainWindow, {
    properties: ['openFile'],
    filters: [{ name: 'Markdown', extensions: ['md', 'markdown', 'txt'] }]
  });

  // If no files
  if (!files) return;

  const file = files[0]; // Grabs first file path in array
  // Loads file contents via path acquired via the dialog
  const fileContent = fs.readFileSync(file).toString();
  console.log(fileContent);
}

Tried reverting back to older versions etc. To no avail.

Thanks for any advice.

andypotato andypotato · Accepted Answer · 2019-08-30T06:58:44

Careful here, showOpenDialog() is an async function and returns a promise.

In your case the correct usage is:

dialog.showOpenDialog(mainWindow, {
    properties: ['openFile'],
    filters: [{ name: 'Markdown', extensions: ['md', 'markdown', 'txt'] }]
}).then(result => {
    const file = result.filePaths[0];
    const fileContent = fs.readFileSync(file).toString();
    console.log(fileContent);
}).catch(err => {
    console.log(err)
});

Also consider using readFile instead of readFileSync to avoid blocking the Electron main thread.

Strange error in Electron. Uncaught Exception: TypeError [ERR_INVALID_ARG_TYPE]: The “path”

1 Answers