Just to add that I've found this bug in my own project too but occasionally source maps will work on first run. Perhaps about 1 time in 10 runs it will work first time without needing a reload. I thought it was worth mentioning since this possibly indicates a race condition.

Not able to reproduce in v0.33.3, seems to have been fixed when updating Chrome.

Still Experiencing this in v0.33.4.

Here's a 34 second video recreating the bug: https://www.dropbox.com/s/r883d31jm1bpb9c/electron-sourcemaps-test.mov?dl=1 (39MB .mov)

And here's a repo of the code that I used, you can clone it to hopefully reproduce this on your dev environment: https://github.com/davej/electron-sourcemaps-test

I observe this issue on osx 10.11.

> process.versions
{
 "http_parser": "2.5.0",
 "node": "4.1.1",
 "v8": "4.5.103.29",
 "uv": "1.7.4",
 "zlib": "1.2.8",
 "ares": "1.10.1-DEV",
 "modules": "46",
 "openssl": "1.0.2d",
 "electron": "0.35.2",
 "atom-shell": "0.35.2",
 "chrome": "45.0.2454.85"
}

Just re-tested this with 1.4.4 and I can confirm this is still broken. Also updated the test case repo.

Closing due to abandonment.

@codebytere: What does 'abandonment' mean in this case? There is a test case repo, a video and 5 thumbs up indicating that other people are experiencing this issue.

Would you like me to confirm that the issue still exists in the latest version of Electron?

That would be great, thanks! We're just weeding out abandoned issues (issues that have seen no action in a significant amount of time) so if this is still an issue and you feel it's important to fix i'll definitely reopen it :)

Just re-tested this with 1.7.8 and I can confirm this is still broken. Also updated the test case repo.

@codebytere: Can you please consider reopening.

Also, OS and system spec information below in case it's relevant.

we're just weeding out abandoned issues, so if this is still in need of a fix i'll reopen :)

@davej thanks for the input! i'll be more verbose in the future so that people can better understand why i might be closing something 😁

Experiencing the same issue:

I recently updated from webpack 1 to webpack 3.10, and am now also experiencing this issue:

• if you start Electron without devtools open, sourcemaps don't work
• if you reload (using location.reload()), they load correctly
• if you start Electron with devtools open, sourcemaps work immediately.

I'm using Webpack 4 and am also experiencing this issue.

I’ve fixed this in my app by waiting for devtools to open before navigating with loadURL/loadFile.

It makes sense that the Chrome debugger needs to be running to transform source maps. To me this seems like a Chrome issue, and not something Electron should try to fix.

Expanding on what @mattdesl referred to, here is a snippet of code that waits for a devtools-opened event on the main window. You can adapt to your environment and then source-maps should always be loaded okay on the first try.

if (isDevelopment) {
    mainWindow.webContents.on('devtools-opened', () => {
        mainWindow.loadURL(...)
    }
} else {
    mainWindow.loadURL(...)
}

It makes sense that the Chrome debugger needs to be running to transform source maps. To me this seems like a Chrome issue, and not something Electron should try to fix.

This makes sense to me, based on the workaround it sounds like devtools needs to be open to fetch and parse these. Gonna close this one out 👍

Update... for me, as of Electron 8, waiting for the 'devtools-opened' event stopped opening the devtools at all. The only way I could get devtools opened at that point was to hit ctrl-shift-i twice in fast succession. I've gone back to just attempting to open them without waiting for the signal, and crossing my fingers that the timing/source-map issue is fixed.

if (isDevelopment) {
    mainWindow.webContents.openDevTools()
    mainWindow.loadURL(...)
} else {
    mainWindow.loadURL(...)
}

Another option if the problem comes back might be to use the new method of opening the devtools in a separate window:

devtools = new BrowserWindow()
mainWindow.webContents.setDevToolsWebContents(devtools.webContents)
mainWindow.webContents.openDevTools({ mode: 'detach' })
mainWindow.loadURL(...)