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Show HN: Time travel debugger for web development

replay.io

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Re: Show HN: Time travel debugger for web development

#191

Earlier quoted context omitted.

seems like it worked but now I'm stuck at "Uploading replay" https://app.replay.io/recording/8731334f-4731-4c10-beee-7e4a...

Thanks for reporting I'll take a look at what went wrong there. I just visited the recording and the upload seems to have completed - I can view the recording from your link and debug it. I assume you shared it publicly?

thanks, yes I shared it publicly but then back to private as there are my cookies there

Re: Show HN: Time travel debugger for web development

#192

Engineer @ Replay here - If you're a console.log kind of developer (isn't everyone at least some of the time?), you should check this out. Imagine being able to add console.log() statements to code that already ran and seeing the results immediately! It's a bit mind blowing the first time you use it.

Do you have a demo video of doing exactly this? I downloaded the app, it's unclear how to edit code that's already run.

The video next to "Print statements from the future" on the webpage shows a bit of it.

You can click on the line-number next to a line of code to add a print at that location. If you hover over the line-number, it'll show you a count (exact and correct) of how many times that line of code hit during execution. Clicking on it adds a print log at that line with a default string.

At that point, the console log in the left should change immediately to include a bunch of new entries with "Loading.." text that resolves to the text of each print statement.

Clicking on the string allows you to replace it with an expression to be evaluated. The expression can include references to local scope variables, etc.

If you edit the expression, the console entries for the prints go back to "Loading.." and the new values are resolved.

The prints in the console are ordered in time sequence along with all the other events that can be shown there (regular console logs, mouse and keyboard and other events, etc.)

Re: Show HN: Time travel debugger for web development

#193

Earlier quoted context omitted.

What I mean is coming up with a condition to make as a watch/breakpoint isn't always obvious. Especially with errors that happen "sometimes randomly".

If an error causes an exception there is an option to suspend execution when one is thrown.

But typically it will throw an exception _after_ the interesting code happened. For instance it might throw a NullPointerException, but you want to know what set it to null in the first place. With breakpoints you have to suspend on exception, and then add additional breakpoints earlier in the code, and then rerun the code. With rewind you can just step backwards.

Re: Show HN: Time travel debugger for web development

#194

Earlier quoted context omitted.

Currently the only way to sign up for a personal account is through google. Is there another way that I am missing, or are there any plans to provide email based signups in the future?

(Replay engineer) Google is currently the only way unfortunately. We wanted to support secure logins at launch, with SSO and Multi-factor Authentication, and focus most of our efforts on the core product. As a result we just went with Google for launch. We don't currently have any plans to add additional authentication mechanisms but we've heard this feedback from a couple folks and we'll sit down to prioritize it af…

Thanks for the update. I had a feeling that this might have been the case due to the launch crunch and it's perfectly understandable. Really excited for the future of this project!

Re: Show HN: Time travel debugger for web development

#195

For those who are looking to similar tooling in back end space, check - https://undo.io/ (It can also support Golang https://docs.undo.io/GoDelve.html ) - Mozilla RR https://rr-project.org/ - GDB https://www.gnu.org/software/gdb/news/reversible.html Unfortunately, works only in Linux. https://en.wikipedia.org/wiki/Time_travel_debugging

Web frontend replay.

https://www.rrweb.io/

Re: Show HN: Time travel debugger for web development

#197
post #53

Earlier quoted context omitted.

Now I'm even more excited. Replay Team - please consider charging a reasonable amount ($10/mo) for individuals/small teams. I want this to be viable as a business.

What, no! I'm a broke college student, I don't want to pay for this, at least not yet.

Having a sound business model to have it keep improved or support broke students with no income and let it rot?

Perfect if they can support both with free plans.

Re: Show HN: Time travel debugger for web development

#198

Earlier quoted context omitted.

The problem with breakpoints is my loop runs 1000 times and I only care about the one time it errors. Making watch logic for that sometimes is too complicated or changes the outcome (race conditions especially). This seems like a great solution. I'll be checking it out!

Err, conditional breakpoints are your friend. Also the GP claims "nobody" uses breakpoints? Everyone in my team uses them all the time. Suppose it all depends on your language/tool chain, in my experience breakpoints are very commonly used by developers in visual studio.

I assume he referred to breakpoints in the browser.

Re: Show HN: Time travel debugger for web development

#199
post #53

Earlier quoted context omitted.

Now I'm even more excited. Replay Team - please consider charging a reasonable amount ($10/mo) for individuals/small teams. I want this to be viable as a business.

What, no! I'm a broke college student, I don't want to pay for this, at least not yet.

I don’t want to pay for anything.
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