How to change a value while debugging to a variable using a conditional breakpoint in a IntelliJ Kotlin project on the fly?

Question

In an Java Project this is possible while debugging by “mis”-using a conditional breakpoint to set a value to a property or variable:

Java Breakpoint

Unfortunately the same thing is not possible in a Kotlin Project. The error is: Assignments are not expressions, and only expressions are allowed in this context:

Kotlin Breakpoint

I know that I can do it in debugger window using “Set Value”, but then i have to do it every time manually. Using a conditional breakpoint/watchpoint the value is set automatically without even suspending the program until I delete the breakpoint. This is pretty useful for smoke test or presentations.

Thanks in advance!

score 2 · Answer 1 · answered Oct 31 '19 at 17:13

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Do not do that in the condition field, use "evaluate and log" - this breakpoint action is created specifically for this.

Also you can unset "suspend" and it will silently set value for you:

answered Oct 31 '19 at 17:13

Egor

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score 1 · Answer 2 · answered Oct 21 '19 at 14:09

1

You could execute a function to set the value:

run { text = "Some Value" }

This is an expression; it returns Unit, but has the side effect of setting your variable.

If the condition field needs you to return a boolean you can add it after:

run { text = "Some Value"; false }

This returns false so the execution wouldn't stop.

answered Oct 21 '19 at 14:09

RobCo

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I thought about the same solution and tried it. It executes but sadly it does not change the value. – Florian Sandro Völkl Oct 21 '19 at 14:27
That's a bummer. It works for the evaluate expression panel. But I'm not exactly sure how this would be possible then. – RobCo Oct 21 '19 at 14:34

How to change a value while debugging to a variable using a conditional breakpoint in a IntelliJ Kotlin project on the fly?

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