Add .loadIntegrations() method to builder

[lhotari]

• makes it easier to customize BlockHound

[bsideup]

Hi @lhotari,

Could you please provide an example how the new API makes it easier compared to the existing ones

Thank you!

[lhotari]

Could you please provide an example how the new API makes it easier compared to the existing ones

I'm sorry I didn't properly explain the context at first.

My use case is such that I'd like to use the builder and also get the integrations loaded. I believe that this would be useful in most cases when customizing the behavior of BlockHound.

I had the problem that some tests were hanging after enabling BlockHound for all tests. Since the exception was swallowed in one particular case, I followed the tip in https://github.com/reactor/BlockHound/blob/master/docs/tips.md#debugging to add a blockingMethodCallback that prints out the stacktrace:

    static {
        BlockHound.Builder builder = BlockHound.builder()
                .blockingMethodCallback(method -> {
                    Error error = new BlockingOperationError(method);
                    // Print out the blocking call to find out problem when exceptions are swallowed
                    error.printStackTrace(System.err);
                    throw error;
                });
        ServiceLoader<BlockHoundIntegration> serviceLoader = ServiceLoader.load(BlockHoundIntegration.class);
        StreamSupport.stream(serviceLoader.spliterator(), false).sorted().forEach(builder::with);
        builder.install();
    }

I had to look into the source code of BlockHound to find out how to get the integrations loaded with the ServiceLoader. After adding the .loadIntegrations to the builder, this type of use case would become simpler:

    static {
        BlockHound.builder()
                .blockingMethodCallback(method -> {
                    Error error = new BlockingOperationError(method);
                    // Print out the blocking call to find out problem when exceptions are swallowed
                    error.printStackTrace(System.err);
                    throw error;
                })
                .loadIntegrations()
                .install();
    }

[bsideup]

@lhotari
No problem, thanks for providing a rich context!

My use case is such that I'd like to use the builder and also get the integrations loaded.

This sounds like the option number 2:

2. BlockHound.install(BlockHoundIntegration... integrations) - same as BlockHound.install(), but adds user-provided integrations to the list.

So that you can do:

BlockHound.install(b -> {
    b. blockingMethodCallback(...);
});

WDYT about adding it to the tips instead? :)

[lhotari]

BlockHound.install(b -> {
    b. blockingMethodCallback(...);
});

Thanks, now I got it. I missed that the existing API could be used that way.
I'll close the PR since it's not needed.

WDYT about adding it to the tips instead? :)

Good idea. I'll do that instead.

[lhotari]

I created #81 to improve the example in tips.