[improve][test] Support decorating topic, subscription, dispatcher, ManagedLedger and ManagedCursors instances in tests

[lhotari]

Motivation

In some Pulsar tests, there's a need to inject special behaviors such as delays, race conditions or failures.
The current solutions require using reflection and replacing instances, which results in hard to maintain test code.

Modifications

• Add a solution for Pulsar broker tests that allows to decorate persistent topics, subscriptions, dispatchers
  managed ledger factory, managed ledger and managed cursor instances.
• Refactor production code so that there are hooks for intercepting the instances in subclasses
• Add a helper methods for creating a Mockito Spy decorator
  • for a dispatcher instance
  • for a ManagedCursorImpl instance

example usage for spying on a dispatcher and cursor instance:

    @Override
    protected void doInitConf() throws Exception {
        super.doInitConf();
        BrokerTestInterceptor.INSTANCE.configure(conf);
    }

    @AfterMethod(alwaysRun = true)
    protected void resetInterceptors() throws Exception {
        BrokerTestInterceptor.INSTANCE.reset();
    }

    @Test
    public void testSomething() throws Exception {
        BrokerTestInterceptor.INSTANCE.applyDispatcherSpyDecorator(PersistentDispatcherMultipleConsumers.class,
                spy -> {
                    doAnswer(invocation -> {
                        List<Entry> entries = invocation.getArgument(0);
                        log.info("intercepted readEntriesComplete with {} entries", entries.size());
                        return invocation.callRealMethod();
                    }).when(spy).readEntriesComplete(any(), any());
                }
        );

        BrokerTestInterceptor.INSTANCE.applyCursorSpyDecorator(spy -> {
            doAnswer(invocation -> {
                log.info("intercepted asyncReadEntriesWithSkipOrWait");
                return invocation.callRealMethod();
            }).when(spy).asyncReadEntriesWithSkipOrWait(anyInt(), anyLong(), any(), any(), any(), any());
            doAnswer(invocation -> {
                log.info("intercepted asyncReplayEntries");
                return invocation.callRealMethod();
            }).when(spy).asyncReplayEntries(any(), any(), any(), anyBoolean());
        });
   ...

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 86.66667% with 6 lines in your changes missing coverage. Please review.

Project coverage is 74.22%. Comparing base (bbc6224) to head (c448596).
Report is 868 commits behind head on master.

Files with missing lines	Patch %	Lines
...ker/service/persistent/PersistentSubscription.java	84.84%	3 Missing and 2 partials ⚠️
...org/apache/pulsar/broker/service/TopicFactory.java	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #23892      +/-   ##
============================================
+ Coverage     73.57%   74.22%   +0.65%     
+ Complexity    32624    32244     -380     
============================================
  Files          1877     1854      -23     
  Lines        139502   143640    +4138     
  Branches      15299    16318    +1019     
============================================
+ Hits         102638   106619    +3981     
+ Misses        28908    28648     -260     
- Partials       7956     8373     +417     

Flag	Coverage Δ
inttests	26.64% <51.11%> (+2.06%)	⬆️
systests	23.17% <60.00%> (-1.15%)	⬇️
unittests	73.75% <86.66%> (+0.90%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...kkeeper/mledger/impl/ManagedLedgerFactoryImpl.java	59.04% <100.00%> (-22.34%)	⬇️
...che/bookkeeper/mledger/impl/ManagedLedgerImpl.java	82.11% <100.00%> (+1.45%)	⬆️
...ache/pulsar/broker/ManagedLedgerClientFactory.java	86.20% <100.00%> (+2.06%)	⬆️
...sar/broker/service/persistent/PersistentTopic.java	79.69% <ø> (+1.23%)	⬆️
...org/apache/pulsar/broker/service/TopicFactory.java	0.00% <0.00%> (ø)
...ker/service/persistent/PersistentSubscription.java	76.67% <84.84%> (-0.02%)	⬇️

... and 1021 files with indirect coverage changes