fix: Remove dependencies on test-jars from ksql-functional-tests jar

[purplefox]

Description

Fixes #2804

• This PR breaks dependencies from ksql-functional-tests (jar) to any test-jars.
• I've refactored the code that creates the ServiceContext and KSqlEngine a little to reduce the coupling with test-jar code.
• I've duplicated some matcher classes - I've put these in their own directory
• I've duplicated some Fake* classes- I've put these in their own directory

Testing done

Ran the full test suite

Reviewer checklist

• Ensure docs are updated if necessary. (eg. if a user visible feature is being added or changed).
• Ensure relevant issues are linked (description should include text like "Fixes #")

[agavra]

This LGTM! Can you also test to make sure that the test UDFs no longer show up in the SHOW FUNCTIONS when we run KSQL? If this fixes that issue then some code duplication is totally okay IMO. Let's get two +1s on this just to get some consensus, maybe @big-andy-coates

[purplefox]

Show functions gives me this, I don't think it contains any test functions:

ksql> show functions;

 Function Name         | Type
-----------------------------------
 ABS                   | SCALAR
 ARRAYCONTAINS         | SCALAR
 AS_ARRAY              | SCALAR
 AS_MAP                | SCALAR
 AVG                   | AGGREGATE
 CEIL                  | SCALAR
 COLLECT_LIST          | AGGREGATE
 COLLECT_SET           | AGGREGATE
 CONCAT                | SCALAR
 COUNT                 | AGGREGATE
 DATETOSTRING          | SCALAR
 ELT                   | SCALAR
 EXP                   | SCALAR
 EXTRACTJSONFIELD      | SCALAR
 FIELD                 | SCALAR
 FLOOR                 | SCALAR
 GEO_DISTANCE          | SCALAR
 HISTOGRAM             | AGGREGATE
 IFNULL                | SCALAR
 INITCAP               | SCALAR
 LCASE                 | SCALAR
 LEN                   | SCALAR
 LN                    | SCALAR
 MASK                  | SCALAR
 MASK_KEEP_LEFT        | SCALAR
 MASK_KEEP_RIGHT       | SCALAR
 MASK_LEFT             | SCALAR
 MASK_RIGHT            | SCALAR
 MAX                   | AGGREGATE
 MIN                   | AGGREGATE
 RANDOM                | SCALAR
 REPLACE               | SCALAR
 ROUND                 | SCALAR
 SIGN                  | SCALAR
 SLICE                 | SCALAR
 SPLIT                 | SCALAR
 SQRT                  | SCALAR
 STRINGTODATE          | SCALAR
 STRINGTOTIMESTAMP     | SCALAR
 SUBSTRING             | SCALAR
 SUM                   | AGGREGATE
 SUM_LIST              | AGGREGATE
 TIMESTAMPTOSTRING     | SCALAR
 TOPK                  | AGGREGATE
 TOPKDISTINCT          | AGGREGATE
 TRIM                  | SCALAR
 UCASE                 | SCALAR
 UNIX_DATE             | SCALAR
 UNIX_TIMESTAMP        | SCALAR
 URL_DECODE_PARAM      | SCALAR
 URL_ENCODE_PARAM      | SCALAR
 URL_EXTRACT_FRAGMENT  | SCALAR
 URL_EXTRACT_HOST      | SCALAR
 URL_EXTRACT_PARAMETER | SCALAR
 URL_EXTRACT_PATH      | SCALAR
 URL_EXTRACT_PORT      | SCALAR
 URL_EXTRACT_PROTOCOL  | SCALAR
 URL_EXTRACT_QUERY     | SCALAR
 WINDOWEND             | AGGREGATE
 WINDOWSTART           | AGGREGATE
-----------------------------------

[big-andy-coates]

Thanks @purplefox

Great to see this resolved!

I'm wondering if it's possible to add a test somewhere that will fail should these things get back on the classpath. That would be the icing on the cake. Unfortunately, I think the only place such a test is actually valid would be in our system tests.

I'm a little wary of adding SqlFormatInjector into the production code base when its only used for tests... @agavra, does it make sense to actually use this injector in our normal flow? So that we always reformat statements? If so, @agavra, do you think you could knock out a quick follow up PR to this one to make that the case?

[big-andy-coates]

Looks like this change is not needed. It would be good to keep this package private and, if you're game, annotate with @VisibleForTestingOnly.

[purplefox]

TestExecutor.getKsqlEngine() requires this to be public

[big-andy-coates]

yay!

[purplefox]

@big-andy-coates In order to test that the test udfs haven't got back on the classpath there is a way we could do it without having to have a reference to the actual class or to be running as an actual test (where the test udf would be there anyway).
Very hacky but something like this at startup of the server

boolean isRunningTestsuite = cl.getResource("Name of some Junit class") != null;
if (!isRunningTestsuite && cl.getResource("Name of some test udf class") != null) {
    // bail out
}