Introduce IterationSelector

[marcphilipp]

Resolves #2738.

[codecov]

Codecov Report

Merging #2743 (ca5b9ea) into main (74a6b4e) will decrease coverage by 0.08%.
The diff coverage is 78.46%.

@@             Coverage Diff              @@
##               main    #2743      +/-   ##
============================================
- Coverage     91.11%   91.02%   -0.09%     
- Complexity     4439     4460      +21     
============================================
  Files           383      384       +1     
  Lines         10747    10799      +52     
  Branches        834      840       +6     
============================================
+ Hits           9792     9830      +38     
- Misses          739      746       +7     
- Partials        216      223       +7     

Impacted Files	Coverage Δ
...org/junit/platform/commons/util/Preconditions.java	91.66% <50.00%> (-2.46%)	⬇️
...t/platform/engine/discovery/IterationSelector.java	55.00% <55.00%> (ø)
...piter/engine/discovery/MethodSelectorResolver.java	96.47% <78.57%> (-3.53%)	⬇️
...ter/engine/descriptor/DynamicDescendantFilter.java	92.30% <94.44%> (ø)
...r/engine/descriptor/TestFactoryTestDescriptor.java	92.30% <100.00%> (+0.24%)	⬆️
.../engine/descriptor/TestTemplateTestDescriptor.java	100.00% <100.00%> (ø)
.../platform/engine/discovery/DiscoverySelectors.java	90.09% <100.00%> (+0.30%)	⬆️
...rt/discovery/EngineDiscoveryRequestResolution.java	82.45% <100.00%> (+0.31%)	⬆️
...orm/engine/support/discovery/SelectorResolver.java	88.63% <100.00%> (+0.26%)	⬆️

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[marcphilipp]

Related Spock PR: spockframework/spock#1379

[marcphilipp]

TODO: Also add support for ConsoleLauncher.

[marcphilipp]

I added support to select iterations via ConsoleLauncher:

$ gw :documentation:consoleLauncher --args="--select-iteration=method:example.ParameterizedTestDemo#palindromes(java.lang.String)[0,2]"
Using gradle at '/Users/marc/Repositories/junit5/gradlew' to run buildfile '/Users/marc/Repositories/junit5/build.gradle.kts':

Type-safe dependency accessors is an incubating feature.
Type-safe project accessors is an incubating feature.

> Task :documentation:consoleLauncher

Thanks for using JUnit! Support its development at https://junit.org/sponsoring

╷
├─ JUnit Vintage ✔
├─ JUnit Platform Suite ✔
└─ JUnit Jupiter ✔
   └─ ParameterizedTestDemo ✔
      └─ palindromes(String) ✔
         ├─ [1] candidate=racecar ✔
         └─ [3] candidate=able was I ere I saw elba ✔

Test run finished after 131 ms
[         5 containers found      ]
[         0 containers skipped    ]
[         5 containers started    ]
[         0 containers aborted    ]
[         5 containers successful ]
[         0 containers failed     ]
[         2 tests found           ]
[         0 tests skipped         ]
[         2 tests started         ]
[         0 tests aborted         ]
[         2 tests successful      ]
[         0 tests failed          ]


BUILD SUCCESSFUL in 4s
95 actionable tasks: 33 executed, 62 up-to-date

Publishing build scan...
https://ge.junit.org/s/rhvdhs6tzwz7o

[sormuras]

Had another brief look at this PR and I like it.

• What should other (not Jupiter, Vintage, TestNGine) TestEngine implementors add to their engines in order to support this new selector?
• Is the CLI syntax "just" an extension of the already exsting one? For example, would those work?
  • -select-iteration="method:example.ParameterizedTestDemo#palindromes(java.lang.String)[0,2]"
  • -select-method="example.ParameterizedTestDemo#palindromes(java.lang.String)"

[marcphilipp]

What should other (not Jupiter, Vintage, TestNGine) TestEngine implementors add to their engines in order to support this new selector?

They'd have to check for IterationSelector as another DiscoverySelector if they have a use case where that makes sense (see spockframework/spock#1379 for an example).

Is the CLI syntax "just" an extension of the already exsting one? For example, would those work?

Yes, they would. The syntax is --select-iteration="<TYPE>:<VALUE>[<INDEX>(,<INDEX>)]" where <VALUE> is the string that would normally be passed to --select-<TYPE>.

[sormuras]

Looks good to me.