fix: false positive with test builder pattern

[maratori]

Fixes #50

[Copilot]

Pull Request Overview

This PR addresses a false-positive detection in the parallel testing analyzer by recognizing builder-pattern test functions.

• Introduces new test cases in t_test.go to cover various builder patterns.
• Refactors analyzeTestRun to use a type switch and explicitly treat call expressions as valid test builders.
• Adds a *ast.CallExpr case to avoid flagging builder invocations as missing t.Parallel().

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
pkg/paralleltest/testdata/src/t/t_test.go	Adds TestBuilder with helper builder-pattern functions to test the analyzer’s behavior.
pkg/paralleltest/paralleltest.go	Refactors analyzeTestRun to a type switch and adds a *ast.CallExpr branch setting hasParallel.

Comments suppressed due to low confidence (1)

pkg/paralleltest/testdata/src/t/t_test.go:342

• [nitpick] Using t as the parameter name for a string callback is ambiguous with the outer *testing.T; consider renaming it to something like name or s for clarity.

t.Run("4", testBuilderWithAnotherCallback(func(t string) {

[Copilot]

[nitpick] Assuming every call expression implies a parallel builder can mask real missing t.Parallel() calls; consider inspecting the returned function literal or validating the callee identity rather than blanket-marking parallel.

Suggested change

	analysis.hasParallel = true
	if methodParallelIsCalledInTestFunction(arg, innerTestVar) {
	analysis.hasParallel = true
	}