if !isTestParam(fn.Type.Params.List[0].Type, prefix[:1]) {
		return
	}

	if tparams := fn.Type.TypeParams; tparams != nil && len(tparams.List) > 0 {
		// Note: cmd/go/internal/load also errors about TestXXX and BenchmarkXXX functions with type parameters.
		// We have currently decided to also warn before compilation/package loading. This can help users in IDEs.
		at := tokenRange{tparams.Opening, tparams.Closing}

// [a-z]) and serves to identify the test routine.
// These TestXxx routines should be declared within the package they are testing.
//
// Functions of the form
//     func BenchmarkXxx(*testing.B)
// are considered benchmarks, and are executed by go test when the -test.bench
// flag is provided.
//
// A sample benchmark function looks like this:
//     func BenchmarkHello(b *testing.B) {

lower case letter) and should have the signature,

	func TestXxx(t *testing.T) { ... }

A benchmark function is one named BenchmarkXxx and should have the signature,

	func BenchmarkXxx(b *testing.B) { ... }

A fuzz test is one named FuzzXxx and should have the signature,

	func FuzzXxx(f *testing.F) { ... }

//	        t.Errorf("Abs(-1) = %d; want 1", got)
//	    }
//	}
//
// For more detail, run "go help test" and "go help testflag".
//
// # Benchmarks
//
// Functions of the form
//
//	func BenchmarkXxx(*testing.B)
//
// are considered benchmarks, and are executed by the "go test" command when
// its -bench flag is provided. Benchmarks are run sequentially.
//
// For a description of the testing flags, see

// lower case letter) and should have the signature,
//
//	func TestXxx(t *testing.T) { ... }
//
// A benchmark function is one named BenchmarkXxx and should have the signature,
//
//	func BenchmarkXxx(b *testing.B) { ... }
//
// A fuzz test is one named FuzzXxx and should have the signature,
//
//	func FuzzXxx(f *testing.F) { ... }
//

! stdout '^\s+BenchmarkX: x_test.go:13: LOG: X running N=\d\d+'
! stdout 'BenchmarkX\s+\d+'

# Same for BenchmarkXX.
stdout -count=1 '^    z_test.go:18: LOG: XX running N=1$'
! stdout  '^    z_test.go:18: LOG: XX running N=\d\d+'
! stdout 'BenchmarkXX\s+\d+'

# BenchmarkX/Y is run in full twice due to -count=2.
# "Run in full" means that it runs for approximately the default benchtime,