Reflective Go Test Runner

test_runner.go

package tests

import (
	"reflect"
	"strings"
	"testing"
)

type TestRunner struct{}

func (tr *TestRunner) Runtests() {
	testSuite := []testing.InternalTest{}

	// Dynamically find methods matching `Test*(*testing.T)`
	typ := reflect.TypeOf(tr)
	val := reflect.ValueOf(tr)
	for i := 0; i < typ.NumMethod(); i++ {
		method := typ.Method(i)

		twoIn := method.Type.NumIn() == 2
		zeroOut := method.Type.NumOut() == 0
		testingArg := method.Type.In(1).String() == "*testing.T"
		testPrefix := strings.HasPrefix(method.Name, "Test")
		if twoIn && zeroOut && testingArg && testPrefix {
			methodVal := val.MethodByName(method.Name)
			methodIface := methodVal.Convert(reflect.TypeOf((*func(*testing.T))(nil)).Elem()).Interface()
			if methodFunc, ok := methodIface.(func(*testing.T)); ok {
				testSuite = append(testSuite, testing.InternalTest{Name: method.Name, F: methodFunc})
			}
		}
	}
	testing.Main(matchString, testSuite, nil, nil)
}