You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: service_test.go
    path of file: ./repos/horusec/internal/services/custom_rules
    
    the code of the file until where you have to start completion: // Copyright 2021 ZUP IT SERVICOS EM TECNOLOGIA E INOVACAO SA
//
// Licensed under the Apache License, Version 2.0 (the 
    
func TestGetCustomRulesByTool(t *testing.T) {
	t.Run("should success load custom rules from file", func(t *testing.T) {
		cfg := config.New()
		cfg.CustomRulesPath = filepath.Join(".", "custom_rules_example.json")

		service := customrules.NewCustomRulesService(cfg)

		assert.Len(t, service.Load(languages.CSharp), 1)
		assert.Len(t, service.Load(languages.Dart), 1)
		assert.Len(t, service.Load(languages.Java), 1)
		assert.Len(t, service.Load(languages.Kotlin), 1)
		assert.Len(t, service.Load(languages.Yaml), 1)
		assert.Len(t, service.Load(languages.Leaks), 1)
		assert.Len(t, service.Load(languages.Javascript), 1)
	})

	t.Run("should use empty rules for all languages when file does not exists", func(t *testing.T) {
		cfg := config.New()
		cfg.CustomRulesPath = filepath.Join(".", "test.json")

		service := customrules.NewCustomRulesService(cfg)

		assertEmptyRulesForAllLanguages(t, service)
	})

	t.Run("should use empty rules for all languages when file is in invalid format", func(t *testing.T) {
		cfg := config.New()
		cfg.CustomRulesPath = filepath.Join(".", "custom_rules_example_invalid.json")

		service := customrules.NewCustomRulesService(cfg)

		assertEmptyRulesForAllLanguages(t, service)
	})
}