Add test for bad configuration

config/config.go

@@ -1,6 +1,7 @@
 package config
 
 import (
+	"errors"
 	"github.com/TwinProduction/gatus/core"
 	"gopkg.in/yaml.v2"
 	"io/ioutil"
@@ -11,7 +12,10 @@ type Config struct {
 	Services []*core.Service `yaml:"services"`
 }
 
-var config *Config
+var (
+	ErrNoServiceInConfig = errors.New("configuration file should contain at least 1 service")
+	config               *Config
+)
 
 func Get() *Config {
 	if config == nil {
@@ -24,24 +28,27 @@ func Get() *Config {
 	return config
 }
 
-func readConfigurationFile(fileName string) (*Config, error) {
-	if bytes, err := ioutil.ReadFile(fileName); err == nil {
+func readConfigurationFile(fileName string) (config *Config, err error) {
+	var bytes []byte
+	if bytes, err = ioutil.ReadFile(fileName); err == nil {
 		// file exists, so we'll parse it and return it
-		return parseConfigBytes(bytes)
-	} else {
-		return nil, err
+		return parseAndValidateConfigBytes(bytes)
 	}
+	return
 }
 
-func parseConfigBytes(yamlBytes []byte) (config *Config, err error) {
+func parseAndValidateConfigBytes(yamlBytes []byte) (config *Config, err error) {
 	err = yaml.Unmarshal(yamlBytes, &config)
-	if err != nil {
-		return
-	}
+	// Check if the configuration file at least has services.
+	if config == nil || len(config.Services) == 0 {
+		err = ErrNoServiceInConfig
+	} else {
+		// Set the default values if they aren't set
 		for _, service := range config.Services {
 			if service.Interval == 0 {
 				service.Interval = 10 * time.Second
 			}
 		}
+	}
 	return
 }

config/config_test.go

@@ -6,8 +6,8 @@ import (
 	"time"
 )
 
-func TestParseConfigBytes(t *testing.T) {
-	config := parseConfigBytes([]byte(`
+func TestParseAndValidateConfigBytes(t *testing.T) {
+	config, err := parseAndValidateConfigBytes([]byte(`
 services:
   - name: twinnation
     url: https://twinnation.org/actuator/health
@@ -20,6 +20,9 @@ services:
       - "$STATUS != 400"
       - "$STATUS != 500"
 `))
+	if err != nil {
+		t.Error("No error should've been returned")
+	}
 	if len(config.Services) != 2 {
 		t.Error("Should have returned two services")
 	}
@@ -44,14 +47,17 @@ services:
 	}
 }
 
-func TestParseConfigBytesDefault(t *testing.T) {
-	config := parseConfigBytes([]byte(`
+func TestParseAndValidateConfigBytesDefault(t *testing.T) {
+	config, err := parseAndValidateConfigBytes([]byte(`
 services:
   - name: twinnation
     url: https://twinnation.org/actuator/health
     conditions:
       - "$STATUS == 200"
 `))
+	if err != nil {
+		t.Error("No error should've been returned")
+	}
 	if config.Services[0].Url != "https://twinnation.org/actuator/health" {
 		t.Errorf("URL should have been %s", "https://twinnation.org/actuator/health")
 	}
@@ -59,3 +65,19 @@ services:
 		t.Errorf("Interval should have been %s, because it is the default value", 10*time.Second)
 	}
 }
+
+func TestParseAndValidateBadConfigBytes(t *testing.T) {
+	_, err := parseAndValidateConfigBytes([]byte(`
+badconfig:
+  - asdsa: w0w
+    usadasdrl: asdxzczxc	
+    asdas:
+      - soup
+`))
+	if err == nil {
+		t.Error("An error should've been returned")
+	}
+	if err != ErrNoServiceInConfig {
+		t.Error("The error returned should have been of type ErrNoServiceInConfig")
+	}
+}