Fix #123: Deduplicate result errors

core/condition.go

@@ -126,7 +126,7 @@ func (c Condition) evaluate(result *Result) bool {
 			conditionToDisplay = prettifyNumericalParameters(parameters, resolvedParameters, "<")
 		}
 	} else {
-		result.Errors = append(result.Errors, fmt.Sprintf("invalid condition '%s' has been provided", condition))
+		result.AddError(fmt.Sprintf("invalid condition '%s' has been provided", condition))
 		return false
 	}
 	if !success {
@@ -242,7 +242,7 @@ func sanitizeAndResolve(elements []string, result *Result) ([]string, []string)
 				} else {
 					if err != nil {
 						if err.Error() != "unexpected end of JSON input" {
-							result.Errors = append(result.Errors, err.Error())
+							result.AddError(err.Error())
 						}
 						if checkingForLength {
 							element = LengthFunctionPrefix + element + FunctionSuffix + " " + InvalidConditionElementSuffix

core/condition_bench_test.go

@@ -38,6 +38,15 @@ func BenchmarkCondition_evaluateWithBodyStringFailure(b *testing.B) {
 	b.ReportAllocs()
 }
 
+func BenchmarkCondition_evaluateWithBodyStringFailureInvalidPath(b *testing.B) {
+	condition := Condition("[BODY].user.name == bob.doe")
+	for n := 0; n < b.N; n++ {
+		result := &Result{body: []byte("{\"name\": \"bob.doe\"}")}
+		condition.evaluate(result)
+	}
+	b.ReportAllocs()
+}
+
 func BenchmarkCondition_evaluateWithBodyStringLen(b *testing.B) {
 	condition := Condition("len([BODY].name) == 8")
 	for n := 0; n < b.N; n++ {

core/result.go

@@ -25,7 +25,7 @@ type Result struct {
 	Duration time.Duration `json:"duration"`
 
 	// Errors encountered during the evaluation of the service's health
-	Errors []string `json:"errors"`
+	Errors []string `json:"errors"` // XXX: find a way to filter out duplicate errors
 
 	// ConditionResults results of the service's conditions
 	ConditionResults []*ConditionResult `json:"conditionResults"`
@@ -46,3 +46,15 @@ type Result struct {
 	// and sets it to nil after the evaluation has been completed.
 	body []byte
 }
+
+// AddError adds an error to the result's list of errors.
+// It also ensures that there are no duplicates.
+func (r *Result) AddError(error string) {
+	for _, resultError := range r.Errors {
+		if resultError == error {
+			// If the error already exists, don't add it
+			return
+		}
+	}
+	r.Errors = append(r.Errors, error)
+}

core/result_test.go

@@ -0,0 +1,21 @@
+package core
+
+import (
+	"testing"
+)
+
+func TestResult_AddError(t *testing.T) {
+	result := &Result{}
+	result.AddError("potato")
+	if len(result.Errors) != 1 {
+		t.Error("should've had 1 error")
+	}
+	result.AddError("potato")
+	if len(result.Errors) != 1 {
+		t.Error("should've still had 1 error, because a duplicate error was added")
+	}
+	result.AddError("tomato")
+	if len(result.Errors) != 2 {
+		t.Error("should've had 2 error")
+	}
+}

core/service.go

@@ -162,14 +162,14 @@ func (service *Service) getIP(result *Result) {
 	} else {
 		urlObject, err := url.Parse(service.URL)
 		if err != nil {
-			result.Errors = append(result.Errors, err.Error())
+			result.AddError(err.Error())
 			return
 		}
 		result.Hostname = urlObject.Hostname()
 	}
 	ips, err := net.LookupIP(result.Hostname)
 	if err != nil {
-		result.Errors = append(result.Errors, err.Error())
+		result.AddError(err.Error())
 		return
 	}
 	result.IP = ips[0].String()
@@ -193,7 +193,7 @@ func (service *Service) call(result *Result) {
 		service.DNS.query(service.URL, result)
 		result.Duration = time.Since(startTime)
 	} else if isServiceStartTLS {
-		result.Connected, certificate, err = client.CanPerformStartTls(strings.TrimPrefix(service.URL, "starttls://"), service.Insecure)
+		result.Connected, certificate, err = client.CanPerformStartTLS(strings.TrimPrefix(service.URL, "starttls://"), service.Insecure)
 		if err != nil {
 			result.Errors = append(result.Errors, err.Error())
 			return
@@ -209,7 +209,7 @@ func (service *Service) call(result *Result) {
 		response, err = client.GetHTTPClient(service.Insecure).Do(request)
 		result.Duration = time.Since(startTime)
 		if err != nil {
-			result.Errors = append(result.Errors, err.Error())
+			result.AddError(err.Error())
 			return
 		}
 		defer response.Body.Close()
@@ -223,7 +223,7 @@ func (service *Service) call(result *Result) {
 		if service.needsToReadBody() {
 			result.body, err = ioutil.ReadAll(response.Body)
 			if err != nil {
-				result.Errors = append(result.Errors, err.Error())
+				result.AddError(err.Error())
 			}
 		}
 	}