Add support for getting the length of the string or the slice of a json path

README.md

@@ -58,7 +58,7 @@ Note that you can also add environment variables in the your configuration file
 Here are some examples of conditions you can use:
 
 | Condition                    | Description                                             | Passing values           | Failing values          |
-| ------------------------------------- | ----------------------------------------- | ------------------------ | ----------------------- |
+| -----------------------------| ------------------------------------------------------- | ------------------------ | ----------------------- |
 | `[STATUS] == 200`            | Status must be equal to 200                             | 200                      | 201, 404, 500           |
 | `[STATUS] < 300`             | Status must lower than 300                              | 200, 201, 299            | 301, 302, 400, 500      |
 | `[STATUS] <= 299`            | Status must be less than or equal to 299                | 200, 201, 299            | 301, 302, 400, 500      |
@@ -67,6 +67,8 @@ Here are some examples of conditions you can use:
 | `[BODY] == 1`                | The body must be equal to 1                             | 1                        | literally anything else |
 | `[BODY].data.id == 1`        | The jsonpath `$.data.id` is equal to 1                  | `{"data":{"id":1}}`      | literally anything else |
 | `[BODY].data[0].id == 1`     | The jsonpath `$.data[0].id` is equal to 1               | `{"data":[{"id":1}]}`    | literally anything else |
+| `len([BODY].data) > 0`       | Array at jsonpath `$.data` has less than 5 elements     | `{"data":[{"id":1}]}`    | `{"data":[{"id":1}]}`   |
+| `len([BODY].name) == 8`      | String at jsonpath `$.name` has a length of 8           | `{"name":"john.doe"}`    | `{"name":"bob"}`        |
 
 **NOTE**: `[BODY]` with JSON path (i.e. `[BODY].id == 1`) is currently in BETA. For the most part, the only thing that doesn't work is arrays.
 

config.yaml

@@ -14,8 +14,4 @@ services:
       - "[STATUS] == 200"
       - "[BODY].id == 24"
       - "[BODY].tags[0] == spring"
-  - name: example
-    url: https://example.org/
-    interval: 30s
-    conditions:
-      - "[STATUS] == 200"
+      - "len([BODY].tags) > 0"

core/condition.go

@@ -41,10 +41,10 @@ func (c *Condition) evaluate(result *Result) bool {
 		return false
 	}
 	conditionToDisplay := condition
-	// If the condition isn't a success, return the resolved condition
+	// If the condition isn't a success, return what the resolved condition was too
 	if !success {
 		log.Printf("[Condition][evaluate] Condition '%s' did not succeed because '%s' is false", condition, resolvedCondition)
-		conditionToDisplay = resolvedCondition
+		conditionToDisplay = fmt.Sprintf("%s (%s)", condition, resolvedCondition)
 	}
 	result.ConditionResults = append(result.ConditionResults, &ConditionResult{Condition: conditionToDisplay, Success: success})
 	return success

core/condition_test.go

@@ -166,3 +166,21 @@ func TestCondition_evaluateWithBodyJsonPathComplexIntFailureUsingLessThan(t *tes
 		t.Errorf("Condition '%s' should have been a failure", condition)
 	}
 }
+
+func TestCondition_evaluateWithBodySliceLength(t *testing.T) {
+	condition := Condition("len([BODY].data) == 3")
+	result := &Result{Body: []byte("{\"data\": [{\"id\": 1}, {\"id\": 2}, {\"id\": 3}]}")}
+	condition.evaluate(result)
+	if !result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a success", condition)
+	}
+}
+
+func TestCondition_evaluateWithBodyStringLength(t *testing.T) {
+	condition := Condition("len([BODY].name) == 8")
+	result := &Result{Body: []byte("{\"name\": \"john.doe\"}")}
+	condition.evaluate(result)
+	if !result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a success", condition)
+	}
+}

core/util.go

@@ -32,16 +32,25 @@ func sanitizeAndResolve(list []string, result *Result) []string {
 			element = body
 		default:
 			// if starts with BodyPlaceHolder, then evaluate json path
-			if strings.HasPrefix(element, BodyPlaceHolder) {
-				resolvedElement, err := jsonpath.Eval(strings.Replace(element, fmt.Sprintf("%s.", BodyPlaceHolder), "", 1), result.Body)
+			if strings.Contains(element, BodyPlaceHolder) {
+				wantLength := false
+				if strings.HasPrefix(element, "len(") && strings.HasSuffix(element, ")") {
+					wantLength = true
+					element = strings.TrimSuffix(strings.TrimPrefix(element, "len("), ")")
+				}
+				resolvedElement, resolvedElementLength, err := jsonpath.Eval(strings.Replace(element, fmt.Sprintf("%s.", BodyPlaceHolder), "", 1), result.Body)
 				if err != nil {
 					result.Errors = append(result.Errors, err.Error())
 					element = fmt.Sprintf("%s %s", element, InvalidConditionElementSuffix)
+				} else {
+					if wantLength {
+						element = fmt.Sprintf("%d", resolvedElementLength)
 					} else {
 						element = resolvedElement
 					}
 				}
 			}
+		}
 		sanitizedList = append(sanitizedList, element)
 	}
 	return sanitizedList

jsonpath/jsonpath.go

@@ -8,26 +8,30 @@ import (
 )
 
 // Eval is a half-baked json path implementation that needs some love
-func Eval(path string, b []byte) (string, error) {
+func Eval(path string, b []byte) (string, int, error) {
 	var object interface{}
 	err := json.Unmarshal(b, &object)
 	if err != nil {
 		// Try to unmarshal it into an array instead
-		return "", err
+		return "", 0, err
 	}
 	return walk(path, object)
 }
 
-func walk(path string, object interface{}) (string, error) {
+func walk(path string, object interface{}) (string, int, error) {
 	keys := strings.Split(path, ".")
 	currentKey := keys[0]
 	switch value := extractValue(currentKey, object).(type) {
 	case map[string]interface{}:
 		return walk(strings.Replace(path, fmt.Sprintf("%s.", currentKey), "", 1), value)
+	case string:
+		return value, len(value), nil
+	case []interface{}:
+		return fmt.Sprintf("%v", value), len(value), nil
 	case interface{}:
-		return fmt.Sprintf("%v", value), nil
+		return fmt.Sprintf("%v", value), 1, nil
 	default:
-		return "", fmt.Errorf("couldn't walk through '%s' because type was '%T', but expected 'map[string]interface{}'", currentKey, value)
+		return "", 0, fmt.Errorf("couldn't walk through '%s' because type was '%T', but expected 'map[string]interface{}'", currentKey, value)
 	}
 }
 

jsonpath/jsonpath_test.go

@@ -8,10 +8,13 @@ func TestEval(t *testing.T) {
 
 	expectedOutput := "value"
 
-	output, err := Eval(path, []byte(data))
+	output, outputLength, err := Eval(path, []byte(data))
 	if err != nil {
 		t.Error("Didn't expect any error, but got", err)
 	}
+	if outputLength != len(expectedOutput) {
+		t.Errorf("Expected output length to be %v, but was %v", len(expectedOutput), outputLength)
+	}
 	if output != expectedOutput {
 		t.Errorf("Expected output to be %v, but was %v", expectedOutput, output)
 	}
@@ -23,7 +26,7 @@ func TestEvalWithLongSimpleWalk(t *testing.T) {
 
 	expectedOutput := "value"
 
-	output, err := Eval(path, []byte(data))
+	output, _, err := Eval(path, []byte(data))
 	if err != nil {
 		t.Error("Didn't expect any error, but got", err)
 	}
@@ -38,10 +41,11 @@ func TestEvalWithArrayOfMaps(t *testing.T) {
 
 	expectedOutput := "2"
 
-	output, err := Eval(path, []byte(data))
+	output, _, err := Eval(path, []byte(data))
 	if err != nil {
 		t.Error("Didn't expect any error, but got", err)
 	}
+
 	if output != expectedOutput {
 		t.Errorf("Expected output to be %v, but was %v", expectedOutput, output)
 	}
@@ -53,7 +57,7 @@ func TestEvalWithArrayOfValues(t *testing.T) {
 
 	expectedOutput := "1"
 
-	output, err := Eval(path, []byte(data))
+	output, _, err := Eval(path, []byte(data))
 	if err != nil {
 		t.Error("Didn't expect any error, but got", err)
 	}
@@ -68,7 +72,7 @@ func TestEvalWithRootArrayOfValues(t *testing.T) {
 
 	expectedOutput := "2"
 
-	output, err := Eval(path, []byte(data))
+	output, _, err := Eval(path, []byte(data))
 	if err != nil {
 		t.Error("Didn't expect any error, but got", err)
 	}
@@ -83,7 +87,7 @@ func TestEvalWithRootArrayOfMaps(t *testing.T) {
 
 	expectedOutput := "1"
 
-	output, err := Eval(path, []byte(data))
+	output, _, err := Eval(path, []byte(data))
 	if err != nil {
 		t.Error("Didn't expect any error, but got", err)
 	}
@@ -96,7 +100,7 @@ func TestEvalWithRootArrayOfMapsUsingInvalidArrayIndex(t *testing.T) {
 	path := "[5].id"
 	data := `[{"id": 1}, {"id": 2}]`
 
-	_, err := Eval(path, []byte(data))
+	_, _, err := Eval(path, []byte(data))
 	if err == nil {
 		t.Error("Should've returned an error, but didn't")
 	}
@@ -108,7 +112,7 @@ func TestEvalWithLongWalkAndArray(t *testing.T) {
 
 	expectedOutput := "1"
 
-	output, err := Eval(path, []byte(data))
+	output, _, err := Eval(path, []byte(data))
 	if err != nil {
 		t.Error("Didn't expect any error, but got", err)
 	}
@@ -123,7 +127,7 @@ func TestEvalWithNestedArray(t *testing.T) {
 
 	expectedOutput := "7"
 
-	output, err := Eval(path, []byte(data))
+	output, _, err := Eval(path, []byte(data))
 	if err != nil {
 		t.Error("Didn't expect any error, but got", err)
 	}
@@ -138,7 +142,7 @@ func TestEvalWithMapOfNestedArray(t *testing.T) {
 
 	expectedOutput := "e"
 
-	output, err := Eval(path, []byte(data))
+	output, _, err := Eval(path, []byte(data))
 	if err != nil {
 		t.Error("Didn't expect any error, but got", err)
 	}