Add JSON validation function and tests: implement JSON validity check and comprehensive unit tests for valid/invalid cases

internal/validate/json.go

@@ -0,0 +1,12 @@
+package validate
+
+import (
+	"encoding/json"
+)
+
+// JSON validates a JSON string, it returns a boolean indicating whether
+// the JSON is valid or not.
+func JSON(jsonStr string) bool {
+	var js json.RawMessage
+	return json.Unmarshal([]byte(jsonStr), &js) == nil
+}

internal/validate/json_test.go

@@ -0,0 +1,44 @@
+package validate
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestJSON(t *testing.T) {
+	validJSON := []string{
+		`{"name": "John", "age": 30}`,
+		`{"name": "John", "friends": ["Alice", "Bob"]}`,
+		`{"items": [{"id": 1, "name": "Item1"}, {"id": 2, "name": "Item2"}]}`,
+		`{"emptyArray": [], "emptyObject": {}}`,
+		`{"nullValue": null}`,
+		`{"booleanTrue": true, "booleanFalse": false}`,
+		`{"numberInt": 123, "numberFloat": 123.456}`,
+		`{"string": "Hello, World!"}`,
+		`{"nested": {"level1": {"level2": {"level3": "value"}}}}`,
+		`{"escapedString": "This is a quote: \"}"}`,
+	}
+
+	for _, jsonStr := range validJSON {
+		assert.True(t, JSON(jsonStr), "Expected JSON to be valid: %s", jsonStr)
+	}
+
+	invalidJSON := []string{
+		`{"name": "John", "age": 30`,
+		`{"name": "John", "friends": ["Alice", "Bob"}`,
+		`{"items": [{"id": 1, "name": "Item1"}, {"id": 2, "name": "Item2"]]}`,
+		`{"unclosedString": "Hello}`,
+		`{"unexpectedToken": tru}`,
+		`{"incompleteObject": {}`,
+		`{name: "John", "age": 30}`,
+		`{"missingComma": "value1" "value2"}`,
+		`["mismatch": "value"]`,
+		`some other thing`,
+		``,
+	}
+
+	for _, jsonStr := range invalidJSON {
+		assert.False(t, JSON(jsonStr), "Expected JSON to be invalid: %s", jsonStr)
+	}
+}