fixup! fixup! fixup! fixup! fixup! fixup! fixup! fixup! Library improvements.

execute_query.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"net/http"
 	"time"
+	"unicode/utf8"
 
 	"github.com/avast/retry-go/v4"
 	"github.com/goccy/go-json"
@@ -23,6 +24,14 @@ func min(a, b int) int {
 	return b
 }
 
+// max returns the larger of two integers
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
 var (
 	// Shared HTTP transport with optimized settings
 	defaultTransport = &http.Transport{
@@ -63,7 +72,7 @@ func (qe *QueryExecutor) executeQuery() ([]byte, error) {
 	}
 	// Set Content-Type header if not already set
 	if httpRequest.Header.Get("Content-Type") == "" {
-		httpRequest.Header.Set("Content-Type", "application/json")
+		httpRequest.Header.Set("Content-Type", "application/json; charset=utf-8")
 	}
 
 	// Explicitly remove Accept-Encoding header to prevent automatic request compression
@@ -83,9 +92,34 @@ func (qe *QueryExecutor) executeQuery() ([]byte, error) {
 			buf.Reset()
 			buf.Write(qe.Query)
 
+			// Comprehensive request body analysis for trailing garbage debugging
+			requestBody := buf.Bytes()
+			qe.Logger.Debug(&libpack_logger.LogMessage{
+				Message: "Request body analysis",
+				Pairs: map[string]interface{}{
+					"body_size":          len(requestBody),
+					"contains_jsonQuery": bytes.Contains(requestBody, []byte(`"jsonQuery"`)),
+					"contains_base64":    bytes.Contains(requestBody, []byte("eyJ")),
+					"first_100_chars":    string(requestBody[:min(100, len(requestBody))]),
+					"last_50_chars":      string(requestBody[max(0, len(requestBody)-50):]),
+					"is_valid_utf8":      utf8.Valid(requestBody),
+					"has_null_bytes":     bytes.Contains(requestBody, []byte{0}),
+					"has_control_chars":  hasControlChars(requestBody),
+				},
+			})
+
+			// Validate request body structure
+			if err := validateRequestBody(requestBody, qe.Logger); err != nil {
+				qe.Logger.Error(&libpack_logger.LogMessage{
+					Message: "Request body validation failed",
+					Pairs:   map[string]interface{}{"error": err.Error()},
+				})
+				return fmt.Errorf("request body validation failed: %w", err)
+			}
+
 			// Set the body of the request (plain JSON, no compression)
-			httpRequest.Body = io.NopCloser(bytes.NewReader(buf.Bytes()))
+			httpRequest.Body = io.NopCloser(bytes.NewReader(requestBody))
-			httpRequest.ContentLength = int64(buf.Len())
+			httpRequest.ContentLength = int64(len(requestBody))
 
 			// Debug log to confirm request is sent as plain JSON
 			qe.Logger.Debug(&libpack_logger.LogMessage{
@@ -351,3 +385,69 @@ func (qe *QueryExecutor) executeQuery() ([]byte, error) {
 
 	return jsonData, nil
 }
+
+// hasControlChars checks if the byte slice contains control characters that might cause parsing issues
+func hasControlChars(data []byte) bool {
+	for _, b := range data {
+		// Check for control characters except for common whitespace (tab, newline, carriage return)
+		if b < 32 && b != 9 && b != 10 && b != 13 {
+			return true
+		}
+	}
+	return false
+}
+
+// validateRequestBody performs comprehensive validation of the request body
+func validateRequestBody(data []byte, logger *libpack_logger.Logger) error {
+	// Check if data is valid UTF-8
+	if !utf8.Valid(data) {
+		return fmt.Errorf("request body contains invalid UTF-8 sequences")
+	}
+
+	// Check for null bytes
+	if bytes.Contains(data, []byte{0}) {
+		return fmt.Errorf("request body contains null bytes")
+	}
+
+	// Check if it's valid JSON
+	var jsonData map[string]interface{}
+	if err := json.Unmarshal(data, &jsonData); err != nil {
+		return fmt.Errorf("request body is not valid JSON: %w", err)
+	}
+
+	// Check for jsonQuery field (this should never be present)
+	if _, exists := jsonData["jsonQuery"]; exists {
+		logger.Error(&libpack_logger.LogMessage{
+			Message: "CRITICAL: jsonQuery field found in request body - this causes trailing garbage",
+			Pairs: map[string]interface{}{
+				"body_size":         len(data),
+				"jsonQuery_present": true,
+			},
+		})
+		return fmt.Errorf("jsonQuery field found in request body - this would cause trailing garbage")
+	}
+
+	// Check for unexpected base64 data that might indicate double encoding
+	if bytes.Contains(data, []byte("eyJ")) {
+		logger.Warning(&libpack_logger.LogMessage{
+			Message: "Potential base64 encoded JSON detected in request body",
+			Pairs: map[string]interface{}{
+				"body_size":       len(data),
+				"contains_base64": true,
+			},
+		})
+	}
+
+	// Log successful validation
+	logger.Debug(&libpack_logger.LogMessage{
+		Message: "Request body validation passed",
+		Pairs: map[string]interface{}{
+			"body_size":          len(data),
+			"valid_utf8":         true,
+			"valid_json":         true,
+			"no_jsonQuery_field": true,
+		},
+	})
+
+	return nil
+}

execute_query_test.go

@@ -230,7 +230,7 @@ func (suite *Tests) TestQueryExecutor_executeQuery() {
 		result, err := qe.executeQuery()
 		assert.NoError(err)
 		assert.NotNil(result)
-		assert.Equal("application/json", receivedHeaders.Get("Content-Type"))
+		assert.Equal("application/json; charset=utf-8", receivedHeaders.Get("Content-Type"))
 	})
 
 	suite.T().Run("should handle invalid JSON response", func(t *testing.T) {

query.go

@@ -20,6 +20,7 @@ func (b *BaseClient) convertToJSON(v any) []byte {
 	}
 
 	buf := getBuffer(estimatedSize)
+	buf.Reset() // Ensure buffer is clean before use
 	defer putBuffer(buf)
 
 	// Use json.NewEncoder for better performance with buffers

trailing_garbage_reproduction_test.go

@@ -0,0 +1,804 @@
+package gql
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"unicode/utf8"
+
+	assertions "github.com/stretchr/testify/assert"
+)
+
+// TestTrailingGarbageReproduction attempts to reproduce the exact "trailing garbage" scenario
+func TestTrailingGarbageReproduction(t *testing.T) {
+	assert := assertions.New(t)
+
+	t.Run("should investigate size discrepancy - 1093 vs 356 bytes", func(t *testing.T) {
+		client := CreateTestClient()
+
+		// Base data from user report
+		variables := map[string]interface{}{
+			"group_description": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+			"user_name":         "2eba巴结",
+		}
+
+		query := "mutation storeMessage($group_description: String!, $user_name: String!) { insert_message(group_description: $group_description, user_name: $user_name) { id } }"
+
+		// Test different scenarios that might increase size to 1093 bytes
+		scenarios := []struct {
+			name       string
+			modifier   func(map[string]interface{}) map[string]interface{}
+			queryMod   func(string) string
+			expectSize int
+		}{
+			{
+				name: "base_case",
+				modifier: func(v map[string]interface{}) map[string]interface{} {
+					return v
+				},
+				queryMod:   func(q string) string { return q },
+				expectSize: 356,
+			},
+			{
+				name: "with_additional_headers_in_variables",
+				modifier: func(v map[string]interface{}) map[string]interface{} {
+					result := make(map[string]interface{})
+					for k, val := range v {
+						result[k] = val
+					}
+					// Add headers that might be included in variables
+					result["authorization"] = "Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c"
+					result["user_agent"] = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36"
+					result["content_type"] = "application/json; charset=utf-8"
+					return result
+				},
+				queryMod:   func(q string) string { return q },
+				expectSize: 700, // Estimated
+			},
+			{
+				name: "with_nested_json_data",
+				modifier: func(v map[string]interface{}) map[string]interface{} {
+					result := make(map[string]interface{})
+					for k, val := range v {
+						result[k] = val
+					}
+					// Add nested JSON that might be double-encoded
+					result["metadata"] = map[string]interface{}{
+						"client_info": map[string]interface{}{
+							"platform": "web",
+							"version":  "1.0.0",
+							"features": []string{"emoji_support", "unicode_text", "file_upload"},
+						},
+						"request_id": "req_123456789_abcdef",
+						"timestamp":  "2023-05-23T18:01:37.000Z",
+					}
+					return result
+				},
+				queryMod:   func(q string) string { return q },
+				expectSize: 800, // Estimated
+			},
+			{
+				name: "with_very_long_query",
+				modifier: func(v map[string]interface{}) map[string]interface{} {
+					return v
+				},
+				queryMod: func(q string) string {
+					// Add a much longer query with many fields
+					return `mutation storeMessage(
+						$group_description: String!, 
+						$user_name: String!,
+						$additional_field1: String,
+						$additional_field2: String,
+						$additional_field3: String,
+						$additional_field4: String,
+						$additional_field5: String
+					) { 
+						insert_message(
+							group_description: $group_description, 
+							user_name: $user_name,
+							additional_field1: $additional_field1,
+							additional_field2: $additional_field2,
+							additional_field3: $additional_field3,
+							additional_field4: $additional_field4,
+							additional_field5: $additional_field5
+						) { 
+							id 
+							created_at
+							updated_at
+							status
+							metadata {
+								source
+								platform
+								version
+							}
+						} 
+					}`
+				},
+				expectSize: 1000, // Estimated
+			},
+		}
+
+		for _, scenario := range scenarios {
+			t.Run(scenario.name, func(t *testing.T) {
+				modifiedVars := scenario.modifier(variables)
+				modifiedQuery := scenario.queryMod(query)
+
+				compiledQuery := client.compileQuery(modifiedQuery, modifiedVars)
+				assert.NotNil(compiledQuery)
+
+				size := len(compiledQuery.JsonQuery)
+				t.Logf("%s: JSON size = %d bytes (expected ~%d)", scenario.name, size, scenario.expectSize)
+
+				if size >= 1090 && size <= 1210 { // Expanded range to include our actual results
+					t.Logf("🎯 FOUND POTENTIAL MATCH: %s produces %d bytes (target: 1093)", scenario.name, size)
+					t.Logf("JSON content: %s", string(compiledQuery.JsonQuery))
+				}
+
+				// Verify it's still valid
+				assert.True(json.Valid(compiledQuery.JsonQuery))
+			})
+		}
+	})
+
+	t.Run("should test potential double-encoding scenarios", func(t *testing.T) {
+		client := CreateTestClient()
+
+		// Test if the JsonQuery field might be getting included somehow
+		query := &Query{
+			Query: "mutation storeMessage($group_description: String!, $user_name: String!) { insert_message(group_description: $group_description, user_name: $user_name) { id } }",
+			Variables: map[string]interface{}{
+				"group_description": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+				"user_name":         "2eba巴结",
+			},
+		}
+
+		// First, compile normally
+		query.JsonQuery = client.convertToJSON(query)
+		normalSize := len(query.JsonQuery)
+		t.Logf("Normal encoding size: %d bytes", normalSize)
+
+		// Test if somehow JsonQuery gets included in serialization (it shouldn't due to json:"-")
+		doubleEncodedBytes, err := json.Marshal(query)
+		assert.NoError(err)
+		doubleEncodedSize := len(doubleEncodedBytes)
+		t.Logf("Double encoding size: %d bytes", doubleEncodedSize)
+
+		// Test if there's a scenario where the JsonQuery field is accidentally included
+		queryWithoutTag := struct {
+			Variables map[string]interface{} `json:"variables,omitempty"`
+			Query     string                 `json:"query,omitempty"`
+			JsonQuery []byte                 `json:"jsonQuery,omitempty"` // Without json:"-"
+		}{
+			Variables: query.Variables,
+			Query:     query.Query,
+			JsonQuery: query.JsonQuery,
+		}
+
+		problematicBytes, err := json.Marshal(queryWithoutTag)
+		assert.NoError(err)
+		problematicSize := len(problematicBytes)
+		t.Logf("Problematic encoding (with JsonQuery field) size: %d bytes", problematicSize)
+
+		if problematicSize >= 1090 && problematicSize <= 1100 {
+			t.Logf("🎯 FOUND ISSUE: Including JsonQuery field produces %d bytes!", problematicSize)
+			t.Logf("This would cause trailing garbage because JsonQuery contains base64 or nested JSON")
+		}
+	})
+
+	t.Run("should test server that detects trailing garbage", func(t *testing.T) {
+		// Create a server that specifically looks for trailing garbage patterns
+		trailingGarbageServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			body := make([]byte, r.ContentLength)
+			n, _ := r.Body.Read(body)
+			actualBody := body[:n]
+
+			t.Logf("Server analyzing %d bytes", len(actualBody))
+
+			// Try to decode JSON and check for trailing data
+			decoder := json.NewDecoder(bytes.NewReader(actualBody))
+			var request map[string]interface{}
+			err := decoder.Decode(&request)
+			if err != nil {
+				t.Logf("JSON decode error: %s", err.Error())
+				w.WriteHeader(http.StatusBadRequest)
+				w.Write([]byte(`{"error":"invalid JSON","code":"invalid-json"}`))
+				return
+			}
+
+			// Check if there's trailing data after the first JSON object
+			remaining := decoder.Buffered()
+			if remaining != nil {
+				buf := make([]byte, 1024)
+				n, _ := remaining.Read(buf)
+				if n > 0 {
+					t.Logf("Found trailing data: %s", string(buf[:n]))
+					w.WriteHeader(http.StatusBadRequest)
+					w.Write([]byte(`{"error":"trailing garbage after JSON","code":"invalid-json"}`))
+					return
+				}
+			}
+
+			// Check for specific patterns that might indicate double encoding
+			if bytes.Contains(actualBody, []byte(`"jsonQuery"`)) {
+				t.Logf("Found jsonQuery field in request - this would cause issues!")
+				w.WriteHeader(http.StatusBadRequest)
+				w.Write([]byte(`{"error":"trailing garbage after JSON","code":"invalid-json"}`))
+				return
+			}
+
+			// Check for base64 patterns that might indicate nested encoding
+			if bytes.Contains(actualBody, []byte("eyJ")) { // Common base64 JSON start
+				t.Logf("Found potential base64 encoded JSON in request")
+				w.WriteHeader(http.StatusBadRequest)
+				w.Write([]byte(`{"error":"trailing garbage after JSON","code":"invalid-json"}`))
+				return
+			}
+
+			// Success
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte(`{"data":{"result":"success"}}`))
+		}))
+		defer trailingGarbageServer.Close()
+
+		client := CreateTestClient()
+
+		// Test the normal case
+		variables := map[string]interface{}{
+			"group_description": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+			"user_name":         "2eba巴结",
+		}
+
+		query := "mutation storeMessage($group_description: String!, $user_name: String!) { insert_message(group_description: $group_description, user_name: $user_name) { id } }"
+		compiledQuery := client.compileQuery(query, variables)
+
+		qe := &QueryExecutor{
+			BaseClient: client,
+			Query:      compiledQuery.JsonQuery,
+			Headers:    map[string]interface{}{"Content-Type": "application/json; charset=utf-8"},
+			CacheKey:   "no-cache",
+			Retries:    false,
+		}
+		qe.endpoint = trailingGarbageServer.URL
+		qe.client = trailingGarbageServer.Client()
+		qe.cache = client.cache
+
+		result, err := qe.executeQuery()
+		assert.NoError(err, "Normal request should succeed")
+		assert.NotNil(result)
+	})
+
+	t.Run("should test Content-Length vs actual body size mismatch", func(t *testing.T) {
+		// Test if there's a mismatch between Content-Length and actual body size
+		var receivedContentLength int64
+		var actualBodySize int
+
+		mismatchServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			receivedContentLength = r.ContentLength
+
+			body := make([]byte, r.ContentLength+100) // Read more than Content-Length
+			n, _ := r.Body.Read(body)
+			actualBodySize = n
+
+			t.Logf("Content-Length header: %d", receivedContentLength)
+			t.Logf("Actual body size read: %d", actualBodySize)
+
+			if int64(actualBodySize) != receivedContentLength {
+				t.Logf("⚠️  MISMATCH: Content-Length=%d but actual body=%d", receivedContentLength, actualBodySize)
+				w.WriteHeader(http.StatusBadRequest)
+				w.Write([]byte(`{"error":"trailing garbage after JSON","code":"invalid-json"}`))
+				return
+			}
+
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte(`{"data":{"result":"success"}}`))
+		}))
+		defer mismatchServer.Close()
+
+		client := CreateTestClient()
+
+		variables := map[string]interface{}{
+			"group_description": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+			"user_name":         "2eba巴结",
+		}
+
+		query := "mutation storeMessage($group_description: String!, $user_name: String!) { insert_message(group_description: $group_description, user_name: $user_name) { id } }"
+		compiledQuery := client.compileQuery(query, variables)
+
+		qe := &QueryExecutor{
+			BaseClient: client,
+			Query:      compiledQuery.JsonQuery,
+			Headers:    map[string]interface{}{"Content-Type": "application/json; charset=utf-8"},
+			CacheKey:   "no-cache",
+			Retries:    false,
+		}
+		qe.endpoint = mismatchServer.URL
+		qe.client = mismatchServer.Client()
+		qe.cache = client.cache
+
+		result, err := qe.executeQuery()
+		assert.NoError(err, "Should not have Content-Length mismatch")
+		assert.NotNil(result)
+		assert.Equal(int64(actualBodySize), receivedContentLength, "Content-Length should match actual body size")
+	})
+}
+
+// TestPotentialRootCauses tests the most likely root causes of the trailing garbage issue
+func TestPotentialRootCauses(t *testing.T) {
+	assert := assertions.New(t)
+
+	t.Run("root_cause_1_JsonQuery_field_accidentally_included", func(t *testing.T) {
+		// This would be the most likely cause - if JsonQuery field gets included in JSON
+		client := CreateTestClient()
+		_ = client // Use the client variable to avoid compiler error
+
+		// Simulate a bug where JsonQuery field is included
+		type BuggyQuery struct {
+			Variables map[string]interface{} `json:"variables,omitempty"`
+			Query     string                 `json:"query,omitempty"`
+			JsonQuery []byte                 `json:"jsonQuery,omitempty"` // BUG: should be json:"-"
+		}
+
+		buggyQuery := &BuggyQuery{
+			Query: "mutation storeMessage($group_description: String!, $user_name: String!) { insert_message(group_description: $group_description, user_name: $user_name) { id } }",
+			Variables: map[string]interface{}{
+				"group_description": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+				"user_name":         "2eba巴结",
+			},
+		}
+
+		// Set JsonQuery to the JSON representation of itself (recursive)
+		normalJson, _ := json.Marshal(map[string]interface{}{
+			"query":     buggyQuery.Query,
+			"variables": buggyQuery.Variables,
+		})
+		buggyQuery.JsonQuery = normalJson
+
+		// Now marshal the buggy query - this would include JsonQuery field
+		buggyJsonBytes, err := json.Marshal(buggyQuery)
+		assert.NoError(err)
+
+		t.Logf("Buggy JSON size: %d bytes", len(buggyJsonBytes))
+		t.Logf("Buggy JSON content: %s", string(buggyJsonBytes))
+
+		// This would create a JSON with nested JSON, potentially causing parsing issues
+		var parsed map[string]interface{}
+		err = json.Unmarshal(buggyJsonBytes, &parsed)
+		assert.NoError(err) // JSON is still valid, but contains extra data
+
+		// Check if this creates the size we're looking for
+		if len(buggyJsonBytes) >= 1090 && len(buggyJsonBytes) <= 1100 {
+			t.Logf("🎯 ROOT CAUSE FOUND: JsonQuery field inclusion creates %d bytes", len(buggyJsonBytes))
+		}
+	})
+
+	t.Run("root_cause_2_buffer_reuse_contamination", func(t *testing.T) {
+		// Test if buffer reuse might cause contamination
+		client := CreateTestClient()
+
+		// Simulate multiple requests that might contaminate buffers
+		for i := 0; i < 3; i++ {
+			variables := map[string]interface{}{
+				"group_description": fmt.Sprintf("Request %d: This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈", i),
+				"user_name":         "2eba巴结",
+				"request_id":        fmt.Sprintf("req_%d", i),
+			}
+
+			query := "mutation storeMessage($group_description: String!, $user_name: String!, $request_id: String) { insert_message(group_description: $group_description, user_name: $user_name, request_id: $request_id) { id } }"
+			compiledQuery := client.compileQuery(query, variables)
+
+			t.Logf("Request %d JSON size: %d bytes", i, len(compiledQuery.JsonQuery))
+
+			// Check for any unexpected content
+			assert.True(json.Valid(compiledQuery.JsonQuery))
+		}
+	})
+
+	t.Run("root_cause_3_encoding_header_mismatch", func(t *testing.T) {
+		// Test if Content-Type charset mismatch causes issues
+		client := CreateTestClient()
+
+		variables := map[string]interface{}{
+			"group_description": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+			"user_name":         "2eba巴结",
+		}
+
+		query := "mutation storeMessage($group_description: String!, $user_name: String!) { insert_message(group_description: $group_description, user_name: $user_name) { id } }"
+		compiledQuery := client.compileQuery(query, variables)
+
+		// Test different charset declarations
+		charsets := []string{
+			"application/json",
+			"application/json; charset=utf-8",
+			"application/json; charset=UTF-8",
+			"application/json; charset=iso-8859-1", // Wrong charset
+		}
+
+		for _, contentType := range charsets {
+			t.Logf("Testing Content-Type: %s", contentType)
+
+			// The JSON should be the same regardless of Content-Type header
+			assert.True(json.Valid(compiledQuery.JsonQuery))
+			assert.Equal(356, len(compiledQuery.JsonQuery)) // Should be consistent
+		}
+	})
+
+	t.Run("root_cause_4_unicode_character_validation", func(t *testing.T) {
+		// Test the exact Unicode characters from production logs
+		client := CreateTestClient()
+
+		// Test various Unicode scenarios that might cause issues
+		unicodeScenarios := []struct {
+			name        string
+			userName    string
+			description string
+			expectValid bool
+		}{
+			{
+				name:        "production_case_exact",
+				userName:    "2eba巴结",
+				description: "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+				expectValid: true,
+			},
+			{
+				name:        "mixed_unicode_emojis",
+				userName:    "用户🎯💻🔥",
+				description: "Test with multiple emojis: 🚀🎉💡🔧⚡️🌟",
+				expectValid: true,
+			},
+			{
+				name:        "chinese_japanese_korean",
+				userName:    "测试用户한국어日本語",
+				description: "Mixed CJK characters: 中文 한국어 日本語",
+				expectValid: true,
+			},
+			{
+				name:        "special_unicode_chars",
+				userName:    "user™®©",
+				description: "Special symbols: ™®©±×÷≠≤≥∞∑∏∆√∫",
+				expectValid: true,
+			},
+		}
+
+		for _, scenario := range unicodeScenarios {
+			t.Run(scenario.name, func(t *testing.T) {
+				variables := map[string]interface{}{
+					"group_description": scenario.description,
+					"user_name":         scenario.userName,
+				}
+
+				query := "mutation storeMessage($group_description: String!, $user_name: String!) { insert_message(group_description: $group_description, user_name: $user_name) { id } }"
+				compiledQuery := client.compileQuery(query, variables)
+
+				// Validate UTF-8 encoding
+				assert.True(utf8.Valid(compiledQuery.JsonQuery), "JSON should be valid UTF-8")
+				assert.True(json.Valid(compiledQuery.JsonQuery), "JSON should be valid")
+
+				// Check for any jsonQuery field inclusion
+				assert.False(bytes.Contains(compiledQuery.JsonQuery, []byte(`"jsonQuery"`)), "Should not contain jsonQuery field")
+
+				// Log the size for analysis
+				t.Logf("%s: JSON size = %d bytes", scenario.name, len(compiledQuery.JsonQuery))
+				t.Logf("Content: %s", string(compiledQuery.JsonQuery))
+
+				// Test with actual server
+				server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+					body := make([]byte, r.ContentLength)
+					n, _ := r.Body.Read(body)
+					actualBody := body[:n]
+
+					// Validate the request body
+					assert.True(utf8.Valid(actualBody), "Request body should be valid UTF-8")
+					assert.True(json.Valid(actualBody), "Request body should be valid JSON")
+					assert.False(bytes.Contains(actualBody, []byte(`"jsonQuery"`)), "Request should not contain jsonQuery field")
+
+					w.Header().Set("Content-Type", "application/json")
+					w.WriteHeader(http.StatusOK)
+					w.Write([]byte(`{"data":{"result":"success"}}`))
+				}))
+				defer server.Close()
+
+				qe := &QueryExecutor{
+					BaseClient: client,
+					Query:      compiledQuery.JsonQuery,
+					Headers:    map[string]interface{}{"Content-Type": "application/json; charset=utf-8"},
+					CacheKey:   "no-cache",
+					Retries:    false,
+				}
+				qe.endpoint = server.URL
+				qe.client = server.Client()
+				qe.cache = client.cache
+
+				result, err := qe.executeQuery()
+				if scenario.expectValid {
+					assert.NoError(err, "Unicode request should succeed")
+					assert.NotNil(result)
+				}
+			})
+		}
+	})
+}
+
+// TestDiagnosticLogging tests the new diagnostic logging functionality
+func TestDiagnosticLogging(t *testing.T) {
+	assert := assertions.New(t)
+
+	t.Run("should_log_request_body_analysis", func(t *testing.T) {
+		// Create a server that captures and analyzes the request
+		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			body := make([]byte, r.ContentLength)
+			n, _ := r.Body.Read(body)
+			actualBody := body[:n]
+
+			// Verify Content-Type includes charset
+			contentType := r.Header.Get("Content-Type")
+			if !strings.Contains(contentType, "charset=utf-8") {
+				t.Errorf("Content-Type should include charset=utf-8, got: %s", contentType)
+			}
+
+			// Verify body size matches Content-Length
+			if int64(len(actualBody)) != r.ContentLength {
+				t.Errorf("Body size mismatch: Content-Length=%d, actual=%d", r.ContentLength, len(actualBody))
+			}
+
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte(`{"data":{"result":"success"}}`))
+		}))
+		defer server.Close()
+
+		client := CreateTestClient()
+
+		// Test with the production case
+		variables := map[string]interface{}{
+			"group_description": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+			"user_name":         "2eba巴结",
+		}
+
+		query := "mutation storeMessage($group_description: String!, $user_name: String!) { insert_message(group_description: $group_description, user_name: $user_name) { id } }"
+		compiledQuery := client.compileQuery(query, variables)
+
+		qe := &QueryExecutor{
+			BaseClient: client,
+			Query:      compiledQuery.JsonQuery,
+			Headers:    map[string]interface{}{"Content-Type": "application/json; charset=utf-8"},
+			CacheKey:   "no-cache",
+			Retries:    false,
+		}
+		qe.endpoint = server.URL
+		qe.client = server.Client()
+		qe.cache = client.cache
+
+		result, err := qe.executeQuery()
+		assert.NoError(err)
+		assert.NotNil(result)
+
+		// The diagnostic logging should have been triggered
+		// We can't easily capture the logs in this test, but we can verify the request succeeded
+		t.Logf("Request completed successfully with diagnostic logging")
+		t.Logf("Request body size: %d bytes", len(compiledQuery.JsonQuery))
+	})
+
+	t.Run("should_detect_jsonQuery_field_inclusion", func(t *testing.T) {
+		// Test the validation function directly
+		client := CreateTestClient()
+
+		// Create a problematic JSON with jsonQuery field
+		problematicJSON := `{
+			"query": "mutation test { result }",
+			"variables": {"test": "value"},
+			"jsonQuery": "eyJxdWVyeSI6Im11dGF0aW9uIHRlc3QgeyByZXN1bHQgfSIsInZhcmlhYmxlcyI6eyJ0ZXN0IjoidmFsdWUifX0="
+		}`
+
+		// This should be detected by our validation
+		err := validateRequestBody([]byte(problematicJSON), client.Logger)
+		assert.Error(err, "Should detect jsonQuery field inclusion")
+		assert.Contains(err.Error(), "jsonQuery field found")
+	})
+
+	t.Run("should_validate_utf8_encoding", func(t *testing.T) {
+		client := CreateTestClient()
+
+		// Test valid UTF-8
+		validJSON := `{"query": "mutation test { result }", "variables": {"user": "2eba巴结"}}`
+		err := validateRequestBody([]byte(validJSON), client.Logger)
+		assert.NoError(err, "Valid UTF-8 should pass validation")
+
+		// Test invalid UTF-8 (manually crafted invalid sequence)
+		invalidUTF8 := []byte(`{"query": "mutation test { result }", "variables": {"user": "test`)
+		invalidUTF8 = append(invalidUTF8, 0xFF, 0xFE) // Invalid UTF-8 sequence
+		invalidUTF8 = append(invalidUTF8, []byte(`"}}`)...)
+
+		err = validateRequestBody(invalidUTF8, client.Logger)
+		assert.Error(err, "Invalid UTF-8 should fail validation")
+		assert.Contains(err.Error(), "invalid UTF-8")
+	})
+
+	t.Run("should_detect_null_bytes", func(t *testing.T) {
+		client := CreateTestClient()
+
+		// Test JSON with null bytes
+		jsonWithNulls := []byte(`{"query": "mutation test { result }", "variables": {"user": "test`)
+		jsonWithNulls = append(jsonWithNulls, 0x00) // Null byte
+		jsonWithNulls = append(jsonWithNulls, []byte(`"}}`)...)
+
+		err := validateRequestBody(jsonWithNulls, client.Logger)
+		assert.Error(err, "JSON with null bytes should fail validation")
+		assert.Contains(err.Error(), "null bytes")
+	})
+
+	t.Run("should_test_exact_production_size_scenario", func(t *testing.T) {
+		client := CreateTestClient()
+
+		// Test the exact scenario that produces ~1093 bytes
+		variables := map[string]interface{}{
+			"group_description": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+			"user_name":         "2eba巴结",
+		}
+
+		// Test with a longer query that might reach 1093 bytes
+		longQuery := `mutation storeMessage(
+			$group_description: String!,
+			$user_name: String!,
+			$additional_metadata: String,
+			$client_info: String,
+			$request_timestamp: String,
+			$platform_data: String
+		) {
+			insert_message(
+				group_description: $group_description,
+				user_name: $user_name,
+				additional_metadata: $additional_metadata,
+				client_info: $client_info,
+				request_timestamp: $request_timestamp,
+				platform_data: $platform_data
+			) {
+				id
+				created_at
+				updated_at
+				status
+				metadata {
+					source
+					platform
+					version
+					client_info
+					request_id
+					processing_time
+				}
+				user_info {
+					name
+					id
+					permissions
+				}
+			}
+		}`
+
+		// Add additional variables to increase size
+		extendedVariables := make(map[string]interface{})
+		for k, v := range variables {
+			extendedVariables[k] = v
+		}
+		extendedVariables["additional_metadata"] = `{"client": "web", "version": "1.0.0", "features": ["unicode", "emoji"]}`
+		extendedVariables["client_info"] = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36"
+		extendedVariables["request_timestamp"] = "2023-05-23T18:01:37.000Z"
+		extendedVariables["platform_data"] = `{"os": "windows", "browser": "chrome", "screen": "1920x1080"}`
+
+		compiledQuery := client.compileQuery(longQuery, extendedVariables)
+		size := len(compiledQuery.JsonQuery)
+
+		t.Logf("Extended query size: %d bytes", size)
+
+		if size >= 1090 && size <= 1100 {
+			t.Logf("🎯 FOUND SIZE MATCH: %d bytes (target: 1093)", size)
+
+			// Validate this doesn't contain jsonQuery field
+			assert.False(bytes.Contains(compiledQuery.JsonQuery, []byte(`"jsonQuery"`)), "Should not contain jsonQuery field")
+			assert.True(json.Valid(compiledQuery.JsonQuery), "Should be valid JSON")
+			assert.True(utf8.Valid(compiledQuery.JsonQuery), "Should be valid UTF-8")
+		}
+
+		// Test with server to ensure no trailing garbage
+		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			body := make([]byte, r.ContentLength)
+			n, _ := r.Body.Read(body)
+			actualBody := body[:n]
+
+			// Strict validation
+			decoder := json.NewDecoder(bytes.NewReader(actualBody))
+			var request map[string]interface{}
+			err := decoder.Decode(&request)
+			if err != nil {
+				t.Errorf("JSON decode error: %s", err.Error())
+				w.WriteHeader(http.StatusBadRequest)
+				return
+			}
+
+			// Check for trailing data
+			remaining := decoder.Buffered()
+			if remaining != nil {
+				buf := make([]byte, 10)
+				n, _ := remaining.Read(buf)
+				if n > 0 {
+					t.Errorf("Found trailing data: %s", string(buf[:n]))
+					w.WriteHeader(http.StatusBadRequest)
+					return
+				}
+			}
+
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte(`{"data":{"result":"success"}}`))
+		}))
+		defer server.Close()
+
+		qe := &QueryExecutor{
+			BaseClient: client,
+			Query:      compiledQuery.JsonQuery,
+			Headers:    map[string]interface{}{"Content-Type": "application/json; charset=utf-8"},
+			CacheKey:   "no-cache",
+			Retries:    false,
+		}
+		qe.endpoint = server.URL
+		qe.client = server.Client()
+		qe.cache = client.cache
+
+		result, err := qe.executeQuery()
+		assert.NoError(err, "Extended query should succeed without trailing garbage")
+		assert.NotNil(result)
+	})
+
+	t.Run("should_demonstrate_diagnostic_logging_output", func(t *testing.T) {
+		// This test specifically demonstrates the diagnostic logging in action
+		client := CreateTestClient()
+
+		// Use the exact production case
+		variables := map[string]interface{}{
+			"group_description": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+			"user_name":         "2eba巴结",
+		}
+
+		query := "mutation storeMessage($group_description: String!, $user_name: String!) { insert_message(group_description: $group_description, user_name: $user_name) { id } }"
+		compiledQuery := client.compileQuery(query, variables)
+
+		// Create a server that will receive the request with diagnostic logging
+		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			t.Logf("Server received request with Content-Type: %s", r.Header.Get("Content-Type"))
+			t.Logf("Server received Content-Length: %d", r.ContentLength)
+
+			body := make([]byte, r.ContentLength)
+			n, _ := r.Body.Read(body)
+			actualBody := body[:n]
+
+			t.Logf("Server read %d bytes", len(actualBody))
+			t.Logf("Request body first 100 chars: %s", string(actualBody[:min(100, len(actualBody))]))
+			t.Logf("Request body last 50 chars: %s", string(actualBody[max(0, len(actualBody)-50):]))
+
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte(`{"data":{"result":"success"}}`))
+		}))
+		defer server.Close()
+
+		qe := &QueryExecutor{
+			BaseClient: client,
+			Query:      compiledQuery.JsonQuery,
+			Headers:    map[string]interface{}{"Content-Type": "application/json; charset=utf-8"},
+			CacheKey:   "no-cache",
+			Retries:    false,
+		}
+		qe.endpoint = server.URL
+		qe.client = server.Client()
+		qe.cache = client.cache
+
+		t.Logf("About to execute query with diagnostic logging enabled...")
+		result, err := qe.executeQuery()
+		assert.NoError(err)
+		assert.NotNil(result)
+		t.Logf("Query executed successfully with full diagnostic logging")
+	})
+}

unicode_debug_test.go

@@ -0,0 +1,316 @@
+package gql
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"unicode/utf8"
+
+	assertions "github.com/stretchr/testify/assert"
+)
+
+// TestUnicodeDebugging creates specific scenarios that might cause "trailing garbage" errors
+func TestUnicodeDebugging(t *testing.T) {
+	assert := assertions.New(t)
+
+	t.Run("should debug exact scenario from user report", func(t *testing.T) {
+		// Recreate the exact scenario from the user's log
+		client := CreateTestClient()
+
+		// Exact data from the user's report
+		variables := map[string]interface{}{
+			"group_description": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+			"user_name":         "2eba巴结",
+		}
+
+		query := "mutation storeMessage($group_description: String!, $user_name: String!) { insert_message(group_description: $group_description, user_name: $user_name) { id } }"
+
+		// Compile the query
+		compiledQuery := client.compileQuery(query, variables)
+		assert.NotNil(compiledQuery)
+
+		jsonBytes := compiledQuery.JsonQuery
+		t.Logf("JSON size: %d bytes", len(jsonBytes))
+		t.Logf("JSON content: %s", string(jsonBytes))
+
+		// Check for potential issues
+		t.Logf("Is valid UTF-8: %v", utf8.Valid(jsonBytes))
+		t.Logf("Is valid JSON: %v", json.Valid(jsonBytes))
+
+		// Check for any trailing bytes or null terminators
+		if len(jsonBytes) > 0 {
+			t.Logf("Last byte: 0x%02x (%c)", jsonBytes[len(jsonBytes)-1], jsonBytes[len(jsonBytes)-1])
+			if len(jsonBytes) > 1 {
+				t.Logf("Second to last byte: 0x%02x (%c)", jsonBytes[len(jsonBytes)-2], jsonBytes[len(jsonBytes)-2])
+			}
+		}
+
+		// Check for any BOM (Byte Order Mark)
+		if len(jsonBytes) >= 3 && jsonBytes[0] == 0xEF && jsonBytes[1] == 0xBB && jsonBytes[2] == 0xBF {
+			t.Logf("WARNING: UTF-8 BOM detected at start of JSON")
+		}
+
+		// Try to parse with different JSON parsers to see if there are differences
+		var parsed1 map[string]interface{}
+		err1 := json.Unmarshal(jsonBytes, &parsed1)
+		t.Logf("Standard json.Unmarshal error: %v", err1)
+
+		// Check if there are any non-printable characters at the end
+		for i := len(jsonBytes) - 1; i >= 0 && i >= len(jsonBytes)-10; i-- {
+			b := jsonBytes[i]
+			if b < 32 && b != '\n' && b != '\r' && b != '\t' {
+				t.Logf("Non-printable character at position %d: 0x%02x", i, b)
+			}
+		}
+
+		// Simulate the exact request size mentioned in the user's log (1093 bytes)
+		t.Logf("Expected size from user log: 1093 bytes, actual size: %d bytes", len(jsonBytes))
+		if len(jsonBytes) != 1093 {
+			t.Logf("Size mismatch - this might indicate a different encoding or additional data")
+		}
+	})
+
+	t.Run("should test potential causes of trailing garbage", func(t *testing.T) {
+		client := CreateTestClient()
+
+		// Test scenarios that might cause trailing garbage
+		testCases := []struct {
+			name        string
+			variables   map[string]interface{}
+			expectIssue bool
+		}{
+			{
+				name: "double_encoding_scenario",
+				variables: map[string]interface{}{
+					"json_string": `{"nested": "json with emoji 😈"}`,
+				},
+				expectIssue: false,
+			},
+			{
+				name: "escaped_unicode_scenario",
+				variables: map[string]interface{}{
+					"escaped": "\\u1F608", // Escaped Unicode
+				},
+				expectIssue: false,
+			},
+			{
+				name: "mixed_encoding_scenario",
+				variables: map[string]interface{}{
+					"mixed": "ASCII text with 😈 emoji and 巴结 Chinese",
+				},
+				expectIssue: false,
+			},
+			{
+				name: "large_unicode_scenario",
+				variables: map[string]interface{}{
+					"large": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+					"user":  "2eba巴结",
+					"extra": "Additional data to increase size",
+				},
+				expectIssue: false,
+			},
+		}
+
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				query := "mutation test($json_string: String, $escaped: String, $mixed: String, $large: String, $user: String, $extra: String) { test }"
+				compiledQuery := client.compileQuery(query, tc.variables)
+
+				assert.NotNil(compiledQuery)
+				jsonBytes := compiledQuery.JsonQuery
+
+				t.Logf("%s - JSON size: %d bytes", tc.name, len(jsonBytes))
+				t.Logf("%s - Is valid UTF-8: %v", tc.name, utf8.Valid(jsonBytes))
+				t.Logf("%s - Is valid JSON: %v", tc.name, json.Valid(jsonBytes))
+
+				// Try to unmarshal
+				var parsed map[string]interface{}
+				err := json.Unmarshal(jsonBytes, &parsed)
+				if tc.expectIssue {
+					assert.Error(err, "Expected error for %s", tc.name)
+				} else {
+					assert.NoError(err, "Should not error for %s", tc.name)
+				}
+			})
+		}
+	})
+
+	t.Run("should test server response to problematic requests", func(t *testing.T) {
+		// Create a server that's very strict about JSON parsing
+		strictServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			body := make([]byte, r.ContentLength)
+			n, _ := r.Body.Read(body)
+			actualBody := body[:n]
+
+			t.Logf("Server received %d bytes", len(actualBody))
+			t.Logf("Server received content: %s", string(actualBody))
+
+			// Try to parse with strict JSON decoder
+			decoder := json.NewDecoder(bytes.NewReader(actualBody))
+			decoder.DisallowUnknownFields()
+
+			var request map[string]interface{}
+			err := decoder.Decode(&request)
+			if err != nil {
+				t.Logf("Server JSON decode error: %s", err.Error())
+				w.WriteHeader(http.StatusBadRequest)
+				w.Write([]byte(fmt.Sprintf(`{"error":"trailing garbage after JSON","code":"invalid-json","details":"%s"}`, err.Error())))
+				return
+			}
+
+			// Check if there's more data after the JSON
+			var extra interface{}
+			err = decoder.Decode(&extra)
+			if err == nil {
+				t.Logf("Server found trailing data after JSON")
+				w.WriteHeader(http.StatusBadRequest)
+				w.Write([]byte(`{"error":"trailing garbage after JSON","code":"invalid-json"}`))
+				return
+			}
+
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte(`{"data":{"result":"success"}}`))
+		}))
+		defer strictServer.Close()
+
+		client := CreateTestClient()
+
+		variables := map[string]interface{}{
+			"group_description": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+			"user_name":         "2eba巴结",
+		}
+
+		query := "mutation storeMessage($group_description: String!, $user_name: String!) { insert_message(group_description: $group_description, user_name: $user_name) { id } }"
+		compiledQuery := client.compileQuery(query, variables)
+
+		qe := &QueryExecutor{
+			BaseClient: client,
+			Query:      compiledQuery.JsonQuery,
+			Headers:    map[string]interface{}{"Content-Type": "application/json; charset=utf-8"},
+			CacheKey:   "no-cache",
+			Retries:    false,
+		}
+		qe.endpoint = strictServer.URL
+		qe.client = strictServer.Client()
+		qe.cache = client.cache
+
+		result, err := qe.executeQuery()
+		if err != nil {
+			t.Logf("Error from strict server: %s", err.Error())
+		} else {
+			t.Logf("Strict server accepted the request successfully")
+		}
+
+		assert.NoError(err, "Strict server should accept properly encoded JSON")
+		assert.NotNil(result)
+	})
+
+	t.Run("should analyze JSON encoder behavior", func(t *testing.T) {
+		client := CreateTestClient()
+
+		// Test the exact data structure
+		query := &Query{
+			Query: "mutation storeMessage($group_description: String!, $user_name: String!) { insert_message(group_description: $group_description, user_name: $user_name) { id } }",
+			Variables: map[string]interface{}{
+				"group_description": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+				"user_name":         "2eba巴结",
+			},
+		}
+
+		// Test different encoding methods
+		t.Run("using_json_Marshal", func(t *testing.T) {
+			jsonBytes, err := json.Marshal(query)
+			assert.NoError(err)
+			t.Logf("json.Marshal size: %d bytes", len(jsonBytes))
+			t.Logf("json.Marshal valid: %v", json.Valid(jsonBytes))
+		})
+
+		t.Run("using_convertToJSON", func(t *testing.T) {
+			jsonBytes := client.convertToJSON(query)
+			assert.NotNil(jsonBytes)
+			t.Logf("convertToJSON size: %d bytes", len(jsonBytes))
+			t.Logf("convertToJSON valid: %v", json.Valid(jsonBytes))
+		})
+
+		t.Run("using_json_Encoder", func(t *testing.T) {
+			var buf bytes.Buffer
+			encoder := json.NewEncoder(&buf)
+			encoder.SetEscapeHTML(false)
+			err := encoder.Encode(query)
+			assert.NoError(err)
+
+			jsonBytes := buf.Bytes()
+			// Remove trailing newline that Encoder adds
+			if len(jsonBytes) > 0 && jsonBytes[len(jsonBytes)-1] == '\n' {
+				jsonBytes = jsonBytes[:len(jsonBytes)-1]
+			}
+
+			t.Logf("json.Encoder size: %d bytes", len(jsonBytes))
+			t.Logf("json.Encoder valid: %v", json.Valid(jsonBytes))
+		})
+	})
+}
+
+// TestUnicodeEncodingComparison compares different encoding approaches
+func TestUnicodeEncodingComparison(t *testing.T) {
+	assert := assertions.New(t)
+
+	// Test data that caused the original issue
+	testData := map[string]interface{}{
+		"group_description": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+		"user_name":         "2eba巴结",
+	}
+
+	t.Run("compare_encoding_methods", func(t *testing.T) {
+		// Method 1: Standard json.Marshal
+		bytes1, err1 := json.Marshal(testData)
+		assert.NoError(err1)
+
+		// Method 2: json.Encoder with SetEscapeHTML(false)
+		var buf2 bytes.Buffer
+		enc2 := json.NewEncoder(&buf2)
+		enc2.SetEscapeHTML(false)
+		err2 := enc2.Encode(testData)
+		assert.NoError(err2)
+		bytes2 := buf2.Bytes()
+		if len(bytes2) > 0 && bytes2[len(bytes2)-1] == '\n' {
+			bytes2 = bytes2[:len(bytes2)-1]
+		}
+
+		// Method 3: json.Encoder with SetEscapeHTML(true) - default
+		var buf3 bytes.Buffer
+		enc3 := json.NewEncoder(&buf3)
+		enc3.SetEscapeHTML(true)
+		err3 := enc3.Encode(testData)
+		assert.NoError(err3)
+		bytes3 := buf3.Bytes()
+		if len(bytes3) > 0 && bytes3[len(bytes3)-1] == '\n' {
+			bytes3 = bytes3[:len(bytes3)-1]
+		}
+
+		t.Logf("Method 1 (json.Marshal) size: %d", len(bytes1))
+		t.Logf("Method 2 (Encoder, EscapeHTML=false) size: %d", len(bytes2))
+		t.Logf("Method 3 (Encoder, EscapeHTML=true) size: %d", len(bytes3))
+
+		t.Logf("Method 1 content: %s", string(bytes1))
+		t.Logf("Method 2 content: %s", string(bytes2))
+		t.Logf("Method 3 content: %s", string(bytes3))
+
+		// All should be valid
+		assert.True(json.Valid(bytes1))
+		assert.True(json.Valid(bytes2))
+		assert.True(json.Valid(bytes3))
+
+		// Check for differences
+		if !bytes.Equal(bytes1, bytes2) {
+			t.Logf("Difference between Marshal and Encoder(EscapeHTML=false)")
+		}
+		if !bytes.Equal(bytes2, bytes3) {
+			t.Logf("Difference between EscapeHTML=false and EscapeHTML=true")
+		}
+	})
+}

unicode_encoding_test.go

@@ -0,0 +1,367 @@
+package gql
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	assertions "github.com/stretchr/testify/assert"
+)
+
+// TestUnicodeEncodingIssue reproduces the "trailing garbage" error with emojis and special characters
+func TestUnicodeEncodingIssue(t *testing.T) {
+	assert := assertions.New(t)
+
+	t.Run("should handle emoji and Chinese characters in GraphQL variables", func(t *testing.T) {
+		// Create a test server that simulates the problematic scenario
+		var receivedBody []byte
+		var receivedContentType string
+		var receivedContentLength int64
+
+		testServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			// Capture the request details for analysis
+			receivedContentType = r.Header.Get("Content-Type")
+			receivedContentLength = r.ContentLength
+
+			// Read the request body to analyze the encoding
+			body := make([]byte, r.ContentLength)
+			r.Body.Read(body)
+			receivedBody = body
+
+			// Log the received data for debugging
+			t.Logf("Received Content-Type: %s", receivedContentType)
+			t.Logf("Received Content-Length: %d", receivedContentLength)
+			t.Logf("Received Body (first 200 chars): %s", string(body[:min(200, len(body))]))
+			t.Logf("Received Body (hex): %x", body[:min(50, len(body))])
+
+			// Check if the JSON is valid
+			var parsedRequest map[string]interface{}
+			err := json.Unmarshal(body, &parsedRequest)
+			if err != nil {
+				t.Logf("JSON parsing error: %s", err.Error())
+				w.WriteHeader(http.StatusBadRequest)
+				w.Write([]byte(`{"error":"trailing garbage after JSON","code":"invalid-json"}`))
+				return
+			}
+
+			// Successful response
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte(`{"data":{"result":"success"}}`))
+		}))
+		defer testServer.Close()
+
+		client := CreateTestClient()
+
+		// Test data that reproduces the issue
+		variables := map[string]interface{}{
+			"group_description": "This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈",
+			"user_name":         "2eba巴结",
+		}
+
+		query := "mutation storeMessage($group_description: String!, $user_name: String!) { insert_message(group_description: $group_description, user_name: $user_name) { id } }"
+
+		// Compile the query to see how it's encoded
+		compiledQuery := client.compileQuery(query, variables)
+		assert.NotNil(compiledQuery)
+		assert.NotNil(compiledQuery.JsonQuery)
+
+		t.Logf("Compiled Query JSON: %s", string(compiledQuery.JsonQuery))
+		t.Logf("Compiled Query JSON (hex): %x", compiledQuery.JsonQuery)
+
+		// Check if the JSON is valid UTF-8
+		assert.True(json.Valid(compiledQuery.JsonQuery), "Compiled JSON should be valid")
+
+		// Verify the JSON contains the Unicode characters correctly
+		var parsedQuery map[string]interface{}
+		err := json.Unmarshal(compiledQuery.JsonQuery, &parsedQuery)
+		assert.NoError(err)
+
+		variables_parsed := parsedQuery["variables"].(map[string]interface{})
+		assert.Equal("This a group for serious buyers and sellers\nOf uber eats and Door dash account \nRippers are not allowed in this group😈", variables_parsed["group_description"])
+		assert.Equal("2eba巴结", variables_parsed["user_name"])
+
+		// Execute the query
+		qe := &QueryExecutor{
+			BaseClient: client,
+			Query:      compiledQuery.JsonQuery,
+			Headers:    map[string]interface{}{"Content-Type": "application/json; charset=utf-8"},
+			CacheKey:   "no-cache",
+			Retries:    false,
+		}
+		qe.endpoint = testServer.URL
+		qe.client = testServer.Client()
+		qe.cache = client.cache
+
+		result, err := qe.executeQuery()
+
+		// Analyze the request that was sent
+		t.Logf("Request body size: %d bytes", len(receivedBody))
+		t.Logf("Content-Type sent: %s", receivedContentType)
+
+		// Check if the request was properly encoded
+		if len(receivedBody) > 0 {
+			var receivedRequest map[string]interface{}
+			parseErr := json.Unmarshal(receivedBody, &receivedRequest)
+			if parseErr != nil {
+				t.Logf("Server couldn't parse JSON: %s", parseErr.Error())
+				t.Logf("Raw body: %s", string(receivedBody))
+			} else {
+				t.Logf("Server successfully parsed JSON")
+				if vars, ok := receivedRequest["variables"].(map[string]interface{}); ok {
+					t.Logf("Received group_description: %s", vars["group_description"])
+					t.Logf("Received user_name: %s", vars["user_name"])
+				}
+			}
+		}
+
+		// The test should pass - no trailing garbage errors
+		assert.NoError(err, "Should not get trailing garbage errors with Unicode characters")
+		assert.NotNil(result)
+	})
+
+	t.Run("should properly encode various Unicode characters", func(t *testing.T) {
+		client := CreateTestClient()
+
+		testCases := []struct {
+			name        string
+			description string
+			variables   map[string]interface{}
+		}{
+			{
+				name:        "emoji_only",
+				description: "Test with various emojis",
+				variables: map[string]interface{}{
+					"message": "Hello 😀😃😄😁😆😅😂🤣😊😇🙂🙃😉😌😍🥰😘😗😙😚😋😛😝😜🤪🤨🧐🤓😎🤩🥳😏😒😞😔😟😕🙁☹️😣😖😫😩🥺😢😭😤😠😡🤬🤯😳🥵🥶😱😨😰😥😓🤗🤔🤭🤫🤥😶😐😑😬🙄😯😦😧😮😲🥱😴🤤😪😵🤐🥴🤢🤮🤧😷🤒🤕🤑🤠😈👿👹👺🤡💩👻💀☠️👽👾🤖🎃😺😸😹😻😼😽🙀😿😾",
+				},
+			},
+			{
+				name:        "chinese_characters",
+				description: "Test with Chinese characters",
+				variables: map[string]interface{}{
+					"name":    "张三李四王五赵六",
+					"address": "北京市朝阳区建国门外大街1号",
+					"company": "中国国际贸易中心有限公司",
+				},
+			},
+			{
+				name:        "japanese_characters",
+				description: "Test with Japanese characters",
+				variables: map[string]interface{}{
+					"name":    "田中太郎",
+					"address": "東京都渋谷区渋谷1-1-1",
+					"message": "こんにちは、世界！",
+				},
+			},
+			{
+				name:        "korean_characters",
+				description: "Test with Korean characters",
+				variables: map[string]interface{}{
+					"name":    "김철수",
+					"address": "서울특별시 강남구 테헤란로 123",
+					"message": "안녕하세요, 세계!",
+				},
+			},
+			{
+				name:        "arabic_characters",
+				description: "Test with Arabic characters",
+				variables: map[string]interface{}{
+					"name":    "محمد أحمد",
+					"address": "الرياض، المملكة العربية السعودية",
+					"message": "مرحبا بالعالم!",
+				},
+			},
+			{
+				name:        "mixed_unicode",
+				description: "Test with mixed Unicode characters",
+				variables: map[string]interface{}{
+					"message": "Hello 世界 🌍 مرحبا こんにちは 안녕하세요 Здравствуй Bonjour ¡Hola! Γεια σας",
+					"symbols": "©®™€£¥₹₽¢₩₪₫₱₡₦₨₹₽₴₸₼₾₿",
+					"math":    "∑∏∫∂∇∆∞≠≤≥±×÷√∛∜∝∞",
+				},
+			},
+		}
+
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				query := "mutation testUnicode($message: String, $name: String, $address: String, $company: String, $symbols: String, $math: String) { test }"
+
+				// Compile the query
+				compiledQuery := client.compileQuery(query, tc.variables)
+				assert.NotNil(compiledQuery, "Query should compile successfully for %s", tc.description)
+				assert.NotNil(compiledQuery.JsonQuery, "JSON query should be generated for %s", tc.description)
+
+				// Verify the JSON is valid
+				assert.True(json.Valid(compiledQuery.JsonQuery), "JSON should be valid for %s", tc.description)
+
+				// Verify we can parse it back
+				var parsedQuery map[string]interface{}
+				err := json.Unmarshal(compiledQuery.JsonQuery, &parsedQuery)
+				assert.NoError(err, "Should be able to parse JSON for %s", tc.description)
+
+				// Verify the variables are preserved correctly
+				if parsedVars, ok := parsedQuery["variables"].(map[string]interface{}); ok {
+					for key, expectedValue := range tc.variables {
+						actualValue := parsedVars[key]
+						assert.Equal(expectedValue, actualValue, "Variable %s should be preserved correctly for %s", key, tc.description)
+					}
+				}
+
+				t.Logf("✓ %s: JSON size: %d bytes", tc.description, len(compiledQuery.JsonQuery))
+			})
+		}
+	})
+
+	t.Run("should handle Content-Type with charset specification", func(t *testing.T) {
+		var receivedContentType string
+		var receivedBody []byte
+
+		testServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			receivedContentType = r.Header.Get("Content-Type")
+			body := make([]byte, r.ContentLength)
+			r.Body.Read(body)
+			receivedBody = body
+
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte(`{"data":{"result":"success"}}`))
+		}))
+		defer testServer.Close()
+
+		client := CreateTestClient()
+
+		variables := map[string]interface{}{
+			"emoji_text": "Test with emoji 😈 and Chinese 巴结",
+		}
+
+		query := "mutation test($emoji_text: String!) { test(text: $emoji_text) }"
+		compiledQuery := client.compileQuery(query, variables)
+
+		// Test different Content-Type headers
+		contentTypes := []string{
+			"application/json",
+			"application/json; charset=utf-8",
+			"application/json; charset=UTF-8",
+		}
+
+		for _, contentType := range contentTypes {
+			t.Run("content_type_"+strings.ReplaceAll(contentType, " ", "_"), func(t *testing.T) {
+				qe := &QueryExecutor{
+					BaseClient: client,
+					Query:      compiledQuery.JsonQuery,
+					Headers:    map[string]interface{}{"Content-Type": contentType},
+					CacheKey:   "no-cache",
+					Retries:    false,
+				}
+				qe.endpoint = testServer.URL
+				qe.client = testServer.Client()
+				qe.cache = client.cache
+
+				result, err := qe.executeQuery()
+
+				assert.NoError(err, "Should handle Content-Type: %s", contentType)
+				assert.NotNil(result)
+				assert.Equal(contentType, receivedContentType, "Content-Type should be preserved")
+
+				// Verify the body is valid JSON with Unicode characters
+				var parsedBody map[string]interface{}
+				parseErr := json.Unmarshal(receivedBody, &parsedBody)
+				assert.NoError(parseErr, "Request body should be valid JSON")
+
+				if vars, ok := parsedBody["variables"].(map[string]interface{}); ok {
+					assert.Equal("Test with emoji 😈 and Chinese 巴结", vars["emoji_text"])
+				}
+			})
+		}
+	})
+}
+
+// TestUnicodeEncodingEdgeCases tests edge cases that might cause encoding issues
+func TestUnicodeEncodingEdgeCases(t *testing.T) {
+	assert := assertions.New(t)
+	client := CreateTestClient()
+
+	t.Run("should handle null bytes and control characters", func(t *testing.T) {
+		// Test with potentially problematic characters
+		variables := map[string]interface{}{
+			"text_with_nulls":    "Text\x00with\x00null\x00bytes",
+			"text_with_controls": "Text\x01\x02\x03\x04\x05with\x06\x07\x08controls",
+			"text_with_tabs":     "Text\twith\ttabs\tand\nnewlines\r\n",
+		}
+
+		query := "mutation test($text_with_nulls: String, $text_with_controls: String, $text_with_tabs: String) { test }"
+		compiledQuery := client.compileQuery(query, variables)
+
+		assert.NotNil(compiledQuery)
+		assert.NotNil(compiledQuery.JsonQuery)
+
+		// The JSON should be valid (Go's json package handles escaping)
+		assert.True(json.Valid(compiledQuery.JsonQuery))
+
+		// Verify we can parse it back
+		var parsedQuery map[string]interface{}
+		err := json.Unmarshal(compiledQuery.JsonQuery, &parsedQuery)
+		assert.NoError(err)
+
+		t.Logf("JSON with control characters: %s", string(compiledQuery.JsonQuery))
+	})
+
+	t.Run("should handle very long Unicode strings", func(t *testing.T) {
+		// Create a very long string with Unicode characters
+		longUnicodeString := strings.Repeat("Hello 世界 😀 مرحبا ", 1000)
+
+		variables := map[string]interface{}{
+			"long_unicode": longUnicodeString,
+		}
+
+		query := "mutation test($long_unicode: String!) { test }"
+		compiledQuery := client.compileQuery(query, variables)
+
+		assert.NotNil(compiledQuery)
+		assert.NotNil(compiledQuery.JsonQuery)
+		assert.True(json.Valid(compiledQuery.JsonQuery))
+
+		t.Logf("Long Unicode JSON size: %d bytes", len(compiledQuery.JsonQuery))
+
+		// Verify the content is preserved
+		var parsedQuery map[string]interface{}
+		err := json.Unmarshal(compiledQuery.JsonQuery, &parsedQuery)
+		assert.NoError(err)
+
+		if vars, ok := parsedQuery["variables"].(map[string]interface{}); ok {
+			assert.Equal(longUnicodeString, vars["long_unicode"])
+		}
+	})
+
+	t.Run("should handle Unicode normalization edge cases", func(t *testing.T) {
+		// Test different Unicode normalization forms
+		variables := map[string]interface{}{
+			"composed":   "é",       // U+00E9 (composed)
+			"decomposed": "e\u0301", // U+0065 U+0301 (decomposed)
+			"ligature":   "fi",       // U+FB01 (ligature)
+			"surrogate":  "𝕳𝖊𝖑𝖑𝖔",   // Mathematical script letters (surrogate pairs)
+		}
+
+		query := "mutation test($composed: String, $decomposed: String, $ligature: String, $surrogate: String) { test }"
+		compiledQuery := client.compileQuery(query, variables)
+
+		assert.NotNil(compiledQuery)
+		assert.NotNil(compiledQuery.JsonQuery)
+		assert.True(json.Valid(compiledQuery.JsonQuery))
+
+		// Verify all forms are preserved
+		var parsedQuery map[string]interface{}
+		err := json.Unmarshal(compiledQuery.JsonQuery, &parsedQuery)
+		assert.NoError(err)
+
+		if vars, ok := parsedQuery["variables"].(map[string]interface{}); ok {
+			for key, expectedValue := range variables {
+				assert.Equal(expectedValue, vars[key], "Unicode form should be preserved for %s", key)
+			}
+		}
+
+		t.Logf("Unicode normalization test JSON: %s", string(compiledQuery.JsonQuery))
+	})
+}