Merge pull request #217 from omeratt/feature/support_external_interceptors

feat: Adding custom debug interceptor support

Author: MaxToyberman

README.md

@@ -190,6 +190,81 @@ getCookies('domain')
 })
 
 ```
+
+## Debug Interceptors & Request/Response Observers
+
+This library now supports custom debug interceptors and request/response observers to help with debugging network requests in development builds. These features are only active in DEBUG builds for security reasons.
+
+### Summary of Recent Enhancements
+
+**Latest Updates (June 2025):**
+1. **Android Custom Debug Interceptor Support** - Added ability to inject custom OkHttp interceptors for debugging network traffic
+2. **Android Debug Interceptor Refactoring** - Improved code organization by extracting interceptor logic into a dedicated method
+3. **iOS Request/Response Observers** - Added observer methods to monitor network requests and responses on iOS for debugging purposes
+
+### Android Debug Interceptor
+
+Add custom debug interceptors to monitor and modify HTTP requests/responses in Android:
+
+```java
+// In your Android application code (Java/Kotlin)
+import com.toyberman.Utils.OkHttpUtils;
+import okhttp3.Interceptor;
+import okhttp3.logging.HttpLoggingInterceptor;
+
+// Example: Add a custom logging interceptor
+Interceptor customInterceptor = new HttpLoggingInterceptor()
+    .setLevel(HttpLoggingInterceptor.Level.BODY);
+
+// Add the interceptor (only works in DEBUG builds)
+OkHttpUtils.addInterceptorForDebug(customInterceptor);
+```
+
+**Features:**
+- Only active in DEBUG builds for security
+- Supports any OkHttp interceptor
+- Useful for detailed request/response logging
+- Can be used for request modification during development
+
+### iOS Request/Response Observers
+
+Monitor network requests and responses on iOS using observer methods:
+
+```objc
+// In your iOS application code (Objective-C)
+#import "RNSslPinning.h"
+
+// Set request observer to monitor outgoing requests
+[RNSslPinning setRequestObserver:^(NSURLRequest *request) {
+    NSLog(@"Request: %@ %@", request.HTTPMethod, request.URL);
+    // Add your custom request monitoring logic here
+}];
+
+// Set response observer to monitor responses with timing
+[RNSslPinning setResponseObserver:^(NSURLRequest *request, NSHTTPURLResponse *response, NSData *data, NSTimeInterval startTime) {
+    NSTimeInterval duration = ([[NSDate date] timeIntervalSince1970] * 1000.0) - startTime;
+    NSLog(@"Response: %ld for %@ (%.2fms)", (long)response.statusCode, request.URL, duration);
+    // Add your custom response monitoring logic here
+}];
+```
+
+**Features:**
+- Only active in DEBUG builds for security  
+- Monitor all outgoing requests
+- Track response data, status codes, and timing
+- Handle both successful responses and error cases
+- Captures original request details for correlation
+
+### Use Cases
+
+- **Network Debugging**: Monitor request/response flow during development
+- **Performance Analysis**: Track request timing and response sizes
+- **SSL/TLS Troubleshooting**: Debug certificate pinning issues
+- **API Development**: Verify request formats and response handling
+- **Integration Testing**: Monitor network calls during automated tests
+
+**Note**: These debugging features are automatically disabled in production builds for security and performance reasons.
+
   ## Multipart request (FormData)
 
 ```javascript

android/src/main/java/com/toyberman/Utils/OkHttpUtils.java

@@ -31,6 +31,7 @@
 
 import okhttp3.CertificatePinner;
 import okhttp3.CookieJar;
+import okhttp3.Interceptor;
 import okhttp3.MediaType;
 import okhttp3.MultipartBody;
 import okhttp3.OkHttpClient;
@@ -54,6 +55,14 @@ public class OkHttpUtils {
     private static SSLContext sslContext;
     private static String content_type = "application/json; charset=utf-8";
     public static MediaType mediaType = MediaType.parse(content_type);
+    private static Interceptor customDebugInterceptor = null;
+
+    // This method is used to add a custom debug interceptor if it exists and the build is in debug mode.
+    private static void addCustomDebugInterceptor(OkHttpClient.Builder clientBuilder) {
+        if (BuildConfig.DEBUG && customDebugInterceptor != null) {
+            clientBuilder.addInterceptor(customDebugInterceptor);
+        }
+    }
 
     public static OkHttpClient buildOkHttpClient(CookieJar cookieJar, String domainName, ReadableArray certs, ReadableMap options) {
 
@@ -82,6 +91,7 @@ public static OkHttpClient buildOkHttpClient(CookieJar cookieJar, String domainN
             if (BuildConfig.DEBUG) {
                 clientBuilder.addInterceptor(logging);
             }
+            addCustomDebugInterceptor(clientBuilder);
 
             client = clientBuilder
                     .build();
@@ -123,6 +133,7 @@ public static OkHttpClient buildDefaultOHttpClient(CookieJar cookieJar, String d
             if (BuildConfig.DEBUG) {
                 clientBuilder.addInterceptor(logging);
             }
+             addCustomDebugInterceptor(clientBuilder);
 
             defaultClient = clientBuilder.build();
         }
@@ -316,4 +327,10 @@ private static void setRequestHeaders(ReadableMap options, Request.Builder reque
             mediaType = MediaType.parse(content_type);
         }
     }
+
+    public static void addInterceptorForDebug(Interceptor interceptor) {
+        if (BuildConfig.DEBUG) {
+            customDebugInterceptor = interceptor;
+        }
+    }
 }

ios/RNSslPinning/RNSslPinning.m

@@ -4,6 +4,9 @@
 #import "RNSslPinning.h"
 #import "AFNetworking.h"
 
+static void (^_requestObserver)(NSURLRequest *) = nil;
+static void (^_responseObserver)(NSURLRequest *, NSHTTPURLResponse *, NSData *, NSTimeInterval) = nil;
+
 @interface RNSslPinning()
 
 @property (nonatomic, strong) NSURLSessionConfiguration *sessionConfig;
@@ -13,6 +16,18 @@ @interface RNSslPinning()
 @implementation RNSslPinning
 RCT_EXPORT_MODULE();
 
++ (void)setRequestObserver:(void (^)(NSURLRequest *))observer {
+#if DEBUG
+  _requestObserver = [observer copy];
+#endif
+}
+
++ (void)setResponseObserver:(void (^)(NSURLRequest *, NSHTTPURLResponse *, NSData *, NSTimeInterval))observer {
+#if DEBUG
+  _responseObserver = [observer copy];
+#endif
+}
+
 - (instancetype)init
 {
     self = [super init];
@@ -65,14 +80,44 @@ - (instancetype)init
 
 
 -(void)performRequest:(AFURLSessionManager*)manager  obj:(NSDictionary *)obj  request:(NSMutableURLRequest*) request callback:(RCTResponseSenderBlock) callback  {
-    
+#if DEBUG
+    if (_requestObserver) {
+        _requestObserver(request);
+    }
+#endif
+
+    NSURLRequest *capturedRequest = [request copy]; // 🧠 Save the original request - for interceptors purposes
+    NSTimeInterval startTime = [[NSDate date] timeIntervalSince1970] * 1000.0;
+
+
     [[manager dataTaskWithRequest:request uploadProgress:nil downloadProgress:nil completionHandler:^(NSURLResponse * _Nonnull response, id _Nullable responseObject, NSError * _Nullable error) {
-        
-        
         NSHTTPURLResponse *httpResp = (NSHTTPURLResponse*) response;
         NSString *bodyString = [[NSString alloc] initWithData: responseObject encoding:NSUTF8StringEncoding];
         NSInteger statusCode = httpResp.statusCode;
 
+        // Don't create a synthetic response - pass the real one to observer along with error
+        if (error && (!httpResp || httpResp.statusCode == 0)) {
+            bodyString = error.localizedDescription;
+        }
+
+#if DEBUG
+        if (_responseObserver) {
+            NSData *rawData = nil;
+            if (responseObject) {
+                rawData = [responseObject isKindOfClass:[NSData class]]
+                    ? responseObject
+                    : [NSJSONSerialization dataWithJSONObject:responseObject options:0 error:nil];
+            } else if (error) {
+                // Create error response data if we have an error but no response data
+                NSString *errorMessage = error.localizedDescription ?: @"Unknown error";
+                rawData = [errorMessage dataUsingEncoding:NSUTF8StringEncoding];
+            }
+            
+            // Pass the raw error to our observer with the start time
+            _responseObserver(capturedRequest, httpResp, rawData ?: [NSData new], startTime);
+        }
+#endif
+
         if (!error) {
             // if(obj[@"responseType"]){
             NSString * responseType = obj[@"responseType"];