Add charles proxy helper in Android example app

android/src/main/java/com/reactnativestripesdk/CharlesProxyHelper.kt

@@ -0,0 +1,81 @@
+package com.reactnativestripesdk
+
+import android.annotation.SuppressLint
+import android.util.Log
+import com.stripe.android.core.networking.ConnectionFactory
+import com.stripe.android.core.networking.StripeRequest
+import java.net.HttpURLConnection
+import java.net.InetSocketAddress
+import java.net.Proxy
+import java.net.URL
+import java.security.SecureRandom
+import java.security.cert.X509Certificate
+import javax.net.ssl.HttpsURLConnection
+import javax.net.ssl.SSLContext
+import javax.net.ssl.SSLSocketFactory
+import javax.net.ssl.TrustManager
+import javax.net.ssl.X509TrustManager
+
+/**
+ * Routes Stripe SDK traffic through Charles Proxy for debugging.
+ * Set ENABLED = true and rebuild to use. Uses 10.0.2.2 (Android emulator host alias).
+ */
+internal object CharlesProxyHelper {
+  private const val TAG = "CharlesProxy"
+
+  // Flip to true and rebuild to route Stripe SDK traffic through Charles Proxy
+  private const val ENABLED = false
+  private const val PROXY_HOST = "10.0.2.2"
+  private const val PROXY_PORT = 8888
+
+  fun enableIfConfigured() {
+    if (!ENABLED) return
+    ConnectionFactory.Default.connectionOpener = ProxyConnectionOpener(PROXY_HOST, PROXY_PORT)
+    Log.d(TAG, "Charles Proxy enabled at $PROXY_HOST:$PROXY_PORT")
+  }
+}
+
+@Suppress("EmptyFunctionBlock", "MagicNumber")
+private class ProxyConnectionOpener(
+  private val host: String,
+  private val port: Int,
+) : ConnectionFactory.ConnectionOpener {
+  override fun open(
+    request: StripeRequest,
+    callback: HttpURLConnection.(request: StripeRequest) -> Unit,
+  ): HttpsURLConnection {
+    val socketAddress = InetSocketAddress.createUnresolved(host, port)
+    val proxy = Proxy(Proxy.Type.HTTP, socketAddress)
+
+    return (URL(request.url).openConnection(proxy) as HttpsURLConnection).apply {
+      sslSocketFactory = trustAllSocketFactory()
+      callback(request)
+    }
+  }
+
+  @SuppressLint("CustomX509TrustManager", "TrustAllX509TrustManager")
+  private fun trustAllSocketFactory(): SSLSocketFactory {
+    val trustAllCerts =
+      arrayOf<TrustManager>(
+        object : X509TrustManager {
+          override fun checkClientTrusted(
+            chain: Array<out X509Certificate>?,
+            authType: String?,
+          ) {
+          }
+
+          override fun checkServerTrusted(
+            chain: Array<out X509Certificate>?,
+            authType: String?,
+          ) {
+          }
+
+          override fun getAcceptedIssuers(): Array<X509Certificate> = emptyArray()
+        },
+      )
+
+    val sslContext = SSLContext.getInstance("SSL")
+    sslContext.init(null, trustAllCerts, SecureRandom())
+    return sslContext.socketFactory
+  }
+}

android/src/main/java/com/reactnativestripesdk/StripeSdkModule.kt

@@ -147,6 +147,7 @@ class StripeSdkModule(
 
   init {
     reactContext.addActivityEventListener(mActivityEventListener)
+    CharlesProxyHelper.enableIfConfigured()
   }
 
   override fun invalidate() {