Refactor OkHttp interceptors and turn them into Kotlin (#32)

## Goal

Convert to Kotlin. I had to do a few things in order for this to work, and I'll point it out in the review via comments.

## Testing

Existing tests passes

embrace-android-okhttp3/api/embrace-android-okhttp3.api

@@ -1,9 +1,9 @@
-public class io/embrace/android/embracesdk/okhttp3/EmbraceCustomPathException : java/io/IOException {
+public final class io/embrace/android/embracesdk/okhttp3/EmbraceCustomPathException : java/io/IOException {
  public fun <init> (Ljava/lang/String;Ljava/lang/Throwable;)V
- public fun getCustomPath ()Ljava/lang/String;
+ public final fun getCustomPath ()Ljava/lang/String;
 }
 
-public class io/embrace/android/embracesdk/okhttp3/EmbraceOkHttp3ApplicationInterceptor : okhttp3/Interceptor {
+public final class io/embrace/android/embracesdk/okhttp3/EmbraceOkHttp3ApplicationInterceptor : okhttp3/Interceptor {
  public fun <init> ()V
  public fun intercept (Lokhttp3/Interceptor$Chain;)Lokhttp3/Response;
 }

embrace-android-okhttp3/src/main/java/io/embrace/android/embracesdk/okhttp3/EmbraceCustomPathException.kt

@@ -0,0 +1,11 @@
+package io.embrace.android.embracesdk.okhttp3
+
+import io.embrace.android.embracesdk.InternalApi
+import java.io.IOException
+
+/**
+ * We use the EmbraceCustomPathException to capture the custom path added in the
+ * intercept chain process for client errors.
+ */
+@InternalApi
+public class EmbraceCustomPathException(public val customPath: String, cause: Throwable?) : IOException(cause)

embrace-android-okhttp3/src/main/java/io/embrace/android/embracesdk/okhttp3/EmbraceOkHttp3ApplicationInterceptor.kt

@@ -0,0 +1,101 @@
+package io.embrace.android.embracesdk.okhttp3
+
+import io.embrace.android.embracesdk.Embrace
+import io.embrace.android.embracesdk.InternalApi
+import io.embrace.android.embracesdk.internal.network.http.EmbraceHttpPathOverride
+import io.embrace.android.embracesdk.network.EmbraceNetworkRequest
+import io.embrace.android.embracesdk.network.http.HttpMethod
+import okhttp3.Interceptor
+import okhttp3.Request
+import okhttp3.Response
+import java.io.IOException
+
+/**
+ * This interceptor will only intercept errors that client app experiences.
+ *
+ * We used OkHttp application interceptor in this case because this interceptor
+ * will be added first in the OkHttp3 interceptors stack. This allows us to catch network errors.
+ * OkHttp network interceptors are added almost at the end of stack, they are closer to "the wire"
+ * so they are not able to see network errors.
+ *
+ * We used the [EmbraceCustomPathException] to capture the custom path added in the interceptor
+ * chain process for client errors on requests to a generic URL like a GraphQL endpoint.
+ */
+@InternalApi
+public class EmbraceOkHttp3ApplicationInterceptor internal constructor(
+ private val embrace: Embrace
+) : Interceptor {
+
+ public constructor() : this(Embrace.getInstance())
+
+ @Throws(IOException::class)
+ override fun intercept(chain: Interceptor.Chain): Response {
+ val startTime = embrace.internalInterface.getSdkCurrentTime()
+ val request: Request = chain.request()
+ return try {
+ // we are not interested in response, just proceed
+ chain.proceed(request)
+ } catch (e: EmbraceCustomPathException) {
+ if (embrace.isStarted && !embrace.internalInterface.isInternalNetworkCaptureDisabled()) {
+ val urlString = EmbraceHttpPathOverride.getURLString(EmbraceOkHttp3PathOverrideRequest(request), e.customPath)
+ embrace.recordNetworkRequest(
+ EmbraceNetworkRequest.fromIncompleteRequest(
+ urlString,
+ HttpMethod.fromString(request.method),
+ startTime,
+ embrace.internalInterface.getSdkCurrentTime(),
+ causeName(e, UNKNOWN_EXCEPTION),
+ causeMessage(e, UNKNOWN_MESSAGE),
+ request.header(embrace.traceIdHeader),
+ if (embrace.internalInterface.isNetworkSpanForwardingEnabled()) request.header(TRACEPARENT_HEADER_NAME) else null,
+ null
+ )
+ )
+ }
+ throw e
+ } catch (e: Exception) {
+ // we are interested in errors.
+ if (embrace.isStarted && !embrace.internalInterface.isInternalNetworkCaptureDisabled()) {
+ val urlString = EmbraceHttpPathOverride.getURLString(EmbraceOkHttp3PathOverrideRequest(request))
+ val errorType = e.javaClass.canonicalName
+ val errorMessage = e.message
+ embrace.recordNetworkRequest(
+ EmbraceNetworkRequest.fromIncompleteRequest(
+ urlString,
+ HttpMethod.fromString(request.method),
+ startTime,
+ embrace.internalInterface.getSdkCurrentTime(),
+ errorType ?: UNKNOWN_EXCEPTION,
+ errorMessage ?: UNKNOWN_MESSAGE,
+ request.header(embrace.traceIdHeader),
+ if (embrace.internalInterface.isNetworkSpanForwardingEnabled()) request.header(TRACEPARENT_HEADER_NAME) else null,
+ null
+ )
+ )
+ }
+ throw e
+ }
+ }
+
+ internal companion object {
+ internal const val TRACEPARENT_HEADER_NAME = "traceparent"
+ internal const val UNKNOWN_EXCEPTION = "Unknown"
+ internal const val UNKNOWN_MESSAGE = "An error occurred during the execution of this network request"
+
+ /**
+ * Return the canonical name of the cause of a [Throwable]. Handles null elements throughout,
+ * including the throwable and its cause, in which case [defaultName] is returned
+ */
+ internal fun causeName(throwable: Throwable?, defaultName: String = ""): String {
+ return throwable?.cause?.javaClass?.canonicalName ?: defaultName
+ }
+
+ /**
+ * Return the message of the cause of a [Throwable]. Handles null elements throughout,
+ * including the throwable and its cause, in which case [defaultMessage] is returned
+ */
+ internal fun causeMessage(throwable: Throwable?, defaultMessage: String = ""): String {
+ return throwable?.cause?.message ?: defaultMessage
+ }
+ }
+}