Custom body decoding

CHANGELOG.md

@@ -1,10 +1,13 @@
 # Change Log
 
-This file follows [Keepachangelog](https://keepachangelog.com/) format. 
+This file follows [Keepachangelog](https://keepachangelog.com/) format.
 Please add your entries according to this format.
 
 ## Unreleased
 
+### Added
+* Decoding of request and response bodies can now be customized. In order to do this a `BodyDecoder` interface needs to be implemented and installed in the `ChuckerInterceptor` via `ChuckerInterceptor.addBinaryDecoder(decoder)` method. Decoded bodies are then displayed in the Chucker UI.
+
 ### Fixed
 
 * Fixed not setting request body type correctly [#538].
@@ -46,16 +49,16 @@ Please add your entries according to this format.
 
 ## Version 3.3.0 *(2020-09-30)*
 
-This is a new minor release with multiple fixes and improvements. 
-After this release we are starting to work on a new major release 4.x with minSDK 21. 
+This is a new minor release with multiple fixes and improvements.
+After this release we are starting to work on a new major release 4.x with minSDK 21.
 Bumping minSDK to 21 is required to keep up with [newer versions of OkHttp](https://medium.com/square-corner-blog/okhttp-3-13-requires-android-5-818bb78d07ce).
 Versions 3.x will be supported for 6 months (till March 2021) getting bugfixes and minor improvements.
 
 ### Summary of changes
 
 * Added a new flag `alwaysReadResponseBody` into Chucker configuration to read the whole response body even if consumer fails to consume it.
 * Added port numbers as part of the URL. Numbers appear if they are different from default 80 or 443.
-* Chucker now shows partially read application responses properly. Earlier in 3.2.0 such responses didn't appear in the UI. 
+* Chucker now shows partially read application responses properly. Earlier in 3.2.0 such responses didn't appear in the UI.
 * Transaction size is defined by actual payload size now, not by `Content-length` header.
 * Added empty state UI for payloads, so no more guessing if there is some error or the payload is really empty.
 * Added ability to export list of transactions.
@@ -198,7 +201,7 @@ This release was possible thanks to the contribution of:
 
 ### This version shouldn't be used as dependency due to [#203](https://github.com/ChuckerTeam/chucker/issues/203). Use 3.1.1 instead.
 
-This is a new minor release of Chucker. Please note that this minor release contains multiple new features (see below) as well as multiple bugfixes. 
+This is a new minor release of Chucker. Please note that this minor release contains multiple new features (see below) as well as multiple bugfixes.
 
 ### Summary of Changes
 
@@ -235,11 +238,11 @@ This is a new minor release of Chucker. Please note that this minor release cont
 This release was possible thanks to the contribution of:
 
 @christopherniksch
-@yoavst 
+@yoavst
 @psh
 @kmayoral
 @vbuberen
-@dcampogiani 
+@dcampogiani
 @ullas-jain
 @rakshit444
 @olivierperez
@@ -249,8 +252,8 @@ This release was possible thanks to the contribution of:
 @koral--
 @redwarp
 @uOOOO
-@sprohaszka 
-@PaulWoitaschek 
+@sprohaszka
+@PaulWoitaschek
 
 
 ## Version 3.0.1 *(2019-08-16)*

README.md

@@ -12,6 +12,7 @@ _A fork of [Chuck](https://github.com/jgilfelt/chuck)_
   * [Multi-Window](#multi-window-)
 * [Configure](#configure-)
   * [Redact-Header️](#redact-header-️)
+  * [Decode-Body](#decode-body-)
 * [Migrating](#migrating-)
 * [Snapshots](#snapshots-)
 * [FAQ](#faq-)
@@ -65,7 +66,7 @@ android {
 
 **That's it!** 🎉 Chucker will now record all HTTP interactions made by your OkHttp client.
 
-Historically, Chucker was distributed through JitPack. 
+Historically, Chucker was distributed through JitPack.
 You can find older version of Chucker here: [![JitPack](https://jitpack.io/v/ChuckerTeam/chucker.svg)](https://jitpack.io/#ChuckerTeam/chucker).
 
 ## Features 🧰
@@ -79,6 +80,7 @@ Don't forget to check the [changelog](CHANGELOG.md) to have a look at all the ch
 * **Empty release artifact** 🧼 (no traces of Chucker in your final APK).
 * Support for body text search with **highlighting** 🕵️‍♂️
 * Support for showing **images** in HTTP Responses 🖼
+* Support for custom decoding of HTTP bodies
 
 ### Multi-Window 🚪
 
@@ -112,6 +114,9 @@ val chuckerInterceptor = ChuckerInterceptor.Builder(context)
         // This is useful in case of parsing errors or when the response body
         // is closed before being read like in Retrofit with Void and Unit types.
         .alwaysReadResponseBody(true)
+        // Use decoder when processing request and response bodies. When multiple decoders are installed they
+        // are applied in an order they were added.
+        .addBodyDecoder(decoder)
         .build()
 
 // Don't forget to plug the ChuckerInterceptor inside the OkHttpClient
@@ -128,10 +133,28 @@ It is intended for **use during development**, and not in release builds or othe
 
 You can redact headers that contain sensitive information by calling `redactHeader(String)` on the `ChuckerInterceptor`.
 
+
 ```kotlin
 interceptor.redactHeader("Auth-Token", "User-Session");
 ```
 
+### Decode-Body 📖
+
+Chucker by default handles only plain text bodies. If you use a binary format like, for example, Protobuf or Thrift it won't be automatically handled by Chucker. You can, however, install a custom decoder that is capable to read data from different encodings.
+
+```kotlin
+object ProtoDecoder : BinaryDecoder {
+    fun decodeRequest(request: Request, body: ByteString): String? = if (request.isExpectedProtoRequest) {
+        decodeProtoBody(body)
+    } else null
+
+    fun decodeResponse(request: Response, body: ByteString): String? = if (request.isExpectedProtoResponse) {
+        decodeProtoBody(body)
+    } else null
+}
+interceptorBuilder.addBodyDecoder(ProtoDecoder).build()
+```
+
 ## Migrating 🚗
 
 If you're migrating **from [Chuck](https://github.com/jgilfelt/chuck) to Chucker**, please refer to this [migration guide](/docs/migrating-from-chuck.md).

build.gradle

@@ -18,6 +18,7 @@ buildscript {
         gsonVersion = '2.8.6'
         okhttpVersion = '4.9.1'
         retrofitVersion = '2.9.0'
+        wireVersion = '3.6.0'
 
         // Debug and quality control
         binaryCompatibilityValidator = '0.2.4'
@@ -51,6 +52,7 @@ buildscript {
         classpath "io.gitlab.arturbosch.detekt:detekt-gradle-plugin:$detektVersion"
         classpath "org.jlleitschuh.gradle:ktlint-gradle:$ktLintGradleVersion"
         classpath "org.jetbrains.kotlinx:binary-compatibility-validator:$binaryCompatibilityValidator"
+        classpath "com.squareup.wire:wire-gradle-plugin:$wireVersion"
     }
 }
 apply plugin: 'binary-compatibility-validator'

gradle/kotlin-static-analysis.gradle

@@ -13,7 +13,7 @@ ktlint {
         include fileTree("scripts/")
     }
     filter {
-        exclude("**/generated/**")
+        exclude { element -> element.file.path.contains("generated/") }
         include("**/kotlin/**")
     }
 }

library-no-op/api/library-no-op.api

@@ -1,3 +1,8 @@
+public abstract interface class com/chuckerteam/chucker/api/BodyDecoder {
+	public abstract fun decodeRequest (Lokhttp3/Request;Lokio/ByteString;)Ljava/lang/String;
+	public abstract fun decodeResponse (Lokhttp3/Response;Lokio/ByteString;)Ljava/lang/String;
+}
+
 public final class com/chuckerteam/chucker/api/Chucker {
 	public static final field INSTANCE Lcom/chuckerteam/chucker/api/Chucker;
 	public static final fun dismissNotifications (Landroid/content/Context;)V
@@ -23,6 +28,7 @@ public final class com/chuckerteam/chucker/api/ChuckerInterceptor : okhttp3/Inte
 
 public final class com/chuckerteam/chucker/api/ChuckerInterceptor$Builder {
 	public fun <init> (Landroid/content/Context;)V
+	public final fun addBodyDecoder (Ljava/lang/Object;)Lcom/chuckerteam/chucker/api/ChuckerInterceptor$Builder;
 	public final fun alwaysReadResponseBody (Z)Lcom/chuckerteam/chucker/api/ChuckerInterceptor$Builder;
 	public final fun build ()Lcom/chuckerteam/chucker/api/ChuckerInterceptor;
 	public final fun collector (Lcom/chuckerteam/chucker/api/ChuckerCollector;)Lcom/chuckerteam/chucker/api/ChuckerInterceptor$Builder;

library-no-op/src/main/java/com/chuckerteam/chucker/api/BodyDecoder.kt

@@ -0,0 +1,17 @@
+package com.chuckerteam.chucker.api
+
+import okhttp3.Request
+import okhttp3.Response
+import okio.ByteString
+import okio.IOException
+
+/**
+ * No-op declaration
+ */
+public interface BodyDecoder {
+    @Throws(IOException::class)
+    public fun decodeRequest(request: Request, body: ByteString): String?
+
+    @Throws(IOException::class)
+    public fun decodeResponse(response: Response, body: ByteString): String?
+}

library-no-op/src/main/java/com/chuckerteam/chucker/api/ChuckerInterceptor.kt

@@ -42,6 +42,8 @@ public class ChuckerInterceptor private constructor(
 
         public fun alwaysReadResponseBody(enable: Boolean): Builder = this
 
+        public fun addBodyDecoder(decoder: Any): Builder = this
+
         public fun build(): ChuckerInterceptor = ChuckerInterceptor(this)
     }
 }

library/api/library.api

@@ -1,3 +1,8 @@
+public abstract interface class com/chuckerteam/chucker/api/BodyDecoder {
+	public abstract fun decodeRequest (Lokhttp3/Request;Lokio/ByteString;)Ljava/lang/String;
+	public abstract fun decodeResponse (Lokhttp3/Response;Lokio/ByteString;)Ljava/lang/String;
+}
+
 public final class com/chuckerteam/chucker/api/Chucker {
 	public static final field INSTANCE Lcom/chuckerteam/chucker/api/Chucker;
 	public static final fun dismissNotifications (Landroid/content/Context;)V
@@ -23,6 +28,7 @@ public final class com/chuckerteam/chucker/api/ChuckerInterceptor : okhttp3/Inte
 
 public final class com/chuckerteam/chucker/api/ChuckerInterceptor$Builder {
 	public fun <init> (Landroid/content/Context;)V
+	public final fun addBodyDecoder (Lcom/chuckerteam/chucker/api/BodyDecoder;)Lcom/chuckerteam/chucker/api/ChuckerInterceptor$Builder;
 	public final fun alwaysReadResponseBody (Z)Lcom/chuckerteam/chucker/api/ChuckerInterceptor$Builder;
 	public final fun build ()Lcom/chuckerteam/chucker/api/ChuckerInterceptor;
 	public final fun collector (Lcom/chuckerteam/chucker/api/ChuckerCollector;)Lcom/chuckerteam/chucker/api/ChuckerInterceptor$Builder;

library/src/main/java/com/chuckerteam/chucker/api/BodyDecoder.kt

@@ -0,0 +1,29 @@
+package com.chuckerteam.chucker.api
+
+import okhttp3.Request
+import okhttp3.Response
+import okio.ByteString
+import okio.IOException
+
+/**
+ * Decodes HTTP request and response bodies to human–readable texts.
+ */
+public interface BodyDecoder {
+    /**
+     * Returns a text representation of [body] that will be displayed in Chucker UI transaction,
+     * or `null` if [request] cannot be handled by this decoder. [Body][body] is no longer than
+     * [max content length][ChuckerInterceptor.Builder.maxContentLength] and is guaranteed to be
+     * gunzipped even if [request] has gzip header.
+     */
+    @Throws(IOException::class)
+    public fun decodeRequest(request: Request, body: ByteString): String?
+
+    /**
+     * Returns a text representation of [body] that will be displayed in Chucker UI transaction,
+     * or `null` if [response] cannot be handled by this decoder. [Body][body] is no longer than
+     * [max content length][ChuckerInterceptor.Builder.maxContentLength] and is guaranteed to be
+     * gunzipped even if [response] has gzip header.
+     */
+    @Throws(IOException::class)
+    public fun decodeResponse(response: Response, body: ByteString): String?
+}

library/src/main/java/com/chuckerteam/chucker/api/ChuckerInterceptor.kt

@@ -4,6 +4,7 @@ import android.content.Context
 import androidx.annotation.VisibleForTesting
 import com.chuckerteam.chucker.internal.data.entity.HttpTransaction
 import com.chuckerteam.chucker.internal.support.CacheDirectoryProvider
+import com.chuckerteam.chucker.internal.support.PlainTextDecoder
 import com.chuckerteam.chucker.internal.support.RequestProcessor
 import com.chuckerteam.chucker.internal.support.ResponseProcessor
 import okhttp3.Interceptor
@@ -31,21 +32,25 @@ public class ChuckerInterceptor private constructor(
 
     private val headersToRedact = builder.headersToRedact.toMutableSet()
 
+    private val decoders = builder.decoders + BUILT_IN_DECODERS
+
     private val collector = builder.collector ?: ChuckerCollector(builder.context)
 
     private val requestProcessor = RequestProcessor(
         builder.context,
         collector,
         builder.maxContentLength,
         headersToRedact,
+        decoders,
     )
 
     private val responseProcessor = ResponseProcessor(
         collector,
         builder.cacheDirectoryProvider ?: CacheDirectoryProvider { builder.context.filesDir },
         builder.maxContentLength,
         headersToRedact,
-        builder.alwaysReadResponseBody
+        builder.alwaysReadResponseBody,
+        decoders,
     )
 
     /** Adds [headerName] into [headersToRedact] */
@@ -82,6 +87,7 @@ public class ChuckerInterceptor private constructor(
         internal var cacheDirectoryProvider: CacheDirectoryProvider? = null
         internal var alwaysReadResponseBody = false
         internal var headersToRedact = emptySet<String>()
+        internal var decoders = emptyList<BodyDecoder>()
 
         /**
          * Sets the [ChuckerCollector] to customize data retention.
@@ -126,6 +132,14 @@ public class ChuckerInterceptor private constructor(
             this.alwaysReadResponseBody = enable
         }
 
+        /**
+         * Adds a [decoder] into Chucker's processing pipeline. Decoders are applied in an order they were added in.
+         * Request and response bodies are set to the first non–null value returned by any of the decoders.
+         */
+        public fun addBodyDecoder(decoder: BodyDecoder): Builder = apply {
+            this.decoders += decoder
+        }
+
         /**
          * Sets provider of a directory where Chucker will save temporary responses
          * before processing them.
@@ -143,5 +157,7 @@ public class ChuckerInterceptor private constructor(
 
     private companion object {
         private const val MAX_CONTENT_LENGTH = 250_000L
+
+        private val BUILT_IN_DECODERS = listOf(PlainTextDecoder)
     }
 }

library/src/main/java/com/chuckerteam/chucker/internal/support/OkioUtils.kt

@@ -1,6 +1,7 @@
 package com.chuckerteam.chucker.internal.support
 
 import okio.Buffer
+import okio.ByteString
 import java.io.EOFException
 import kotlin.math.min
 
@@ -23,4 +24,10 @@ internal val Buffer.isProbablyPlainText
         false // Truncated UTF-8 sequence
     }
 
+internal val ByteString.isProbablyPlainText: Boolean
+    get() {
+        val byteCount = min(size, MAX_PREFIX_SIZE.toInt())
+        return Buffer().write(this, offset = 0, byteCount).isProbablyPlainText
+    }
+
 private fun Int.isPlainTextChar() = Character.isWhitespace(this) || !Character.isISOControl(this)

library/src/main/java/com/chuckerteam/chucker/internal/support/PlainTextDecoder.kt

@@ -0,0 +1,28 @@
+package com.chuckerteam.chucker.internal.support
+
+import com.chuckerteam.chucker.api.BodyDecoder
+import okhttp3.Headers
+import okhttp3.MediaType
+import okhttp3.Request
+import okhttp3.Response
+import okio.ByteString
+import kotlin.text.Charsets.UTF_8
+
+internal object PlainTextDecoder : BodyDecoder {
+    override fun decodeRequest(
+        request: Request,
+        body: ByteString,
+    ) = body.tryDecodeAsPlainText(request.headers, request.body?.contentType())
+
+    override fun decodeResponse(
+        response: Response,
+        body: ByteString,
+    ) = body.tryDecodeAsPlainText(response.headers, response.body?.contentType())
+
+    private fun ByteString.tryDecodeAsPlainText(
+        headers: Headers,
+        contentType: MediaType?,
+    ) = if (headers.hasSupportedContentEncoding && isProbablyPlainText) {
+        string(contentType?.charset() ?: UTF_8)
+    } else null
+}