Make gzip optional (#221)

* make gzip optional

* update unit test

* add more unit test

* unit test bug fix

---------

Co-authored-by: Wenxi Zeng <wzeng@twilio.com>

Author: wenxi-zeng

core/src/main/java/com/segment/analytics/kotlin/core/HTTPClient.kt

@@ -88,9 +88,14 @@ internal fun HttpURLConnection.createGetConnection(): Connection {
 }
 
 internal fun HttpURLConnection.createPostConnection(): Connection {
-    val outputStream: OutputStream
-    setRequestProperty("Content-Encoding", "gzip")
-    outputStream = GZIPOutputStream(this.outputStream)
+    val encoding = getRequestProperty("Content-Encoding") ?: ""
+    val outputStream: OutputStream =
+        if (encoding.contains("gzip")) {
+            GZIPOutputStream(this.outputStream)
+        }
+        else {
+            this.outputStream
+        }
     return object : Connection(this, null, outputStream) {
         @Throws(IOException::class)
         override fun close() {
@@ -148,6 +153,7 @@ open class RequestFactory {
     open fun upload(apiHost: String): HttpURLConnection {
         val connection: HttpURLConnection = openConnection("https://$apiHost/b")
         connection.setRequestProperty("Content-Type", "text/plain")
+        connection.setRequestProperty("Content-Encoding", "gzip")
         connection.doOutput = true
         connection.setChunkedStreamingMode(0)
         return connection

core/src/test/kotlin/com/segment/analytics/kotlin/core/HTTPClientTests.kt

@@ -6,6 +6,7 @@ import io.mockk.every
 import io.mockk.mockk
 import io.mockk.spyk
 import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertFalse
 import org.junit.jupiter.api.Assertions.assertTrue
 import org.junit.jupiter.api.Assertions.fail
 import org.junit.jupiter.api.Test
@@ -18,6 +19,7 @@ import java.net.HttpURLConnection
 import java.net.MalformedURLException
 import java.net.URL
 import java.net.http.HttpClient
+import java.util.zip.GZIPOutputStream
 
 @TestInstance(TestInstance.Lifecycle.PER_CLASS)
 class HTTPClientTests {
@@ -45,7 +47,9 @@ class HTTPClientTests {
 
     @Test
     fun `settings connection has correct configuration`() {
-        httpClient.upload("api.segment.io/v1").connection.let {
+        httpClient.upload("api.segment.io/v1").also {
+            assertTrue(it.outputStream is GZIPOutputStream)
+        }.connection.let {
             assertEquals(
                 "https://api.segment.io/v1/b",
                 it.url.toString()
@@ -129,11 +133,28 @@ class HTTPClientTests {
             )
         }
 
-        httpClient.upload("api.segment.io/v1").connection.let {
+        httpClient.upload("api.segment.io/v1").also {
+            assertFalse(it.outputStream is GZIPOutputStream)
+        }.connection.let {
             assertEquals(
                 "https://api.test.com",
                 it.url.toString()
             )
         }
     }
+
+    @Test
+    fun `custom requestFactory can remove gzip`() {
+        val httpClient = HTTPClient("123", object : RequestFactory() {
+            override fun upload(apiHost: String): HttpURLConnection {
+                val connection: HttpURLConnection = openConnection("https://$apiHost/b")
+                connection.setRequestProperty("Content-Type", "text/plain")
+                connection.doOutput = true
+                connection.setChunkedStreamingMode(0)
+                return connection
+            }
+        })
+
+        assertFalse(httpClient.upload("api.segment.io/v1").outputStream is GZIPOutputStream)
+    }
 }