allowed multiple values per header

Author: Bilal Al

client/src/main/java/io/split/client/RequestDecorator.java

@@ -6,11 +6,12 @@
 import java.util.Map;
 import java.util.Arrays;
 import java.util.Set;
+import java.util.List;
 
 class NoOpHeaderDecorator implements  UserCustomHeaderDecorator {
     public NoOpHeaderDecorator() {}
     @Override
-    public Map<String, String> getHeaderOverrides() {
+    public Map<String, List<String>> getHeaderOverrides() {
         return new HashMap<>();
     }
 }
@@ -41,10 +42,17 @@ public RequestDecorator(UserCustomHeaderDecorator headerDecorator) {
 
     public HttpUriRequestBase decorateHeaders(HttpUriRequestBase request) {
         try {
-            Map<String, String> headers = _headerDecorator.getHeaderOverrides();
+            Map<String, List<String>> headers = _headerDecorator.getHeaderOverrides();
             for (Map.Entry entry : headers.entrySet()) {
                 if (isHeaderAllowed(entry.getKey().toString())) {
-                    request.setHeader(entry.getKey().toString(), entry.getValue());
+                    List<String> values = (List<String>) entry.getValue();
+                    for (int i = 0; i < values.size(); i++) {
+                        if (i == 0) {
+                            request.setHeader(entry.getKey().toString(), values.get(i));
+                        } else {
+                            request.addHeader(entry.getKey().toString(), values.get(i));
+                        }
+                    }
                 }
             }
         } catch (Exception e) {

client/src/main/java/io/split/client/UserCustomHeaderDecorator.java

@@ -1,12 +1,13 @@
 package io.split.client;
 
 import java.util.Map;
+import java.util.List;
 
 public interface UserCustomHeaderDecorator
 {
     /**
      * Get the additional headers needed for all http operations
      * @return HashMap of addition headers
      */
-    Map<String, String> getHeaderOverrides();
+    Map<String, List<String>> getHeaderOverrides();
 }

client/src/test/java/io/split/client/RequestDecoratorTest.java

@@ -2,10 +2,18 @@
 
 import org.apache.hc.client5.http.classic.methods.HttpGet;
 import org.apache.hc.client5.http.classic.methods.HttpPost;
+import org.apache.hc.core5.http.Header;
+import org.apache.hc.core5.http.HeaderElement;
 import org.apache.hc.core5.http.ProtocolException;
 import org.junit.Assert;
 import org.junit.Test;
+import static org.hamcrest.core.IsEqual.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
 
+import java.util.List;
+import java.util.Arrays;
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -24,15 +32,15 @@ public void testNoOp() {
 
     @Test
     public void testAddCustomHeaders() throws ProtocolException {
-        class MyCustomHeaders implements  UserCustomHeaderDecorator {
+        class MyCustomHeaders implements UserCustomHeaderDecorator {
             public MyCustomHeaders() {}
             @Override
-            public Map<String, String> getHeaderOverrides() {
-                return new HashMap<String, String>()
+            public Map<String, List<String>> getHeaderOverrides() {
+                return new HashMap<String, List<String>>()
                 {{
-                    put("first", "1");
-                    put("second", "2");
-                    put("third", "3");
+                    put("first", List.of("1"));
+                    put("second", List.of("2.1", "2.2"));
+                    put("third", List.of("3"));
                 }};
             }
         }
@@ -41,38 +49,42 @@ public Map<String, String> getHeaderOverrides() {
         HttpGet request = new HttpGet("http://anyhost");
         request.addHeader("first", "myfirstheader");
         request  = (HttpGet) decorator.decorateHeaders(request);
-        Assert.assertEquals(3, request.getHeaders().length);
+
+        Assert.assertEquals(4, request.getHeaders().length);
         Assert.assertEquals("1", request.getHeader("first").getValue());
-        Assert.assertEquals("2", request.getHeader("second").getValue());
+
+        Header[] second = request.getHeaders("second");
+        Assert.assertEquals("2.1", second[0].getValue());
+        Assert.assertEquals("2.2", second[1].getValue());
         Assert.assertEquals("3", request.getHeader("third").getValue());
 
         HttpPost request2 = new HttpPost("http://anyhost");
         request2.addHeader("myheader", "value");
         request2  = (HttpPost) decorator.decorateHeaders(request2);
-        Assert.assertEquals(4, request2.getHeaders().length);
+        Assert.assertEquals(5, request2.getHeaders().length);
     }
 
     @Test
     public void testAddBlockedHeaders() throws ProtocolException {
         class MyCustomHeaders implements  UserCustomHeaderDecorator {
             public MyCustomHeaders() {}
             @Override
-            public Map<String, String> getHeaderOverrides() {
-                return new HashMap<String, String>()
+            public Map<String, List<String>> getHeaderOverrides() {
+                return new HashMap<String, List<String>>()
                 {{
-                    put("first", "1");
-                    put("SplitSDKVersion", "2.4");
-                    put("SplitMachineip", "xx");
-                    put("splitMachineName", "xx");
-                    put("splitimpressionsmode", "xx");
-                    put("HOST", "xx");
-                    put("referrer", "xx");
-                    put("content-type", "xx");
-                    put("content-length", "xx");
-                    put("content-encoding", "xx");
-                    put("ACCEPT", "xx");
-                    put("keep-alive", "xx");
-                    put("x-fastly-debug", "xx");
+                    put("first", List.of("1"));
+                    put("SplitSDKVersion", List.of("2.4"));
+                    put("SplitMachineip", List.of("xx"));
+                    put("splitMachineName", List.of("xx"));
+                    put("splitimpressionsmode", List.of("xx"));
+                    put("HOST", List.of("xx"));
+                    put("referrer", List.of("xx"));
+                    put("content-type", List.of("xx"));
+                    put("content-length", List.of("xx"));
+                    put("content-encoding", List.of("xx"));
+                    put("ACCEPT", List.of("xx"));
+                    put("keep-alive", List.of("xx"));
+                    put("x-fastly-debug", List.of("xx"));
 
                 }};
             }
@@ -90,7 +102,7 @@ public void customDecoratorError() {
         class MyCustomHeaders implements  UserCustomHeaderDecorator {
             public MyCustomHeaders() {}
             @Override
-            public Map<String, String> getHeaderOverrides() {
+            public Map<String, List<String>> getHeaderOverrides() {
                 throw new RuntimeException();
             }
         }

client/src/test/java/io/split/client/SplitClientConfigTest.java

@@ -241,7 +241,7 @@ public void IntegrationConfigAsyncNotNull() {
     public void checkUserCustomdHeaderDecorator() {
         UserCustomHeaderDecorator ucd = new UserCustomHeaderDecorator() {
             @Override
-            public Map<String, String> getHeaderOverrides() {
+            public Map<String, List<String>> getHeaderOverrides() {
                 return null;
             }
         };