Improved basic SimpleHttpClientTest and add one for redirects

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/http/SimpleHTTPClient.java

@@ -90,9 +90,13 @@ public class SimpleHTTPClient {
       setHeaders(c);
       c.setInstanceFollowRedirects(false);
 
-      switch (c.getResponseCode()) {
+      int responseCode = c.getResponseCode();
+      System.out.println("Processing response code "+ responseCode);
+      switch (responseCode) {
         case HttpURLConnection.HTTP_MOVED_PERM:
         case HttpURLConnection.HTTP_MOVED_TEMP:
+        case 308: // Same as HTTP_MOVED_PERM, but does not allow changing the request method from POST to GET
+          System.out.println("Processing redirect to "+c.getHeaderField("Location"));
           String location = c.getHeaderField("Location");
           location = URLDecoder.decode(location, "UTF-8");
           URL base = new URL(url);

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/SimpleHTTPClientTest.java

@@ -1,24 +1,103 @@
 package org.hl7.fhir.utilities;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.io.IOException;
+import java.util.stream.Stream;
 
+import okhttp3.HttpUrl;
+import okhttp3.mockwebserver.MockResponse;
+import okhttp3.mockwebserver.MockWebServer;
+import okhttp3.mockwebserver.RecordedRequest;
 import org.hl7.fhir.utilities.http.HTTPResult;
 import org.hl7.fhir.utilities.http.SimpleHTTPClient;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.CsvSource;
+import org.junit.jupiter.params.provider.MethodSource;
 
 public class SimpleHTTPClientTest {
+
+  private MockWebServer server;
+
+
+
+  @BeforeEach
+  void setup() {
+    setupMockServer();
+  }
+
+  void setupMockServer() {
+    server = new MockWebServer();
+  }
+
   @Test
-  public void testSimpleHTTPClient() throws IOException {
+  public void testGetApplicationJson() throws IOException, InterruptedException {
+
+    HttpUrl serverUrl = server.url("fhir/us/core/package-list.json?nocache=1724353440974");
+
+    server.enqueue(
+      new MockResponse()
+        .setBody("Monkeys").setResponseCode(200)
+    );
 
     SimpleHTTPClient http = new SimpleHTTPClient();
-    String url = "https://hl7.org/fhir/us/core/package-list.json?nocache=" + System.currentTimeMillis();
 
-    HTTPResult res = http.get(url, "application/json");
+    HTTPResult res = http.get(serverUrl.url().toString(), "application/json");
+
+    assertThat(res.getCode()).isEqualTo(200);
+
+    RecordedRequest packageRequest = server.takeRequest();
+
+    assert packageRequest.getRequestUrl() != null;
+    assertThat(packageRequest.getRequestUrl().toString()).isEqualTo(serverUrl.url().toString());
+    assertThat(packageRequest.getMethod()).isEqualTo("GET");
+    assertThat(packageRequest.getHeader("Accept")).isEqualTo("application/json");
+
+  }
+
+  public static Stream<Arguments> getRedirectArgs() {
+    return Stream.of(
+      Arguments.of(301, new String[]{"url1", "url2"}),
+      Arguments.of(301, new String[]{"url1", "url2", "url3"}),
+      Arguments.of(301, new String[]{"url1", "url2", "url3", "url4"}),
+      Arguments.of(302, new String[]{"url1", "url2"}),
+      Arguments.of(302, new String[]{"url1", "url2", "url3"}),
+      Arguments.of(302, new String[]{"url1", "url2", "url3", "url4"}),
+      Arguments.of(308, new String[]{"url1", "url2"}),
+      Arguments.of(308, new String[]{"url1", "url2", "url3"}),
+      Arguments.of(308, new String[]{"url1", "url2", "url3", "url4"})
+    );
+  }
+
+  @ParameterizedTest
+  @MethodSource("getRedirectArgs")
+  public void testRedirects(int code, String[] urlArgs) throws IOException, InterruptedException {
+
+    HttpUrl[] url = new HttpUrl[urlArgs.length];
+    for (int i = 0; i < urlArgs.length; i++) {
+      url[i] = server.url(urlArgs[i]);
+      if (i > 0 && i < urlArgs.length - 1) {
+        server.enqueue(
+          new MockResponse()
+            .setResponseCode(code)
+            .addHeader("Location", url[i].url().toString()));
+      } else if (i == urlArgs.length - 1) {
+        server.enqueue(
+          new MockResponse()
+            .setBody("Monkeys").setResponseCode(200)
+        );
+      }
+    }
+
+    SimpleHTTPClient http = new SimpleHTTPClient();
+
+    HTTPResult res = http.get(url[0].url().toString(), "application/json");
+
+    assertThat(res.getCode()).isEqualTo(200);
 
-//    System.out.println(res.getCode());
-//    System.out.println(new String(res.getContent(), StandardCharsets.UTF_8));
-    assertTrue(res.getCode() != 400);
   }
 }