code: // Licensed to the Software Freedom Conservancy (SFC) under one
  // or more contributor license agreements.  See the NOTICE file
  // distributed with this work for additional information
  // regarding copyright ownership.  The SFC licenses this file
  // to you under the Apache License, Version 2.0 (the
  // "License"); you may not use this file except in compliance
  // with the License.  You may obtain a copy of the License at
  //
  //   http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing,
  // software distributed under the License is distributed on an
  // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  // KIND, either express or implied.  See the License for the
  // specific language governing permissions and limitations
  // under the License.
  
  package org.openqa.selenium.grid.web;
  
  import static java.net.HttpURLConnection.HTTP_INTERNAL_ERROR;
  import static java.net.HttpURLConnection.HTTP_OK;
  import static org.assertj.core.api.Assertions.assertThat;
  import static org.openqa.selenium.json.Json.JSON_UTF_8;
  import static org.openqa.selenium.remote.http.HttpMethod.POST;
  
  import com.google.common.collect.ImmutableList;
  import com.google.common.collect.ImmutableSet;
  import org.junit.jupiter.api.Test;
  import org.openqa.selenium.remote.http.Contents;
  import org.openqa.selenium.remote.http.HttpHandler;
  import org.openqa.selenium.remote.http.HttpRequest;
  import org.openqa.selenium.remote.http.HttpResponse;
  
  class EnsureSpecCompliantHeadersTest {
  
    private final HttpHandler alwaysOk =
        req -> new HttpResponse().setContent(Contents.utf8String("Cheese"));
  
    @Test
    void shouldBlockRequestsWithNoContentType() {
      HttpResponse res =
          new EnsureSpecCompliantHeaders(ImmutableList.of(), ImmutableSet.of())
              .apply(alwaysOk)
              .execute(new HttpRequest(POST, "/session"));
  
      assertThat(res.getStatus()).isEqualTo(HTTP_INTERNAL_ERROR);
    }
  
    @Test
    void shouldAllowRequestsWithNoContentTypeWhenSkipCheckOnMatches() {
      HttpResponse res =
          new EnsureSpecCompliantHeaders(ImmutableList.of(), ImmutableSet.of("/gouda"))
              .apply(alwaysOk)
              .execute(new HttpRequest(POST, "/gouda"));
  
      assertThat(res.getStatus()).isEqualTo(HTTP_OK);
    }
  
    @Test
    void requestsWithAnOriginHeaderShouldBeBlocked() {
      HttpResponse res =
          new EnsureSpecCompliantHeaders(ImmutableList.of(), ImmutableSet.of())
              .apply(alwaysOk)
              .execute(
                  new HttpRequest(POST, "/session")
                      .addHeader("Content-Type", JSON_UTF_8)
                      .addHeader("Origin", "example.com"));
  
      assertThat(res.getStatus()).isEqualTo(HTTP_INTERNAL_ERROR);
    }
  
    @Test
    void requestsWithAnAllowedOriginHeaderShouldBeAllowed() {
      HttpResponse res =
          new EnsureSpecCompliantHeaders(ImmutableList.of("example.com"), ImmutableSet.of())
              .apply(alwaysOk)
              .execute(
                  new HttpRequest(POST, "/session")
                      .addHeader("Content-Type", JSON_UTF_8)
                      .addHeader("Origin", "example.com"));
  
      assertThat(res.getStatus()).isEqualTo(HTTP_OK);
      assertThat(Contents.string(res)).isEqualTo("Cheese");
    }
  
    @Test
    void shouldAllowRequestsWithNoOriginHeader() {
      HttpResponse res =
          new EnsureSpecCompliantHeaders(ImmutableList.of(), ImmutableSet.of())
              .apply(alwaysOk)
              .execute(new HttpRequest(POST, "/session").addHeader("Content-Type", JSON_UTF_8));
  
      assertThat(res.getStatus()).isEqualTo(HTTP_OK);
      assertThat(Contents.string(res)).isEqualTo("Cheese");
    }
  }
  