Support HtmlUnit and Selenium localhost resolution

Provide variants of `WebClient` and `WebConnectionHtmlUnitDriver` that
automatically resolve relative URLs to "localhost:${local.server.port}".

Fixes gh-5472

spring-boot-test/src/main/java/org/springframework/boot/test/web/htmlunit/LocalHostWebClient.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2012-2016 the original author or authors.
+ *
+ * Licensed 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.springframework.boot.test.web.htmlunit;
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+
+import com.gargoylesoftware.htmlunit.FailingHttpStatusCodeException;
+import com.gargoylesoftware.htmlunit.Page;
+import com.gargoylesoftware.htmlunit.WebClient;
+
+import org.springframework.core.env.Environment;
+import org.springframework.util.Assert;
+
+/**
+ * {@link WebClient} will automatically prefix relative URLs with
+ * <code>localhost:$&#123;local.server.port&#125;</code>.
+ *
+ * @author Phillip Webb
+ * @since 1.4.0
+ */
+public class LocalHostWebClient extends WebClient {
+
+	private final Environment environment;
+
+	public LocalHostWebClient(Environment environment) {
+		Assert.notNull(environment, "Environment must not be null");
+		this.environment = environment;
+	}
+
+	@Override
+	public <P extends Page> P getPage(String url)
+			throws IOException, FailingHttpStatusCodeException, MalformedURLException {
+		if (url.startsWith("/")) {
+			String port = this.environment.getProperty("local.server.port", "8080");
+			url = "http://localhost:" + port + url;
+		}
+		return super.getPage(url);
+	}
+
+}

spring-boot-test/src/main/java/org/springframework/boot/test/web/htmlunit/package-info.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2012-2016 the original author or authors.
+ *
+ * Licensed 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.
+ */
+
+/**
+ * HtmlUnit support classes.
+ */
+package org.springframework.boot.test.web.htmlunit;

spring-boot-test/src/main/java/org/springframework/boot/test/web/htmlunit/webdriver/LocalHostWebConnectionHtmlUnitDriver.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2012-2016 the original author or authors.
+ *
+ * Licensed 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.springframework.boot.test.web.htmlunit.webdriver;
+
+import com.gargoylesoftware.htmlunit.BrowserVersion;
+import org.openqa.selenium.Capabilities;
+
+import org.springframework.core.env.Environment;
+import org.springframework.test.web.servlet.htmlunit.webdriver.WebConnectionHtmlUnitDriver;
+import org.springframework.util.Assert;
+
+/**
+ * {@link LocalHostWebConnectionHtmlUnitDriver} will automatically prefix relative URLs
+ * with <code>localhost:$&#123;local.server.port&#125;</code>.
+ *
+ * @author Phillip Webb
+ * @since 1.4.0
+ */
+public class LocalHostWebConnectionHtmlUnitDriver extends WebConnectionHtmlUnitDriver {
+
+	private final Environment environment;
+
+	public LocalHostWebConnectionHtmlUnitDriver(Environment environment) {
+		Assert.notNull(environment, "Environment must not be null");
+		this.environment = environment;
+	}
+
+	public LocalHostWebConnectionHtmlUnitDriver(Environment environment,
+			boolean enableJavascript) {
+		super(enableJavascript);
+		Assert.notNull(environment, "Environment must not be null");
+		this.environment = environment;
+	}
+
+	public LocalHostWebConnectionHtmlUnitDriver(Environment environment,
+			BrowserVersion browserVersion) {
+		super(browserVersion);
+		Assert.notNull(environment, "Environment must not be null");
+		this.environment = environment;
+	}
+
+	public LocalHostWebConnectionHtmlUnitDriver(Environment environment,
+			Capabilities capabilities) {
+		super(capabilities);
+		Assert.notNull(environment, "Environment must not be null");
+		this.environment = environment;
+	}
+
+	@Override
+	public void get(String url) {
+		if (url.startsWith("/")) {
+			String port = this.environment.getProperty("local.server.port", "8080");
+			url = "http://localhost:" + port + url;
+		}
+		super.get(url);
+	}
+
+}

spring-boot-test/src/main/java/org/springframework/boot/test/web/htmlunit/webdriver/package-info.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2012-2016 the original author or authors.
+ *
+ * Licensed 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.
+ */
+
+/**
+ * Selenium support classes.
+ */
+package org.springframework.boot.test.web.htmlunit.webdriver;