Ensure that a context path without a leading slash is handled correctly

A context path should either be an empty String, or a String that
begins with a slash. This commit updates both CurlDocumentation and
RestDocumentationConfigurer to prepend a / to the specified context
path when required.

See gh-49

spring-restdocs/src/main/java/org/springframework/restdocs/config/RestDocumentationConfigurer.java

@@ -109,7 +109,8 @@ public class RestDocumentationConfigurer extends MockMvcConfigurerAdapter {
 	 * @return {@code this}
 	 */
 	public RestDocumentationConfigurer withContextPath(String contextPath) {
-		this.contextPath = contextPath;
+		this.contextPath = (StringUtils.hasText(contextPath) && !contextPath
+				.startsWith("/")) ? "/" + contextPath : contextPath;
 		return this;
 	}
 

spring-restdocs/src/main/java/org/springframework/restdocs/curl/CurlDocumentation.java

@@ -90,7 +90,9 @@ public abstract class CurlDocumentation {
 			}
 
 			if (StringUtils.hasText(request.getContextPath())) {
-				this.writer.print(String.format("/%s", request.getContextPath()));
+				this.writer.print(String.format(
+						request.getContextPath().startsWith("/") ? "%s" : "/%s",
+						request.getContextPath()));
 			}
 
 			this.writer.print(request.getRequestUriWithQueryString().replace("&", "\\&"));

spring-restdocs/src/test/java/org/springframework/restdocs/config/RestDocumentationConfigurerTests.java

@@ -78,12 +78,23 @@ public class RestDocumentationConfigurerTests {
 	}
 
 	@Test
-	public void customContextPath() {
+	public void customContextPathWithoutSlash() {
 		String contextPath = "context-path";
 		RequestPostProcessor postProcessor = new RestDocumentationConfigurer()
 				.withContextPath(contextPath).beforeMockMvcCreated(null, null);
 		postProcessor.postProcessRequest(this.request);
 
+		assertUriConfiguration("http", "localhost", 8080);
+		assertThat(this.request.getContextPath(), equalTo("/" + contextPath));
+	}
+
+	@Test
+	public void customContextPathWithSlash() {
+		String contextPath = "/context-path";
+		RequestPostProcessor postProcessor = new RestDocumentationConfigurer()
+				.withContextPath(contextPath).beforeMockMvcCreated(null, null);
+		postProcessor.postProcessRequest(this.request);
+
 		assertUriConfiguration("http", "localhost", 8080);
 		assertThat(this.request.getContextPath(), equalTo(contextPath));
 	}

spring-restdocs/src/test/java/org/springframework/restdocs/curl/CurlDocumentationTests.java

@@ -221,13 +221,24 @@ public class CurlDocumentationTests {
 	}
 
 	@Test
-	public void requestWithContextPath() throws IOException {
+	public void requestWithContextPathWithSlash() throws IOException {
+		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/foo");
+		request.setServerName("api.example.com");
+		request.setContextPath("/v3");
+		documentCurlRequest("request-with-custom-context-with-slash").handle(
+				new StubMvcResult(request, null));
+		assertThat(requestSnippetLines("request-with-custom-context-with-slash"),
+				hasItem("$ curl http://api.example.com/v3/foo -i"));
+	}
+
+	@Test
+	public void requestWithContextPathWithoutSlash() throws IOException {
 		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/foo");
 		request.setServerName("api.example.com");
 		request.setContextPath("v3");
-		documentCurlRequest("request-with-custom-context").handle(
+		documentCurlRequest("request-with-custom-context-without-slash").handle(
 				new StubMvcResult(request, null));
-		assertThat(requestSnippetLines("request-with-custom-context"),
+		assertThat(requestSnippetLines("request-with-custom-context-without-slash"),
 				hasItem("$ curl http://api.example.com/v3/foo -i"));
 	}