Make new snippet relaxed when adding descriptors to relaxed snippet

Closes gh-400

Author: wilkinsona

spring-restdocs-core/src/main/java/org/springframework/restdocs/payload/AbstractFieldsSnippet.java

@@ -305,6 +305,15 @@ protected final List<FieldDescriptor> getFieldDescriptors() {
 		return this.fieldDescriptors;
 	}
 
+	/**
+	 * Returns whether or not this snippet ignores undocumented fields.
+	 *
+	 * @return {@code true} if undocumented fields are ignored, otherwise {@code false}
+	 */
+	protected final boolean isIgnoredUndocumentedFields() {
+		return this.ignoreUndocumentedFields;
+	}
+
 	/**
 	 * Returns a model for the given {@code descriptor}.
 	 *

spring-restdocs-core/src/main/java/org/springframework/restdocs/payload/RequestFieldsSnippet.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2016 the original author or authors.
+ * Copyright 2014-2017 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.
@@ -206,7 +206,8 @@ public final RequestFieldsSnippet andWithPrefix(String pathPrefix,
 		combinedDescriptors.addAll(getFieldDescriptors());
 		combinedDescriptors.addAll(PayloadDocumentation.applyPathPrefix(pathPrefix,
 				Arrays.asList(additionalDescriptors)));
-		return new RequestFieldsSnippet(combinedDescriptors, this.getAttributes());
+		return new RequestFieldsSnippet(combinedDescriptors, getAttributes(),
+				isIgnoredUndocumentedFields());
 	}
 
 	/**
@@ -225,7 +226,8 @@ public final RequestFieldsSnippet andWithPrefix(String pathPrefix,
 				getFieldDescriptors());
 		combinedDescriptors.addAll(
 				PayloadDocumentation.applyPathPrefix(pathPrefix, additionalDescriptors));
-		return new RequestFieldsSnippet(combinedDescriptors, this.getAttributes());
+		return new RequestFieldsSnippet(combinedDescriptors, getAttributes(),
+				isIgnoredUndocumentedFields());
 	}
 
 }

spring-restdocs-core/src/main/java/org/springframework/restdocs/payload/ResponseFieldsSnippet.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2016 the original author or authors.
+ * Copyright 2014-2017 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.
@@ -210,7 +210,8 @@ public final ResponseFieldsSnippet andWithPrefix(String pathPrefix,
 		combinedDescriptors.addAll(getFieldDescriptors());
 		combinedDescriptors.addAll(PayloadDocumentation.applyPathPrefix(pathPrefix,
 				Arrays.asList(additionalDescriptors)));
-		return new ResponseFieldsSnippet(combinedDescriptors, this.getAttributes());
+		return new ResponseFieldsSnippet(combinedDescriptors, this.getAttributes(),
+				isIgnoredUndocumentedFields());
 	}
 
 	/**
@@ -229,7 +230,8 @@ public final ResponseFieldsSnippet andWithPrefix(String pathPrefix,
 				getFieldDescriptors());
 		combinedDescriptors.addAll(
 				PayloadDocumentation.applyPathPrefix(pathPrefix, additionalDescriptors));
-		return new ResponseFieldsSnippet(combinedDescriptors, this.getAttributes());
+		return new ResponseFieldsSnippet(combinedDescriptors, this.getAttributes(),
+				isIgnoredUndocumentedFields());
 	}
 
 }

spring-restdocs-core/src/test/java/org/springframework/restdocs/payload/RequestFieldsSnippetTests.java

@@ -158,6 +158,20 @@ public void allUndocumentedRequestFieldsCanBeIgnored() throws IOException {
 								.content("{\"a\": 5, \"b\": 4}").build());
 	}
 
+	@Test
+	public void allUndocumentedFieldsContinueToBeIgnoredAfterAddingDescriptors()
+			throws IOException {
+		this.snippets.expectRequestFields()
+				.withContents(tableWithHeader("Path", "Type", "Description")
+						.row("`b`", "`Number`", "Field b")
+						.row("`c.d`", "`Number`", "Field d"));
+
+		new RequestFieldsSnippet(Arrays.asList(fieldWithPath("b").description("Field b")),
+				true).andWithPrefix("c.", fieldWithPath("d").description("Field d"))
+						.document(this.operationBuilder.request("http://localhost")
+								.content("{\"a\":5,\"b\":4,\"c\":{\"d\": 3}}").build());
+	}
+
 	@Test
 	public void missingOptionalRequestField() throws IOException {
 		this.snippets.expectRequestFields()

spring-restdocs-core/src/test/java/org/springframework/restdocs/payload/ResponseFieldsSnippetTests.java

@@ -134,6 +134,21 @@ public void allUndocumentedFieldsCanBeIgnored() throws IOException {
 								.content("{\"a\": 5, \"b\": 4}").build());
 	}
 
+	@Test
+	public void allUndocumentedFieldsContinueToBeIgnoredAfterAddingDescriptors()
+			throws IOException {
+		this.snippets.expectResponseFields()
+				.withContents(tableWithHeader("Path", "Type", "Description")
+						.row("`b`", "`Number`", "Field b")
+						.row("`c.d`", "`Number`", "Field d"));
+
+		new ResponseFieldsSnippet(
+				Arrays.asList(fieldWithPath("b").description("Field b")), true)
+						.andWithPrefix("c.", fieldWithPath("d").description("Field d"))
+						.document(this.operationBuilder.response()
+								.content("{\"a\":5,\"b\":4,\"c\":{\"d\": 3}}").build());
+	}
+
 	@Test
 	public void responseFieldsWithCustomAttributes() throws IOException {
 		TemplateResourceResolver resolver = mock(TemplateResourceResolver.class);