Polish "Use Jackson configuration with JsonPath"

Polish contribution to use a factory method in `AbstractJsonMarshalTester`
rather than additional constructor arguments.

Also change the `JsonContent` tests so that the `Configuration` constructor
is package private. This keeps JsonPath classes out of our public API, at
the expense of limiting custom JsonPath configurations to just our code.

See gh-16629

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/json/AbstractJsonMarshalTester.java

 /*
- * Copyright 2012-2018 the original author or authors.
+ * Copyright 2012-2019 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.
@@ -26,7 +26,6 @@ import java.io.Reader;
 import java.io.StringReader;
 import java.lang.reflect.Field;
 
-import com.jayway.jsonpath.Configuration;
 import org.assertj.core.api.Assertions;
 
 import org.springframework.beans.factory.ObjectFactory;
@@ -73,8 +72,6 @@ public abstract class AbstractJsonMarshalTester<T> {
 
 	private ResolvableType type;
 
-	private Configuration configuration;
-
 	/**
 	 * Create a new uninitialized {@link AbstractJsonMarshalTester} instance.
 	 */
@@ -88,22 +85,9 @@ public abstract class AbstractJsonMarshalTester<T> {
 	 * @param type the type under test
 	 */
 	public AbstractJsonMarshalTester(Class<?> resourceLoadClass, ResolvableType type) {
-		this(resourceLoadClass, type, Configuration.defaultConfiguration());
-	}
-
-	/**
-	 * Create a new {@link AbstractJsonMarshalTester} instance.
-	 * @param resourceLoadClass the source class used when loading relative classpath
-	 * resources
-	 * @param type the type under test
-	 * @param configuration the json-path configuration
-	 */
-	public AbstractJsonMarshalTester(Class<?> resourceLoadClass, ResolvableType type,
-			Configuration configuration) {
 		Assert.notNull(resourceLoadClass, "ResourceLoadClass must not be null");
 		Assert.notNull(type, "Type must not be null");
-		Assert.notNull(configuration, "Configuration must not be null");
-		initialize(resourceLoadClass, type, configuration);
+		initialize(resourceLoadClass, type);
 	}
 
 	/**
@@ -113,23 +97,9 @@ public abstract class AbstractJsonMarshalTester<T> {
 	 * @param type the type under test
 	 */
 	protected final void initialize(Class<?> resourceLoadClass, ResolvableType type) {
-		initialize(resourceLoadClass, type, Configuration.defaultConfiguration());
-	}
-
-	/**
-	 * Initialize the marshal tester for use.
-	 * @param resourceLoadClass the source class used when loading relative classpath
-	 * resources
-	 * @param type the type under test
-	 * @param configuration the json-path configuration
-	 */
-	protected final void initialize(Class<?> resourceLoadClass, ResolvableType type,
-			Configuration configuration) {
-		if (this.resourceLoadClass == null && this.type == null
-				&& this.configuration == null) {
+		if (this.resourceLoadClass == null && this.type == null) {
 			this.resourceLoadClass = resourceLoadClass;
 			this.type = type;
-			this.configuration = configuration;
 		}
 	}
 
@@ -159,8 +129,18 @@ public abstract class AbstractJsonMarshalTester<T> {
 		verify();
 		Assert.notNull(value, "Value must not be null");
 		String json = writeObject(value, this.type);
-		return new JsonContent<>(this.resourceLoadClass, this.type, json,
-				this.configuration);
+		return getJsonContent(json);
+	}
+
+	/**
+	 * Factory method used to get a {@link JsonContent} instance from a source JSON
+	 * string.
+	 * @param json the source JSON
+	 * @return a new {@link JsonContent} instance
+	 * @since 2.1.5
+	 */
+	protected JsonContent<T> getJsonContent(String json) {
+		return new JsonContent<>(getResourceLoadClass(), getType(), json);
 	}
 
 	/**

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/json/BasicJsonTester.java

 /*
- * Copyright 2012-2018 the original author or authors.
+ * Copyright 2012-2019 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.
@@ -20,8 +20,6 @@ import java.io.File;
 import java.io.InputStream;
 import java.nio.charset.Charset;
 
-import com.jayway.jsonpath.Configuration;
-
 import org.springframework.core.io.Resource;
 import org.springframework.util.Assert;
 
@@ -51,8 +49,6 @@ public class BasicJsonTester {
 
 	private JsonLoader loader;
 
-	private Configuration configuration;
-
 	/**
 	 * Create a new uninitialized {@link BasicJsonTester} instance.
 	 */
@@ -74,21 +70,8 @@ public class BasicJsonTester {
 	 * @since 1.4.1
 	 */
 	public BasicJsonTester(Class<?> resourceLoadClass, Charset charset) {
-		this(resourceLoadClass, charset, Configuration.defaultConfiguration());
-	}
-
-	/**
-	 * Create a new {@link BasicJsonTester} instance.
-	 * @param resourceLoadClass the source class used to load resources
-	 * @param charset the charset used to load resources
-	 * @param configuration the json-path configuration
-	 */
-	public BasicJsonTester(Class<?> resourceLoadClass, Charset charset,
-			Configuration configuration) {
 		Assert.notNull(resourceLoadClass, "ResourceLoadClass must not be null");
-		Assert.notNull(configuration, "Configuration must not be null");
 		this.loader = new JsonLoader(resourceLoadClass, charset);
-		this.configuration = configuration;
 	}
 
 	/**
@@ -109,22 +92,8 @@ public class BasicJsonTester {
 	 * @since 1.4.1
 	 */
 	protected final void initialize(Class<?> resourceLoadClass, Charset charset) {
-		initialize(resourceLoadClass, charset, Configuration.defaultConfiguration());
-	}
-
-	/**
-	 * Initialize the marshal tester for use.
-	 * @param resourceLoadClass the source class used when loading relative classpath
-	 * resources
-	 * @param charset the charset used when loading relative classpath resources
-	 * @param configuration the json-path configuration
-	 * @since
-	 */
-	protected final void initialize(Class<?> resourceLoadClass, Charset charset,
-			Configuration configuration) {
-		if (this.loader == null && this.configuration == null) {
+		if (this.loader == null) {
 			this.loader = new JsonLoader(resourceLoadClass, charset);
-			this.configuration = configuration;
 		}
 	}
 
@@ -196,8 +165,7 @@ public class BasicJsonTester {
 	}
 
 	private JsonContent<Object> getJsonContent(String json) {
-		return new JsonContent<>(this.loader.getResourceLoadClass(), null, json,
-				this.configuration);
+		return new JsonContent<>(this.loader.getResourceLoadClass(), null, json);
 	}
 
 }

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/json/GsonTester.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2019 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.
@@ -20,7 +20,6 @@ import java.io.IOException;
 import java.io.Reader;
 
 import com.google.gson.Gson;
-import com.jayway.jsonpath.Configuration;
 
 import org.springframework.beans.factory.ObjectFactory;
 import org.springframework.core.ResolvableType;
@@ -75,20 +74,7 @@ public class GsonTester<T> extends AbstractJsonMarshalTester<T> {
 	 * @see #initFields(Object, Gson)
 	 */
 	public GsonTester(Class<?> resourceLoadClass, ResolvableType type, Gson gson) {
-		this(resourceLoadClass, type, gson, Configuration.defaultConfiguration());
-	}
-
-	/**
-	 * Create a new {@link GsonTester} instance.
-	 * @param resourceLoadClass the source class used to load resources
-	 * @param type the type under test
-	 * @param gson the Gson instance
-	 * @param configuration the json-path configuration
-	 * @see #initFields(Object, Gson)
-	 */
-	public GsonTester(Class<?> resourceLoadClass, ResolvableType type, Gson gson,
-			Configuration configuration) {
-		super(resourceLoadClass, type, configuration);
+		super(resourceLoadClass, type);
 		Assert.notNull(gson, "Gson must not be null");
 		this.gson = gson;
 	}

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/json/JacksonTester.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2019 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.
@@ -59,6 +59,7 @@ import org.springframework.util.Assert;
  * @param <T> the type under test
  * @author Phillip Webb
  * @author Madhura Bhave
+ * @author Diego Berrueta
  * @since 1.4.0
  */
 public class JacksonTester<T> extends AbstractJsonMarshalTester<T> {
@@ -89,14 +90,20 @@ public class JacksonTester<T> extends AbstractJsonMarshalTester<T> {
 
 	public JacksonTester(Class<?> resourceLoadClass, ResolvableType type,
 			ObjectMapper objectMapper, Class<?> view) {
-		super(resourceLoadClass, type, Configuration.builder()
-				.jsonProvider(new JacksonJsonProvider(objectMapper))
-				.mappingProvider(new JacksonMappingProvider(objectMapper)).build());
+		super(resourceLoadClass, type);
 		Assert.notNull(objectMapper, "ObjectMapper must not be null");
 		this.objectMapper = objectMapper;
 		this.view = view;
 	}
 
+	@Override
+	protected JsonContent<T> getJsonContent(String json) {
+		Configuration configuration = Configuration.builder()
+				.jsonProvider(new JacksonJsonProvider(this.objectMapper))
+				.mappingProvider(new JacksonMappingProvider(this.objectMapper)).build();
+		return new JsonContent<>(getResourceLoadClass(), getType(), json, configuration);
+	}
+
 	@Override
 	protected T readObject(InputStream inputStream, ResolvableType type)
 			throws IOException {

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/json/JsonContent.java

 /*
- * Copyright 2012-2018 the original author or authors.
+ * Copyright 2012-2019 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.
@@ -29,6 +29,7 @@ import org.springframework.util.Assert;
  *
  * @param <T> the source type that created the content
  * @author Phillip Webb
+ * @author Diego Berrueta
  * @since 1.4.0
  */
 public final class JsonContent<T> implements AssertProvider<JsonContentAssert> {
@@ -56,9 +57,9 @@ public final class JsonContent<T> implements AssertProvider<JsonContentAssert> {
 	 * @param resourceLoadClass the source class used to load resources
 	 * @param type the type under test (or {@code null} if not known)
 	 * @param json the actual JSON content
-	 * @param configuration the json-path configuration
+	 * @param configuration the JsonPath configuration
 	 */
-	public JsonContent(Class<?> resourceLoadClass, ResolvableType type, String json,
+	JsonContent(Class<?> resourceLoadClass, ResolvableType type, String json,
 			Configuration configuration) {
 		Assert.notNull(resourceLoadClass, "ResourceLoadClass must not be null");
 		Assert.notNull(json, "JSON must not be null");

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/json/JsonContentAssert.java

@@ -46,6 +46,7 @@ import org.springframework.util.StringUtils;
  *
  * @author Phillip Webb
  * @author Andy Wilkinson
+ * @author Diego Berrueta
  * @since 1.4.0
  */
 public class JsonContentAssert extends AbstractAssert<JsonContentAssert, CharSequence> {
@@ -84,8 +85,8 @@ public class JsonContentAssert extends AbstractAssert<JsonContentAssert, CharSeq
 	 * @param json the actual JSON content
 	 * @param configuration the json-path configuration
 	 */
-	public JsonContentAssert(Class<?> resourceLoadClass, Charset charset,
-			CharSequence json, Configuration configuration) {
+	JsonContentAssert(Class<?> resourceLoadClass, Charset charset, CharSequence json,
+			Configuration configuration) {
 		super(json, JsonContentAssert.class);
 		this.configuration = configuration;
 		this.loader = new JsonLoader(resourceLoadClass, charset);

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/json/JsonbTester.java

 /*
- * Copyright 2012-2018 the original author or authors.
+ * Copyright 2012-2019 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.
@@ -21,8 +21,6 @@ import java.io.Reader;
 
 import javax.json.bind.Jsonb;
 
-import com.jayway.jsonpath.Configuration;
-
 import org.springframework.beans.factory.ObjectFactory;
 import org.springframework.core.ResolvableType;
 import org.springframework.util.Assert;
@@ -76,20 +74,7 @@ public class JsonbTester<T> extends AbstractJsonMarshalTester<T> {
 	 * @see #initFields(Object, Jsonb)
 	 */
 	public JsonbTester(Class<?> resourceLoadClass, ResolvableType type, Jsonb jsonb) {
-		this(resourceLoadClass, type, jsonb, Configuration.defaultConfiguration());
-	}
-
-	/**
-	 * Create a new {@link JsonbTester} instance.
-	 * @param resourceLoadClass the source class used to load resources
-	 * @param type the type under test
-	 * @param jsonb the Jsonb instance
-	 * @param configuration the json-path configuration
-	 * @see #initFields(Object, Jsonb)
-	 */
-	public JsonbTester(Class<?> resourceLoadClass, ResolvableType type, Jsonb jsonb,
-			Configuration configuration) {
-		super(resourceLoadClass, type, configuration);
+		super(resourceLoadClass, type);
 		Assert.notNull(jsonb, "Jsonb must not be null");
 		this.jsonb = jsonb;
 	}

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/json/JacksonTesterIntegrationTests.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2019 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.
@@ -36,6 +36,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  *
  * @author Phillip Webb
  * @author Madhura Bhave
+ * @author Diego Berrueta
  */
 public class JacksonTesterIntegrationTests {
 
@@ -91,14 +92,14 @@ public class JacksonTesterIntegrationTests {
 				.isEqualTo(stringWithSpecialCharacters);
 	}
 
-	// This test confirms that the handling of special characters is symmetrical between
-	// the serialisation (via the JacksonTester) and the parsing (via json-path). By
-	// default json-path uses SimpleJson as its parser, which has a slightly different
-	// behaviour to Jackson and breaks the symmetry. However JacksonTester
-	// configures json-path to use Jackson for evaluating the path expressions and
-	// restores the symmetry.
 	@Test
 	public void parseSpecialCharactersTest() throws Exception {
+		// Confirms that the handling of special characters is symmetrical between
+		// the serialization (via the JacksonTester) and the parsing (via json-path). By
+		// default json-path uses SimpleJson as its parser, which has a slightly different
+		// behavior to Jackson and breaks the symmetry. JacksonTester
+		// configures json-path to use Jackson for evaluating the path expressions and
+		// restores the symmetry. See gh-15727
 		String stringWithSpecialCharacters = "\u0006\u007F";
 		assertThat(this.stringJson.write(stringWithSpecialCharacters))
 				.extractingJsonPathStringValue("@")