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Merge pull request #167 from danieltaub96/master
DataFetcherConstructor args constructor as the annotation + tests
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‎README.md

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@@ -16,6 +16,16 @@ dependencies {
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}
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```
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(Maven syntax)
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```groovy
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<dependency>
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<groupId>io.github.graphql-java</groupId>
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<artifactId>graphql-java-annotations</artifactId>
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<version>5.2</version>
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</dependency>
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```
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## Defining Objects
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To have a union, you must annotate an interface with `@GraphQLUnion`. In the annotation, you must declare all the
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possible types of the union, and a type resolver.
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If no type resolver is specified, `UnionTypeResovler` is used. It follows this algorithm:
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If no type resolver is specified, `UnionTypeResolver` is used. It follows this algorithm:
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The resolver assumes the the DB entity's name is the same as the API entity's name.
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If so, it takes the result from the dataFetcher and decides to which
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API entity it should be mapped (according to the name).
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which will be used as data fetcher.
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An instance of the data fetcher will be created. The `args` attribute on the annotation can be used to specify a list of
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String arguments to pass to the construcor, allowing to reuse the same class on different fields, with different parameter.
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String arguments to pass to the constructor, allowing to reuse the same class on different fields, with different parameter.
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The `firstArgIsTargetName` attribute can also be set on `@GraphQLDataFetcher` to pass the field name as a single parameter of the constructor.
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Assuming you are using `@GraphQLDataFetcher` this way:
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```java
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@GraphQLField
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@GraphQLDataFetcher(value = HelloWorldDataFetcher.class, args = { "arg1", "arg2" })
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public String getHelloWorld(){
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return null;
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}
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```
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Then the class that extends from `DataFetcher.class` will get this args to two supported constructors <br>
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Or to a constructor that expecting String array that's way (`String[] args` or `String... args`) or for a constructor that expecting the same number of args that you send with in the annotation.<br>
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You get to choose which implementation you want.
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```java
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public class HelloWorldDataFetcher implements DataFetcher<String> {
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public HelloWorldDataFetcher(String[] args){
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// Do something with your args
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}
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// Note that you need to expect the same number of args as you send with in the annotation args
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public HelloWorldDataFetcher(String arg1, String arg2){
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// Do something with your args
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}
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@Override
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public String get(DataFetchingEnvironment environment) {
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return "something";
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}
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}
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```
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If no argument is needed and a `getInstance` method is present, this method will be called instead of the constructor.
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## Type extensions
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Classes marked as "extensions" will actually not define a new type, but rather set new fields on the class it extends when it will be created.
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All GraphQL annotations can be used on extension classes.
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Extensions are registered in GraqhQLAnnotationProcessor by using `registerTypeExtension`. Note that extensions must be registered before the type itself is requested with `getObject()` :
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Extensions are registered in GraphQLAnnotationProcessor by using `registerTypeExtension`. Note that extensions must be registered before the type itself is requested with `getObject()` :
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```
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GraphQLAnnotationsProcessor processor = GraphQLAnnotations.getInstance();

‎src/main/java/graphql/annotations/processor/util/DataFetcherConstructor.java

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@@ -38,14 +38,31 @@ public DataFetcher constructDataFetcher(String fieldName, GraphQLDataFetcher ann
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if (args.length == 0) {
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return newInstance(annotatedDataFetcher.value());
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} else {
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try {
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final Constructor<? extends DataFetcher> ctr = annotatedDataFetcher.value().getDeclaredConstructor(
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stream(args).map(v -> String.class).toArray(Class[]::new));
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return constructNewInstance(ctr, (Object[]) args);
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} catch (final NoSuchMethodException e) {
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throw new GraphQLAnnotationsException("Unable to instantiate DataFetcher via constructor for: " + fieldName, e);
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}
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return Stream.of(annotatedDataFetcher.value().getConstructors())
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// filter only constructor that have the same args as the annotation args
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// or that get String[], String... args
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.filter(x -> (x.getParameterCount() == args.length) ||
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(x.getParameterTypes().length == 1 && x.getParameterTypes()[0] == String[].class))
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.map(x -> {
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try {
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Constructor<? extends DataFetcher> constructor;
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if (x.getParameterTypes().length == 1 && x.getParameterTypes()[0] == String[].class) {
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constructor = annotatedDataFetcher.value().getDeclaredConstructor(String[].class);
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return constructNewInstance(constructor, new Object[]{args});
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}
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constructor = annotatedDataFetcher.value().getDeclaredConstructor(
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stream(args).map(v -> String.class).toArray(Class[]::new));
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return constructNewInstance(constructor, (Object[]) args);
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} catch (NoSuchMethodException e) {
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throw new GraphQLAnnotationsException("Unable to instantiate DataFetcher via constructor for: " + fieldName, e);
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}
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})
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.findFirst()
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.orElseThrow(NoArgsConstructorException::new);
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}
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}
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public static class NoArgsConstructorException extends RuntimeException {
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}
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}

‎src/test/java/graphql/annotations/processor/util/DataFetcherConstructorTest.java

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/**
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* Copyright 2016 Yurii Rashkovskii
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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*/
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package graphql.annotations.processor.util;
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import graphql.annotations.annotationTypes.GraphQLDataFetcher;
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import graphql.schema.DataFetcher;
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import org.testng.annotations.Test;
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import java.lang.annotation.Annotation;
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import static org.testng.Assert.assertEquals;
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import static org.testng.Assert.assertNull;
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/**
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* @author danieltaub on 07/05/2018.
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*/
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public class DataFetcherConstructorTest {
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private DataFetcherConstructor constructor = new DataFetcherConstructor();
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@Test
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public void graphQLDataFetcherWithArrayCtorTest() {
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GraphQLDataFetcher graphQLDataFetcher = getGraphQLDataFetcher(DataFetcherMock.class, false, "Arg1", "Arg2");
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DataFetcherMock dataFetcher = (DataFetcherMock) constructor.constructDataFetcher(null, graphQLDataFetcher);
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assertEquals(dataFetcher.getArgs().length, 2);
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assertEquals(dataFetcher.getArgs()[0], "Arg1");
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assertEquals(dataFetcher.getArgs()[1], "Arg2");
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}
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@Test
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public void graphQLDataFetcherWithParamsCtorTest() {
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GraphQLDataFetcher graphQLDataFetcher = getGraphQLDataFetcher(DataFetcherMock.class, false, "Arg1", "Arg2", "Arg3");
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DataFetcherMock dataFetcher = (DataFetcherMock) constructor.constructDataFetcher(null, graphQLDataFetcher);
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assertEquals(dataFetcher.getArgs().length, 3);
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assertEquals(dataFetcher.getArgs()[0], "Arg1");
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assertEquals(dataFetcher.getArgs()[1], "Arg2");
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assertEquals(dataFetcher.getArgs()[2], "Arg3");
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}
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@Test
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public void graphQLDataFetcherDefaultCtorTest() {
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GraphQLDataFetcher graphQLDataFetcher = getGraphQLDataFetcher(DataFetcherMock.class, false);
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DataFetcherMock dataFetcher = (DataFetcherMock) constructor.constructDataFetcher(null, graphQLDataFetcher);
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assertNull(dataFetcher.getArgs());
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}
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private GraphQLDataFetcher getGraphQLDataFetcher(final Class<? extends DataFetcher> value,
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boolean argsInTarget, String... args) {
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GraphQLDataFetcher annotation = new GraphQLDataFetcher() {
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@Override
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public Class<? extends Annotation> annotationType() {
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return GraphQLDataFetcher.class;
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}
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@Override
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public Class<? extends DataFetcher> value() {
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return value;
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}
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@Override
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public String[] args() {
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return args;
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}
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@Override
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public boolean firstArgIsTargetName() {
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return argsInTarget;
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}
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};
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return annotation;
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}
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}

‎src/test/java/graphql/annotations/processor/util/DataFetcherMock.java

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/**
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* Copyright 2016 Yurii Rashkovskii
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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*/
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package graphql.annotations.processor.util;
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import graphql.schema.DataFetcher;
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import graphql.schema.DataFetchingEnvironment;
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/**
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* @author danieltaub on 07/05/2018.
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*/
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public class DataFetcherMock implements DataFetcher {
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private String[] args;
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public DataFetcherMock(String... args) {
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this.args = args;
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}
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public DataFetcherMock(String arg1, String arg2, String arg3) {
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this.args = new String[]{
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arg1, arg2, arg3
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};
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}
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public DataFetcherMock() {
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}
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@Override
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public Object get(DataFetchingEnvironment environment) {
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return null;
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}
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public String[] getArgs() {
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return args;
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}
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}

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