DATACMNS-1785 - Polishing.

Introduce constructors accepting non-null ConversionService, handle conversion service defaulting in configuration classes by using ObjectProvider. Extract common code to create a predicate in getPredicate(…) method. Add unit test.

Convert spaces to tabs.

Related ticket: #2200.
Original pull request: #2274.

src/test/java/org/springframework/data/web/querydsl/ReactiveQuerydslPredicateArgumentResolverUnitTests.java

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+/*
+ * Copyright 2015-2021 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
+ *
+ *      https://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.data.web.querydsl;
+
+import static org.assertj.core.api.Assertions.*;
+
+import java.util.Optional;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.core.MethodParameter;
+import org.springframework.core.convert.support.DefaultConversionService;
+import org.springframework.data.querydsl.QUser;
+import org.springframework.data.querydsl.SimpleEntityPathResolver;
+import org.springframework.data.querydsl.User;
+import org.springframework.data.querydsl.binding.QuerydslBinderCustomizer;
+import org.springframework.data.querydsl.binding.QuerydslBindings;
+import org.springframework.data.querydsl.binding.QuerydslBindingsFactory;
+import org.springframework.data.querydsl.binding.QuerydslPredicate;
+import org.springframework.lang.Nullable;
+import org.springframework.mock.http.server.reactive.MockServerHttpRequest;
+import org.springframework.mock.web.server.MockServerWebExchange;
+
+import com.querydsl.core.types.Predicate;
+
+/**
+ * Unit tests for {@link ReactiveQuerydslPredicateArgumentResolver}.
+ *
+ * @author Mark Paluch
+ */
+class ReactiveQuerydslPredicateArgumentResolverUnitTests {
+
+	ReactiveQuerydslPredicateArgumentResolver resolver;
+
+	@BeforeEach
+	void setUp() {
+
+		resolver = new ReactiveQuerydslPredicateArgumentResolver(
+				new QuerydslBindingsFactory(SimpleEntityPathResolver.INSTANCE), DefaultConversionService.getSharedInstance());
+	}
+
+	@Test // DATACMNS-1785
+	void supportsParameterReturnsTrueWhenMethodParameterIsPredicateButNotAnnotatedAsSuch() {
+		assertThat(resolver.supportsParameter(getMethodParameterFor("predicateWithoutAnnotation", Predicate.class)))
+				.isTrue();
+	}
+
+	@Test // DATACMNS-1785
+	void supportsParameterShouldThrowExceptionWhenMethodParameterIsNoPredicateButAnnotatedAsSuch() {
+		assertThatIllegalArgumentException().isThrownBy(
+				() -> resolver.supportsParameter(getMethodParameterFor("nonPredicateWithAnnotation", String.class)));
+	}
+
+	@Test // DATACMNS-1785
+	void supportsParameterReturnsFalseWhenMethodParameterIsNoPredicate() {
+		assertThat(resolver.supportsParameter(getMethodParameterFor("nonPredicateWithoutAnnotation", String.class)))
+				.isFalse();
+	}
+
+	@Test // DATACMNS-1785
+	void resolveArgumentShouldCreateSingleStringParameterPredicateCorrectly() {
+
+		MockServerHttpRequest request = MockServerHttpRequest.get("").queryParam("firstname", "rand").build();
+
+		Object predicate = resolver.resolveArgumentValue(getMethodParameterFor("simpleFind", Predicate.class), null,
+				MockServerWebExchange.from(request));
+
+		assertThat(predicate).isEqualTo(QUser.user.firstname.eq("rand"));
+	}
+
+	@Test // DATACMNS-1785
+	void resolveArgumentShouldHonorCustomSpecification() {
+
+		MockServerHttpRequest request = MockServerHttpRequest.get("").queryParam("firstname", "egwene")
+				.queryParam("lastname", "al'vere").build();
+
+		Object predicate = resolver.resolveArgumentValue(getMethodParameterFor("specificFind", Predicate.class), null,
+				MockServerWebExchange.from(request));
+
+		assertThat(predicate).isEqualTo(
+				QUser.user.firstname.eq("egwene".toUpperCase()).and(QUser.user.lastname.toLowerCase().eq("al'vere")));
+	}
+
+	@Test // DATACMNS-1785
+	void returnsEmptyPredicateForEmptyInput() {
+
+		MethodParameter parameter = getMethodParameterFor("predicateWithoutAnnotation", Predicate.class);
+
+		MockServerHttpRequest request = MockServerHttpRequest.get("").queryParam("firstname", "").build();
+
+		assertThat(resolver.resolveArgumentValue(parameter, null, MockServerWebExchange.from(request))) //
+				.isNotNull();
+	}
+
+	@Test // DATACMNS-1785
+	void forwardsNullValueForNullablePredicate() {
+
+		MethodParameter parameter = getMethodParameterFor("nullablePredicateWithoutAnnotation", Predicate.class);
+
+		MockServerHttpRequest request = MockServerHttpRequest.get("").queryParam("firstname", "").build();
+
+		assertThat(resolver.resolveArgumentValue(parameter, null, MockServerWebExchange.from(request))).isNull();
+	}
+
+	@Test // DATACMNS-1785
+	void returnsOptionalIfDeclared() {
+
+		MethodParameter parameter = getMethodParameterFor("optionalPredicateWithoutAnnotation", Optional.class);
+
+		MockServerHttpRequest request = MockServerHttpRequest.get("").queryParam("firstname", "").build();
+
+		assertThat(resolver.resolveArgumentValue(parameter, null, MockServerWebExchange.from(request))) //
+				.isInstanceOfSatisfying(Optional.class, it -> assertThat(it).isEmpty());
+
+		request = MockServerHttpRequest.get("").queryParam("firstname", "Matthews").build();
+
+		assertThat(resolver.resolveArgumentValue(parameter, null, MockServerWebExchange.from(request))) //
+				.isInstanceOfSatisfying(Optional.class, it -> assertThat(it).isPresent());
+	}
+
+	private static MethodParameter getMethodParameterFor(String methodName, Class<?>... args) throws RuntimeException {
+
+		try {
+			return new MethodParameter(Sample.class.getMethod(methodName, args), args.length == 0 ? -1 : 0);
+		} catch (NoSuchMethodException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	static class SpecificBinding implements QuerydslBinderCustomizer<QUser> {
+
+		public void customize(QuerydslBindings bindings, QUser user) {
+
+			bindings.bind(user.firstname).firstOptional((path, value) -> value.map(it -> path.eq(it.toUpperCase())));
+			bindings.bind(user.lastname).first((path, value) -> path.toLowerCase().eq(value));
+
+			bindings.excluding(user.address);
+		}
+	}
+
+	interface Sample {
+
+		User predicateWithoutAnnotation(Predicate predicate);
+
+		User nonPredicateWithAnnotation(@QuerydslPredicate String predicate);
+
+		User nonPredicateWithoutAnnotation(String predicate);
+
+		User simpleFind(@QuerydslPredicate Predicate predicate);
+
+		User specificFind(@QuerydslPredicate(bindings = SpecificBinding.class) Predicate predicate);
+
+		// Nullability
+
+		User nullablePredicateWithoutAnnotation(@Nullable Predicate predicate);
+
+		User optionalPredicateWithoutAnnotation(Optional<Predicate> predicate);
+	}
+
+}