LambdaResolutionTest.java
/*
* Copyright (C) 2015-2016 Federico Tomassetti
* Copyright (C) 2017-2024 The JavaParser Team.
*
* This file is part of JavaParser.
*
* JavaParser can be used either under the terms of
* a) the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* b) the terms of the Apache License
*
* You should have received a copy of both licenses in LICENCE.LGPL and
* LICENCE.APACHE. Please refer to those files for details.
*
* JavaParser is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*/
package com.github.javaparser.symbolsolver.resolution;
import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
import static org.junit.jupiter.api.Assertions.assertEquals;
import com.github.javaparser.StaticJavaParser;
import com.github.javaparser.ast.CompilationUnit;
import com.github.javaparser.ast.body.MethodDeclaration;
import com.github.javaparser.ast.expr.Expression;
import com.github.javaparser.ast.expr.LambdaExpr;
import com.github.javaparser.ast.expr.MethodCallExpr;
import com.github.javaparser.ast.stmt.ReturnStmt;
import com.github.javaparser.resolution.Navigator;
import com.github.javaparser.resolution.types.ResolvedType;
import com.github.javaparser.symbolsolver.JavaSymbolSolver;
import com.github.javaparser.symbolsolver.javaparsermodel.JavaParserFacade;
import com.github.javaparser.symbolsolver.resolution.typesolvers.ReflectionTypeSolver;
import org.junit.jupiter.api.Disabled;
import org.junit.jupiter.api.Test;
class LambdaResolutionTest extends AbstractResolutionTest {
@Test
void lambdaMapParameter() {
CompilationUnit cu = parseSample("Lambda");
com.github.javaparser.ast.body.ClassOrInterfaceDeclaration clazz = Navigator.demandClass(cu, "Agenda");
MethodDeclaration method = Navigator.demandMethod(clazz, "lambdaMap");
ReturnStmt returnStmt = Navigator.demandReturnStmt(method);
MethodCallExpr methodCallExpr =
(MethodCallExpr) returnStmt.getExpression().get();
Expression expression = methodCallExpr.getArguments().get(0);
JavaParserFacade javaParserFacade = JavaParserFacade.get(new ReflectionTypeSolver());
ResolvedType type = javaParserFacade.getType(expression);
assertEquals(
"java.util.function.Function<? super java.lang.String, ? extends java.lang.String>", type.describe());
}
@Test
void personsStream() {
CompilationUnit cu = parseSample("Lambda");
com.github.javaparser.ast.body.ClassOrInterfaceDeclaration clazz = Navigator.demandClass(cu, "Agenda");
MethodDeclaration method = Navigator.demandMethod(clazz, "lambdaMap");
ReturnStmt returnStmt = Navigator.demandReturnStmt(method);
Expression expression = returnStmt.getExpression().get();
expression = Navigator.findMethodCall(expression, "stream").get();
JavaParserFacade javaParserFacade = JavaParserFacade.get(new ReflectionTypeSolver());
ResolvedType type = javaParserFacade.getType(expression);
assertEquals("java.util.stream.Stream<java.lang.String>", type.describe());
}
@Test
void lambdaMap() {
CompilationUnit cu = parseSample("Lambda");
com.github.javaparser.ast.body.ClassOrInterfaceDeclaration clazz = Navigator.demandClass(cu, "Agenda");
MethodDeclaration m1 = Navigator.demandMethod(clazz, "lambdaMap");
MethodDeclaration m2 = Navigator.demandMethod(clazz, "lambdaMap2");
ReturnStmt returnStmt1 = Navigator.demandReturnStmt(m1);
ReturnStmt returnStmt2 = Navigator.demandReturnStmt(m2);
Expression e1 = returnStmt1.getExpression().get();
Expression e2 = returnStmt2.getExpression().get();
JavaParserFacade javaParserFacade = JavaParserFacade.get(new ReflectionTypeSolver());
ResolvedType type1 = javaParserFacade.getType(e1);
ResolvedType type2 = javaParserFacade.getType(e2);
assertEquals("java.util.stream.Stream<java.lang.String>", type1.describe());
assertEquals("java.util.stream.Stream<java.util.stream.IntStream>", type2.describe());
}
@Test
void lambdaReduce() {
CompilationUnit cu = parseSample("Lambda");
com.github.javaparser.ast.body.ClassOrInterfaceDeclaration clazz = Navigator.demandClass(cu, "Agenda");
MethodDeclaration method = Navigator.demandMethod(clazz, "reduce");
ReturnStmt returnStmt = Navigator.demandReturnStmt(method);
Expression expr = returnStmt.getExpression().get();
JavaParserFacade javaParserFacade = JavaParserFacade.get(new ReflectionTypeSolver());
ResolvedType type1 = javaParserFacade.getType(expr);
assertEquals("java.util.Optional<java.lang.Integer>", type1.describe());
}
@Test
void lambdaPrint() {
CompilationUnit cu = parseSample("Lambda");
com.github.javaparser.ast.body.ClassOrInterfaceDeclaration clazz = Navigator.demandClass(cu, "Agenda");
MethodDeclaration method = Navigator.demandMethod(clazz, "print");
ReturnStmt returnStmt = Navigator.demandReturnStmt(method);
Expression expr = returnStmt.getExpression().get();
JavaParserFacade javaParserFacade = JavaParserFacade.get(new ReflectionTypeSolver());
ResolvedType type1 = javaParserFacade.getType(expr);
assertEquals("void", type1.describe());
}
@Test
void lambdaBifunc() {
CompilationUnit cu = parseSample("Lambda");
com.github.javaparser.ast.body.ClassOrInterfaceDeclaration clazz = Navigator.demandClass(cu, "Agenda");
MethodDeclaration method = Navigator.demandMethod(clazz, "bifunc");
ReturnStmt returnStmt = Navigator.demandReturnStmt(method);
Expression expr = returnStmt.getExpression().get();
JavaParserFacade javaParserFacade = JavaParserFacade.get(new ReflectionTypeSolver());
ResolvedType type1 = javaParserFacade.getType(expr);
assertEquals("double", type1.describe());
}
@Test
void lambdaCollectParam() {
CompilationUnit cu = parseSample("LambdaCollect");
com.github.javaparser.ast.body.ClassOrInterfaceDeclaration clazz = Navigator.demandClass(cu, "Agenda");
MethodDeclaration method = Navigator.demandMethod(clazz, "lambdaMap");
ReturnStmt returnStmt = Navigator.demandReturnStmt(method);
MethodCallExpr methodCallExpr =
(MethodCallExpr) returnStmt.getExpression().get();
// Collectors.toList()
Expression expression = methodCallExpr.getArguments().get(0);
JavaParserFacade javaParserFacade = JavaParserFacade.get(new ReflectionTypeSolver());
ResolvedType type = javaParserFacade.getType(expression);
assertEquals("java.util.stream.Collector<T, ?, java.util.List<T>>", type.describe());
}
@Test
void lambdaCollect() {
CompilationUnit cu = parseSample("LambdaCollect");
com.github.javaparser.ast.body.ClassOrInterfaceDeclaration clazz = Navigator.demandClass(cu, "Agenda");
MethodDeclaration method = Navigator.demandMethod(clazz, "lambdaMap");
ReturnStmt returnStmt = Navigator.demandReturnStmt(method);
Expression expression = returnStmt.getExpression().get();
JavaParserFacade javaParserFacade = JavaParserFacade.get(new ReflectionTypeSolver());
ResolvedType type = javaParserFacade.getType(expression);
assertEquals("java.util.List<java.lang.String>", type.describe());
}
@Test
void lambdaBlockExplicitReturn() {
CompilationUnit cu = parseSample("LambdaMulti");
com.github.javaparser.ast.body.ClassOrInterfaceDeclaration clazz = Navigator.demandClass(cu, "Agenda");
MethodDeclaration method = Navigator.demandMethod(clazz, "lambdaSingleReturn");
ReturnStmt returnStmt = Navigator.demandReturnStmt(method);
Expression expression = returnStmt.getExpression().get();
JavaParserFacade javaParserFacade = JavaParserFacade.get(new ReflectionTypeSolver());
ResolvedType type = javaParserFacade.getType(expression);
assertEquals("java.lang.String", type.describe());
}
@Test
void lambdaBlockMultiLineReturn() {
CompilationUnit cu = parseSample("LambdaMulti");
com.github.javaparser.ast.body.ClassOrInterfaceDeclaration clazz = Navigator.demandClass(cu, "Agenda");
MethodDeclaration method = Navigator.demandMethod(clazz, "multiLineReturn");
ReturnStmt returnStmt = Navigator.demandReturnStmt(method);
Expression expression = returnStmt.getExpression().get();
JavaParserFacade javaParserFacade = JavaParserFacade.get(new ReflectionTypeSolver());
ResolvedType type = javaParserFacade.getType(expression);
assertEquals("java.lang.String", type.describe());
}
@Test
void typeOfVoidLambda() {
CompilationUnit cu = parseSample("LambdaVoid");
com.github.javaparser.ast.body.ClassOrInterfaceDeclaration clazz = Navigator.demandClass(cu, "Agenda");
MethodDeclaration method = Navigator.demandMethod(clazz, "lambdaEmpty");
MethodCallExpr methodCallExpr =
Navigator.findMethodCall(method, "forEach").get();
LambdaExpr lambdaExpr = (LambdaExpr) methodCallExpr.getArguments().get(0);
JavaParserFacade javaParserFacade = JavaParserFacade.get(new ReflectionTypeSolver());
ResolvedType type = javaParserFacade.getType(lambdaExpr);
assertEquals("java.util.function.Consumer<? super java.lang.String>", type.describe());
}
@Test
void lambdaAsVararg() {
String source = "import java.util.function.Consumer;\n" + "class Test {\n"
+ " void acceptConsumers(Consumer<String>... consumers) {}\n"
+ " void test(Consumer<String> first) {\n"
+ " acceptConsumers(first, s -> System.out.println(s));\n"
+ " }\n"
+ "}";
StaticJavaParser.getParserConfiguration().setSymbolResolver(new JavaSymbolSolver(new ReflectionTypeSolver()));
final CompilationUnit cu = StaticJavaParser.parse(source);
final LambdaExpr lambda = cu.findFirst(LambdaExpr.class).get();
assertEquals(
"java.util.function.Consumer<java.lang.String>",
lambda.calculateResolvedType().describe());
}
@Test
void lambdaOverloadsWithDifferentParameterCounts1() {
String source = "import java.util.function.Consumer;\n" + "class Test {\n"
+ " void foo(Consumer<String> consumer) {}\n"
+ " void foo(Runnable r) {}\n"
+ " void test() {\n"
+ " foo(input -> {});\n"
+ " }\n"
+ "}";
StaticJavaParser.getParserConfiguration().setSymbolResolver(new JavaSymbolSolver(new ReflectionTypeSolver()));
final CompilationUnit cu = StaticJavaParser.parse(source);
final MethodCallExpr call = cu.findFirst(MethodCallExpr.class).get();
assertEquals(
"Test.foo(java.util.function.Consumer<java.lang.String>)",
call.resolve().getQualifiedSignature());
assertEquals("void", call.calculateResolvedType().describe());
}
@Test
void lambdaOverloadsWithDifferentParameterCounts2() {
String source = "import java.util.function.Consumer;\n" + "class Test {\n"
+ " void foo(Consumer<java.lang.String> consumer) {}\n"
+ " void foo(Runnable r) {}\n"
+ " void test() {\n"
+ " foo(() -> {});\n"
+ " }\n"
+ "}";
StaticJavaParser.getParserConfiguration().setSymbolResolver(new JavaSymbolSolver(new ReflectionTypeSolver()));
final CompilationUnit cu = StaticJavaParser.parse(source);
final MethodCallExpr call = cu.findFirst(MethodCallExpr.class).get();
assertEquals("Test.foo(java.lang.Runnable)", call.resolve().getQualifiedSignature());
assertEquals("void", call.calculateResolvedType().describe());
}
@Test
void lambdaOverloadsWithDifferentReturnTypes1() {
String source = "import java.util.function.Consumer;\n" + "import java.util.function.Function;\n"
+ "class Test {\n"
+ " void foo(Consumer<String> consumer) {}\n"
+ " void foo(Function<Integer, String> func) {}\n"
+ " void test() {\n"
+ " foo(input -> {});\n"
+ " }\n"
+ "}";
StaticJavaParser.getParserConfiguration().setSymbolResolver(new JavaSymbolSolver(new ReflectionTypeSolver()));
final CompilationUnit cu = StaticJavaParser.parse(source);
final MethodCallExpr call = cu.findFirst(MethodCallExpr.class).get();
assertEquals(
"Test.foo(java.util.function.Consumer<java.lang.String>)",
call.resolve().getQualifiedSignature());
assertEquals("void", call.calculateResolvedType().describe());
}
@Test
void lambdaOverloadsWithDifferentReturnTypes2() {
String source = "import java.util.function.Consumer;\n" + "import java.util.function.Function;\n"
+ "class Test {\n"
+ " void foo(Consumer<String> consumer) {}\n"
+ " void foo(Function<Integer, String> func) {}\n"
+ " void test() {\n"
+ " foo(input -> { return \"\"; });\n"
+ " }\n"
+ "}";
StaticJavaParser.getParserConfiguration().setSymbolResolver(new JavaSymbolSolver(new ReflectionTypeSolver()));
final CompilationUnit cu = StaticJavaParser.parse(source);
final MethodCallExpr call = cu.findFirst(MethodCallExpr.class).get();
assertEquals(
"Test.foo(java.util.function.Function<java.lang.Integer, java.lang.String>)",
call.resolve().getQualifiedSignature());
assertEquals("void", call.calculateResolvedType().describe());
}
@Test
void lambdaUsedAsPolymorphicArgument() {
String source = "import java.util.function.Consumer;\n" + "import java.util.HashMap;"
+ "class Test {\n"
+ " void test() {\n"
+ " HashMap<String, Consumer> map = new HashMap<>();"
+ " map.put(\"\", input -> {});\n"
+ " }\n"
+ "}";
StaticJavaParser.getParserConfiguration().setSymbolResolver(new JavaSymbolSolver(new ReflectionTypeSolver()));
final CompilationUnit cu = StaticJavaParser.parse(source);
final MethodCallExpr call = cu.findFirst(MethodCallExpr.class).get();
assertDoesNotThrow(() -> call.resolve().getQualifiedSignature());
assertDoesNotThrow(() -> call.calculateResolvedType().describe());
assertEquals("java.util.HashMap.put(K, V)", call.resolve().getQualifiedSignature());
}
@Test
void lambdaUsedAsOverloadedArrayAlternativeArgument() {
String source = "import java.util.function.Consumer;\n" + "import java.util.function.Function;\n"
+ "class Foo<S extends Consumer, T> {\n"
+ " void foo(Object[] ts) {}\n"
+ " void foo(T t) {}\n"
+ "}\n"
+ "class Test {\n"
+ " void test() {\n"
+ " Foo<Consumer<Integer>, Function<Integer, Integer>> foo = new Foo<>();\n"
+ " foo.foo(value -> { return 2; });\n"
+ " }\n"
+ "}";
StaticJavaParser.getParserConfiguration().setSymbolResolver(new JavaSymbolSolver(new ReflectionTypeSolver()));
final CompilationUnit cu = StaticJavaParser.parse(source);
final MethodCallExpr call = cu.findFirst(MethodCallExpr.class).get();
assertDoesNotThrow(() -> call.resolve().getQualifiedSignature());
assertDoesNotThrow(() -> call.calculateResolvedType().describe());
assertEquals("Foo.foo(T)", call.resolve().getQualifiedSignature());
}
@Disabled("Disambiguation for lambdas used as polymorphic is not supported yet.")
@Test
void lambdaUsedAsOverloadedPolymorphicArgument1() {
String source = "import java.util.function.Consumer;\n" + "import java.util.function.Function;\n"
+ "class Foo<S extends Consumer, T> {\n"
+ " void foo(T t) {}\n"
+ " void foo(S s) {}\n"
+ "}\n"
+ "class Test {\n"
+ " void test() {\n"
+ " Foo<Consumer<Integer>, Function<Integer, Integer>> foo = new Foo<>();\n"
+ " foo.foo(value -> { return 2; });\n"
+ " }\n"
+ "}";
StaticJavaParser.getParserConfiguration().setSymbolResolver(new JavaSymbolSolver(new ReflectionTypeSolver()));
final CompilationUnit cu = StaticJavaParser.parse(source);
final MethodCallExpr call = cu.findFirst(MethodCallExpr.class).get();
assertDoesNotThrow(() -> call.resolve().getQualifiedSignature());
assertDoesNotThrow(() -> call.calculateResolvedType().describe());
assertEquals("Foo.foo(java.util.function.Function)", call.resolve().getQualifiedSignature());
}
}