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feat(jdk-codemodel): resolve identifier symbols via javac element API (#22)
1 parent 56f6f5d commit a4bd431

3 files changed

Lines changed: 311 additions & 1 deletion

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‎jdk-codemodel/src/main/java/build/codemodel/jdk/JdkExpressionConverter.java‎

Lines changed: 39 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -68,6 +68,7 @@
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import build.codemodel.jdk.expression.PrefixOperator;
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import build.codemodel.jdk.expression.PrefixUnary;
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import build.codemodel.jdk.expression.SwitchExpression;
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import build.codemodel.jdk.expression.Symbol;
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import build.codemodel.jdk.expression.Ternary;
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import build.codemodel.jdk.expression.UnknownExpression;
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import build.codemodel.jdk.statement.ExpressionStatement;
@@ -102,6 +103,7 @@
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import java.util.List;
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import java.util.Optional;
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import java.util.function.Function;
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import javax.lang.model.element.Element;
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import javax.lang.model.type.TypeKind;
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import javax.lang.model.type.TypeMirror;
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@@ -218,7 +220,43 @@ public Expression visitLiteral(final LiteralTree t, final Void v) {
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@Override
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public Expression visitIdentifier(final IdentifierTree t, final Void v) {
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return Identifier.of(codeModel, t.getName().toString());
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final var identifier = Identifier.of(codeModel, t.getName().toString());
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resolveSymbol(t).ifPresent(identifier::addTrait);
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return identifier;
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}
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private Optional<Symbol> resolveSymbol(final IdentifierTree t) {
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if (trees == null || compilationUnit == null) {
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return Optional.empty();
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}
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final var name = t.getName().toString();
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final var path = trees.getPath(compilationUnit, t);
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if (path == null) {
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return Optional.empty();
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}
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final var typeMirror = trees.getTypeMirror(path);
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final TypeUsage typeUsage = typeMirror != null && typeMirror.getKind() != TypeKind.ERROR
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? typeResolver.apply(typeMirror)
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: UnknownTypeUsage.create(codeModel);
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if ("this".equals(name)) {
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return Optional.of(new Symbol.ThisReference(typeUsage));
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}
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if ("super".equals(name)) {
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return Optional.of(new Symbol.SuperReference(typeUsage));
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}
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final Element element = trees.getElement(path);
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if (element == null) {
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return Optional.empty();
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}
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return Optional.ofNullable(switch (element.getKind()) {
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case LOCAL_VARIABLE -> new Symbol.LocalVariable(typeUsage);
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case PARAMETER -> new Symbol.Parameter(typeUsage);
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case FIELD, ENUM_CONSTANT -> new Symbol.Field(typeUsage);
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case CLASS, INTERFACE, ENUM, ANNOTATION_TYPE, RECORD -> new Symbol.TypeReference(typeUsage);
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default -> null;
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});
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}
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@Override

‎jdk-codemodel/src/main/java/build/codemodel/jdk/expression/Symbol.java‎

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,82 @@
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package build.codemodel.jdk.expression;
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/*-
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* #%L
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* JDK Code Model
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* %%
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* Copyright (C) 2026 Workday, Inc.
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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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* limitations under the License.
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* #L%
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*/
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import build.codemodel.foundation.descriptor.Singular;
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import build.codemodel.foundation.descriptor.Trait;
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import build.codemodel.foundation.usage.TypeUsage;
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/**
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* A {@link Trait} on an {@link Identifier} that captures the result of javac symbol resolution:
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* what the identifier refers to and, for variable-kind symbols, its declared type.
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*
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* <p>Exactly one {@link Symbol} may be present on an {@link Identifier} ({@link Singular}).
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*
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* @author reed.vonredwitz
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* @since Apr-2026
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*/
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@Singular
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public sealed interface Symbol extends Trait
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permits Symbol.LocalVariable, Symbol.Parameter, Symbol.Field,
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Symbol.TypeReference, Symbol.ThisReference, Symbol.SuperReference {
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/**
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* A local variable reference, e.g. {@code x} in {@code int x = 1; return x;}.
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*
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* @param declaredType the declared type of the variable
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*/
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record LocalVariable(TypeUsage declaredType) implements Symbol {}
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/**
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* A method or constructor parameter reference.
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*
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* @param declaredType the declared type of the parameter
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*/
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record Parameter(TypeUsage declaredType) implements Symbol {}
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/**
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* A field reference, e.g. {@code field} in {@code this.field} or a bare {@code field}.
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*
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* @param declaredType the declared type of the field
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*/
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record Field(TypeUsage declaredType) implements Symbol {}
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/**
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* A type name reference, e.g. {@code String} in {@code String.valueOf(...)}.
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*
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* @param type the type being referenced
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*/
67+
record TypeReference(TypeUsage type) implements Symbol {}
68+
69+
/**
70+
* A {@code this} reference.
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*
72+
* @param declaredType the type of the enclosing instance
73+
*/
74+
record ThisReference(TypeUsage declaredType) implements Symbol {}
75+
76+
/**
77+
* A {@code super} reference.
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*
79+
* @param declaredType the type of the direct superclass
80+
*/
81+
record SuperReference(TypeUsage declaredType) implements Symbol {}
82+
}

‎jdk-codemodel/src/test/java/build/codemodel/jdk/SymbolResolutionTests.java‎

Lines changed: 190 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,190 @@
1+
package build.codemodel.jdk;
2+
3+
import build.codemodel.foundation.usage.NamedTypeUsage;
4+
import build.codemodel.imperative.Return;
5+
import build.codemodel.jdk.descriptor.MethodBodyDescriptor;
6+
import build.codemodel.jdk.expression.Identifier;
7+
import build.codemodel.jdk.expression.Symbol;
8+
import build.codemodel.objectoriented.descriptor.MethodDescriptor;
9+
import com.google.testing.compile.JavaFileObjects;
10+
import org.junit.jupiter.api.Test;
11+
12+
import java.util.List;
13+
import java.util.Optional;
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15+
import static org.assertj.core.api.Assertions.assertThat;
16+
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/**
18+
* Tests for {@link Symbol} resolution on {@link Identifier} expressions.
19+
*
20+
* @author reed.vonredwitz
21+
* @since Apr-2026
22+
*/
23+
class SymbolResolutionTests {
24+
25+
@Test
26+
void shouldResolveLocalVariable() {
27+
final var source = JavaFileObjects.forSourceString("com.example.Foo", """
28+
package com.example;
29+
public class Foo {
30+
public String bar() {
31+
String result = "hello";
32+
return result;
33+
}
34+
}
35+
""");
36+
final var codeModel = JdkInitializerTests.runInternal(
37+
new JdkInitializer(List.of(), List.of(), List.of(source)));
38+
39+
final var typeName = codeModel.getNameProvider().getTypeName(Optional.empty(), "com.example.Foo");
40+
final var descriptor = codeModel.getTypeDescriptor(typeName).orElseThrow();
41+
final var method = descriptor.traits(MethodDescriptor.class)
42+
.filter(m -> m.methodName().name().toString().equals("bar"))
43+
.findFirst().orElseThrow();
44+
final var body = method.getTrait(MethodBodyDescriptor.class).orElseThrow().body();
45+
46+
final var ret = body.statements()
47+
.filter(s -> s instanceof Return)
48+
.map(s -> (Return) s)
49+
.findFirst().orElseThrow();
50+
51+
final var identifier = (Identifier) ret.expression().orElseThrow();
52+
assertThat(identifier.name()).isEqualTo("result");
53+
54+
final var symbol = identifier.getTrait(Symbol.class).orElseThrow();
55+
assertThat(symbol).isInstanceOf(Symbol.LocalVariable.class);
56+
final var local = (Symbol.LocalVariable) symbol;
57+
assertThat(local.declaredType()).isInstanceOf(NamedTypeUsage.class);
58+
assertThat(local.declaredType().toString()).contains("String");
59+
}
60+
61+
@Test
62+
void shouldResolveParameter() {
63+
final var source = JavaFileObjects.forSourceString("com.example.Foo", """
64+
package com.example;
65+
public class Foo {
66+
public String bar(String input) {
67+
return input;
68+
}
69+
}
70+
""");
71+
final var codeModel = JdkInitializerTests.runInternal(
72+
new JdkInitializer(List.of(), List.of(), List.of(source)));
73+
74+
final var typeName = codeModel.getNameProvider().getTypeName(Optional.empty(), "com.example.Foo");
75+
final var descriptor = codeModel.getTypeDescriptor(typeName).orElseThrow();
76+
final var method = descriptor.traits(MethodDescriptor.class)
77+
.filter(m -> m.methodName().name().toString().equals("bar"))
78+
.findFirst().orElseThrow();
79+
final var body = method.getTrait(MethodBodyDescriptor.class).orElseThrow().body();
80+
81+
final var ret = body.statements()
82+
.filter(s -> s instanceof Return)
83+
.map(s -> (Return) s)
84+
.findFirst().orElseThrow();
85+
86+
final var identifier = (Identifier) ret.expression().orElseThrow();
87+
final var symbol = identifier.getTrait(Symbol.class).orElseThrow();
88+
assertThat(symbol).isInstanceOf(Symbol.Parameter.class);
89+
assertThat(((Symbol.Parameter) symbol).declaredType().toString()).contains("String");
90+
}
91+
92+
@Test
93+
void shouldResolveField() {
94+
final var source = JavaFileObjects.forSourceString("com.example.Foo", """
95+
package com.example;
96+
public class Foo {
97+
private String value = "hello";
98+
public String bar() {
99+
return value;
100+
}
101+
}
102+
""");
103+
final var codeModel = JdkInitializerTests.runInternal(
104+
new JdkInitializer(List.of(), List.of(), List.of(source)));
105+
106+
final var typeName = codeModel.getNameProvider().getTypeName(Optional.empty(), "com.example.Foo");
107+
final var descriptor = codeModel.getTypeDescriptor(typeName).orElseThrow();
108+
final var method = descriptor.traits(MethodDescriptor.class)
109+
.filter(m -> m.methodName().name().toString().equals("bar"))
110+
.findFirst().orElseThrow();
111+
final var body = method.getTrait(MethodBodyDescriptor.class).orElseThrow().body();
112+
113+
final var ret = body.statements()
114+
.filter(s -> s instanceof Return)
115+
.map(s -> (Return) s)
116+
.findFirst().orElseThrow();
117+
118+
final var identifier = (Identifier) ret.expression().orElseThrow();
119+
final var symbol = identifier.getTrait(Symbol.class).orElseThrow();
120+
assertThat(symbol).isInstanceOf(Symbol.Field.class);
121+
assertThat(((Symbol.Field) symbol).declaredType().toString()).contains("String");
122+
}
123+
124+
@Test
125+
void shouldResolveThisReference() {
126+
final var source = JavaFileObjects.forSourceString("com.example.Foo", """
127+
package com.example;
128+
public class Foo {
129+
public Foo bar() {
130+
return this;
131+
}
132+
}
133+
""");
134+
final var codeModel = JdkInitializerTests.runInternal(
135+
new JdkInitializer(List.of(), List.of(), List.of(source)));
136+
137+
final var typeName = codeModel.getNameProvider().getTypeName(Optional.empty(), "com.example.Foo");
138+
final var descriptor = codeModel.getTypeDescriptor(typeName).orElseThrow();
139+
final var method = descriptor.traits(MethodDescriptor.class)
140+
.filter(m -> m.methodName().name().toString().equals("bar"))
141+
.findFirst().orElseThrow();
142+
final var body = method.getTrait(MethodBodyDescriptor.class).orElseThrow().body();
143+
144+
final var ret = body.statements()
145+
.filter(s -> s instanceof Return)
146+
.map(s -> (Return) s)
147+
.findFirst().orElseThrow();
148+
149+
final var identifier = (Identifier) ret.expression().orElseThrow();
150+
final var symbol = identifier.getTrait(Symbol.class).orElseThrow();
151+
assertThat(symbol).isInstanceOf(Symbol.ThisReference.class);
152+
assertThat(((Symbol.ThisReference) symbol).declaredType().toString()).contains("Foo");
153+
}
154+
155+
@Test
156+
void shouldResolveTypeReference() {
157+
final var source = JavaFileObjects.forSourceString("com.example.Foo", """
158+
package com.example;
159+
public class Foo {
160+
public String bar() {
161+
return String.valueOf(42);
162+
}
163+
}
164+
""");
165+
final var codeModel = JdkInitializerTests.runInternal(
166+
new JdkInitializer(List.of(), List.of(), List.of(source)));
167+
168+
final var typeName = codeModel.getNameProvider().getTypeName(Optional.empty(), "com.example.Foo");
169+
final var descriptor = codeModel.getTypeDescriptor(typeName).orElseThrow();
170+
final var method = descriptor.traits(MethodDescriptor.class)
171+
.filter(m -> m.methodName().name().toString().equals("bar"))
172+
.findFirst().orElseThrow();
173+
final var body = method.getTrait(MethodBodyDescriptor.class).orElseThrow().body();
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175+
final var ret = body.statements()
176+
.filter(s -> s instanceof Return)
177+
.map(s -> (Return) s)
178+
.findFirst().orElseThrow();
179+
180+
// String.valueOf(42) is a MethodInvocation whose receiver is a MemberSelect on "String"
181+
// The MemberSelect target is an Identifier("String") tagged as TypeReference
182+
final var methodInvocation = ret.expression().orElseThrow();
183+
assertThat(methodInvocation).isInstanceOf(build.codemodel.jdk.expression.MethodInvocation.class);
184+
final var invocation = (build.codemodel.jdk.expression.MethodInvocation) methodInvocation;
185+
final var receiver = (Identifier) invocation.target().orElseThrow();
186+
assertThat(receiver.name()).isEqualTo("String");
187+
final var symbol = receiver.getTrait(Symbol.class).orElseThrow();
188+
assertThat(symbol).isInstanceOf(Symbol.TypeReference.class);
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}
190+
}

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