Loosen the rules for AutoBuilder copy-constructors.

If the built type has a method `T getFoo()` and its constructor has a parameter `U foo`, then we should still generate a copy-constructor provided `T` is assignable to `U`. The copy-constructor will call `getFoo()` on its parameter and by default that is the value that will get passed to the constructor when `build()` is called.

RELNOTES=AutoBuilder copy-constructors no longer require an exact match between a property and the corresponding constructor parameter.
PiperOrigin-RevId: 508917172

Author: eamonnmcmanus

value/src/it/functional/src/test/java/com/google/auto/value/AutoBuilderKotlinTest.java

@@ -19,6 +19,7 @@
 import static org.junit.Assert.assertThrows;
 
 import com.google.common.collect.ImmutableList;
+import java.util.List;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -31,6 +32,10 @@ static KotlinDataBuilder builder() {
       return new AutoBuilder_AutoBuilderKotlinTest_KotlinDataBuilder();
     }
 
+    static KotlinDataBuilder builder(KotlinData kotlinData) {
+      return new AutoBuilder_AutoBuilderKotlinTest_KotlinDataBuilder(kotlinData);
+    }
+
     abstract KotlinDataBuilder setInt(int x);
 
     abstract KotlinDataBuilder setString(String x);
@@ -43,6 +48,11 @@ public void simpleKotlin() {
     KotlinData x = KotlinDataBuilder.builder().setInt(23).setString("skidoo").build();
     assertThat(x.getInt()).isEqualTo(23);
     assertThat(x.getString()).isEqualTo("skidoo");
+
+    KotlinData y = KotlinDataBuilder.builder(x).setString("chromosomes").build();
+    assertThat(y.getInt()).isEqualTo(23);
+    assertThat(y.getString()).isEqualTo("chromosomes");
+
     assertThrows(IllegalStateException.class, () -> KotlinDataBuilder.builder().build());
   }
 
@@ -240,4 +250,34 @@ public void kotlinSomeDefaults_missingRequired() {
     assertThat(e).hasMessageThat().contains("requiredInt");
     assertThat(e).hasMessageThat().contains("requiredString");
   }
+
+  @AutoBuilder(ofClass = KotlinDataWithList.class)
+  interface KotlinDataWithListBuilder {
+    static KotlinDataWithListBuilder builder() {
+      return new AutoBuilder_AutoBuilderKotlinTest_KotlinDataWithListBuilder();
+    }
+
+    static KotlinDataWithListBuilder builder(KotlinDataWithList kotlinData) {
+      return new AutoBuilder_AutoBuilderKotlinTest_KotlinDataWithListBuilder(kotlinData);
+    }
+
+    KotlinDataWithListBuilder list(List<? extends CharSequence> list);
+
+    KotlinDataWithListBuilder number(int number);
+
+    KotlinDataWithList build();
+  }
+
+  // The `getList()` method returns `List<CharSequence>` as seen from Java, but the `list` parameter
+  // to the constructor has type `List<? extends CharSequence>`.
+  @Test
+  public void kotlinWildcards() {
+    List<String> strings = ImmutableList.of("foo");
+    KotlinDataWithList x = KotlinDataWithListBuilder.builder().list(strings).number(17).build();
+    assertThat(x.getList()).isEqualTo(strings);
+    assertThat(x.getNumber()).isEqualTo(17);
+    KotlinDataWithList y = KotlinDataWithListBuilder.builder(x).number(23).build();
+    assertThat(y.getList()).isEqualTo(strings);
+    assertThat(y.getNumber()).isEqualTo(23);
+  }
 }

value/src/it/functional/src/test/java/com/google/auto/value/AutoBuilderTest.java

@@ -502,7 +502,7 @@ public void propertyBuilder() {
   }
 
   static <T> String concatList(ImmutableList<T> list) {
-    // We're avoiding streams for now so we compile this in Java 7 mode in CompileWithEclipseTest.
+    // We're avoiding streams for now since we compile this in Java 7 mode in CompileWithEclipseTest
     StringBuilder sb = new StringBuilder();
     for (T element : list) {
       sb.append(element);

value/src/it/functional/src/test/java/com/google/auto/value/KotlinData.kt

@@ -46,3 +46,7 @@ data class KotlinDataSomeDefaults(
   val optionalInt: Int = 23,
   val optionalString: String = "Skidoo"
 )
+
+// CharSequence is an interface so the parameter appears from Java as List<? extends CharSequence>,
+// but getList() appears as returning List<CharSequence>.
+data class KotlinDataWithList(val list: List<CharSequence>, val number: Int)

value/src/main/java/com/google/auto/value/processor/AutoBuilderProcessor.java

@@ -387,7 +387,7 @@ private ImmutableMap<String, String> propertyToGetterName(
       return ImmutableMap.of();
     }
     TypeElement type = MoreTypes.asTypeElement(builtType);
-    Map<String, ExecutableElement> noArgInstanceMethods =
+    Map<String, ExecutableElement> nameToMethod =
         MoreElements.getLocalAndInheritedMethods(type, typeUtils(), elementUtils()).stream()
             .filter(m -> m.getParameters().isEmpty())
             .filter(m -> !m.getModifiers().contains(Modifier.STATIC))
@@ -405,16 +405,18 @@ private ImmutableMap<String, String> propertyToGetterName(
                   String name = param.getSimpleName().toString();
                   // Parameter name is `bar`; we look for `bar()` and `getBar()` (or `getbar()` etc)
                   // in that order. If `bar` is boolean we also look for `isBar()`.
-                  ExecutableElement getter = noArgInstanceMethods.get(name);
+                  ExecutableElement getter = nameToMethod.get(name);
                   if (getter == null) {
-                    getter = noArgInstanceMethods.get("get" + name);
+                    getter = nameToMethod.get("get" + name);
                     if (getter == null && param.asType().getKind() == TypeKind.BOOLEAN) {
-                      getter = noArgInstanceMethods.get("is" + name);
+                      getter = nameToMethod.get("is" + name);
                     }
                   }
                   if (getter != null
+                      && !typeUtils().isAssignable(getter.getReturnType(), param.asType())
                       && !MoreTypes.equivalence()
                           .equivalent(getter.getReturnType(), param.asType())) {
+                    // TODO(b/268680785): we should not need to have two type checks here
                     getter = null;
                   }
                   return new SimpleEntry<>(name, getter);