Primitive array fields (e.g. `int[]`) generate invalid `toArray(new int[0])` in collection helper methods

[AndreasIgel]

Location

Generated builder code for fields with primitive array types like int[], double[], boolean[], etc.

Description

When a DTO has a primitive array field (e.g., int[] scores), the generated builder produces collection helper methods that call List<Integer>.toArray(new int[0]). This does not compile because toArray(T[]) requires an object array type (T must be a reference type), but int is a primitive type.

Generated code (broken)

public ComplexTypesBenchmarkBuilder scores(List<Integer> scores) {
 this.scores = changedValue(scores.toArray(new int[0]));
 return this;
}

public ComplexTypesBenchmarkBuilder scores(Consumer<ArrayListBuilder<Integer>> scoresBuilderConsumer) {
 ArrayListBuilder<Integer> builder = this.scores.isSet()
 ? new ArrayListBuilder<Integer>(java.util.List.of(this.scores.value()))
 : new ArrayListBuilder<Integer>();
 scoresBuilderConsumer.accept(builder);
 this.scores = changedValue(builder.build().toArray(new int[0]));
 return this;
}

Compilation errors

no suitable method found for toArray(int[])
 method Collection.<T>toArray(IntFunction<T[]>) is not applicable
 (cannot infer type-variable(s) T
 (argument mismatch; int[] cannot be converted to IntFunction<T[]>))
 method List.<T>toArray(T[]) is not applicable
 (inference variable T has incompatible bounds
 equality constraints: Integer
 lower bounds: int)

incompatible types: inference variable E has incompatible bounds
 equality constraints: Integer
 lower bounds: int[]

Reproduction

@SimpleBuilder
public class ComplexTypesBenchmark {

 private int[] scores;

 public int[] getScores() {
 return scores;
 }

 public void setScores(int[] scores) {
 this.scores = scores;
 }
}

Expected

The generated collection helper methods should produce compilable code for primitive array types.

Actual

The generated code uses toArray(new int[0]) which fails to compile because int is not a reference type and cannot be used as the type parameter T in toArray(T[]).