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Fix NPE for new arrays with initializers in ReplaceCollectionToArrayArgWithEmptyArray #704

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Merged
merged 3 commits into from
Aug 8, 2025
Merged

Fix NPE for new arrays with initializers in ReplaceCollectionToArrayArgWithEmptyArray #704

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ea49c55
Handle braces initializer syntax for new arrays
greg-at-moderne Aug 8, 2025
2e3440b
Handle the case of non-empty init of new array
greg-at-moderne Aug 8, 2025
15ef9cd
Formatting suggestion
greg-at-moderne Aug 8, 2025
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14 changes: 12 additions & 2 deletions src/main/java/org/openrewrite/staticanalysis/ReplaceCollectionToArrayArgWithEmptyArray.java
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Original file line number Diff line number Diff line change
Expand Up @@ -64,21 +64,31 @@ private static class ReplaceCollectionToArrayArgWithEmptyArrayVisitor<P> extends

@Override
public J.NewArray visitNewArray(J.NewArray newArray, P p) {
if (COLLECTION_TO_ARRAY.advanced().isFirstArgument(getCursor()) && newArray.getDimensions().size() == 1) {
boolean isInitializerEmpty = newArray.getInitializer() == null
|| (newArray.getInitializer().size() == 1 && newArray.getInitializer().get(0) instanceof J.Empty);
if (COLLECTION_TO_ARRAY.advanced().isFirstArgument(getCursor()) && isInitializerEmpty) {
J.NewArray newArrayZero = newArray.withDimensions(ListUtils.mapFirst(newArray.getDimensions(), d -> {
if (d.getIndex() instanceof J.Literal && Integer.valueOf(0).equals(((J.Literal) d.getIndex()).getValue())) {
return d;
}
JavaType.Primitive type;
if (d.getIndex() instanceof J.Empty) {
type = JavaType.Primitive.Int;
} else {
type = (JavaType.Primitive) requireNonNull(d.getIndex().getType());
}

return d.withIndex(new J.Literal(
Tree.randomId(),
Space.EMPTY,
Markers.EMPTY,
0,
"0",
emptyList(),
(JavaType.Primitive) requireNonNull(d.getIndex().getType())
type
));
}));
newArrayZero = newArrayZero.withInitializer(null);
return maybeAutoFormat(newArray, newArrayZero, p);
}
return super.visitNewArray(newArray, p);
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45 changes: 45 additions & 0 deletions ...st/java/org/openrewrite/staticanalysis/ReplaceCollectionToArrayArgWithEmptyArrayTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -83,4 +83,49 @@ void test(Collection<Integer> args){
)
);
}

@Test
void replaceEmptyArrayInitializerWithZero() {
rewriteRun(
//language=java
java(
"""
import java.util.Collection;

class A {
void test(Collection<Integer> args){
Integer[] array = args.toArray(new Integer[]{});
}
}
""",
"""
import java.util.Collection;

class A {
void test(Collection<Integer> args){
Integer[] array = args.toArray(new Integer[0]);
}
}
"""
)
);
}

@Test
void dontChangeNonEmptyInitializer() {
rewriteRun(
//language=java
java(
"""
import java.util.Collection;

class A {
void test(Collection<Integer> args){
Integer[] array = args.toArray(new Integer[]{1, 2, 3});
}
}
"""
)
);
}
}