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Fixes related to captured types and inference #1655

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Merged
msridhar merged 1 commit into from
Jul 26, 2026
+70 −0
Merged

Fixes related to captured types and inference #1655

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6 changes: 6 additions & 0 deletions nullaway/src/main/java/com/uber/nullaway/generics/ConstraintSolverImpl.java
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Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@
import com.sun.tools.javac.code.BoundKind;
import com.sun.tools.javac.code.Symbol;
import com.sun.tools.javac.code.Type;
import com.sun.tools.javac.code.Type.CapturedType;
import com.sun.tools.javac.code.Type.ClassType;
import com.sun.tools.javac.code.Type.TypeVar;
import com.sun.tools.javac.code.Type.WildcardType;
Expand Down Expand Up @@ -155,6 +156,11 @@ class AddSubtypeConstraintsVisitor extends Types.DefaultTypeVisitor<@Nullable Vo
return visitType(subtype, supertype);
}

@Override
public @Nullable Void visitCapturedType(CapturedType subtype, Type supertype) {
return visitTypeVar(subtype, supertype);
}

@Override
public @Nullable Void visitWildcardType(WildcardType subtype, Type supertype) {
if (config.handleWildcardGenerics()) {
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5 changes: 5 additions & 0 deletions nullaway/src/main/java/com/uber/nullaway/generics/TypeSubstitutionUtils.java
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Expand Up @@ -339,6 +339,11 @@ public Type visitTypeVar(Type.TypeVar t, Type other) {
return updateDirectNullabilityAnnotationsForType(t, other);
}

@Override
public Type visitCapturedType(Type.CapturedType t, Type other) {
return updateDirectNullabilityAnnotationsForType(t, other);
}

@Override
public Type visitForAll(Type.ForAll t, Type other) {
Type methodType = t.qtype;
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59 changes: 59 additions & 0 deletions nullaway/src/test/java/com/uber/nullaway/jspecify/GenericLambdaTests.java
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Original file line number Diff line number Diff line change
Expand Up @@ -180,6 +180,65 @@ class Bar {
.doTest();
}

@Test
public void varAndGenericInference() {
makeHelper()
.addSourceLines(
"Test.java",
"""
import java.util.concurrent.CompletableFuture;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;
@NullMarked
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coderabbitai[bot] marked this conversation as resolved.
final class Test {
static void reproduce() {
var future = future();
run(() -> future.join());
}
private static CompletableFuture<?> future() {
return new CompletableFuture<>();
}
private static <T extends @Nullable Object> T run(Action<T> action) {
return action.run();
}
private interface Action<T extends @Nullable Object> {
T run();
}
}
""")
.doTest();
}
Comment on lines +183 to +210

@coderabbitai coderabbitai Bot Jul 26, 2026

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📐 Maintainability & Code Quality | 🟠 Major | ⚡ Quick win

Add Javadoc for the new non-trivial test methods.

  • nullaway/src/test/java/com/uber/nullaway/jspecify/GenericLambdaTests.java#L183-L210: Document the nullable-upper-bound inference scenario.
  • nullaway/src/test/java/com/uber/nullaway/jspecify/GenericLambdaTests.java#L212-L240: Document the conflicting non-null upper-bound diagnostic scenario.

As per coding guidelines, “Add Javadoc to every non-trivial method, including private methods.”

📍 Affects 1 file
  • nullaway/src/test/java/com/uber/nullaway/jspecify/GenericLambdaTests.java#L183-L210 (this comment)
  • nullaway/src/test/java/com/uber/nullaway/jspecify/GenericLambdaTests.java#L212-L240
🤖 Prompt for AI Agents 
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@nullaway/src/test/java/com/uber/nullaway/jspecify/GenericLambdaTests.java`
around lines 183 - 210, Add Javadoc describing the nullable-upper-bound
inference scenario for varAndGenericInference in
nullaway/src/test/java/com/uber/nullaway/jspecify/GenericLambdaTests.java lines
183-210. Also add Javadoc describing the conflicting non-null upper-bound
diagnostic scenario for the test method in lines 212-240; no other changes are
needed.

Source: Coding guidelines


@Test
public void varAndGenericInferenceWithNonNullUpperBound() {
makeHelper()
.addSourceLines(
"Test.java",
"""
import java.util.concurrent.CompletableFuture;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.NonNull;
@NullMarked
final class Test {
static void reproduce() {
var future = future();
// BUG: Diagnostic contains: inference failure: type variable T constrained to be both @NonNull and @Nullable
run(() -> future.join());
}
private static CompletableFuture<?> future() {
return new CompletableFuture<>();
}
private static <T> T run(Action<T> action) {
return action.run();
}
private interface Action<T> {
T run();
}
}
""")
.doTest();
}

private CompilationTestHelper makeHelper() {
return makeTestHelperWithArgs(
JSpecifyJavacConfig.withJSpecifyModeArgs(
Expand Down
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