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Merged
timtebeek merged 3 commits into from
Aug 11, 2026
Merged

SimplifyBooleanExpressionVisitor: correctly negate a nested ternary #8456

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a6d524f
SimplifyBooleanExpressionVisitor: correctly negate a nested ternary
martinfrancois Aug 11, 2026
fcebfc1
Keep parentheses when a negation becomes a ternary
timtebeek Aug 11, 2026
241a5d6
Reuse ParenthesizeVisitor.maybeParenthesize for the negated ternary
timtebeek Aug 11, 2026
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26 changes: 26 additions & 0 deletions rewrite-java-test/src/test/java/org/openrewrite/java/ParenthesizeVisitorTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -174,6 +174,32 @@ void method() {
);
}

@Test
void ternaryAsConditionOrCastOperand() {
rewriteRun(
java(
"""
class Test {
void method(boolean x, boolean y, boolean z) {
boolean a = (x ? y : z) ? y : z;
Object b = (Object) (x ? y : z);
boolean c = (x ? y : z);
}
}
""",
"""
class Test {
void method(boolean x, boolean y, boolean z) {
boolean a = (x ? y : z) ? y : z;
Object b = (Object) (x ? y : z);
boolean c = x ? y : z;
}
}
"""
)
);
}

@Test
void instanceofExpressions() {
rewriteRun(
Expand Down
102 changes: 102 additions & 0 deletions ...test/src/test/java/org/openrewrite/java/cleanup/SimplifyBooleanExpressionVisitorTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -592,6 +592,108 @@ boolean m4(boolean a, boolean b, boolean c) {
);
}

@Test
void nestedTernaryNegation() {
rewriteRun(
java(
"""
public class A {
boolean m1(boolean a, boolean b, boolean x, boolean y, boolean z) {
return !(a ? b ? x : y : z);
}
boolean m2(boolean a, boolean b, boolean x, boolean y, boolean z) {
return !(a ? x : b ? y : z);
}
boolean m3(boolean a, boolean b, boolean x, boolean y, boolean z) {
return !(a ? !b ? x : y : z);
}
boolean m4(boolean a, boolean b, boolean x, boolean y, boolean z) {
return a ? b ? x : y : z;
}
}
""",
"""
public class A {
boolean m1(boolean a, boolean b, boolean x, boolean y, boolean z) {
return a ? b ? !x : !y : !z;
}
boolean m2(boolean a, boolean b, boolean x, boolean y, boolean z) {
return a ? !x : b ? !y : !z;
}
boolean m3(boolean a, boolean b, boolean x, boolean y, boolean z) {
return a ? b ? !y : !x : !z;
}
boolean m4(boolean a, boolean b, boolean x, boolean y, boolean z) {
return a ? b ? x : y : z;
}
}
"""
)
);
}

@Test
void negatedTernaryBranchWrappedInParentheses() {
rewriteRun(
java(
"""
public class A {
boolean m1(boolean a, Object o, boolean c) {
return !(a ? o instanceof String : c);
}
}
""",
"""
public class A {
boolean m1(boolean a, Object o, boolean c) {
return a ? !(o instanceof String) : !c;
}
}
"""
)
);
}

@Test
void negatedTernaryAsOperandKeepsParentheses() {
rewriteRun(
java(
"""
public class A {
boolean m1(boolean a, boolean b, boolean c, boolean d) {
return !(a ? b : c) && d;
}
boolean m2(boolean a, boolean b, boolean c, boolean d) {
return !(a ? b : c) ? c : d;
}
boolean m3(boolean a, boolean b, boolean c, boolean d) {
return d ? !(a ? b : c) : d;
}
boolean m4(boolean a, boolean b, boolean c) {
return !!(a ? b : c);
}
}
""",
"""
public class A {
boolean m1(boolean a, boolean b, boolean c, boolean d) {
return (a ? !b : !c) && d;
}
boolean m2(boolean a, boolean b, boolean c, boolean d) {
return (a ? !b : !c) ? c : d;
}
boolean m3(boolean a, boolean b, boolean c, boolean d) {
return d ? a ? !b : !c : d;
}
boolean m4(boolean a, boolean b, boolean c) {
return a ? b : c;
}
}
"""
)
);
}

@Test
void differentFieldAccesses() {
rewriteRun(
Expand Down
7 changes: 6 additions & 1 deletion rewrite-java/src/main/java/org/openrewrite/java/ParenthesizeVisitor.java
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Original file line number Diff line number Diff line change
Expand Up @@ -269,7 +269,12 @@ public J visitTernary(J.Ternary ternary, P p) {
if (needsParentheses(t, parent.getValue())) {
return parenthesize(t);
} else if (parent.getValue() instanceof J.Binary ||
parent.getValue() instanceof J.InstanceOf) {
parent.getValue() instanceof J.InstanceOf ||
parent.getValue() instanceof J.TypeCast) {
return parenthesize(t);
} else if (parent.getValue() instanceof J.Ternary &&
t.isScope(((J.Ternary) parent.getValue()).getCondition())) {
// `a ? b : c ? d : e` groups as `a ? b : (c ? d : e)`, so a ternary condition needs parentheses
return parenthesize(t);
}

Expand Down
22 changes: 12 additions & 10 deletions ...ite-java/src/main/java/org/openrewrite/java/cleanup/SimplifyBooleanExpressionVisitor.java
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Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,7 @@
import org.openrewrite.Tree;
import org.openrewrite.java.JavaVisitor;
import org.openrewrite.java.MethodMatcher;
import org.openrewrite.java.ParenthesizeVisitor;
import org.openrewrite.java.search.SemanticallyEqual;
import org.openrewrite.java.tree.*;
import org.openrewrite.marker.Markers;
Expand Down Expand Up @@ -146,6 +147,9 @@ public J visitUnary(J.Unary unary, ExecutionContext ctx) {

if (asUnary.getOperator() == J.Unary.Type.Not) {
j = unpackExpression(asUnary.getExpression(), asUnary);
if (j instanceof J.Ternary) {
j = ParenthesizeVisitor.maybeParenthesize((Expression) j, getCursor());
}
}
if (asUnary != j) {
j = j.withPrefix(asUnary.getPrefix());
Expand Down Expand Up @@ -232,15 +236,13 @@ private Expression maybeNegate(Expression expr) {
} else if (expr instanceof J.Unary && ((J.Unary) expr).getOperator() == J.Unary.Type.Not) {
return ((J.Unary) expr).getExpression().withPrefix(expr.getPrefix());
} else if (expr instanceof J.Ternary) {
// The negation of `c ? t : f` is `c ? !t : !f`. Flipping the condition and swapping the
// branches instead would preserve the ternary's value rather than negate it.
J.Ternary ternary = (J.Ternary) expr;
Expression negatedCondition = maybeNegate(ternary.getCondition());
if (negatedCondition != ternary.getCondition()) {
return ternary
.withCondition(negatedCondition)
.withTruePart(ternary.getFalsePart())
.withFalsePart(ternary.getTruePart())
.withPrefix(expr.getPrefix());
}
return ternary
.withTruePart(maybeNegate(ternary.getTruePart()))
.withFalsePart(maybeNegate(ternary.getFalsePart()))
.withPrefix(expr.getPrefix());
} else if (isLiteralTrue(expr)) {
return ((J.Literal) expr).withValue(false).withValueSource("false");
} else if (isLiteralFalse(expr)) {
Expand Down Expand Up @@ -416,9 +418,9 @@ private static J.Unary not(Expression sideRetained) {
!(sideRetained instanceof J.Parentheses) &&
!(sideRetained instanceof J.Unary)) {
sideRetained = new J.Parentheses<>(Tree.randomId(),
Space.EMPTY,
sideRetained.getPrefix(),
Markers.EMPTY,
JRightPadded.build(sideRetained));
JRightPadded.build(sideRetained.withPrefix(Space.EMPTY)));
}
return new J.Unary(Tree.randomId(),
sideRetained.getPrefix(),
Expand Down
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