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fix(printer): don't wrap broken when-guards in parentheses #1018

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fix(printer): don't wrap broken when-guards in parentheses #1018

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dde248b
fix(printer): don't wrap broken when-guards in parentheses
Aug 8, 2026
3982298
fix(printer): don't wrap broken when-guards in parentheses
Aug 8, 2026
728b405
fix(printer): don't wrap broken when-guards in parentheses
Aug 8, 2026
bcdb1e7
fix(printer): don't wrap broken when-guards in parentheses
Aug 8, 2026
4616440
fix(printer): don't wrap broken when-guards in parentheses
Aug 8, 2026
736f0ee
test: update when-guard snapshots for #1001
braxtonzhangio Aug 13, 2026
920ad36
test: update when-guard snapshots for #1001
braxtonzhangio Aug 13, 2026
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15 changes: 6 additions & 9 deletions src/printers/expressions.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -705,15 +705,12 @@ export default {
},

guard(path, print) {
return [
"when ",
group([
ifBreak("("),
indent([softline, path.call(print, "namedChildren", 0)]),
softline,
ifBreak(")")
])
];
// Break after `when` without wrapping the guard expression in parentheses
// (issue #1001). A space is used when the group fits on one line.
return group([
"when",
indent([line, path.call(print, "namedChildren", 0)])
]);
}
} satisfies Partial<NamedNodePrinters>;

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5 changes: 2 additions & 3 deletions test/unit-test/expressions/_output.java
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Expand Up @@ -292,9 +292,8 @@ void parenthesesWithLeadingAndTrailingBreak() {
)[ffffffffff];

switch (a) {
case Bbbbbbbbbb bbbbbbbbbb when (
cccccccccc && dddddddddd && eeeeeeeeee
) -> ffffffffff;
case Bbbbbbbbbb bbbbbbbbbb when
cccccccccc && dddddddddd && eeeeeeeeee -> ffffffffff;
}

return (
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35 changes: 14 additions & 21 deletions test/unit-test/pattern-matching/_output.java
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Expand Up @@ -33,32 +33,27 @@ void test(Buyer other) {
case Buyer b when this.bestPrice > b.bestPrice -> {
return true;
}
case Buyer titi when (
this.bestPriceaaaaaaaazzzzzaaaaaaaaaq > b.bestPrice
) -> true;
case Buyer titi when (
this.bestPriceaaaaaazzzaaaaaaaaaq > b.bestPrice
) -> true;
case Buyer b when (
case Buyer titi when
this.bestPriceaaaaaaaazzzzzaaaaaaaaaq > b.bestPrice -> true;
case Buyer titi when
this.bestPriceaaaaaazzzaaaaaaaaaq > b.bestPrice -> true;
case Buyer b when
this.bestPrice > b.bestPrice &&
this.bestPrice > b.bestPrice &&
this.bestPrice > b.bestPrice &&
this.bestPrice > b.bestPrice
) -> true;
case Buyer b when (
this.bestPrice > b.bestPrice -> true;
case Buyer b when
this.bestPrice > b.bestPrice &&
this.bestPrice > b.bestPrice &&
this.bestPrice > b.bestPrice &&
this.bestPrice > b.bestPrice
) -> {
this.bestPrice > b.bestPrice -> {
return true;
}
case Buyer b when (
case Buyer b when
this.bestPrice > b.bestPrice &&
this.bestPrice > b.bestPrice &&
this.bestPrice > b.bestPrice &&
this.bestPrice > b.bestPrice
) -> {
this.bestPrice > b.bestPrice -> {
return true;
}
default -> false;
Expand Down Expand Up @@ -94,17 +89,15 @@ case MyRecord(
case MyRecord(
LongTypeName longVariableName,
LongTypeName longVariableName
) when (
) when
this.longVariableName > longVariableName &&
this.longVariableName > longVariableName
) -> 0;
this.longVariableName > longVariableName -> 0;
case MyRecord(
LongTypeName longVariableName,
LongTypeName longVariableName
) when (
) when
this.longVariableName > longVariableName &&
this.longVariableName > longVariableName
) -> longMethodName(
this.longVariableName > longVariableName -> longMethodName(
longVariableName,
longVariableName,
longVariableName,
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3 changes: 3 additions & 0 deletions test/unit-test/switch-when-guard-parens/.prettierrc.json
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Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
{
"printWidth": 40
}
8 changes: 8 additions & 0 deletions test/unit-test/switch-when-guard-parens/_input.java
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@@ -0,0 +1,8 @@
class T {
boolean f(Object x) {
return switch (x) {
case A a when a.equals(a.aaaa) -> true;
default -> false;
};
}
}
9 changes: 9 additions & 0 deletions test/unit-test/switch-when-guard-parens/_output.java
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Original file line number Diff line number Diff line change
@@ -0,0 +1,9 @@
class T {
boolean f(Object x) {
return switch (x) {
case A a when
a.equals(a.aaaa) -> true;
default -> false;
};
}
}
5 changes: 2 additions & 3 deletions test/unit-test/unnamed-variables-and-patterns/_output.java
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Expand Up @@ -120,10 +120,9 @@ int wrappingMultipleSwitchPatterns() {
case
MyRecord(LongTypeName longVariableName, LongTypeName longVariableName),
MyRecord(LongTypeName longVariableName, LongTypeName longVariableName)
when (
when
this.longVariableName > longVariableName &&
this.longVariableName > longVariableName
) -> longMethodName(
this.longVariableName > longVariableName -> longMethodName(
longVariableName,
longVariableName,
longVariableName,
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