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feat(minifier): support remaining expressions for single use variable inlining #13280

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Merged
graphite-app merged 1 commit into from
Aug 24, 2025
Merged

feat(minifier): support remaining expressions for single use variable inlining #13280

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124 changes: 114 additions & 10 deletions crates/oxc_minifier/src/peephole/minimize_statements.rs
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1107,8 +1107,39 @@ impl<'a> PeepholeOptimizations {
return Some(changed);
}
}
Expression::AssignmentExpression(_assign_expr) => {
// TODO: requires implementing `MayHaveSideEffects` to `AssignmentTarget`
Expression::AssignmentExpression(assign_expr) => {
if assign_expr.left.may_have_side_effects(ctx) {
// Do not reorder past a side effect in an assignment target, as that may
// change the replacement value. For example, "fn()" may change "a" here:
// ```js
// let a = 1;
// foo[fn()] = a;
// ```
return Some(false);
}
if assign_expr.operator != AssignmentOperator::Assign && replacement_has_side_effect
{
// If this is a read-modify-write assignment and the replacement has side
// effects, don't reorder it past the assignment target. The assignment
// target is being read so it may be changed by the side effect. For
// example, "fn()" may change "foo" here:
// ```js
// let a = fn();
// foo += a;
// ```
return Some(false);
}
// If we get here then it should be safe to attempt to substitute the
// replacement past the left operand into the right operand.
if let Some(changed) = Self::substitute_single_use_symbol_in_expression(
&mut assign_expr.right,
search_for,
replacement,
replacement_has_side_effect,
ctx,
) {
return Some(changed);
}
}
Expression::LogicalExpression(logical_expr) => {
if let Some(changed) = Self::substitute_single_use_symbol_in_expression(
Expand All @@ -1130,8 +1161,16 @@ impl<'a> PeepholeOptimizations {
return Some(changed);
}
}
Expression::PrivateInExpression(_private_in_expr) => {
// TODO: implement
Expression::PrivateInExpression(private_in_expr) => {
if let Some(changed) = Self::substitute_single_use_symbol_in_expression(
&mut private_in_expr.right,
search_for,
replacement,
replacement_has_side_effect,
ctx,
) {
return Some(changed);
}
}
Expression::ConditionalExpression(cond_expr) => {
if let Some(changed) = Self::substitute_single_use_symbol_in_expression(
Expand Down Expand Up @@ -1203,8 +1242,16 @@ impl<'a> PeepholeOptimizations {
return Some(changed);
}
}
Expression::PrivateFieldExpression(_private_field_expr) => {
// TODO: implement
Expression::PrivateFieldExpression(private_field_expr) => {
if let Some(changed) = Self::substitute_single_use_symbol_in_expression(
&mut private_field_expr.object,
search_for,
replacement,
replacement_has_side_effect,
ctx,
) {
return Some(changed);
}
}
Expression::CallExpression(call_expr) => {
// Don't substitute something into a call target that could change "this"
Expand Down Expand Up @@ -1260,8 +1307,55 @@ impl<'a> PeepholeOptimizations {
}
}
}
Expression::NewExpression(_new_expr) => {
// TODO: implement
Expression::NewExpression(new_expr) => {
// Don't substitute something into a call target that could change "this"
if !((replacement.is_member_expression()
|| matches!(replacement, Expression::ChainExpression(_)))
&& new_expr.callee.is_identifier_reference())
{
if let Some(changed) = Self::substitute_single_use_symbol_in_expression(
&mut new_expr.callee,
search_for,
replacement,
replacement_has_side_effect,
ctx,
) {
return Some(changed);
}

for arg in &mut new_expr.arguments {
match arg {
Argument::SpreadElement(spread_elem) => {
if let Some(changed) =
Self::substitute_single_use_symbol_in_expression(
&mut spread_elem.argument,
search_for,
replacement,
replacement_has_side_effect,
ctx,
)
{
return Some(changed);
}
// spread element may have sideeffects
return Some(false);
}
match_expression!(Argument) => {
if let Some(changed) =
Self::substitute_single_use_symbol_in_expression(
arg.to_expression_mut(),
search_for,
replacement,
replacement_has_side_effect,
ctx,
)
{
return Some(changed);
}
}
}
}
}
}
Expression::ArrayExpression(array_expr) => {
for elem in &mut array_expr.elements {
Expand Down Expand Up @@ -1391,8 +1485,18 @@ impl<'a> PeepholeOptimizations {
chain_expr.expression = expr.into_chain_element().expect("should be chain element");
return changed;
}
Expression::SequenceExpression(_sequence_expr) => {
// TODO: implement
Expression::SequenceExpression(sequence_expr) => {
for expr in &mut sequence_expr.expressions {
if let Some(changed) = Self::substitute_single_use_symbol_in_expression(
expr,
search_for,
replacement,
replacement_has_side_effect,
ctx,
) {
return Some(changed);
}
}
}
_ => {}
}
Expand Down
96 changes: 48 additions & 48 deletions crates/oxc_minifier/tests/peephole/esbuild.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1793,54 +1793,54 @@ fn test_inline_single_use_variable() {
"var foo; function wrapper(arg0, arg1) { let x = foo; x ||= 2}",
"var foo; function wrapper(arg0, arg1) { let x = foo; x ||= 2;}",
);
// test(
// "var foo; function wrapper(arg0, arg1) { let x = foo; arg0 = x}",
// "var foo; function wrapper(arg0, arg1) { arg0 = foo;}",
// );
// test(
// "var foo; function wrapper(arg0, arg1) { let x = foo; arg0 += x}",
// "var foo; function wrapper(arg0, arg1) { arg0 += foo;}",
// );
// test(
// "var foo; function wrapper(arg0, arg1) { let x = foo; arg0 ||= x}",
// "var foo; function wrapper(arg0, arg1) { arg0 ||= foo;}",
// );
// test(
// "function wrapper(arg0, arg1) { let x = fn(); arg0 = x}",
// "function wrapper(arg0, arg1) { arg0 = fn();}",
// );
// test(
// "function wrapper(arg0, arg1) { let x = fn(); arg0 += x}",
// "function wrapper(arg0, arg1) { let x = fn(); arg0 += x;}",
// );
// test(
// "function wrapper(arg0, arg1) { let x = fn(); arg0 ||= x}",
// "function wrapper(arg0, arg1) { let x = fn(); arg0 ||= x;}",
// );
// test(
// "var foo; function wrapper(arg0, arg1) { let x = foo; y.z = x}",
// "var foo; function wrapper(arg0, arg1) { let x = foo; y.z = x;}",
// );
// test(
// "var foo; function wrapper(arg0, arg1) { let x = foo; y.z += x}",
// "var foo; function wrapper(arg0, arg1) { let x = foo; y.z += x;}",
// );
// test(
// "var foo; function wrapper(arg0, arg1) { let x = foo; y.z ||= x}",
// "var foo; function wrapper(arg0, arg1) { let x = foo; y.z ||= x;}",
// );
// test(
// "function wrapper(arg0, arg1) { let x = fn(); y.z = x}",
// "function wrapper(arg0, arg1) { let x = fn(); y.z = x;}",
// );
// test(
// "function wrapper(arg0, arg1) { let x = fn(); y.z += x}",
// "function wrapper(arg0, arg1) { let x = fn(); y.z += x;}",
// );
// test(
// "function wrapper(arg0, arg1) { let x = fn(); y.z ||= x}",
// "function wrapper(arg0, arg1) { let x = fn(); y.z ||= x;}",
// );
test(
"var foo; function wrapper(arg0, arg1) { let x = foo; arg0 = x}",
"var foo; function wrapper(arg0, arg1) { arg0 = foo;}",
);
test(
"var foo; function wrapper(arg0, arg1) { let x = foo; arg0 += x}",
"var foo; function wrapper(arg0, arg1) { arg0 += foo;}",
);
test(
"var foo; function wrapper(arg0, arg1) { let x = foo; arg0 ||= x}",
"var foo; function wrapper(arg0, arg1) { arg0 ||= foo;}",
);
test(
"function wrapper(arg0, arg1) { let x = fn(); arg0 = x}",
"function wrapper(arg0, arg1) { arg0 = fn();}",
);
test(
"function wrapper(arg0, arg1) { let x = fn(); arg0 += x}",
"function wrapper(arg0, arg1) { let x = fn(); arg0 += x;}",
);
test(
"function wrapper(arg0, arg1) { let x = fn(); arg0 ||= x}",
"function wrapper(arg0, arg1) { let x = fn(); arg0 ||= x;}",
);
test(
"var foo; function wrapper(arg0, arg1) { let x = foo; y.z = x}",
"var foo; function wrapper(arg0, arg1) { let x = foo; y.z = x;}",
);
test(
"var foo; function wrapper(arg0, arg1) { let x = foo; y.z += x}",
"var foo; function wrapper(arg0, arg1) { let x = foo; y.z += x;}",
);
test(
"var foo; function wrapper(arg0, arg1) { let x = foo; y.z ||= x}",
"var foo; function wrapper(arg0, arg1) { let x = foo; y.z ||= x;}",
);
test(
"function wrapper(arg0, arg1) { let x = fn(); y.z = x}",
"function wrapper(arg0, arg1) { let x = fn(); y.z = x;}",
);
test(
"function wrapper(arg0, arg1) { let x = fn(); y.z += x}",
"function wrapper(arg0, arg1) { let x = fn(); y.z += x;}",
);
test(
"function wrapper(arg0, arg1) { let x = fn(); y.z ||= x}",
"function wrapper(arg0, arg1) { let x = fn(); y.z ||= x;}",
);
test(
"function wrapper(arg0, arg1) { let x = arg0; return x ? y : z;}",
"function wrapper(arg0, arg1) { return arg0 ? y : z;}",
Expand Down
116 changes: 116 additions & 0 deletions crates/oxc_minifier/tests/peephole/inline_single_use_variable.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,122 @@ use super::{test, test_same};
fn test_inline_single_use_variable() {
test_same("function wrapper(arg0, arg1) {using x = foo; return x}");
test_same("async function wrapper(arg0, arg1) { await using x = foo; return x}");

test(
"
class Foo {
#foo;
static {
let v = this;
let r = #foo in v;
console.log(r);
}
}
",
"
class Foo {
#foo;
static {
let r = #foo in this;
console.log(r);
}
}
",
);
test(
"
class Foo {
#foo;
static {
let x = foo;
this.#foo = x;
}
}
",
"
class Foo {
#foo;
static {
this.#foo = foo;
}
}
",
);
test(
"
class Foo {
#foo;
static {
let x = this;
let y = x.#foo;
console.log(y);
}
}
",
"
class Foo {
#foo;
static {
let y = this.#foo;
console.log(y);
}
}
",
);
test(
"function wrapper(arg0, arg1) { let x = arg0; return new arg1(...x);}",
"function wrapper(arg0, arg1) { return new arg1(...arg0);}",
);
test(
"function wrapper(arg0, arg1) { let x = arg0; return new arg1(x, ...arg1);}",
"function wrapper(arg0, arg1) { return new arg1(arg0, ...arg1);}",
);
test_same("function wrapper(arg0, arg1) { let x = arg0; return new arg1(...arg1, x);}");
test(
"function wrapper(arg0, arg1) { let x = arg0; new arg1(x);}",
"function wrapper(arg0, arg1) { new arg1(arg0);}",
);
test(
"function wrapper(arg0, arg1) { let x = arg0; new x()}",
"function wrapper(arg0, arg1) { new arg0();}",
);
test(
"function wrapper(arg0, arg1) { let x = arg0; new (0, x)()}",
"function wrapper(arg0, arg1) { new arg0();}",
);
test(
"function wrapper(arg0, arg1) { let x = arg0.foo; new x.bar()}",
"function wrapper(arg0, arg1) { new arg0.foo.bar();}",
);
test(
"function wrapper(arg0, arg1) { let x = arg0.foo; new x[bar]()}",
"function wrapper(arg0, arg1) { new arg0.foo[bar]();}",
);
test_same("function wrapper(arg0, arg1) { let x = arg0.foo; new x()}");
test_same("function wrapper(arg0, arg1) { let x = arg0[foo]; new x()}");
test_same("function wrapper(arg0, arg1) { let x = arg0?.foo; new x()}");
test_same("function wrapper(arg0, arg1) { let x = arg0?.[foo]; new x()}");
test(
"function wrapper(arg0, arg1) { let x = arg0.foo; new (0, x)()}",
"function wrapper(arg0, arg1) { let x = arg0.foo; new x();}",
);
test(
"function wrapper(arg0, arg1) { let x = arg0[foo]; new (0, x)()}",
"function wrapper(arg0, arg1) { let x = arg0[foo]; new x();}",
);
test(
"function wrapper(arg0, arg1) { let x = arg0?.foo; new (0, x)()}",
"function wrapper(arg0, arg1) { let x = arg0?.foo; new x();}",
);
test(
"function wrapper(arg0, arg1) { let x = arg0?.[foo]; new (0, x)()}",
"function wrapper(arg0, arg1) { let x = arg0?.[foo]; new x();}",
);
test(
"function wrapper(arg0, arg1) { let x = arg0; return (x(), 1);}",
"function wrapper(arg0, arg1) { return (arg0(), 1);}",
);
test_same("function wrapper(arg0, arg1) { let x = arg0; return (foo(), x(), 1);}");
}

#[test]
Expand Down
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