Skip to content

feat(minifier): compress a = a + b to a += b #8314

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
graphite-app merged 1 commit into from
Jan 7, 2025
Merged

feat(minifier): compress a = a + b to a += b #8314

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
86 changes: 84 additions & 2 deletions crates/oxc_minifier/src/ast_passes/peephole_substitute_alternate_syntax.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -140,14 +140,19 @@ impl<'a> Traverse<'a> for PeepholeSubstituteAlternateSyntax {
Self::swap_binary_expressions(e);
self.try_compress_type_of_equal_string(e);
}
Expression::AssignmentExpression(e) => {
self.try_compress_normal_assignment_to_combined_assignment(e, ctx);
}
_ => {}
}

// Fold
if let Some(folded_expr) = match expr {
Expression::Identifier(ident) => self.try_compress_undefined(ident, ctx),
Expression::BooleanLiteral(_) => self.try_compress_boolean(expr, ctx),
Expression::AssignmentExpression(e) => Self::try_compress_assignment_expression(e, ctx),
Expression::AssignmentExpression(e) => {
Self::try_compress_assignment_to_update_expression(e, ctx)
}
Expression::LogicalExpression(e) => Self::try_compress_is_null_or_undefined(e, ctx),
Expression::NewExpression(e) => Self::try_fold_new_expression(e, ctx),
Expression::TemplateLiteral(t) => Self::try_fold_template_literal(t, ctx),
Expand Down Expand Up @@ -525,7 +530,32 @@ impl<'a, 'b> PeepholeSubstituteAlternateSyntax {
}
}

fn try_compress_assignment_expression(
/// Compress `a = a + b` to `a += b`
fn try_compress_normal_assignment_to_combined_assignment(
&mut self,
expr: &mut AssignmentExpression<'a>,
ctx: Ctx<'a, 'b>,
) {
if !matches!(expr.operator, AssignmentOperator::Assign) {
return;
}
let AssignmentTarget::AssignmentTargetIdentifier(write_id_ref) = &mut expr.left else {
return;
};

let Expression::BinaryExpression(binary_expr) = &mut expr.right else { return };
let Some(new_op) = binary_expr.operator.to_assignment_operator() else { return };
let Expression::Identifier(read_id_ref) = &mut binary_expr.left else { return };
if write_id_ref.name != read_id_ref.name {
return;
}

expr.operator = new_op;
expr.right = ctx.ast.move_expression(&mut binary_expr.right);
self.changed = true;
}

fn try_compress_assignment_to_update_expression(
expr: &mut AssignmentExpression<'a>,
ctx: Ctx<'a, 'b>,
) -> Option<Expression<'a>> {
Expand Down Expand Up @@ -1020,6 +1050,58 @@ mod test {
test("x !== false", "x !== !1");
}

/// Based on https://github.com/terser/terser/blob/58ba5c163fa1684f2a63c7bc19b7ebcf85b74f73/test/compress/assignment.js
#[test]
fn test_fold_normal_assignment_to_combined_assignment() {
test("x = x + 3", "x += 3");
test("x = x - 3", "x -= 3");
test("x = x / 3", "x /= 3");
test("x = x * 3", "x *= 3");
test("x = x >> 3", "x >>= 3");
test("x = x << 3", "x <<= 3");
test("x = x >>> 3", "x >>>= 3");
test("x = x | 3", "x |= 3");
test("x = x ^ 3", "x ^= 3");
test("x = x % 3", "x %= 3");
test("x = x & 3", "x &= 3");
test("x = x + g()", "x += g()");
test("x = x - g()", "x -= g()");
test("x = x / g()", "x /= g()");
test("x = x * g()", "x *= g()");
test("x = x >> g()", "x >>= g()");
test("x = x << g()", "x <<= g()");
test("x = x >>> g()", "x >>>= g()");
test("x = x | g()", "x |= g()");
test("x = x ^ g()", "x ^= g()");
test("x = x % g()", "x %= g()");
test("x = x & g()", "x &= g()");

test_same("x = 3 + x");
test_same("x = 3 - x");
test_same("x = 3 / x");
test_same("x = 3 * x");
test_same("x = 3 >> x");
test_same("x = 3 << x");
test_same("x = 3 >>> x");
test_same("x = 3 | x");
test_same("x = 3 ^ x");
test_same("x = 3 % x");
test_same("x = 3 & x");
test_same("x = g() + x");
test_same("x = g() - x");
test_same("x = g() / x");
test_same("x = g() * x");
test_same("x = g() >> x");
test_same("x = g() << x");
test_same("x = g() >>> x");
test_same("x = g() | x");
test_same("x = g() ^ x");
test_same("x = g() % x");
test_same("x = g() & x");

test_same("x = (x -= 2) ^ x");
}

#[test]
fn test_fold_subtraction_assignment() {
test("x -= 1", "--x");
Expand Down
19 changes: 19 additions & 0 deletions crates/oxc_syntax/src/operator.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -313,6 +313,25 @@ impl BinaryOperator {
}
}

/// Get [`AssignmentOperator`] corresponding to this [`BinaryOperator`].
pub fn to_assignment_operator(self) -> Option<AssignmentOperator> {
match self {
Self::Addition => Some(AssignmentOperator::Addition),
Self::Subtraction => Some(AssignmentOperator::Subtraction),
Self::Multiplication => Some(AssignmentOperator::Multiplication),
Self::Division => Some(AssignmentOperator::Division),
Self::Remainder => Some(AssignmentOperator::Remainder),
Self::Exponential => Some(AssignmentOperator::Exponential),
Self::ShiftLeft => Some(AssignmentOperator::ShiftLeft),
Self::ShiftRight => Some(AssignmentOperator::ShiftRight),
Self::ShiftRightZeroFill => Some(AssignmentOperator::ShiftRightZeroFill),
Self::BitwiseOR => Some(AssignmentOperator::BitwiseOR),
Self::BitwiseXOR => Some(AssignmentOperator::BitwiseXOR),
Self::BitwiseAnd => Some(AssignmentOperator::BitwiseAnd),
_ => None,
}
}

/// The string representation of this operator as it appears in source code.
pub fn as_str(&self) -> &'static str {
match self {
Expand Down
8 changes: 4 additions & 4 deletions tasks/minsize/minsize.snap
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,9 +3,9 @@ Original | minified | minified | gzip | gzip | Fixture
-------------------------------------------------------------------------------------
72.14 kB | 23.68 kB | 23.70 kB | 8.61 kB | 8.54 kB | react.development.js

173.90 kB | 59.79 kB | 59.82 kB | 19.42 kB | 19.33 kB | moment.js
173.90 kB | 59.78 kB | 59.82 kB | 19.42 kB | 19.33 kB | moment.js

287.63 kB | 90.06 kB | 90.07 kB | 32.07 kB | 31.95 kB | jquery.js
287.63 kB | 90.05 kB | 90.07 kB | 32.07 kB | 31.95 kB | jquery.js

342.15 kB | 118.16 kB | 118.14 kB | 44.52 kB | 44.37 kB | vue.js

Expand All @@ -19,9 +19,9 @@ Original | minified | minified | gzip | gzip | Fixture

2.14 MB | 726.02 kB | 724.14 kB | 180.14 kB | 181.07 kB | victory.js

3.20 MB | 1.01 MB | 1.01 MB | 331.84 kB | 331.56 kB | echarts.js
3.20 MB | 1.01 MB | 1.01 MB | 331.82 kB | 331.56 kB | echarts.js

6.69 MB | 2.32 MB | 2.31 MB | 492.75 kB | 488.28 kB | antd.js

10.95 MB | 3.50 MB | 3.49 MB | 909.11 kB | 915.50 kB | typescript.js
10.95 MB | 3.50 MB | 3.49 MB | 909.10 kB | 915.50 kB | typescript.js

Loading