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Merged
graphite-app merged 1 commit into from
Mar 1, 2025
Merged

feat(minifier): support binary expression in remove_unused_expression #9456

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62 changes: 31 additions & 31 deletions crates/oxc_minifier/src/peephole/minimize_conditions.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1308,8 +1308,8 @@ mod test {
test("if((-0 != +0) !== false){}", "");
test_same("foo(x >> y == 0)");

test("(x = 1) === 1", "(x = 1) == 1");
test("(x = 1) !== 1", "(x = 1) != 1");
test("v = (x = 1) === 1", "v = (x = 1) == 1");
test("v = (x = 1) !== 1", "v = (x = 1) != 1");
test("v = !0 + null !== 1", "v = !1");
}

Expand Down Expand Up @@ -1360,39 +1360,39 @@ mod test {

#[test]
fn test_fold_is_null_or_undefined() {
test("foo === null || foo === undefined", "foo == null");
test("foo === undefined || foo === null", "foo == null");
test("foo === null || foo === void 0", "foo == null");
test("foo === null || foo === void 0 || foo === 1", "foo == null || foo === 1");
test("foo === 1 || foo === null || foo === void 0", "foo === 1 || foo == null");
test_same("foo === void 0 || bar === null");
test_same("var undefined = 1; foo === null || foo === undefined");
test_same("foo !== 1 && foo === void 0 || foo === null");
test_same("foo.a === void 0 || foo.a === null"); // cannot be folded because accessing foo.a might have a side effect

test("foo !== null && foo !== undefined", "foo != null");
test("foo !== undefined && foo !== null", "foo != null");
test("foo !== null && foo !== void 0", "foo != null");
test("foo !== null && foo !== void 0 && foo !== 1", "foo != null && foo !== 1");
test("foo !== 1 && foo !== null && foo !== void 0", "foo !== 1 && foo != null");
test("foo !== 1 || foo !== void 0 && foo !== null", "foo !== 1 || foo != null");
test_same("foo !== void 0 && bar !== null");

test("(_foo = foo) === null || _foo === undefined", "(_foo = foo) == null");
test("(_foo = foo) === null || _foo === void 0", "(_foo = foo) == null");
test("(_foo = foo.bar) === null || _foo === undefined", "(_foo = foo.bar) == null");
test("(_foo = foo) !== null && _foo !== undefined", "(_foo = foo) != null");
test("(_foo = foo) === undefined || _foo === null", "(_foo = foo) == null");
test("(_foo = foo) === void 0 || _foo === null", "(_foo = foo) == null");
test("v = foo === null || foo === undefined", "v = foo == null");
test("v = foo === undefined || foo === null", "v = foo == null");
test("v = foo === null || foo === void 0", "v = foo == null");
test("v = foo === null || foo === void 0 || foo === 1", "v = foo == null || foo === 1");
test("v = foo === 1 || foo === null || foo === void 0", "v = foo === 1 || foo == null");
test_same("v = foo === void 0 || bar === null");
test_same("var undefined = 1; v = foo === null || foo === undefined");
test_same("v = foo !== 1 && foo === void 0 || foo === null");
test_same("v = foo.a === void 0 || foo.a === null"); // cannot be folded because accessing foo.a might have a side effect

test("v = foo !== null && foo !== undefined", "v = foo != null");
test("v = foo !== undefined && foo !== null", "v = foo != null");
test("v = foo !== null && foo !== void 0", "v = foo != null");
test("v = foo !== null && foo !== void 0 && foo !== 1", "v = foo != null && foo !== 1");
test("v = foo !== 1 && foo !== null && foo !== void 0", "v = foo !== 1 && foo != null");
test("v = foo !== 1 || foo !== void 0 && foo !== null", "v = foo !== 1 || foo != null");
test_same("v = foo !== void 0 && bar !== null");

test("v = (_foo = foo) === null || _foo === undefined", "v = (_foo = foo) == null");
test("v = (_foo = foo) === null || _foo === void 0", "v = (_foo = foo) == null");
test("v = (_foo = foo.bar) === null || _foo === undefined", "v = (_foo = foo.bar) == null");
test("v = (_foo = foo) !== null && _foo !== undefined", "v = (_foo = foo) != null");
test("v = (_foo = foo) === undefined || _foo === null", "v = (_foo = foo) == null");
test("v = (_foo = foo) === void 0 || _foo === null", "v = (_foo = foo) == null");
test(
"(_foo = foo) === null || _foo === void 0 || _foo === 1",
"(_foo = foo) == null || _foo === 1",
"v = (_foo = foo) === null || _foo === void 0 || _foo === 1",
"v = (_foo = foo) == null || _foo === 1",
);
test(
"_foo === 1 || (_foo = foo) === null || _foo === void 0",
"_foo === 1 || (_foo = foo) == null",
"v = _foo === 1 || (_foo = foo) === null || _foo === void 0",
"v = _foo === 1 || (_foo = foo) == null",
);
test_same("(_foo = foo) === void 0 || bar === null");
test_same("v = (_foo = foo) === void 0 || bar === null");
}

#[test]
Expand Down
6 changes: 3 additions & 3 deletions crates/oxc_minifier/src/peephole/minimize_not_expression.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -82,10 +82,10 @@ mod test {

#[test]
fn minimize_nots_with_binary_expressions() {
test("!(x === undefined)", "x !== void 0");
test("!(x === undefined)", "x");
test("!(typeof(x) === 'undefined')", "");
test("!(typeof(x()) === 'undefined')", "x() !== void 0");
test("!(x === void 0)", "x !== void 0");
test("!(typeof(x()) === 'undefined')", "x()");
test("!(x === void 0)", "x");
test("!!delete x.y", "delete x.y");
test("!!!delete x.y", "delete x.y");
test("!!!!delete x.y", "delete x.y");
Expand Down
2 changes: 1 addition & 1 deletion crates/oxc_minifier/src/peephole/remove_dead_code.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -470,7 +470,7 @@ mod test {
test("{if(false)if(false)if(false)foo(); {bar()}}", "bar()");

test("{'hi'}", "");
test("{x==3}", "x == 3");
test("{x==3}", "x");
test("{`hello ${foo}`}", "`${foo}`");
test("{ (function(){x++}) }", "");
test("{ (function foo(){x++; foo()}) }", "");
Expand Down
111 changes: 109 additions & 2 deletions crates/oxc_minifier/src/peephole/remove_unused_expression.rs
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Expand Up @@ -24,9 +24,9 @@ impl<'a> PeepholeOptimizations {
Expression::TemplateLiteral(_) => self.fold_template_literal(e, ctx),
Expression::ObjectExpression(_) => self.fold_object_expression(e, ctx),
Expression::ConditionalExpression(_) => self.fold_conditional_expression(e, ctx),
Expression::BinaryExpression(_) => self.fold_binary_expression(e, ctx),
// TODO
// Expression::BinaryExpression(_)
// | Expression::CallExpression(_)
// Expression::CallExpression(_)
// | Expression::NewExpression(_) => {
// false
// }
Expand Down Expand Up @@ -347,6 +347,89 @@ impl<'a> PeepholeOptimizations {

false
}

fn fold_binary_expression(&self, e: &mut Expression<'a>, ctx: Ctx<'a, '_>) -> bool {
let Expression::BinaryExpression(binary_expr) = e else {
return false;
};

match binary_expr.operator {
BinaryOperator::Equality
| BinaryOperator::Inequality
| BinaryOperator::StrictEquality
| BinaryOperator::StrictInequality
| BinaryOperator::LessThan
| BinaryOperator::LessEqualThan
| BinaryOperator::GreaterThan
| BinaryOperator::GreaterEqualThan => {
let left = self.remove_unused_expression(&mut binary_expr.left, ctx);
let right = self.remove_unused_expression(&mut binary_expr.right, ctx);
match (left, right) {
(true, true) => true,
(true, false) => {
*e = ctx.ast.move_expression(&mut binary_expr.right);
false
}
(false, true) => {
*e = ctx.ast.move_expression(&mut binary_expr.left);
false
}
(false, false) => {
*e = ctx.ast.expression_sequence(
binary_expr.span,
ctx.ast.vec_from_array([
ctx.ast.move_expression(&mut binary_expr.left),
ctx.ast.move_expression(&mut binary_expr.right),
]),
);
false
}
}
}
BinaryOperator::Addition => {
Self::fold_string_addition_chain(e, ctx);
matches!(e, Expression::StringLiteral(_))
}
_ => !e.may_have_side_effects(&ctx),
}
}

/// returns whether the passed expression is a string
fn fold_string_addition_chain(e: &mut Expression<'a>, ctx: Ctx<'a, '_>) -> bool {
let Expression::BinaryExpression(binary_expr) = e else {
return e.to_primitive(&ctx).is_string() == Some(true);
};
if binary_expr.operator != BinaryOperator::Addition {
return e.to_primitive(&ctx).is_string() == Some(true);
}

let left_is_string = Self::fold_string_addition_chain(&mut binary_expr.left, ctx);
if left_is_string {
if !binary_expr.left.may_have_side_effects(&ctx) {
binary_expr.left =
ctx.ast.expression_string_literal(binary_expr.left.span(), "", None);
}

let right_as_primitive = binary_expr.right.to_primitive(&ctx);
if right_as_primitive.is_symbol() == Some(false)
&& !binary_expr.right.may_have_side_effects(&ctx)
{
*e = ctx.ast.move_expression(&mut binary_expr.left);
return true;
}
return true;
}

let right_as_primitive = binary_expr.right.to_primitive(&ctx);
if right_as_primitive.is_string() == Some(true) {
if !binary_expr.right.may_have_side_effects(&ctx) {
binary_expr.right =
ctx.ast.expression_string_literal(binary_expr.right.span(), "", None);
}
return true;
}
false
}
}

#[cfg(test)]
Expand Down Expand Up @@ -509,4 +592,28 @@ mod test {
test("foo() ? bar() : 2", "!foo() || bar()"); // can be improved to "foo() && bar()"
test_same("foo() ? bar() : baz()");
}

#[test]
fn test_fold_binary_expression() {
test("var a, b; a === b", "var a, b;");
test("var a, b; a() === b", "var a, b; a()");
test("var a, b; a === b()", "var a, b; b()");
test("var a, b; a() === b()", "var a, b; a(), b()");

test("var a, b; a !== b", "var a, b;");
test("var a, b; a == b", "var a, b;");
test("var a, b; a != b", "var a, b;");
test("var a, b; a < b", "var a, b;");
test("var a, b; a > b", "var a, b;");
test("var a, b; a <= b", "var a, b;");
test("var a, b; a >= b", "var a, b;");

test_same("var a, b; a + b");
test("var a, b; 'a' + b", "var a, b; '' + b");
test_same("var a, b; a + '' + b");
test("var a, b, c; 'a' + (b === c)", "var a, b, c;");
test("var a, b; 'a' + +b", "var a, b; '' + +b"); // can be improved to "var a, b; +b"
test_same("var a, b; a + ('' + b)");
test("var a, b, c; a + ('' + (b === c))", "var a, b, c; a + ''");
}
}
38 changes: 19 additions & 19 deletions crates/oxc_minifier/src/peephole/substitute_alternate_syntax.rs
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Expand Up @@ -1215,25 +1215,25 @@ mod test {

#[test]
fn test_fold_true_false_comparison() {
test("x == true", "x == !0");
test("x == false", "x == !1");
test("x != true", "x != !0");
test("x < true", "x < !0");
test("x <= true", "x <= !0");
test("x > true", "x > !0");
test("x >= true", "x >= !0");
test("v = x == true", "v = x == !0");
test("v = x == false", "v = x == !1");
test("v = x != true", "v = x != !0");
test("v = x < true", "v = x < !0");
test("v = x <= true", "v = x <= !0");
test("v = x > true", "v = x > !0");
test("v = x >= true", "v = x >= !0");

test("x instanceof true", "x instanceof !0");
test("x + false", "x + !1");
test("v = x instanceof true", "v = x instanceof !0");
test("v = x + false", "v = x + !1");

// Order: should perform the nearest.
test("x == x instanceof false", "x == x instanceof !1");
test("x in x >> true", "x in x >> !0");
test("x == fake(false)", "x == fake(!1)");
test("v = x == x instanceof false", "v = x == x instanceof !1");
test("v = x in x >> true", "v = x in x >> !0");
test("v = x == fake(false)", "v = x == fake(!1)");

// The following should not be folded.
test("x === true", "x === !0");
test("x !== false", "x !== !1");
test("v = x === true", "v = x === !0");
test("v = x !== false", "v = x !== !1");
}

/// Based on https://github.com/terser/terser/blob/58ba5c163fa1684f2a63c7bc19b7ebcf85b74f73/test/compress/assignment.js
Expand Down Expand Up @@ -1622,11 +1622,11 @@ mod test {

#[test]
fn test_fold_loose_equals_undefined() {
test_same("foo != null");
test("foo != undefined", "foo != null");
test("foo != void 0", "foo != null");
test("undefined != foo", "foo != null");
test("void 0 != foo", "foo != null");
test_same("v = foo != null");
test("v = foo != undefined", "v = foo != null");
test("v = foo != void 0", "v = foo != null");
test("v = undefined != foo", "v = foo != null");
test("v = void 0 != foo", "v = foo != null");
}

#[test]
Expand Down
4 changes: 2 additions & 2 deletions crates/oxc_minifier/tests/peephole/esbuild.rs
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Expand Up @@ -623,15 +623,15 @@ fn js_parser_test() {
test("a ? b() : b()", "a, b();");
test("a ? b?.() : b?.()", "a, b?.();");
test("a ? b?.[c] : b?.[c]", "a, b?.[c];");
test("a ? b == c : b == c", "a, b == c;");
test("a ? b == c : b == c", "a, b, c;");
test("a ? b.c(d + e[f]) : b.c(d + e[f])", "a, b.c(d + e[f]);");
// test("a ? -b : !b", "a ? -b : b;");
test("a ? b() : b(c)", "a ? b() : b(c);");
test("a ? b(c) : b(d)", "a ? b(c) : b(d);");
test("a ? b?.c : b.c", "a ? b?.c : b.c;");
test("a ? b?.() : b()", "a ? b?.() : b();");
test("a ? b?.[c] : b[c]", "a ? b?.[c] : b[c];");
test("a ? b == c : b != c", "a ? b == c : b != c;");
// test("a ? b == c : b != c", "a ? (b, c) : (b, c);");
test("a ? b.c(d + e[f]) : b.c(d + e[g])", "a ? b.c(d + e[f]) : b.c(d + e[g]);");
test("(a, b) ? c : d", "a, b ? c : d;");
test(
Expand Down
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