feat(es/minfiier): Compute more with sequential inliner (#6169)

crates/swc/tests/tsc-references/compoundAdditionAssignmentLHSCanBeAssigned.2.minified.js

@@ -1,5 +1,5 @@
 //// [compoundAdditionAssignmentLHSCanBeAssigned.ts]
-var E, a, b, x1, x2, x3, x4, x6;
+var E;
 !function(E) {
     E[E.a = 0] = "a", E[E.b = 1] = "b";
-}(E || (E = {})), x1 += a, x1 += b, x1 += !0, x1 += 0, x1 += "", x1 += E.a, x1 += {}, x1 += null, x1 += void 0, x2 += a, x2 += b, x2 += !0, x2 += 0, x2 += "", x2 += E.a, x2 += {}, x2 += null, x2 += void 0, x3 += a, x3 += 0, x3 += E.a, x3 += null, x3 += void 0, x4 += a, x4 += 0, x4 += E.a, x4 += null, x4 += void 0, x6 += a, x6 += "";
+}(E || (E = {})), E.a, E.a, E.a, E.a;

crates/swc/tests/tsc-references/compoundAdditionAssignmentWithInvalidOperands.2.minified.js

@@ -1,5 +1,5 @@
 //// [compoundAdditionAssignmentWithInvalidOperands.ts]
-var E, a, x1, x2, x3, x4, x5;
+var E;
 !function(E) {
     E[E.a = 0] = "a", E[E.b = 1] = "b";
-}(E || (E = {})), x1 += a, x1 += !0, x1 += 0, x1 += E.a, x1 += {}, x1 += null, x1 += void 0, x2 += a, x2 += !0, x2 += 0, x2 += E.a, x2 += {}, x2 += null, x2 += void 0, x3 += a, x3 += !0, x3 += 0, x3 += E.a, x3 += {}, x3 += null, x3 += void 0, x4 += a, x4 += !0, x4 += {}, x5 += a, x5 += !0, x5 += {};
+}(E || (E = {})), E.a, E.a, E.a;

crates/swc/tests/tsc-references/compoundArithmeticAssignmentLHSCanBeAssigned.2.minified.js

@@ -1,5 +1,5 @@
 //// [compoundArithmeticAssignmentLHSCanBeAssigned.ts]
-var E, a, b, c, x1, x2, x3;
+var E;
 !function(E) {
     E[E.a = 0] = "a", E[E.b = 1] = "b", E[E.c = 2] = "c";
-}(E || (E = {})), x1 *= a, x1 *= b, x1 *= c, x1 *= null, x1 *= void 0, x2 *= a, x2 *= b, x2 *= c, x2 *= null, x2 *= void 0, x3 *= a, x3 *= b, x3 *= c, x3 *= null, x3 *= void 0;
+}(E || (E = {}));

crates/swc/tests/tsc-references/compoundArithmeticAssignmentWithInvalidOperands.2.minified.js

@@ -1,5 +1,5 @@
 //// [compoundArithmeticAssignmentWithInvalidOperands.ts]
-var E, a, b, x1, x2, x3, x4, x5, x6;
+var E;
 !function(E) {
     E[E.a = 0] = "a", E[E.b = 1] = "b";
-}(E || (E = {})), x1 *= a, x1 *= b, x1 *= !0, x1 *= 0, x1 *= "", x1 *= E.a, x1 *= {}, x1 *= null, x1 *= void 0, x2 *= a, x2 *= b, x2 *= !0, x2 *= 0, x2 *= "", x2 *= E.a, x2 *= {}, x2 *= null, x2 *= void 0, x3 *= a, x3 *= b, x3 *= !0, x3 *= 0, x3 *= "", x3 *= E.a, x3 *= {}, x3 *= null, x3 *= void 0, x4 *= a, x4 *= b, x4 *= !0, x4 *= 0, x4 *= "", x4 *= E.a, x4 *= {}, x4 *= null, x4 *= void 0, x5 *= b, x5 *= !0, x5 *= "", x5 *= {}, x6 *= b, x6 *= !0, x6 *= "", x6 *= {};
+}(E || (E = {})), E.a, E.a, E.a, E.a;

crates/swc/tests/tsc-references/destructuringControlFlow.2.minified.js

@@ -1,4 +1,4 @@
 //// [destructuringControlFlow.ts]
-(0, [
+[
     "foo"
-][1]).toUpperCase();
+][1].toUpperCase();

crates/swc/tests/tsc-references/symbolType12.2.minified.js

@@ -1,3 +1,3 @@
 //// [symbolType12.ts]
 var s = Symbol.for("assign"), str = "";
-s *= s, s *= 0, s /= s, s /= 0, s %= s, s %= 0, s += s, s += 0, s += "", str += s, s -= s, s -= 0, s <<= s, s <<= 0, s >>= s, s >>= 0, s >>>= s, s >>>= 0, s &= s, s &= 0, s ^= s, s ^= 0, s |= s, s |= 0, str += s || str;
+s *= 0, s /= s, s /= 0, s %= s, s %= 0, str += s = s + 0 + "", s -= s, s -= 0, s <<= s, s <<= 0, s >>= s, s >>= 0, s >>>= s, s >>>= 0, s &= s, s &= 0, s ^= s, s ^= 0, s |= s, s |= 0, str += s || str;

crates/swc_ecma_minifier/src/compress/optimize/inline.rs

@@ -1,7 +1,9 @@
 use swc_atoms::js_word;
 use swc_common::{util::take::Take, EqIgnoreSpan, Spanned};
 use swc_ecma_ast::*;
+use swc_ecma_transforms_optimization::simplify::expr_simplifier;
 use swc_ecma_utils::{class_has_side_effect, find_pat_ids, ExprExt};
+use swc_ecma_visit::VisitMutWith;
 
 use super::Optimizer;
 use crate::{
@@ -680,6 +682,30 @@ where
 
     /// Actually inlines variables.
     pub(super) fn inline(&mut self, e: &mut Expr) {
+        if let Expr::Member(me) = e {
+            if let MemberProp::Computed(ref mut prop) = me.prop {
+                if let Expr::Lit(Lit::Num(..)) = &*prop.expr {
+                    if let Expr::Ident(obj) = &*me.obj {
+                        let new = self.vars.lits_for_array_access.get(&obj.to_id());
+
+                        if let Some(new) = new {
+                            report_change!("inline: Inlined array access");
+                            self.changed = true;
+
+                            me.obj = new.clone();
+                            // TODO(kdy1): Optimize performance by skipping visiting of children
+                            // nodes.
+                            e.visit_mut_with(&mut expr_simplifier(
+                                self.marks.unresolved_mark,
+                                Default::default(),
+                            ));
+                        }
+                        return;
+                    }
+                }
+            }
+        }
+
         if let Expr::Ident(i) = e {
             let id = i.to_id();
             if let Some(value) = self

crates/swc_ecma_minifier/src/compress/optimize/sequences.rs

@@ -1665,6 +1665,20 @@ where
                 };
 
                 if !self.is_skippable_for_seq(Some(a), &Expr::Ident(b_left.clone())) {
+                    // Let's be safe
+                    if IdentUsageFinder::find(&b_left.to_id(), &b_assign.right) {
+                        return Ok(false);
+                    }
+
+                    // As we are not *skipping* lhs, we can inline here
+                    if let Some(a_id) = a.id() {
+                        if a_id == b_left.to_id() {
+                            if self.replace_seq_assignment(a, b)? {
+                                return Ok(true);
+                            }
+                        }
+                    }
+
                     return Ok(false);
                 }
 
@@ -2202,7 +2216,7 @@ where
         }
 
         macro_rules! take_a {
-            ($force_drop:expr) => {
+            ($force_drop:expr, $drop_op:expr) => {
                 match a {
                     Mergable::Var(a) => {
                         if self.options.unused {
@@ -2224,15 +2238,17 @@ where
                         .unwrap_or_else(|| undefined(DUMMY_SP))
                     }
                     Mergable::Expr(a) => {
-                        if can_remove {
+                        if can_remove || $force_drop {
                             if let Expr::Assign(e) = a {
-                                report_change!(
-                                    "sequences: Dropping assignment as we are going to drop the \
-                                     variable declaration. ({})",
-                                    left_id
-                                );
-
-                                **a = *e.right.take();
+                                if e.op == op!("=") || $drop_op {
+                                    report_change!(
+                                        "sequences: Dropping assignment as we are going to drop \
+                                         the variable declaration. ({})",
+                                        left_id
+                                    );
+
+                                    **a = *e.right.take();
+                                }
                             }
                         }
 
@@ -2256,7 +2272,10 @@ where
             Expr::Assign(b @ AssignExpr { op: op!("="), .. }) => {
                 if let Some(b_left) = b.left.as_ident() {
                     if b_left.to_id() == left_id.to_id() {
-                        let mut a_expr = take_a!(true);
+                        report_change!("sequences: Merged assignment into another assignment");
+                        self.changed = true;
+
+                        let mut a_expr = take_a!(true, false);
                         let a_expr = self.ignore_return_value(&mut a_expr);
 
                         if let Some(a) = a_expr {
@@ -2271,19 +2290,35 @@ where
             }
             Expr::Assign(b) => {
                 if let Some(b_left) = b.left.as_ident() {
-                    if b_left.to_id() == left_id.to_id() {
-                        if let Some(bin_op) = b.op.to_update() {
-                            b.op = op!("=");
+                    let a_op = match a {
+                        Mergable::Var(_) => Some(op!("=")),
+                        Mergable::Expr(Expr::Assign(AssignExpr { op: a_op, .. })) => Some(*a_op),
+                        Mergable::FnDecl(_) => Some(op!("=")),
+                        _ => None,
+                    };
 
-                            let to = take_a!(true);
+                    if let Some(a_op) = a_op {
+                        if can_drop_op_for(a_op, b.op) {
+                            if b_left.to_id() == left_id.to_id() {
+                                if let Some(bin_op) = b.op.to_update() {
+                                    report_change!(
+                                        "sequences: Merged assignment into another (op) assignment"
+                                    );
+                                    self.changed = true;
 
-                            b.right = Box::new(Expr::Bin(BinExpr {
-                                span: DUMMY_SP,
-                                op: bin_op,
-                                left: to,
-                                right: b.right.take(),
-                            }));
-                            return Ok(true);
+                                    b.op = op!("=");
+
+                                    let to = take_a!(true, true);
+
+                                    b.right = Box::new(Expr::Bin(BinExpr {
+                                        span: DUMMY_SP,
+                                        op: bin_op,
+                                        left: to,
+                                        right: b.right.take(),
+                                    }));
+                                    return Ok(true);
+                                }
+                            }
                         }
                     }
                 }
@@ -2319,7 +2354,7 @@ where
             left_id.span.ctxt
         );
 
-        let to = take_a!(false);
+        let to = take_a!(false, false);
 
         replace_id_with_expr(b, left_id.to_id(), to);
 
@@ -2449,3 +2484,16 @@ pub(crate) fn is_trivial_lit(e: &Expr) -> bool {
         _ => false,
     }
 }
+
+/// This assumes `a.left.to_id() == b.left.to_id()`
+fn can_drop_op_for(a: AssignOp, b: AssignOp) -> bool {
+    if a == op!("=") {
+        return true;
+    }
+
+    if a == b {
+        return matches!(a, op!("+=") | op!("*="));
+    }
+
+    false
+}

crates/swc_ecma_minifier/tests/benches-full/echarts.js

@@ -5298,7 +5298,7 @@
                     var width = data[i++], height = data[i++];
                     if (x1 = x0 + width, y1 = y0 + height, isStroke) {
                         if (containStroke(x0, y0, x1, y0, lineWidth, x, y) || containStroke(x1, y0, x1, y1, lineWidth, x, y) || containStroke(x1, y1, x0, y1, lineWidth, x, y) || containStroke(x0, y1, x0, y0, lineWidth, x, y)) return !0;
-                    } else w += windingLine(x1, y0, x1, y1, x, y), w += windingLine(x0, y1, x0, y0, x, y);
+                    } else w = windingLine(x1, y0, x1, y1, x, y) + windingLine(x0, y1, x0, y0, x, y);
                     break;
                 case CMD$1.Z:
                     if (isStroke) {
@@ -12349,7 +12349,7 @@
     function decodePolygon(coordinate, encodeOffsets, encodeScale) {
         for(var result = [], prevX = encodeOffsets[0], prevY = encodeOffsets[1], i = 0; i < coordinate.length; i += 2){
             var x = coordinate.charCodeAt(i) - 64, y = coordinate.charCodeAt(i + 1) - 64;
-            x = x >> 1 ^ -(1 & x), y = y >> 1 ^ -(1 & y), x += prevX, y += prevY, prevX = x, prevY = y, result.push([
+            y = y >> 1 ^ -(1 & y), x = (x >> 1 ^ -(1 & x)) + prevX, y += prevY, prevX = x, prevY = y, result.push([
                 x / encodeScale,
                 y / encodeScale
             ]);
@@ -15423,17 +15423,17 @@
                                         case 'half-year':
                                         case 'quarter':
                                         case 'month':
-                                            approxInterval1 = approxInterval, interval = (approxInterval1 /= 2592000000) > 6 ? 6 : approxInterval1 > 3 ? 3 : approxInterval1 > 2 ? 2 : 1, getterName = monthGetterName(isUTC), setterName = monthSetterName(isUTC);
+                                            interval = (approxInterval1 = approxInterval / 2592000000) > 6 ? 6 : approxInterval1 > 3 ? 3 : approxInterval1 > 2 ? 2 : 1, getterName = monthGetterName(isUTC), setterName = monthSetterName(isUTC);
                                             break;
                                         case 'week':
                                         case 'half-week':
                                         case 'day':
-                                            approxInterval2 = approxInterval, interval = (approxInterval2 /= 86400000) > 16 ? 16 : approxInterval2 > 7.5 ? 7 : approxInterval2 > 3.5 ? 4 : approxInterval2 > 1.5 ? 2 : 1, getterName = dateGetterName(isUTC), setterName = dateSetterName(isUTC);
+                                            interval = (approxInterval2 = approxInterval / 86400000) > 16 ? 16 : approxInterval2 > 7.5 ? 7 : approxInterval2 > 3.5 ? 4 : approxInterval2 > 1.5 ? 2 : 1, getterName = dateGetterName(isUTC), setterName = dateSetterName(isUTC);
                                             break;
                                         case 'half-day':
                                         case 'quarter-day':
                                         case 'hour':
-                                            approxInterval3 = approxInterval, interval = (approxInterval3 /= 3600000) > 12 ? 12 : approxInterval3 > 6 ? 6 : approxInterval3 > 3.5 ? 4 : approxInterval3 > 2 ? 2 : 1, getterName = hoursGetterName(isUTC), setterName = hoursSetterName(isUTC);
+                                            interval = (approxInterval3 = approxInterval / 3600000) > 12 ? 12 : approxInterval3 > 6 ? 6 : approxInterval3 > 3.5 ? 4 : approxInterval3 > 2 ? 2 : 1, getterName = hoursGetterName(isUTC), setterName = hoursSetterName(isUTC);
                                             break;
                                         case 'minute':
                                             interval = getMinutesAndSecondsInterval(approxInterval, !0), getterName = minutesGetterName(isUTC), setterName = minutesSetterName(isUTC);
@@ -34777,7 +34777,7 @@
             var blockMetaList = result1.meta, buttonContainer = document.createElement('div');
             buttonContainer.style.cssText = 'position:absolute;bottom:0;left:0;right:0;';
             var buttonStyle = "float:right;margin-right:20px;border:none;cursor:pointer;padding:2px 5px;font-size:12px;border-radius:3px", closeButton = document.createElement('div'), refreshButton = document.createElement('div');
-            buttonStyle += ';background-color:' + model.get('buttonColor'), buttonStyle += ';color:' + model.get('buttonTextColor');
+            buttonStyle = ';background-color:' + model.get('buttonColor') + ';color:' + model.get('buttonTextColor');
             var self1 = this;
             function close() {
                 container.removeChild(root), self1._dom = null;

crates/swc_ecma_minifier/tests/benches-full/moment.js

@@ -799,7 +799,7 @@
                 getParsingFlags(config).invalidFormat = !0, config._d = new Date(NaN);
                 return;
             }
-            for(i = 0; i < config._f.length; i++)currentScore = 0, validFormatFound = !1, tempConfig = copyConfig({}, config), null != config._useUTC && (tempConfig._useUTC = config._useUTC), tempConfig._f = config._f[i], configFromStringAndFormat(tempConfig), isValid(tempConfig) && (validFormatFound = !0), currentScore += getParsingFlags(tempConfig).charsLeftOver, currentScore += 10 * getParsingFlags(tempConfig).unusedTokens.length, getParsingFlags(tempConfig).score = currentScore, bestFormatIsValid ? currentScore < scoreToBeat && (scoreToBeat = currentScore, bestMoment = tempConfig) : (null == scoreToBeat || currentScore < scoreToBeat || validFormatFound) && (scoreToBeat = currentScore, bestMoment = tempConfig, validFormatFound && (bestFormatIsValid = !0));
+            for(i = 0; i < config._f.length; i++)currentScore = 0, validFormatFound = !1, tempConfig = copyConfig({}, config), null != config._useUTC && (tempConfig._useUTC = config._useUTC), tempConfig._f = config._f[i], configFromStringAndFormat(tempConfig), isValid(tempConfig) && (validFormatFound = !0), currentScore = getParsingFlags(tempConfig).charsLeftOver + 10 * getParsingFlags(tempConfig).unusedTokens.length, getParsingFlags(tempConfig).score = currentScore, bestFormatIsValid ? currentScore < scoreToBeat && (scoreToBeat = currentScore, bestMoment = tempConfig) : (null == scoreToBeat || currentScore < scoreToBeat || validFormatFound) && (scoreToBeat = currentScore, bestMoment = tempConfig, validFormatFound && (bestFormatIsValid = !0));
             extend(config, bestMoment || tempConfig);
         }(config) : format ? configFromStringAndFormat(config) : isUndefined(input = (config1 = config)._i) ? config1._d = new Date(hooks.now()) : isDate(input) ? config1._d = new Date(input.valueOf()) : 'string' == typeof input ? function(config) {
             var matched = aspNetJsonRegex.exec(config._i);

crates/swc_ecma_minifier/tests/benches-full/terser.js

@@ -1912,8 +1912,8 @@
         base && base.PROPS && (props = props.concat(base.PROPS));
         for(var code = "return function AST_" + type + "(props){ if (props) { ", i = props.length; --i >= 0;)code += "this." + props[i] + " = props." + props[i] + ";";
         const proto = base && Object.create(base.prototype);
-        (proto && proto.initialize || methods && methods.initialize) && (code += "this.initialize();"), code += "}", code += "this.flags = 0;";
-        var ctor = Function(code += "}")();
+        (proto && proto.initialize || methods && methods.initialize) && (code += "this.initialize();");
+        var ctor = Function(code = "}this.flags = 0;}")();
         if (proto && (ctor.prototype = proto, ctor.BASE = base), base && base.SUBCLASSES.push(ctor), ctor.prototype.CTOR = ctor, ctor.prototype.constructor = ctor, ctor.PROPS = props || null, ctor.SELF_PROPS = self_props, ctor.SUBCLASSES = [], type && (ctor.prototype.TYPE = ctor.TYPE = type), methods) for(i in methods)HOP(methods, i) && ("$" === i[0] ? ctor[i.substr(1)] = methods[i] : ctor.prototype[i] = methods[i]);
         return ctor.DEFMETHOD = function(name, method) {
             this.prototype[name] = method;

crates/swc_ecma_minifier/tests/fixture/issues/2257/full/output.js

@@ -6035,7 +6035,7 @@
                     if (number != number) return "NaN";
                     if (number <= -1000000000000000000000 || number >= 1e21) return String(number);
                     if (number < 0 && (sign = "-", number = -number), number > 1e-21) {
-                        if (z = (e = log(number * pow(2, 69, 1)) - 69) < 0 ? number * pow(2, -e, 1) : number / pow(2, e, 1), z *= 0x10000000000000, (e = 52 - e) > 0) {
+                        if (z = ((e = log(number * pow(2, 69, 1)) - 69) < 0 ? number * pow(2, -e, 1) : number / pow(2, e, 1)) * 0x10000000000000, (e = 52 - e) > 0) {
                             for(multiply(data, 0, z), j = fractDigits; j >= 7;)multiply(data, 1e7, 0), j -= 7;
                             for(multiply(data, pow(10, j, 1), 0), j = e - 1; j >= 23;)divide(data, 8388608), j -= 23;
                             divide(data, 1 << j), multiply(data, 1, 1), divide(data, 2), result = dataToString(data);
@@ -16028,7 +16028,7 @@
                     }, _proto.componentWillReceiveProps = function(nextProps) {
                         if (this.props.value !== nextProps.value) {
                             var changedBits, oldValue = this.props.value, newValue = nextProps.value;
-                            (oldValue === newValue ? 0 !== oldValue || 1 / oldValue == 1 / newValue : oldValue != oldValue && newValue != newValue) ? changedBits = 0 : (changedBits = "function" == typeof calculateChangedBits ? calculateChangedBits(oldValue, newValue) : 1073741823, 0 != (changedBits |= 0) && this.emitter.set(nextProps.value, changedBits));
+                            (oldValue === newValue ? 0 !== oldValue || 1 / oldValue == 1 / newValue : oldValue != oldValue && newValue != newValue) ? changedBits = 0 : 0 != (changedBits = ("function" == typeof calculateChangedBits ? calculateChangedBits(oldValue, newValue) : 1073741823) | 0) && this.emitter.set(nextProps.value, changedBits);
                         }
                     }, _proto.render = function() {
                         return this.props.children;

crates/swc_ecma_minifier/tests/fixture/issues/firebase-core/1/output.js

@@ -1287,7 +1287,7 @@
                     d = !0;
                 }
                 d || (b1 = "", xa(c, function(c, d) {
-                    b1 += d, b1 += ":", b1 += c, b1 += "\r\n";
+                    b1 = d + ":" + c + "\r\n";
                 }), c = b1, "string" == typeof a ? null != c && encodeURIComponent(String(c)) : R(a, b, c));
             }
             function Hd(a, b, c) {