Breaks with some transformations

[theKashey]

I've tried to apply swc for node_modules and run into the issue with react code

before transpilation

function ce(e, t, n, r) {
    for (var a in this.dispatchConfig = e, this._targetInst = t, this.nativeEvent = n, e = this.constructor.Interface) {
      e.hasOwnProperty(a) && ((t = e[a]) ? this[a] = t(n) : "target" === a ? this.target = r : this[a] = n[a]);
    }

    return this.isDefaultPrevented = (null != n.defaultPrevented ? n.defaultPrevented : !1 === n.returnValue) ? ie : le, this.isPropagationStopped = le, this;
  }

after transpilation

var ce = function ce(e1, t1, n1, r) {
            for(var a in (this.dispatchConfig = e1, this._targetInst = t1, this.nativeEvent = n1, e1 = this.constructor.Interface))e1.hasOwnProperty(a) && t1 = e1[a] ? (this[a] = t1(n1)) : 'target' === a ? (this.target = r) : (this[a] = n1[a]);
            return (this.isDefaultPrevented = null != n1.defaultPrevented ? n1.defaultPrevented : !1 === n1.returnValue ? ie : le, this.isPropagationStopped = le, this);
        };

The key moment is && ((t = e[a]) ? !== && t1 = e1[a] ?, in the second case this is a syntax error (just drop code to the dev console).

I didn't found a way how to disable this transformation, and it's a critical for me.

What I did

swc.transform(code, {
    "jsc": {
      "parser": {
        "syntax": "ecmascript",
      },
      "target": "es5",
      // "transform": {
      //   "optimizer": undefined // this makes no sence
      // }
    }

[theKashey]

Wow! It was fast!

[kdy1]

@theKashey :). As this is bugfix, I'll publish v1.0.28 soon

[theKashey]

Sorry @kdy, but that's not the end

source

break e leads to e:

function Ii(e, t, n) {
if ("selectionStart" in a) var o = {
        start: a.selectionStart,
        end: a.selectionEnd
      }; 
      else e:{   <-----
        var l = (o = (o = a.ownerDocument) && o.defaultView || window).getSelection && o.getSelection();
        if (l && 0 !== l.rangeCount) {
          o = l.anchorNode;
          var c = l.anchorOffset, s = l.focusNode;
          l = l.focusOffset;
          try {
            o.nodeType, s.nodeType
          } catch (e) {
            o = null;
            break e  <-----
          }

result

break e2 leads to nowhere, while should lead to e1

var Ii = function Ii(e1, t1, n1) {
                if ('selectionStart' in a) var o = {
                    start: a.selectionStart,
                    end: a.selectionEnd
                };
                else e1: { <<-----
                    var l = (o = (o = a.ownerDocument) && o.defaultView || window).getSelection && o.getSelection();
                    if (l && 0 !== l.rangeCount) {
                        o = l.anchorNode;
                        var c = l.anchorOffset, s = l.focusNode;
                        l = l.focusOffset;
                        try {
                            o.nodeType, s.nodeType;
                        } catch (e2) {
                            o = null;
                            break e2; <-----, this label does not exists
                        }

SWC is used on minified bundle.

The same code, without minification produces almost identical source code, and does not contain the issue.

original source code

function Sh(a, b, c) {
  if (Ud(e)) {
    if ("selectionStart" in e) var f = {
      start: e.selectionStart,
      end: e.selectionEnd
    };else a: {
      f = (f = e.ownerDocument) && f.defaultView || window;
      var g = f.getSelection && f.getSelection();

      if (g && 0 !== g.rangeCount) {
        f = g.anchorNode;
        var h = g.anchorOffset,
            k = g.focusNode;
        g = g.focusOffset;

        try {
          f.nodeType, k.nodeType;
        } catch (db) {
          f = null;
          break a;
        }

Produced code - almost identical.

Link to the scripts:

• https://release-qhrjhutjfr.now.sh/esm/tomskii.js (base)
• https://release-qhrjhutjfr.now.sh/ie11/tomskii.js (es6 -> es3 using swc)

[theKashey]

source code

    !(__WEBPACK_AMD_DEFINE_ARRAY__ = [], __WEBPACK_AMD_DEFINE_RESULT__ = (function () {
      return classNames;
    }).apply(exports, __WEBPACK_AMD_DEFINE_ARRAY__),
				__WEBPACK_AMD_DEFINE_RESULT__ !== undefined && (module.exports = __WEBPACK_AMD_DEFINE_RESULT__));

result code

!__WEBPACK_AMD_DEFINE_ARRAY__ = [], __WEBPACK_AMD_DEFINE_RESULT__ = (function() {
                    return classNames;
                }).apply(exports, __WEBPACK_AMD_DEFINE_ARRAY__), __WEBPACK_AMD_DEFINE_RESULT__ !== undefined && (module.exports = __WEBPACK_AMD_DEFINE_RESULT__);

!(__WEBPACK_AMD_DEFINE_ARRAY !== !__WEBPACK_AMD_DEFINE_ARRAY__ = []

Yet again - syntax error :(

[swc-bot]

This closed issue has been automatically locked because it had no new activity for a month. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.