Uglifyjs: Properties not resolved with compress option

[chrismanley]

Bug report

Not exactly sure how to describe what is happening, but the code sample and output are hopefully enough to be obvious. The entire 'dimensions' object is dropped and a new property 'a2' is created and used, but clearly it doesn't actually exist and things blow up.

ES5

Uglify version 3.2.0

Note: This did work OK with the 3.1.x line.

JavaScript input

testFunc = function () {

    var dimensions = {
        minX: 5,
        maxX: 6,
        minY: 7,
        maxY: 8
    };
    var scale = 1;

    var d = {
        x: (dimensions.maxX + dimensions.minX) / 2,
        y: (dimensions.maxY + dimensions.minY) / 2
    };

    var dcx = (d.x * scale);
    var dcy = (d.y * scale);

    var dc = [dcx, dcy];
    return {
        position: dc
    };
};

The uglifyjs CLI command executed or minify() options used.

uglifyjs file.js -b -m -c > testout.js

JavaScript output or error produced.

testFunc = function() {
    return {
        position: [ 1 * ((a2.maxX + a2.minX) / 2), 1 * ((a2.maxY + a2.minY) / 2) ]
    };
};

[kzc]

Confirmed bug. Thanks for the report.

$ cat t2519.js 
function testFunc() {
    var dimensions = {
        minX: 5,
        maxX: 6,
        minY: 7,
        maxY: 8
    };
    var scale = 1;

    var d = {
        x: (dimensions.maxX + dimensions.minX) / 2,
        y: (dimensions.maxY + dimensions.minY) / 2
    };

    var dcx = (d.x * scale);
    var dcy = (d.y * scale);

    var dc = [dcx, dcy];
    return {
        position: dc
    };
}
console.log(testFunc());

```
$ cat t2519.js | node
{ position: [ 5.5, 7.5 ] }

$ cat t2519.js | bin/uglifyjs -bc | node
position: [ 1 * ((dimensions.maxX + dimensions.minX) / 2), 1 * ((dimensions.maxY + dimensions.minY) / 2) ]
^
ReferenceError: dimensions is not defined

```js
$ cat t2519.js | bin/uglifyjs -bc
function testFunc() {
    return {
        position: [ 1 * ((dimensions.maxX + dimensions.minX) / 2), 1 * ((dimensions.maxY + dimensions.minY) / 2) ]
    };
}

console.log(testFunc());

[kzc]

Disable the compress option hoist_props as a temporary workaround:

$ cat t2519.js | bin/uglifyjs -m -c hoist_props=false -b | node
{ position: [ 5.5, 7.5 ] }

$ cat t2519.js | bin/uglifyjs -m -c hoist_props=false -b
function testFunc() {
    var n = {
        minX: 5,
        maxX: 6,
        minY: 7,
        maxY: 8
    }, m = {
        x: (n.maxX + n.minX) / 2,
        y: (n.maxY + n.minY) / 2
    };
    return {
        position: [ 1 * m.x, 1 * m.y ]
    };
}

console.log(testFunc());

[kzc]

The fix will be in the next release - 3.2.1.

[ambewas]

@kzc is there a timeline available for when this patch will be released? We've got a production release on monday and either I'm going to be disabling the hoist_props option for all our apps, or if this patch is released before that, I'm just going to wait it out.

[kzc]

Releases are generally made on the weekend. Either disable the option or lock down a specific version of uglify in the meantime.