Uglifyjs: v3.9.0 triggers error "TypeError: aStr.charAt is not a function"

[mmacvicar-splunk]

Bug report or feature request?
Bug Report

Uglify version (uglifyjs -V)
uglify-js 2.8.29

We're getting the following error from [email protected] since yesterday, that we don't get when using [email protected]:

/mypath/node_modules/map-stream/index.js:103
        throw err
        ^
TypeError: aStr.charAt is not a function
    at BasicSourceMapConsumer.SourceMapConsumer_parseMappings [as _parseMappings] (/mypath/node_modules/source-map/lib/source-map-consumer.js:439:16)
    at BasicSourceMapConsumer.get (/mypath/node_modules/source-map/lib/source-map-consumer.js:68:12)
    at BasicSourceMapConsumer.SourceMapConsumer_originalPositionFor [as originalPositionFor] (/mypath/node_modules/source-map/lib/source-map-consumer.js:606:12)
    at SourceMapGenerator.<anonymous> (/mypath/node_modules/source-map/lib/source-map-generator.js:198:43)
    at Array.forEach (<anonymous>)
    at MappingList_forEach [as unsortedForEach] (/mypath/node_modules/source-map/lib/mapping-list.js:44:17)
    at SourceMapGenerator_applySourceMap [as applySourceMap] (/mypath/node_modules/source-map/lib/source-map-generator.js:195:20)
    at applySourceMap (/mypath/node_modules/vinyl-sourcemaps-apply/index.js:27:15)
    at /mypath/node_modules/gulp-uglify/lib/minify.js:73:9
    at DestroyableTransform._transform (/mypath/node_modules/gulp-uglify/composer.js:12:19)

npm install gulp-uglify is picking up [email protected] and other times [email protected] and it might be relevant that the dependencies changed between versions:

`-- [email protected]
  `-- [email protected]

`-- [email protected]
  +-- [email protected]
  `-- [email protected]

[alexlamsl]

From the stacktrace, it looks like gulp-uglify is using [email protected] to read the source map produced by [email protected] − specifically the mappings property doesn't seem to be a string so it can't do charAt() on it.

It would be a lot more helpful if I can have source input in order to reproduce this issue locally.

(Not sure why you reported uglify-js 2.8.29 when the rest of it is about 3.9.0)

[alexlamsl]

(Not sure why you reported uglify-js 2.8.29 when the rest of it is about 3.9.0)

Not certain if this is the root cause, but looks like you have an old version of uglify-js installed globally, which in turn would pull in an old version of source-map as well. Please try removing them and see if the issue persists:

$ npm uninstall -g uglify-js
$ npm uninstall -g source-map

[alexlamsl]

... and I have a theory as to what could have happened − let me spin up a PR and check.

[wvankuipers]

I have the exact same issue, no global packages installed

[wvankuipers]

Reverting to 3.8.0 will make the build work form me again.

[alexlamsl]

If any of you can try out #3781 to confirm the fix, I would be grateful.

[alexlamsl]

Easiest way I can think of is download this file then replace the one in node_modules/uglify-js/lib/sourcemap.js, assuming you have 3.9.0 installed of course.

[wvankuipers]

I did

npm i -S git://github.com/alexlamsl/UglifyJS2.git#issue-3780

And it is working for me when running a build 👍

[alexlamsl]

Thanks for the verification - will publish 3.9.1 as soon as the tests are done.

[mmacvicar-splunk]

Apologies for the abysmal bug report, and thank you for the fix. I've verified v3.9.1 works well for us.

[alexlamsl]

Thanks for validating the fix.

No need to apologise − not everyone knows every detail about the software stack they are using.