Class constructor FileManager cannot be invoked without 'new'

[Meow-z]

• I have searched the issues of this repository and believe that this is not a duplicate.

Reproduction link

https://github.com/ant-design/ant-design/

Steps to reproduce

编译报错
./node_modules/antd/es/tag/style/index.less

Class constructor FileManager cannot be invoked without 'new'
in undefined (line undefined, column undefined)

What is expected?

成功编译

What is actually happening?

./node_modules/antd/es/tag/style/index.less

Class constructor FileManager cannot be invoked without 'new'
in undefined (line undefined, column undefined)

Environment	Info
antd	3.22.0
React	16.8.2
System	macOs Mojave 10.14.5
Browser	任何

[Meow-z]

锁定之前版本 3.16.0，不会报错。

[afc163]

Trace less/less.js#3414

[montanaflynn]

What's this fix for this? All our builds stopped working, here's the error:

./node_modules/antd/es/style/index.less
Module build failed: 

Class constructor FileManager cannot be invoked without 'new'
      in undefined (line undefined, column undefined)

[afc163]

It is a bug of less, not antd's, please trace less/less.js#3414 and webpack-contrib/less-loader#300 for further fix.

[montanaflynn]

@afc163 they suggest locking the less version, which would be done in antd's package.json.

[afc163]

antd didn't depend less.

[montanaflynn]

@afc163 less-loader then, we fixed it by adding:

  "devDependencies": {
    "less-loader": "^5.0.0"
  }

[afc163]

devDependencies won't affect your project.

[montanaflynn]

@afc163 it did, and it fixed the issue for us. Literally that's all we added and the problem went away.