npm-deps throws errors when using a dependency with es6 modules


  • Type: Defect Defect
  • Status: Open Open
  • Priority: Major Major
  • Resolution: Unresolved
  • Affects Version/s: None
  • Fix Version/s: None
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Using npm-deps to specify a dependency on a library with es6 modules causes errors in Google Closure, making the dependency unusable.


rc-time-picker comes as a set of es6 modules in the es/ subfolder as well as "traditional" module.exports in the lib/ subdirectory. The package.json specifies both as module and main respectively (see

Using this in a clojurescript build with npm-deps like the following makes google closure pick the es6 part and later complain about the file mixing goog.provide and es6 modules:

(require '[ :as b])

(b/build ["src/"]
         {:main '
          :output-to "js/app.js"
          :optimizations :simple
          :npm-deps {"react"          "16.2.0",
                     "react-dom"      "16.2.0",
                     "rc-time-picker" "^3.3.1",}
          :install-deps true})

A simple app.cljs requiring "rc-time-picker" :as ... causes the following errors during compilation:

WARNING: WARNING - File cannot be a combination of goog.provide, goog.module, and/or ES6 module: .../out/node_modules/rc-time-picker/es/Combobox.js
ERROR: JSC_LANGUAGE_FEATURE. This language feature is only supported for ECMASCRIPT6 mode or better: modules. at ...out/node_modules/rc-time-picker/es/TimePicker.js line 12 :66

Specifying :language-in and :language-out doesn't help.

The error messages are caused by the Clojurescript code which copies the code from node_modules/rc-time-picker/es/ to out/node_modules/rc-time-picker and where it adds various goog.provide statements to the top of the file, while the end of the file is a export default ... statement.


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