WebStorm doesn't yet include predefined libraries for EcmaScript6, so the types introduced in ES6 API are not known to it. Please follow
https://youtrack.jetbrains.com/issue/WEB-11478 for updates. As a workaround I can suggest creating a new .js file with the corresponding stubs and passing it to WebStorm (as a javascript library).Open plugins\JavaScriptLanguage\lib\JavaScriptLanguage.jar!\com\intellij\lang\javascript\index\predefined\EcmaScript.js file in editor to see what such stubs may look like
WebStorm doesn't yet include predefined libraries for EcmaScript6, so the types introduced in ES6 API are not known to it. Please follow
https://youtrack.jetbrains.com/issue/WEB-11478 for updates.As a workaround I can suggest creating a new .js file with the corresponding stubs and passing it to WebStorm (as a javascript library).Open plugins\JavaScriptLanguage\lib\JavaScriptLanguage.jar!\com\intellij\lang\javascript\index\predefined\EcmaScript.js file in editor to see what such stubs may look like