WebpackError: ReferenceError: document is not defined - IE check

[jaysella]

Description

I recently added const isIE = /*@cc_on!@*/ false || !!document.documentMode as a check to see if a user is using Internet Explorer and conditionally add a message asking them to use a modern browser (Chrome/Firefox). While this works as expected using gatsby develop, it fails using gatsby build stating:

error Building static HTML failed
WebpackError: ReferenceError: document is not defined

Steps to reproduce

Running gatsby build within project folder after declaring const isIE = /*@cc_on!@*/ false || !!document.documentMode and running a check on the const {isIE && ()} in one of the js files. Gatsby develop works fine as expected.

Expected result

Site builds without error and conditionally displays message if user is using IE

Actual result

Site unable to build with gatsby build but fine with gatsby develop.

WebpackError: ReferenceError: document is not defined
  - header.js:20 Module../src/components/header.js
    lib/src/components/header.js:20:27
  - bootstrap:19 __webpack_require__
    lib/webpack/bootstrap:19:1
  - bootstrap:19 __webpack_require__
    lib/webpack/bootstrap:19:1
  - bootstrap:19 __webpack_require__
    lib/webpack/bootstrap:19:1
  - sync-requires.js:8 Object../.cache/sync-requires.js
    lib/.cache/sync-requires.js:8:58
  - bootstrap:19 __webpack_require__
    lib/webpack/bootstrap:19:1
  - static-entry.js:9 Module../.cache/static-entry.js
    lib/.cache/static-entry.js:9:22
  - bootstrap:19 __webpack_require__
    lib/webpack/bootstrap:19:1
  - bootstrap:83 
    lib/webpack/bootstrap:83:1
  - universalModuleDefinition:3 webpackUniversalModuleDefinition
    lib/webpack/universalModuleDefinition:3:1
  - universalModuleDefinition:10 Object.<anonymous>
    lib/webpack/universalModuleDefinition:10:2
  - static-entry.js:84 Module._compile
    lib/.cache/static-entry.js:84:3
  - static-entry.js:101 Object.Module._extensions..js
    lib/.cache/static-entry.js:101:9

Environment

  System:
    OS: macOS 10.14.5
    CPU: (8) x64 Intel(R) Core(TM) i5-8259U CPU @ 2.30GHz
    Shell: 3.2.57 - /bin/bash
  Binaries:
    Node: 10.15.3 - /usr/local/bin/node
    Yarn: 1.15.2 - /usr/local/bin/yarn
    npm: 6.9.0 - /usr/local/bin/npm
  Languages:
    Python: 2.7.10 - /usr/bin/python
  Browsers:
    Chrome: 75.0.3770.90
    Safari: 12.1.1
  npmPackages:
    gatsby: ^2.9.0 => 2.9.0 
    gatsby-image: ^2.1.3 => 2.1.3 
    gatsby-plugin-google-analytics: ^2.0.21 => 2.0.21 
    gatsby-plugin-hotjar: ^1.0.1 => 1.0.1 
    gatsby-plugin-manifest: ^2.1.1 => 2.1.1 
    gatsby-plugin-offline: ^2.1.1 => 2.1.1 
    gatsby-plugin-react-helmet: ^3.0.12 => 3.0.12 
    gatsby-plugin-sass: ^2.0.11 => 2.0.11 
    gatsby-plugin-sharp: ^2.1.3 => 2.1.3 
    gatsby-plugin-sitemap: ^2.1.0 => 2.1.0 
    gatsby-remark-external-links: 0.0.4 => 0.0.4 
    gatsby-source-contentful: ^2.0.69 => 2.0.69 
    gatsby-source-filesystem: ^2.0.39 => 2.0.39 
    gatsby-transformer-remark: ^2.3.12 => 2.3.12 
    gatsby-transformer-sharp: ^2.1.21 => 2.1.21 
  npmGlobalPackages:
    gatsby-cli: 2.6.7

[DSchau]

@j-651 you'll want to do this check "in the browser." As a proxy for this, you can use lifecycle events (componentDidMount) or hooks (useEffect).

The code could look something like this:

import React, { useState, useEffect } from 'react'

function Something() {
  const [isIE, setIsIE] = useState(false)
  useEffect(() => {
    setIsIE(/*@cc_on!@*/ false || !!document.documentMode)
  }, [])

  return (
    <p>{isIE ? 'Internet Explorer' : 'Not IE'}</p>
  )
}

export default Something

Going to close this as answered--thanks for the question!