Unexpected import error for dom4

[rafaellichen]

Environment

@blueprintjs/core: 3.54.0
rollup: 2.71.1
@babel/core: 7.17.10

I am using rollup and babel to compile everything into a single .js file.

Issue

The following issue appears after upgrading @blueprintjs/core library:

Uncaught (in promise) Error: Module name "dom4" has not been loaded yet for context: _. Use require([])
http://requirejs.org/docs/errors.html#notloaded
    at makeError (require.js?v=d37b48bb2137faa0ab98157e240c084dd5b1b5e74911723aa1d1f04c928c2a03dedf922d049e4815f7e5a369faa2e6b6a1000aae958b7953b5cc60411154f593:168)
    at Object.localRequire [as require] (require.js?v=d37b48bb2137faa0ab98157e240c084dd5b1b5e74911723aa1d1f04c928c2a03dedf922d049e4815f7e5a369faa2e6b6a1000aae958b7953b5cc60411154f593:1433)
    at requirejs (require.js?v=d37b48bb2137faa0ab98157e240c084dd5b1b5e74911723aa1d1f04c928c2a03dedf922d049e4815f7e5a369faa2e6b6a1000aae958b7953b5cc60411154f593:1794)
    at ...

and the above stack trace leads to

if (typeof require !== "undefined" && typeof window !== "undefined" && typeof document !== "undefined") {
    // we're in browser
    require("dom4"); // only import actual dom4 if we're in the browser (not server-compatible)
    // we'll still need dom4 types for the TypeScript to compile, these are included in package.json
}

Cause

The older version of @blueprintjs/core@3.48.0 compiles to the following. However, in the newer version of BP, it no longer contains the following code for dom4 after compilation.

var dom4_max = {};
var hasRequiredDom4_max;
function requireDom4_max () {...}
if (typeof commonjsRequire !== "undefined" && typeof window !== "undefined" && typeof document !== "undefined") {
    // we're in browser
    requireDom4_max(); // only import actual dom4 if we're in the browser (not server-compatible)
    // we'll still need dom4 types for the TypeScript to compile, these are included in package.json
}

[adidahiya]

Related threads: #5160 (comment), #131 (comment).

I think this may be a problem with your bundler; it should support conditional imports.

This problem may go away with Blueprint v5, when we drop IE11 support and therefore may no longer need dom4 at all.