I'm writing the test suite for a web app, and I need to import the JSX from the source into a test environment. Part of this process uses @babel/register to correctly transpile my JSX into standard JS. My babel config looks like the following:
{
"presets": ["@babel/preset-env"],
"plugins": [
"@babel/plugin-syntax-jsx",
["babel-plugin-transform-jsx-to-htm",{
"import": {
"module": "htm/preact",
"export": "html"
},
"tag": "$$html"
}]
]
}
And I execute with node -r @babel/register ...<unrelated test command here>
The problem I'm running into is when one of my source files imports from a library that only offers ESM output, no CJS. Here's the error I'm met with:
Error [ERR_REQUIRE_ESM]: Must use import to load ES Module: <file path to non-working ESM module>
require() of ES modules is not supported.
require() of <file path to non-working ESM module> from <file path to source that imports it> is an ES module file as it is a .js file whose nearest parent package.json contains "type": "module" which defines all .js files in that package scope as ES modules.
Instead rename <esm file>.js to end in .cjs, change the requiring code to use import(), or remove "type": "module" from <file path to non-working ESM module>/package.json.
at Module._extensions..js (internal/modules/cjs/loader.js:1080:13)
at Object.newLoader [as .js] (/home/ryun/Projects/foobar/node_modules/pirates/lib/index.js:104:7)
at Module.load (internal/modules/cjs/loader.js:928:32)
at Function.Module._load (internal/modules/cjs/loader.js:769:14)
at Module.require (internal/modules/cjs/loader.js:952:19)
at require (internal/modules/cjs/helpers.js:88:18)
at Object.<anonymous> (<file path to source that imports it>.jsx:1:1)
at Module._compile (internal/modules/cjs/loader.js:1063:30)
at Module._compile (/home/ryun/Projects/foobar/node_modules/pirates/lib/index.js:99:24)
at Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
At the bottom of the docs page for @babel/register, it states: Note: @babel/register does not support compiling native Node.js ES modules on the fly, since currently there is no stable API for intercepting ES modules loading. Because of this, I figure @babel/register is a no-go, but no work around is offered. I can't figure out what I'm supposed to do there besides hard-fork that lib I'm using and have it export CJS just for the sake of my test suite.