Adding support for NodeNext, Node16, .cts, .mts, .cjs, .mjs

This feature has already been implemented. Here are my notes from when I was doing the work

TODOs

Implement node module type classifier:

• if NodeNext or Node12: ask classifier for CJS or ESM determination Add ForceNodeNextCJSEmit

Does our code check for .d.ts extensions anywhere?

• if so, teach it about .d.cts and .d.mts

For nodenext and node12, support supplemental "flavor" information:

Think about splitting out index.ts further:

• register.ts - hooking stuff
• types.ts
• env.ts - env vars and global registration types (process.symbol)
• service.ts

TESTS

Matrix:

• package.json type absent, commonjs, and module
• import and require
• from cjs and esm
• .cts, .cjs
• .mts, .mjs
• typechecking, transpileOnly, and swc
• dynamic import
• import = require
• static import
• allowJs on and off

Notes about specific matrix entries:

• require mjs, mts from cjs throws error

Rethink: getOutput: null in transpile-only mode. Also may return emitskipped getOutputTranspileOnly: configured module option getOutputForceCommonJS: commonjs module option getOutputForceNodeCommonJS: nodenext cjs module option getOutputForceESM: esnext module option

Add second layer of classification to classifier: if classifier returns auto (no moduleType override)

• if getOutput emits, done
• else call nodeModuleTypeClassifier
  • delegate to appropriate getOutput based on its response