feat: transform module globals before compiling with tsc.

.github/workflows/ci.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Setup Node
         uses: actions/setup-node@v4.0.2
         with:
-          node-version: '20.12.1'
+          node-version: '20.11.0'
       - name: Install Dependencies
         run: npm ci
       - name: Save error log

.github/workflows/publish.yml

@@ -14,7 +14,7 @@ jobs:
       - name: Setup Node
         uses: actions/setup-node@v4.0.2
         with:
-          node-version: '20.12.1'
+          node-version: '20.11.0'
       - name: Install Dependencies
         run: npm ci
       - name: Save error log

README.md

@@ -10,11 +10,12 @@ Tool for building a Node.js [dual package](https://nodejs.org/api/packages.html#
 
 - Bidirectional ESM ↔️ CJS dual builds inferred from the package.json `type`.
 - Correctly preserves module systems for `.mts` and `.cts` file extensions.
+- Resolves the [differences between ES modules and CommonJS](https://nodejs.org/api/esm.html#differences-between-es-modules-and-commonjs).
 - Use only one package.json and tsconfig.json.
 
 ## Requirements
 
-- Node >= 16.19.0.
+- Node >= 20.11.0
 
 ## Example
 
@@ -67,26 +68,13 @@ If you prefer to have both builds in directories inside of your defined `outDir`
 
 Assuming an `outDir` of `dist`, running the above will create `dist/esm` and `dist/cjs` directories.
 
-### Parallel builds
-
-This is experimental, as your mileage may vary based on the size of your `node_modules` directory.
-
-```json
-"scripts": {
-  "build": "duel --parallel"
-}
-```
-
-You _might_ reduce your build times, but only if your project has minimal dependencies. This requires first copying your project to a parent directory of `--project` if it exists as a writable folder. Common [gitignored directories for Node.js projects](https://github.com/github/gitignore/blob/main/Node.gitignore) are not copied, with the exception of `node_modules`. See the [notes](#notes) as to why this can't be improved much further. In most cases, you're better off with serial builds.
-
 ## Options
 
 The available options are limited, because you should define most of them inside your project's `tsconfig.json` file.
 
 - `--project, -p` The path to the project's configuration file. Defaults to `tsconfig.json`.
 - `--pkg-dir, -k` The directory to start looking for a package.json file. Defaults to the cwd.
 - `--dirs, -d` Outputs both builds to directories inside of `outDir`. Defaults to `false`.
-- `--parallel, -l` Run the builds in parallel. Defaults to `false`.
 
 You can run `duel --help` to get the same info. Below is the output of that:
 
@@ -97,7 +85,6 @@ Options:
 --project, -p [path] 	 Compile the project given the path to its configuration file, or to a folder with a 'tsconfig.json'.
 --pkg-dir, -k [path] 	 The directory to start looking for a package.json file. Defaults to cwd.
 --dirs, -d 		 Output both builds to directories inside of outDir. [esm, cjs].
---parallel, -l 		 Run the builds in parallel.
 --help, -h 		 Print this message.
 ```
 
@@ -115,5 +102,4 @@ These are definitely edge cases, and would only really come up if your project m
 
 ## Notes
 
-As far as I can tell, `duel` is one (if not the only) way to get a correct dual package build using `tsc` with only **one package.json and tsconfig.json file**, _and also preserving module system by file extension_. Basically, how you expect things to work. The Microsoft backed TypeScript team [keep](https://github.com/microsoft/TypeScript/pull/54546) [talking](https://github.com/microsoft/TypeScript/issues/54593) about dual build support, but their philosophy is mainly one of self-preservation, rather than collaboration. For instance, they continue to [refuse to rewrite specifiers](https://github.com/microsoft/TypeScript/issues/16577). The downside of their decisions, and the fact that `npm` does not support using alternative names for the package.json file, is that `duel` must copy your project
-directory before attempting to run the builds in parallel.
+As far as I can tell, `duel` is one (if not the only) way to get a correct dual package build using `tsc` with only **one package.json and tsconfig.json file**, _while also preserving module system by file extension_. Basically, how you expect things to work. The Microsoft backed TypeScript team [keep](https://github.com/microsoft/TypeScript/pull/54546) [talking](https://github.com/microsoft/TypeScript/issues/54593) about dual build support, but they continue to [refuse to rewrite specifiers](https://github.com/microsoft/TypeScript/issues/16577).