style: Typos, minor adjustments

README.md

@@ -1,7 +1,7 @@
 # ts-run
 > The minimalist TypeScript script runner for NodeJS.
 
-Runs TypeScript scripts from the command line as if they were written in plain JavaScript:
+Run TypeScript scripts from the command line as if they were written in plain JavaScript:
 
 ```sh
 ts-run ./some-script.ts

rollup.config.js

@@ -33,7 +33,7 @@ export default defineConfig([
         external: /(?:esm|cjs)-hooks.js$/
     },
 
-    // This second configuration bundles Sucrase's parser to lib/cjs-transform.cjs
+    // This second configuration bundles Sucrase's parser to lib/transform.cjs
     {
         input: 'source/transform.cts',
         output: {
@@ -54,7 +54,7 @@ export default defineConfig([
             terser(),
 
             // This plugin fixes https://github.com/alangpierce/sucrase/issues/825
-            // by replacing sucrase's computeSourceMap.js with our own.
+            // by replacing Sucrase's computeSourceMap.js with our own.
             {
                 name: 'fix-sucrase',
                 async load(id) {
@@ -64,7 +64,7 @@ export default defineConfig([
                 }
             }
         ],
-        // sucrase has MANY circular dependencies :/
+        // Sucrase has MANY circular dependencies :/
         onLog(level, log, handler) {
             if (log.code === 'CIRCULAR_DEPENDENCY')
                 return

source/ambient.d.ts

@@ -2,11 +2,6 @@ declare global {
     namespace NodeJS {
         type ModuleType = 'commonjs' | 'module'
 
-        // In package.json.
-        interface PackageType {
-            type?: ModuleType
-        }
-
         // The data passed to the initialize() hook.
         interface InitializeHookData {
             self: string
@@ -17,6 +12,11 @@ declare global {
             _compile(code: string, filename: string): string
         }
     }
+
+    // Fields of interest in package.json.
+    interface PackageJson {
+        type?: NodeJS.ModuleType
+    }
 }
 
 declare module 'module' {

source/cjs-hooks.ts

@@ -30,7 +30,7 @@ function nearestPackageType(file: string, defaultType: NodeJS.ModuleType): NodeJ
         if (!format) {
             try {
                 const data = readFileSync(pkgFile, 'utf-8')
-                const { type } = JSON.parse(data) as NodeJS.PackageType
+                const { type } = JSON.parse(data) as PackageJson
                 format = type === 'module' || type ==='commonjs'
                     ? type
                     : unknownType

source/esm-hooks.ts

@@ -50,7 +50,12 @@ async function nearestPackageType(file: string): Promise<NodeJS.ModuleType> {
         let format = pkgTypeCache.get(pkgFile)
         if (!format) {
             format = await readFile(pkgFile, 'utf-8')
-                .then(data => (JSON.parse(data) as NodeJS.PackageType).type ?? unknownType)
+                .then(data => {
+                    const { type } = JSON.parse(data) as PackageJson
+                    return type === 'module' || type === 'commonjs'
+                        ? type
+                        : unknownType
+                })
                 .catch(err => {
                     const { code } = err as NodeJS.ErrnoException
                     if (code !== 'ENOENT')
@@ -71,17 +76,17 @@ export const load: LoadHook = async (url, context, nextLoad) => {
 
     // If this is not a TypeScript file, defer to the next hook in the chain.
     const { protocol, pathname } = new URL(url)
-    const ext = /(\.[cm]?ts)$/.exec(pathname)
+    const [ , ext ] = /(\.[cm]?ts)$/.exec(pathname) ?? []
     if (protocol !== 'file:' || !ext)
         return nextLoad(url, context)
 
     // Determine the output format based on the file's extension
     // or the nearest package.json's `type` field.
     const filePath = fileURLToPath(url)
     const format: NodeJS.ModuleType = (
-        ext[1] === '.ts'
+        ext === '.ts'
             ? await nearestPackageType(filePath)
-            : ext[1] === '.mts'
+            : ext === '.mts'
                 ? 'module'
                 : 'commonjs'
     )

source/index.ts

@@ -24,7 +24,7 @@ if (
             defaultModuleType = type
     }
 
-    // Install the esm hooks -- those are run in a worker thread.
+    // Register the esm hooks -- those are run in a worker thread.
     const self = import.meta.url
     Module.register<NodeJS.InitializeHookData>('./esm-hooks.js', {
         parentURL: self,

source/transform.cts

@@ -1,12 +1,12 @@
-import { transform as sucrase, type Transform, type TransformResult } from 'sucrase'
+import { transform as parse, type Transform, type TransformResult } from 'sucrase'
 
 const transforms: Record<NodeJS.ModuleType, Transform[]> = {
     commonjs: [ 'typescript', 'imports' ],
     module: [ 'typescript' ]
 }
 
 export function transform(source: string, format: NodeJS.ModuleType, filePath: string) {
-    const { code, sourceMap } = sucrase(source, {
+    const { code, sourceMap } = parse(source, {
         filePath,
         transforms: transforms[format],
         preserveDynamicImport: true,

tsconfig.json

@@ -15,7 +15,6 @@
     // Output
     "target": "ESNext",
     "module": "ESNext",
-    "checkJs": true,
     "noEmit": true,
 
     // Libs
@@ -34,6 +33,7 @@
     "noUnusedParameters": false,
     "noFallthroughCasesInSwitch": false,
     "forceConsistentCasingInFileNames": true,
-    "isolatedModules": true
+    "isolatedModules": true,
+    "checkJs": true
   }
 }