Make esbuild optional

esbuild is a large dependency, and pinning to a specific version makes it less likely that it can be shared across other dependencies. To make i18next-parser lighter:

- Dynamically import esbuild if needed. Change esbuild to an optional peer dependency.
- Update the version range.
- Try loading .ts files using Node.js support for stripping TypeScript types (enabled by default in current Node.js versions), to potentially remove having to import ESBuild at all.

This is a potentially breaking change: if a someone uses a .ts i18next-parser configuration, doesn't have type stripping enabled (or has a configuration file that's incompatible with Node.js's type stripping), and doesn't otherwise have esbuild installed, then they'll have to install it.

Author: joshkel

bin/cli.js

@@ -58,13 +58,15 @@ import i18nTransform from '../dist/transform.js'
         `${pkg.name}.config.mjs`,
         `${pkg.name}.config.json`,
         `${pkg.name}.config.ts`,
+        `${pkg.name}.config.mts`,
         `${pkg.name}.config.yaml`,
         `${pkg.name}.config.yml`,
       ],
       loaders: {
         '.js': esConfigLoader,
         '.mjs': esConfigLoader,
         '.ts': tsConfigLoader,
+        '.mts': tsConfigLoader,
         '.yaml': yamlConfigLoader,
         '.yml': yamlConfigLoader,
       },

package.json

@@ -33,7 +33,6 @@
     "colors": "^1.4.0",
     "commander": "^12.1.0",
     "eol": "^0.9.1",
-    "esbuild": "^0.25.0",
     "fs-extra": "^11.2.0",
     "gulp-sort": "^2.0.0",
     "i18next": "^23.5.1 || ^24.2.0",
@@ -58,6 +57,7 @@
     "broccoli-funnel": "^3.0.8",
     "c8": "^10.1.2",
     "chai": "^5.1.1",
+    "esbuild": "^0.27.0",
     "execa": "^9.5.2",
     "gulp": "^5.0.0",
     "husky": "^9.1.6",
@@ -67,6 +67,14 @@
     "prettier": "^3.3.3",
     "sinon": "^19.0.2"
   },
+  "peerDependencies": {
+    "esbuild": "^0.25.0 || ^0.26.0 || ^0.27.0"
+  },
+  "peerDependenciesMeta": {
+    "esbuild": {
+      "optional": true
+    }
+  },
   "repository": {
     "type": "git",
     "url": "https://github.com/i18next/i18next-parser"

src/helpers.js

@@ -1,5 +1,4 @@
 import { pathToFileURL } from 'url'
-import { build } from 'esbuild'
 import { rmSync } from 'fs'
 import yaml from 'js-yaml'
 import { builtinModules } from 'module'
@@ -286,7 +285,22 @@ async function esConfigLoader(filepath) {
 }
 
 async function tsConfigLoader(filepath) {
+  // Newer Node.js has --experimental-strip-types by default. Try that.
+  try {
+    return await esConfigLoader(filepath)
+  } catch (err) {
+    // Fall through.
+  }
+
   const outfile = filepath + '.bundle.mjs'
+  let build
+  try {
+    ;({ build } = await import('esbuild'))
+  } catch (err) {
+    throw new Error(
+      'esbuild is required to load TypeScript configuration files. Please install it as a peer dependency; e.g.: npm install -D esbuild'
+    )
+  }
   await build({
     absWorkingDir: process.cwd(),
     entryPoints: [filepath],