introduce support for CommonJS modules

package.json

@@ -11,6 +11,7 @@
     "@typescript-eslint/parser": "^4.28.2",
     "copyfiles": "2.1.0",
     "eslint": "^7.30.0",
+    "replace-ext": "^2.0.0",
     "rollup": "^0.66.6",
     "rollup-plugin-node-resolve": "^3.4.0",
     "rollup-plugin-typescript2": "^0.25.2",

src/package.json

@@ -3,7 +3,9 @@
   "version": "0.0.0",
   "description": "Functionality on top of HTML canvas element, including support for HiDPI and pixel-perfect rendering",
   "scripts": {
-    "build": "tsc --project tsconfig.json && node ../tools/build-package-json package.json ../dist/fancy-canvas/package.json"
+    "build": "npm run build:commonjs && npm run build:esmodule && node ../tools/build-package-json package.json ../dist/fancy-canvas/package.json",
+    "build:commonjs": "tsc --project tsconfig.json --module commonjs && node ../tools/replace-extension ../dist/fancy-canvas .js .cjs",
+    "build:esmodule": "tsc --project tsconfig.json --module es2015 && node ../tools/replace-extension ../dist/fancy-canvas .js .mjs"
   },
   "keywords": [
     "html",
@@ -14,5 +16,11 @@
   ],
   "author": "smakarov@tradingview.com",
   "license": "MIT",
-  "private": true
+  "private": true,
+  "main": "./index.cjs",
+  "module": "./index.mjs",
+  "exports": {
+    "import": "./index.mjs",
+    "require": "./index.cjs"
+  }
 }

tools/build-package-json.js

@@ -31,8 +31,10 @@ var output = {
 
 	// entry points
 	bin: input.bin,
+	exports: input.exports,
 	main: input.main,
 	man: input.man,
+	module: input.module,
 
 	// contents
 	files: ["**/*.js", "**/*.d.ts"],

tools/replace-extension.js

@@ -0,0 +1,16 @@
+const { readdirSync, renameSync } = require('fs');
+const { extname, join } = require('path');
+const replaceExt = require('replace-ext');
+
+const args = process.argv.slice(2);
+const dir = args[0];
+const oldExtension = args[1];
+const newExtension = args[2];
+
+readdirSync(dir).forEach(fileName => {
+	if (extname(fileName) === oldExtension) {
+		const oldFilePath = join(dir, fileName);
+		const newFilePath = join(dir, replaceExt(fileName, newExtension));
+		renameSync(oldFilePath, newFilePath);
+	}
+});

tsconfig.json

@@ -9,7 +9,6 @@
 		"noUnusedLocals": true,
 		"sourceMap": false,
 		"target": "es5",
-		"module": "es2015",
 		"lib": [
 			"es5",
 			"es2015.symbol.wellknown",