Support named exports in the ESM mode

Allow importing single exported named functions:

    import { bold, green } from "picocolors"

Expose an ESM module with named exports: `picocolors.mjs`. Generate its
content from `picololors.js` by `build.mjs`. Test that the exports can
be imported by `test/esm.mjs`.

Also upgrade development dependencies. Keep the same major versions
of `chalk` and `clean-publish` not to break the legacy Node.js tests.

Also include tests with Node.js 20 and move versions older than 18
to the legacy group. Upgrade GitHub actions for modern Node.js.

.github/workflows/benchmarks.yaml

@@ -14,10 +14,10 @@ jobs:
     name: Benchmarks
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-node@v2
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
       - run: npm install
       - name: Ensure color support detection
         run: node tests/environments.js

.github/workflows/testing.yaml

@@ -13,23 +13,26 @@ jobs:
     strategy:
       matrix:
         node-version:
+          - 20
           - 18
-          - 16
-          - 14
-          - 12
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-node@v2
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
       - run: npm install
+      - run: npm run build
       - run: node tests/test.js
+      - run: node tests/esm.mjs
   legacy:
     name: Node v${{ matrix.node-version }} (Legacy)
     runs-on: ubuntu-latest
     strategy:
       matrix:
         node-version:
+          - 16
+          - 14
+          - 12
           - 10
           - 8
           - 6

.gitignore

@@ -1 +1,2 @@
 node_modules
+picocolors.mjs

build-esm.mjs

@@ -0,0 +1,28 @@
+import { readFile, writeFile } from "node:fs/promises"
+
+let script = await readFile("picocolors.js", "utf8")
+
+script = script.replace('require != null && require("tty")', '(await import("tty"))')
+
+let lines = script.split(/\r?\n/)
+lines.splice(-3, 3)
+script = lines.join("\n")
+
+script += `
+let colors = createColors()
+colors.createColors = createColors
+let {
+  reset, bold, dim, italic, underline, inverse, hidden, strikethrough, 
+  black, red, green, yellow, blue, magenta, cyan, white, gray,
+  bgBlack, bgRed, bgGreen, bgYellow, bgBlue, bgMagenta, bgCyan, bgWhite
+} = colors
+
+export {
+  isColorSupported, reset, bold, dim, italic, underline, inverse, hidden, strikethrough, 
+  black, red, green, yellow, blue, magenta, cyan, white, gray,
+  bgBlack, bgRed, bgGreen, bgYellow, bgBlue, bgMagenta, bgCyan, bgWhite, createColors
+}
+export default colors
+`;
+
+await writeFile("picocolors.mjs", script)

package.json

@@ -2,13 +2,22 @@
   "name": "picocolors",
   "version": "1.0.0",
   "main": "./picocolors.js",
+  "module": "./picocolors.mjs",
   "types": "./picocolors.d.ts",
   "browser": {
     "./picocolors.js": "./picocolors.browser.js"
   },
+  "exports": {
+    ".": {
+      "types": "./picocolors.d.ts",
+      "require": "./picocolors.js",
+      "import": "./picocolors.mjs"
+    }
+  },
   "sideEffects": false,
   "description": "The tiniest and the fastest library for terminal output formatting with ANSI colors",
   "scripts": {
+    "build": "node build-esm.mjs",
     "test": "node tests/test.js"
   },
   "files": [
@@ -26,15 +35,15 @@
   "repository": "alexeyraspopov/picocolors",
   "license": "ISC",
   "devDependencies": {
-    "ansi-colors": "^4.1.1",
+    "ansi-colors": "^4.1.3",
     "benchmark": "^2.1.4",
     "chalk": "^4.1.2",
-    "clean-publish": "^3.0.3",
-    "cli-color": "^2.0.0",
-    "colorette": "^2.0.12",
-    "kleur": "^4.1.4",
-    "nanocolors": "^0.2.12",
-    "prettier": "^2.4.1"
+    "clean-publish": "^3.4.5",
+    "cli-color": "^2.0.3",
+    "colorette": "^2.0.20",
+    "kleur": "^4.1.5",
+    "nanocolors": "^0.2.13",
+    "prettier": "^2.8.8"
   },
   "prettier": {
     "printWidth": 100,

tests/esm.mjs

@@ -0,0 +1,27 @@
+import pc from "../picocolors.mjs"
+import { bold, createColors } from "../picocolors.mjs"
+import assert from "node:assert"
+
+test("import all", () => {
+	assert.equal(typeof pc, "object")
+	assert.equal(typeof pc.bold, "function")
+	assert.equal(typeof pc.createColors, "function")
+})
+
+test("import bold", () => {
+	assert.equal(typeof bold, "function")
+})
+
+test("import createColors", () => {
+	assert.equal(typeof createColors, "function")
+})
+
+function test(name, fn) {
+	try {
+		fn()
+		console.log(pc.green("✓ " + name))
+	} catch (error) {
+		console.log(pc.red("✗ " + name))
+		throw error
+	}
+}