Adopt ESM (#316)

* esm

* node 18

* next

* 4.0.0-rc.1

* adopt named exports

* adopt d3-array

Author: mbostock

.eslintrc.json

@@ -2,7 +2,7 @@
   "extends": "eslint:recommended",
   "parserOptions": {
     "sourceType": "module",
-    "ecmaVersion": 2018
+    "ecmaVersion": 2020
   },
   "env": {
     "es6": true,

.github/workflows/nodejs.yml

@@ -8,7 +8,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest]
-        node-version: [14.x, 16.x]
+        node-version: [14.x, 16.x, 18.x]
 
     runs-on: ${{ matrix.os }}
 

LICENSE

@@ -1,4 +1,4 @@
-Copyright 2018-2021 Observable, Inc.
+Copyright 2018-2022 Observable, Inc.
 
 Permission to use, copy, modify, and/or distribute this software for any purpose
 with or without fee is hereby granted, provided that the above copyright notice

README.md

@@ -5,7 +5,7 @@ const extensionRe = /\.[^/]*$/;
 const mains = ["unpkg", "jsdelivr", "browser", "main"];
 
 (async () => {
-  console.log(`import dependency from "./dependency.mjs";`);
+  console.log(`import dependency from "./dependency.js";`);
   {
     const package = await resolve("d3");
     console.log(`export const d3 = dependency("${package.name}", "${package.version}", "${package.export}");`);

bin/resolve-dependencies

@@ -1,37 +1,51 @@
 {
   "name": "@observablehq/stdlib",
-  "version": "3.24.0",
-  "license": "ISC",
-  "main": "dist/stdlib.js",
-  "module": "src/index.mjs",
+  "version": "4.0.0-rc.1",
   "author": {
     "name": "Observable, Inc.",
     "url": "https://observablehq.com"
   },
+  "license": "ISC",
+  "type": "module",
+  "main": "src/index.js",
+  "module": "src/index.js",
+  "jsdelivr": "dist/stdlib.js",
+  "unpkg": "dist/stdlib.js",
+  "exports": {
+    "umd": "./dist/stdlib.js",
+    "default": "./src/index.js"
+  },
   "repository": {
     "type": "git",
     "url": "https://github.com/observablehq/stdlib.git"
   },
+  "files": [
+    "dist/**/*.js",
+    "src/**/*.js"
+  ],
+  "engines": {
+    "node": ">=14.5.0"
+  },
   "scripts": {
-    "test": "mocha 'test/**/*-test.mjs' && eslint src test --ext mjs",
-    "prepublishOnly": "rollup -c",
+    "test": "mocha 'test/**/*-test.js' && eslint src test",
+    "prepublishOnly": "rm -rf dist && rollup -c",
     "postpublish": "git push && git push --tags"
   },
-  "files": [
-    "src/**/*.mjs",
-    "dist/**/*.js"
-  ],
   "dependencies": {
-    "d3-dsv": "^2.0.0",
+    "d3-array": "^3.2.0",
+    "d3-dsv": "^3.0.1",
     "d3-require": "^1.3.0"
   },
   "devDependencies": {
-    "@rollup/plugin-node-resolve": "^13.3.0",
-    "eslint": "^8.18.0",
+    "@rollup/plugin-node-resolve": "^15.0.1",
+    "eslint": "^8.27.0",
     "exceljs": "^4.3.0",
-    "mocha": "^10.0.0",
-    "node-fetch": "^2.6.1",
-    "rollup": "^2.37.1",
+    "mocha": "^10.1.0",
+    "node-fetch": "^3.2.10",
+    "rollup": "^3.2.5",
     "rollup-plugin-terser": "^7.0.2"
+  },
+  "publishConfig": {
+    "tag": "next"
   }
 }

package.json

@@ -1,12 +1,12 @@
 import node from "@rollup/plugin-node-resolve";
 import {terser} from "rollup-plugin-terser";
-import * as meta from "./package.json";
+import * as meta from "./package.json" assert {type: "json"};
 
 const copyright = `// @observablehq/stdlib v${meta.version} Copyright ${(new Date).getFullYear()} Observable, Inc.`;
 
 export default [
   {
-    input: "src/index.mjs",
+    input: "src/index.js",
     plugins: [
       node(),
       terser({

rollup.config.js

@@ -1,4 +1,4 @@
-import dependency from "./dependency.mjs";
+import {dependency} from "./dependency.js";
 export const d3 = dependency("d3", "7.6.1", "dist/d3.min.js");
 export const inputs = dependency("@observablehq/inputs", "0.10.4", "dist/inputs.min.js");
 export const plot = dependency("@observablehq/plot", "0.6.0", "dist/plot.umd.min.js");

src/array.mjs

@@ -1,4 +1,4 @@
-export default function dependency(name, version, main) {
+export function dependency(name, version, main) {
   return {
     resolve(path = main) {
       return `${name}@${version}/${path}`;