Adopt ESM (#344)

* esm * node 18 * next * 5.0.0-rc.1 * remove jsdom * break circular import * bump versions in README
observablehq · Nov 10, 2022 · 9e1817b · 9e1817b
1 parent d9c5077
commit 9e1817b
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diff --git a/.eslintrc.json b/.eslintrc.json
@@ -2,11 +2,12 @@
   "extends": "eslint:recommended",
   "parserOptions": {
     "sourceType": "module",
-    "ecmaVersion": 8
+    "ecmaVersion": 2020
   },
   "env": {
     "browser": true,
     "es6": true,
+    "es2020": true,
     "node": true
   },
   "rules": {

diff --git a/.github/workflows/nodejs.yml b/.github/workflows/nodejs.yml
@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [14.x, 16.x]
+        node-version: [14.x, 16.x, 18.x]
 
     steps:
       - uses: actions/checkout@v1

diff --git a/README.md b/README.md
@@ -9,12 +9,12 @@ For example, to render the “hello” cell from the [“Hello World” notebook
 ```html
 <!DOCTYPE html>
 <meta charset="utf-8">
-<link rel="stylesheet" type="text/css" href="https://cdn.jsdelivr.net/npm/@observablehq/inspector@3/dist/inspector.css">
+<link rel="stylesheet" type="text/css" href="https://cdn.jsdelivr.net/npm/@observablehq/inspector@4/dist/inspector.css">
 <body>
 <script type="module">
 
-import {Runtime, Inspector} from "https://cdn.jsdelivr.net/npm/@observablehq/runtime@4/dist/runtime.js";
-import define from "https://api.observablehq.com/@observablehq/hello-world.js?v=3";
+import {Runtime, Inspector} from "https://cdn.jsdelivr.net/npm/@observablehq/runtime@5/dist/runtime.js";
+import define from "https://api.observablehq.com/@observablehq/hello-world.js?v=4";
 
 const runtime = new Runtime();
 const main = runtime.module(define, name => {

diff --git a/package.json b/package.json
@@ -1,38 +1,49 @@
 {
   "name": "@observablehq/runtime",
-  "version": "4.28.0",
-  "license": "ISC",
-  "main": "dist/runtime.umd.js",
-  "module": "src/index.js",
+  "version": "5.0.0-rc.1",
   "author": {
     "name": "Observable, Inc.",
     "url": "https://observablehq.com"
   },
+  "license": "ISC",
+  "type": "module",
+  "main": "src/index.js",
+  "module": "src/index.js",
+  "jsdelivr": "dist/runtime.umd.js",
+  "unpkg": "dist/runtime.umd.js",
+  "exports": {
+    "umd": "./dist/runtime.umd.js",
+    "default": "./src/index.js"
+  },
   "repository": {
     "type": "git",
     "url": "https://github.com/observablehq/runtime.git"
   },
+  "files": [
+    "dist/**/*.js",
+    "src/**/*.js"
+  ],
   "scripts": {
-    "test": "tape -r esm 'test/**/*-test.js'",
+    "test": "mocha 'test/**/*-test.js' && eslint src test",
     "prepublishOnly": "rm -rf dist && rollup -c",
     "postpublish": "git push && git push --tags"
   },
-  "files": [
-    "src/**/*.js",
-    "dist/**/*.js"
-  ],
+  "_moduleAliases": {
+    "@observablehq/runtime": "./src/index.js"
+  },
   "dependencies": {
-    "@observablehq/inspector": "^3.2.2",
-    "@observablehq/stdlib": "^3.4.1"
+    "@observablehq/inspector": "4.0.0-rc.1",
+    "@observablehq/stdlib": "4.0.0-rc.1"
   },
   "devDependencies": {
-    "eslint": "^7.18.0",
-    "esm": "^3.2.25",
-    "jsdom": "^17.0.0",
-    "rollup": "^2.37.1",
-    "rollup-plugin-node-resolve": "^5.2.0",
-    "rollup-plugin-terser": "^7.0.2",
-    "tape": "^4.13.3",
-    "tape-await": "^0.1.2"
+    "@rollup/plugin-node-resolve": "^15.0.1",
+    "eslint": "^8.27.0",
+    "mocha": "^10.1.0",
+    "module-alias": "^2.2.2",
+    "rollup": "^3.2.5",
+    "rollup-plugin-terser": "^7.0.2"
+  },
+  "publishConfig": {
+    "tag": "next"
   }
 }
diff --git a/rollup.config.js b/rollup.config.js
@@ -1,6 +1,6 @@
-import node from "rollup-plugin-node-resolve";
+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/runtime v${meta.version} Copyright ${(new Date).getFullYear()} Observable, Inc.`;
 

diff --git a/src/array.js b/src/array.js
@@ -1,3 +1,3 @@
-var prototype = Array.prototype;
-export var map = prototype.map;
-export var forEach = prototype.forEach;
+const prototype = Array.prototype;
+export const map = prototype.map;
+export const forEach = prototype.forEach;
diff --git a/src/constant.js b/src/constant.js
@@ -1,5 +1,3 @@
-export default function(x) {
-  return function() {
-    return x;
-  };
+export function constant(x) {
+  return () => x;
 }
diff --git a/src/errors.js b/src/errors.js
@@ -1,8 +1,8 @@
-export function RuntimeError(message, input) {
-  this.message = message + "";
-  this.input = input;
+export class RuntimeError extends Error {
+  constructor(message, input) {
+    super(message);
+    this.input = input;
+  }
 }
 
-RuntimeError.prototype = Object.create(Error.prototype);
 RuntimeError.prototype.name = "RuntimeError";
-RuntimeError.prototype.constructor = RuntimeError;
diff --git a/src/generatorish.js b/src/generatorish.js
@@ -1,4 +1,4 @@
-export default function generatorish(value) {
+export function generatorish(value) {
   return value
       && typeof value.next === "function"
       && typeof value.return === "function";

diff --git a/src/identity.js b/src/identity.js
@@ -1,3 +1,3 @@
-export default function(x) {
+export function identity(x) {
   return x;
 }
diff --git a/src/index.js b/src/index.js
@@ -1,6 +1,4 @@
-import {Inspector} from "@observablehq/inspector";
-import {Library} from "@observablehq/stdlib";
-import {RuntimeError} from "./errors";
-import Runtime from "./runtime";
-
-export {Inspector, Library, Runtime, RuntimeError};
+export {Inspector} from "@observablehq/inspector";
+export {Library} from "@observablehq/stdlib";
+export {RuntimeError} from "./errors.js";
+export {Runtime} from "./runtime.js";
diff --git a/src/load.js b/src/load.js
diff --git a/src/module.js b/src/module.js
@@ -1,11 +1,14 @@
-import constant from "./constant";
-import {RuntimeError} from "./errors";
-import identity from "./identity";
-import rethrow from "./rethrow";
-import {variable_variable, variable_invalidation, variable_visibility} from "./runtime";
-import Variable, {TYPE_DUPLICATE, TYPE_IMPLICIT, TYPE_NORMAL, no_observer, variable_stale} from "./variable";
-
-export default function Module(runtime, builtins = []) {
+import {constant} from "./constant.js";
+import {RuntimeError} from "./errors.js";
+import {identity} from "./identity.js";
+import {rethrow} from "./rethrow.js";
+import {Variable, TYPE_DUPLICATE, TYPE_IMPLICIT, TYPE_NORMAL, no_observer, variable_stale} from "./variable.js";
+
+export const variable_variable = Symbol("variable");
+export const variable_invalidation = Symbol("invalidation");
+export const variable_visibility = Symbol("visibility");
+
+export function Module(runtime, builtins = []) {
   Object.defineProperties(this, {
     _runtime: {value: runtime},
     _scope: {value: new Map},
@@ -31,19 +34,19 @@ Object.defineProperties(Module.prototype, {
 });
 
 function module_redefine(name) {
-  var v = this._scope.get(name);
-  if (!v) throw new RuntimeError(name + " is not defined");
-  if (v._type === TYPE_DUPLICATE) throw new RuntimeError(name + " is defined more than once");
+  const v = this._scope.get(name);
+  if (!v) throw new RuntimeError(`${name} is not defined`);
+  if (v._type === TYPE_DUPLICATE) throw new RuntimeError(`${name} is defined more than once`);
   return v.define.apply(v, arguments);
 }
 
 function module_define() {
-  var v = new Variable(TYPE_NORMAL, this);
+  const v = new Variable(TYPE_NORMAL, this);
   return v.define.apply(v, arguments);
 }
 
 function module_import() {
-  var v = new Variable(TYPE_NORMAL, this);
+  const v = new Variable(TYPE_NORMAL, this);
   return v.import.apply(v, arguments);
 }
 
@@ -52,8 +55,8 @@ function module_variable(observer) {
 }
 
 async function module_value(name) {
-  var v = this._scope.get(name);
-  if (!v) throw new RuntimeError(name + " is not defined");
+  let v = this._scope.get(name);
+  if (!v) throw new RuntimeError(`${name} is not defined`);
   if (v._observer === no_observer) {
     v = this.variable(true).define([name], identity);
     try {
@@ -137,7 +140,7 @@ function module_derive(injects, injectModule) {
 }
 
 function module_resolve(name) {
-  var variable = this._scope.get(name), value;
+  let variable = this._scope.get(name), value;
   if (!variable) {
     variable = new Variable(TYPE_IMPLICIT, this);
     if (this._builtins.has(name)) {

diff --git a/src/noop.js b/src/noop.js
@@ -1 +1 @@
-export default function() {}
+export function noop() {}
diff --git a/src/rethrow.js b/src/rethrow.js
@@ -1,5 +1,5 @@
-export default function(e) {
-  return function() {
-    throw e;
+export function rethrow(error) {
+  return () => {
+    throw error;
   };
 }
diff --git a/src/runtime.js b/src/runtime.js
@@ -1,21 +1,16 @@
 import {Library, FileAttachments} from "@observablehq/stdlib";
-import {RuntimeError} from "./errors";
-import generatorish from "./generatorish";
-import load from "./load";
-import Module from "./module";
-import noop from "./noop";
-import Variable, {TYPE_IMPLICIT, no_observer, variable_stale} from "./variable";
+import {RuntimeError} from "./errors.js";
+import {generatorish} from "./generatorish.js";
+import {Module, variable_variable, variable_invalidation, variable_visibility} from "./module.js";
+import {noop} from "./noop.js";
+import {Variable, TYPE_IMPLICIT, no_observer, variable_stale} from "./variable.js";
 
 const frame = typeof requestAnimationFrame === "function" ? requestAnimationFrame
   : typeof setImmediate === "function" ? setImmediate
   : f => setTimeout(f, 0);
 
-export var variable_variable = {};
-export var variable_invalidation = {};
-export var variable_visibility = {};
-
-export default function Runtime(builtins = new Library, global = window_global) {
-  var builtin = this.module();
+export function Runtime(builtins = new Library, global = window_global) {
+  const builtin = this.module();
   Object.defineProperties(this, {
     _dirty: {value: new Set},
     _updates: {value: new Set},
@@ -28,15 +23,11 @@ export default function Runtime(builtins = new Library, global = window_global)
     _builtin: {value: builtin},
     _global: {value: global}
   });
-  if (builtins) for (var name in builtins) {
+  if (builtins) for (const name in builtins) {
     (new Variable(TYPE_IMPLICIT, builtin)).define(name, [], builtins[name]);
   }
 }
 
-Object.defineProperties(Runtime, {
-  load: {value: load, writable: true, configurable: true}
-});
-
 Object.defineProperties(Runtime.prototype, {
   _precompute: {value: runtime_precompute, writable: true, configurable: true},
   _compute: {value: runtime_compute, writable: true, configurable: true},
@@ -91,7 +82,7 @@ function runtime_computeSoon() {
 }
 
 async function runtime_computeNow() {
-  var queue = [],
+  let queue = [],
       variables,
       variable,
       precomputes = this._precomputes;
@@ -247,7 +238,7 @@ function variable_compute(variable) {
     if (variable._version !== version) throw variable_stale;
 
     // Replace any reference to invalidation with the promise, lazily.
-    for (var i = 0, n = inputs.length; i < n; ++i) {
+    for (let i = 0, n = inputs.length; i < n; ++i) {
       switch (inputs[i]) {
         case variable_invalidation: {
           inputs[i] = invalidation = variable_invalidator(variable);
@@ -361,7 +352,7 @@ function variable_return(generator) {
 
 function variable_reachable(variable) {
   if (variable._observer !== no_observer) return true; // Directly reachable.
-  var outputs = new Set(variable._outputs);
+  const outputs = new Set(variable._outputs);
   for (const output of outputs) {
     if (output._observer !== no_observer) return true;
     output._outputs.forEach(outputs.add, outputs);
@@ -370,5 +361,5 @@ function variable_reachable(variable) {
 }
 
 function window_global(name) {
-  return window[name];
+  return globalThis[name];
 }
Original file line number	Diff line number	Diff line change
		@@ -1 +1 @@
		export default function() {}
		export function noop() {}