Sane buildflow (#703)

* Migrate to Mocha 10

- Rename src/*.js to src/*.mjs and test/*.js to test/*.spec.mjs
- Move misplaced "eslint-plugin-local-rules" to devDependencies
- Remove unused reify now that we are fully .mjs
- Deprecate load*/download functions and remove associated tests
- Remove dead code (private load*() function, isNode/isBrowser...)
- Support multiple test runner:

```sh
npx mocha
npx bun test
npx jasmine "**/*.spec.mjs" # may fail on strict compare
```

* Rework eslint rules

There are currently 3 local rules:
- ban forEach => migrate to a "selector" rule
- prevent import loop => did nothing
- force import extension => esbuild enforce it already

This halves (226 => 139) our NPM dependencies

* Use eslint@9

Use new configuration format since package.json based configuration have been droped

* Apply remarks

README.md

@@ -41,7 +41,7 @@ Select one of the following sources in the next example:
 
 <!-- using module declaration (need full path) -->
 <script type=module>
-import { parse } from "https://unpkg.com/opentype.js/dist/opentype.module.js";
+import { parse } from "https://unpkg.com/opentype.js/dist/opentype.mjs";
 parse(...);
 </script>
 ```
@@ -80,14 +80,18 @@ If you plan on improving or debugging opentype.js, you can:
 
 ### Loading a WOFF/OTF/TTF font
 
+This is done in two steps: first, we load the font file into an `ArrayBuffer` ...
 ```js
-// case 1: from an URL
+// either from an URL
 const buffer = fetch('/fonts/my.woff').then(res => res.arrayBuffer());
-// case 2: from filesystem (node)
+// ... or from filesystem (node)
 const buffer = require('fs').promises.readFile('./my.woff');
-// case 3: from an <input type=file id=myfile>
+// ... or from an <input type=file id=myfile> (browser)
 const buffer = document.getElementById('myfile').files[0].arrayBuffer();
+```
 
+... then we `.parse()` it into a `Font` instance
+```js
 // if running in async context:
 const font = opentype.parse(await buffer);
 console.log(font);
@@ -99,7 +103,8 @@ buffer.then(data => {
 })
 ```
 
-### Loading a WOFF2 font
+<details>
+<summary>Loading a WOFF2 font</summary>
 
 WOFF2 Brotli compression perform [29% better](https://www.w3.org/TR/WOFF20ER/#appendixB) than it WOFF predecessor.
 But this compression is also more complex, and would result in a much heavier (&gt;10×!) opentype.js library (≈120KB => ≈1400KB).
@@ -123,30 +128,14 @@ if (!window.Module) {
 // decompress before parsing
 const font = opentype.parse(Module.decompress(await buffer));
 ```
+</details>
 
-### Loading a font (1.x style)
-
-This example relies on the deprecated `.load()` method
+### Craft a font
 
-```js
-// case 1: from an URL
-const font = opentype.load('./fonts/my.woff', {}, {isUrl: true});
-// case 2: from filesystem
-const font = opentype.load('./fonts/my.woff', {}, {isUrl: false});
-
-// ... play with `font` ...
-console.log(font.supported);
-```
+It is also possible to craft a Font from scratch by defining each glyph bézier paths.
 
-### Writing a font
-Once you have a `Font` object (either by using `opentype.load()` or by creating a new one from scratch) you can write it
-back out as a binary file.
-
-In the browser, you can use `Font.download()` to instruct the browser to download a binary .OTF file. The name is based
-on the font name.
 ```javascript
-// Create the bézier paths for each of the glyphs.
-// Note that the .notdef glyph is required.
+// this .notdef glyph is required.
 const notdefGlyph = new opentype.Glyph({
     name: '.notdef',
     advanceWidth: 650,
@@ -164,21 +153,27 @@ const aGlyph = new opentype.Glyph({
     path: aPath
 });
 
-const glyphs = [notdefGlyph, aGlyph];
 const font = new opentype.Font({
     familyName: 'OpenTypeSans',
     styleName: 'Medium',
     unitsPerEm: 1000,
     ascender: 800,
     descender: -200,
-    glyphs: glyphs});
-font.download();
+    glyphs: [notdefGlyph, aGlyph]});
 ```
 
-If you want to inspect the font, use `font.toTables()`
-to generate an object showing the data structures that map directly to binary values.
-If you want to get an `ArrayBuffer`, use `font.toArrayBuffer()`.
+### Saving a Font
+
+Once you have a `Font` object (from crafting or from `.parse()`) you can save it back out as file.
 
+```js
+// using node:fs
+fs.writeFileSync("out.otf", Buffer.from(font.toArrayBuffer()));
+
+// using the browser to createElement a <a> that will be clicked 
+const href = window.URL.createObjectURL(new Blob([font.toArrayBuffer()]), {type: "font/opentype"});
+Object.assign(document.createElement('a'), {download: "out.otf", href}).click();
+```
 
 ### The Font object
 A Font represents a loaded OpenType font file. It contains a set of glyphs and methods to draw text on a drawing context, or to get a path representing the text.

docs/examples/creating-fonts.html

@@ -44,7 +44,7 @@ <h1><output name="fontFamilyName"></output></h1>
 </form>
 
 <script type="module">
-    import * as opentype from "/dist/opentype.module.js";
+    import * as opentype from "/dist/opentype.mjs";
     function hexDump(bytes) {
         var hexString = bytes.map(function(v) {
             var h = v.toString(16);

docs/examples/font-editor.html

@@ -174,7 +174,7 @@ <h1>Experimental font editor</h1>
 
 <textarea id="code"></textarea>
 <script type="module">
-import * as opentype from "/dist/opentype.module.js";
+import * as opentype from "/dist/opentype.mjs";
 
 function linePoint(t, x1, y1, x2, y2) {
     return [x1 + t * (x2 - x1),

docs/examples/reading-writing.html

@@ -42,7 +42,7 @@ <h1><output name="fontFamilyName"></output></h1>
 </form>
 
 <script type="module">
-import * as opentype from "/dist/opentype.module.js";
+import * as opentype from "/dist/opentype.mjs";
 
 // Create a canvas and adds it to the document.
 // Returns the 2d drawing context.

docs/examples/typescript/index.ts

@@ -1,9 +1,9 @@
 
-import opentype from '../../dist/opentype.module'
+import opentype from '../../dist/opentype.mjs'
 console.log(opentype)
 // or
-import { load } from '../../dist/opentype.module'
+import { load } from '../../dist/opentype.mjs'
 console.log(load)
 // or
-import * as mySpecialOpentype from '../../dist/opentype.module'
+import * as mySpecialOpentype from '../../dist/opentype.mjs'
 console.log(mySpecialOpentype)

docs/font-inspector.html

@@ -99,7 +99,7 @@ <h1>Free Software</h1>
 
 
 <script type="module">
-import * as opentype from "/dist/opentype.module.js";
+import * as opentype from "/dist/opentype.mjs";
 
 var font = null;
 const fontSize = 32;

docs/glyph-inspector.html

@@ -69,7 +69,7 @@ <h1>Free Software</h1>
 
 
 <script type="module">
-import * as opentype from "/dist/opentype.module.js";
+import * as opentype from "/dist/opentype.mjs";
 
 window.opentype = opentype;
 

docs/index.html

@@ -76,7 +76,7 @@ <h1>Free Software</h1>
 
 
 <script type="module">
-import * as opentype from "/dist/opentype.module.js";
+import * as opentype from "/dist/opentype.mjs";
 
 const form = document.forms.demo;
 form.oninput = renderText;

docs/module.html

@@ -1,4 +1,4 @@
 <script type="module">
-    import * as ot from '/dist/opentype.module.js';
+    import * as ot from '/dist/opentype.mjs';
     console.log(ot)
 </script>

eslint.config.mjs

@@ -0,0 +1,50 @@
+import js from "@eslint/js";
+
+export default [
+  js.configs.recommended,
+  {
+    languageOptions: {
+      ecmaVersion: 2018,
+      sourceType: "module",
+      globals: {
+        console: "readonly",
+        // ugly platform-dependant classes and objects
+        DecompressionStream: "readonly",
+        Response: "readonly",
+        TextDecoder: "readonly",
+        SVGPathElement: "readonly",
+        DOMParser: "readonly",
+        Image: "readonly",
+        document: "readonly",
+      }
+    },
+    rules: {
+      "indent": [
+        "error",
+        4,
+        {
+          "SwitchCase": 1
+        }
+      ],
+      "linebreak-style": [
+        "error",
+        "unix"
+      ],
+      "quotes": [
+        "error",
+        "single"
+      ],
+      "semi": [
+        "error",
+        "always"
+      ],
+      "no-restricted-syntax": [
+        "error",
+        {
+          "message": "For consistency, Use `for()` loops instead of `.forEach()`",
+          "selector": "MemberExpression > Identifier[name=\"forEach\"]"
+        }
+      ]
+    }
+  }
+]