feat: Initial prototype

tests/renderer.test.mjs

@@ -0,0 +1,47 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import {normalizeText, render, styles} from '../bitmap.js';
+
+test('compact lettering renders a known phrase with correct spacing', () => {
+    assert.equal(render('HI', 'compact'), [
+        '#   # #####', '#   #   #', '#   #   #', '#####   #',
+        '#   #   #', '#   #   #', '#   # #####',
+    ].join('\n'));
+});
+
+for (const style of styles) {
+    test(`${style} renders digits, punctuation and multiline input`, () => {
+        const first = render('Hello 123!', style);
+        assert.equal(first.split('\n').length, 7);
+        assert.match(first, /\S/);
+        assert.equal(render('Hello 123!\r\nWorld?', style), `${first}\n\n${render('World?', style)}`);
+    });
+}
+
+for (const [text, expected] of [
+    ['çığöşü İ', 'CIGOSU I'],
+    ['café', 'CAFE'],
+    ['abc 123!?', 'ABC 123!?'],
+]) {
+    test(`normalizes ${text}`, () => assert.equal(normalizeText(text), expected));
+}
+
+test('unsupported characters have a visible fallback', () => {
+    assert.equal(render('🙂'), render('?'));
+});
+test('all printable ASCII characters have distinct supported glyphs', () => {
+    for (let code = 32; code <= 126; code++) {
+        const char = String.fromCharCode(code);
+        if (char === '?') continue;
+        assert.notEqual(render(char), render('?'), `missing ${char}`);
+    }
+});
+test('banner uses the original normalized letter as ink', () => {
+    assert.match(render('a', 'banner'), /^ AAA\n/);
+    assert.doesNotMatch(render('a', 'banner'), /#/);
+});
+test('rejects invalid styles and overlong text', () => {
+    assert.throws(() => render('hello', 'unknown'), /Unknown/);
+    assert.throws(() => render('x'.repeat(501)), /too long/);
+    assert.doesNotThrow(() => render('x'.repeat(500)));
+});