Initial commit of 001code-html Scratch frontend project.

Includes scratch-gui, scratch-vm, scratch-blocks, scratch-render, scratch-l10n, and deployment config.

Co-authored-by: Cursor <cursoragent@cursor.com>

scratch-vm/test/unit/util_rateLimiter.js

@@ -0,0 +1,32 @@
+const test = require('tap').test;
+const RateLimiter = require('../../src/util/rateLimiter.js');
+
+test('rate limiter', t => {
+    // Create a rate limiter with maximum of 20 sends per second
+    const rate = 20;
+    const limiter = new RateLimiter(rate);
+
+    // Simulate time passing with a stubbed timer
+    let simulatedTime = Date.now();
+    limiter._timer = {timeElapsed: () => simulatedTime};
+
+    // The rate limiter starts with a number of tokens equal to the max rate
+    t.equal(limiter._count, rate);
+
+    // Running okayToSend a number of times equal to the max rate
+    // uses up all of the tokens
+    for (let i = 0; i < rate; i++) {
+        t.true(limiter.okayToSend());
+        // Tokens are counting down
+        t.equal(limiter._count, rate - (i + 1));
+    }
+    t.false(limiter.okayToSend());
+
+    // Advance the timer enough so we get exactly one more token
+    // One extra millisecond is required to get over the threshold
+    simulatedTime += (1000 / rate) + 1;
+    t.true(limiter.okayToSend());
+    t.false(limiter.okayToSend());
+
+    t.end();
+});