[Init] Initial commit - NetMesh terminal manager

components/terminal/runtime/terminalWriteAckDeferral.test.ts

@@ -0,0 +1,49 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import type { Terminal as XTerm } from "@xterm/xterm";
+
+import {
+  XTERM_WRITE_CALLBACK_BATCH_BYTES,
+  XTERM_WRITE_CALLBACK_FAST_PATH_MAX_BYTES,
+} from "./terminalFlowConstants.ts";
+import {
+  accumulateDeferredTerminalWriteAck,
+  clearDeferredTerminalWriteAck,
+  shouldDeferTerminalWriteCallback,
+} from "./terminalWriteAckDeferral.ts";
+
+const createTerm = (): XTerm => ({}) as XTerm;
+
+test("shouldDeferTerminalWriteCallback allows small writes under the batch ceiling", () => {
+  assert.equal(
+    shouldDeferTerminalWriteCallback(
+      XTERM_WRITE_CALLBACK_FAST_PATH_MAX_BYTES,
+      0,
+      100,
+      XTERM_WRITE_CALLBACK_FAST_PATH_MAX_BYTES,
+      XTERM_WRITE_CALLBACK_BATCH_BYTES,
+    ),
+    true,
+  );
+});
+
+test("shouldDeferTerminalWriteCallback rejects writes that would cross the batch ceiling", () => {
+  assert.equal(
+    shouldDeferTerminalWriteCallback(
+      100,
+      XTERM_WRITE_CALLBACK_BATCH_BYTES - 50,
+      100,
+      XTERM_WRITE_CALLBACK_FAST_PATH_MAX_BYTES,
+      XTERM_WRITE_CALLBACK_BATCH_BYTES,
+    ),
+    false,
+  );
+});
+
+test("accumulateDeferredTerminalWriteAck tracks ingress bytes per terminal", () => {
+  const term = createTerm();
+  assert.equal(accumulateDeferredTerminalWriteAck(term, 10), 10);
+  assert.equal(accumulateDeferredTerminalWriteAck(term, 5), 15);
+  assert.equal(clearDeferredTerminalWriteAck(term), 15);
+  assert.equal(clearDeferredTerminalWriteAck(term), 0);
+});