[Init] Initial commit - NetMesh terminal manager

application/state/textEditorSaveCoordinator.test.ts

@@ -0,0 +1,130 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+import { createTextEditorSaveCoordinator } from "./textEditorSaveCoordinator.ts";
+
+const deferred = <T = void>() => {
+  let resolve!: (value: T | PromiseLike<T>) => void;
+  let reject!: (reason?: unknown) => void;
+  const promise = new Promise<T>((res, rej) => {
+    resolve = res;
+    reject = rej;
+  });
+  return { promise, resolve, reject };
+};
+
+test("text editor save coordinator joins duplicate saves already in flight", async () => {
+  const pending = deferred();
+  const saved: string[] = [];
+  const savingStates: boolean[] = [];
+  const coordinator = createTextEditorSaveCoordinator({
+    onSave: async (content) => {
+      saved.push(content);
+      await pending.promise;
+    },
+    onSavingChange: (saving) => savingStates.push(saving),
+  });
+
+  const first = coordinator.save("remote text");
+  const second = coordinator.save("remote text");
+
+  assert.deepEqual(saved, ["remote text"]);
+  pending.resolve();
+
+  assert.equal(await first, true);
+  assert.equal(await second, true);
+  assert.deepEqual(saved, ["remote text"]);
+  assert.deepEqual(savingStates, [true, false]);
+});
+
+test("text editor save coordinator saves newer content after an in-flight save finishes", async () => {
+  const firstSave = deferred();
+  const secondSave = deferred();
+  const saved: string[] = [];
+  const coordinator = createTextEditorSaveCoordinator({
+    onSave: async (content) => {
+      saved.push(content);
+      await (content === "v1" ? firstSave.promise : secondSave.promise);
+    },
+  });
+
+  const first = coordinator.save("v1");
+  const second = coordinator.save("v2");
+
+  assert.deepEqual(saved, ["v1"]);
+  firstSave.resolve();
+  await new Promise<void>((resolve) => setTimeout(resolve, 0));
+  assert.deepEqual(saved, ["v1", "v2"]);
+  secondSave.resolve();
+
+  assert.equal(await first, true);
+  assert.equal(await second, true);
+});
+
+test("text editor save coordinator returns false to duplicate callers when the in-flight save fails", async () => {
+  const pending = deferred();
+  const errors: string[] = [];
+  const coordinator = createTextEditorSaveCoordinator({
+    onSave: async () => {
+      await pending.promise;
+      throw new Error("denied");
+    },
+    onSaveError: (error) => {
+      errors.push(error instanceof Error ? error.message : String(error));
+    },
+  });
+
+  const first = coordinator.save("content");
+  const second = coordinator.save("content");
+
+  pending.resolve();
+
+  assert.equal(await first, false);
+  assert.equal(await second, false);
+  assert.deepEqual(errors, ["denied"]);
+});
+
+test("text editor save coordinator reset prevents an old in-flight save from updating the next file", async () => {
+  const pending = deferred();
+  const successes: string[] = [];
+  const errors: string[] = [];
+  const savingStates: boolean[] = [];
+  const coordinator = createTextEditorSaveCoordinator({
+    onSave: async () => {
+      await pending.promise;
+    },
+    onSaveSuccess: (content) => successes.push(content),
+    onSaveError: (error) => errors.push(error instanceof Error ? error.message : String(error)),
+    onSavingChange: (saving) => savingStates.push(saving),
+  });
+
+  const save = coordinator.save("old file");
+  coordinator.reset();
+  pending.resolve();
+
+  assert.equal(await save, false);
+  assert.deepEqual(successes, []);
+  assert.deepEqual(errors, []);
+  assert.deepEqual(savingStates, [true, false]);
+});
+
+test("text editor save coordinator reset cancels queued stale saves", async () => {
+  const firstSave = deferred();
+  const saved: string[] = [];
+  const coordinator = createTextEditorSaveCoordinator({
+    onSave: async (content) => {
+      saved.push(content);
+      await firstSave.promise;
+    },
+  });
+
+  const first = coordinator.save("old v1");
+  const queued = coordinator.save("old v2");
+  coordinator.reset();
+  firstSave.resolve();
+  await new Promise<void>((resolve) => setTimeout(resolve, 0));
+
+  assert.equal(await first, false);
+  assert.equal(await queued, false);
+  assert.deepEqual(saved, ["old v1"]);
+});