fix: avoid duplicate text when a page is edited externally in sync mode

client/spaces/evented_space_primitives.test.ts

@@ -0,0 +1,84 @@
+import { describe, expect, test } from "vitest";
+import type { FileMeta } from "@silverbulletmd/silverbullet/type/index";
+import { EventedSpacePrimitives } from "./evented_space_primitives.ts";
+import type { SpacePrimitives } from "./space_primitives.ts";
+import type { EventHook } from "../plugos/hooks/event.ts";
+import type { DataStore } from "../data/datastore.ts";
+
+function meta(name: string, lastModified: number): FileMeta {
+  return {
+    name,
+    lastModified,
+    created: lastModified,
+    contentType: "text/markdown",
+    size: 0,
+    perm: "rw",
+  };
+}
+
+function setup(lastModified = 2000) {
+  const events: { name: string; args: unknown[] }[] = [];
+  const wrapped = {
+    readFile: async (path: string) => ({
+      data: new Uint8Array(),
+      meta: meta(path, lastModified),
+    }),
+    writeFile: async (path: string) => meta(path, lastModified),
+    getFileMeta: async (path: string) => meta(path, lastModified),
+  } as unknown as SpacePrimitives;
+  const store = new Map<string, unknown>();
+  const ds = {
+    get: async (key: string[]) => store.get(key.join("/")),
+    set: async (key: string[], value: unknown) => {
+      store.set(key.join("/"), value);
+    },
+  } as unknown as DataStore;
+  const eventHook = {
+    dispatchEvent: async (name: string, ...args: unknown[]) => {
+      events.push({ name, args });
+      return [];
+    },
+  } as unknown as EventHook;
+  const sp = new EventedSpacePrimitives(wrapped, eventHook, ds);
+  return { sp, events };
+}
+
+const fileChanged = (events: { name: string; args: unknown[] }[]) =>
+  events.filter((e) => e.name === "file:changed");
+
+// file:changed fires from inside writeFile, before it returns, so ownWrite is
+// a listener's only way to tell its own write from somebody else's.
+describe("EventedSpacePrimitives file:changed ownWrite flag", () => {
+  test("a write of our own is flagged as such", async () => {
+    const { sp, events } = setup();
+    await sp.enable();
+
+    await sp.writeFile("index.md", new Uint8Array());
+
+    expect(fileChanged(events).map((e) => e.args)).toEqual([
+      ["index.md", undefined, 2000, true],
+    ]);
+  });
+
+  test("a change merely observed by a metadata probe is not", async () => {
+    const { sp, events } = setup();
+    await sp.enable();
+
+    await sp.getFileMeta("index.md");
+
+    expect(fileChanged(events).map((e) => e.args)).toEqual([
+      ["index.md", undefined, 2000, false],
+    ]);
+  });
+
+  test("a change merely observed by a read is not", async () => {
+    const { sp, events } = setup();
+    await sp.enable();
+
+    await sp.readFile("index.md");
+
+    expect(fileChanged(events).map((e) => e.args)).toEqual([
+      ["index.md", undefined, 2000, false],
+    ]);
+  });
+});