[IMP] model: create snapshot when loading xlsx file

Before this commit, when uploading an XLSX file, the code in the
Odoo repository would create a spreadsheet document with data that
is encoded in xml. Whenever the file is loaded, we parse the stringified
xml to convert it to the o-spreadsheet json structure. The problem is
that this conversion can be quite slow and costly when the XLSX file is
large.

This commit mitigates the issue by saving a snapshot once the XLSX file is
loaded for the first time.

Task: 4080514

src/model.ts

@@ -281,7 +281,10 @@ export class Model extends EventBus<any> implements CommandDispatcher {
 
     this.joinSession();
 
-    if (config.snapshotRequested) {
+    if (
+      config.snapshotRequested ||
+      (data["[Content_Types].xml"] && this.config.mode !== "readonly")
+    ) {
       const startSnapshot = performance.now();
       console.debug("Snapshot requested");
       this.session.snapshot(this.exportData());

tests/model/model.test.ts

@@ -1,9 +1,12 @@
 import { CommandResult, CorePlugin } from "../../src";
+import { MESSAGE_VERSION } from "../../src/constants";
 import { toZone } from "../../src/helpers";
 import { Model, ModelConfig } from "../../src/model";
 import { corePluginRegistry, featurePluginRegistry } from "../../src/plugins/index";
 import { UIPlugin } from "../../src/plugins/ui_plugin";
 import { Command, CommandTypes, CoreCommand, DispatchResult, coreTypes } from "../../src/types";
+import { MockTransportService } from "../__mocks__/transport_service";
+import { getTextXlsxFiles } from "../__xlsx__/read_demo_xlsx";
 import { setupCollaborativeEnv } from "../collaborative/collaborative_helpers";
 import { copy, selectCell, setCellContent } from "../test_helpers/commands_helpers";
 import {
@@ -366,4 +369,22 @@ describe("Model", () => {
       ],
     });
   });
+
+  test("snapshot when importing xlsx file", async () => {
+    jest.spyOn(console, "warn").mockImplementation(() => {});
+    const transport = new MockTransportService();
+    const spy = jest.spyOn(transport, "sendMessage");
+    const xlsxData = await getTextXlsxFiles();
+    new Model(xlsxData, {
+      transportService: transport,
+      client: { id: "test", name: "Test" },
+    });
+    expect(spy).toHaveBeenCalledWith({
+      type: "SNAPSHOT",
+      version: MESSAGE_VERSION,
+      nextRevisionId: expect.any(String),
+      serverRevisionId: "START_REVISION",
+      data: expect.any(Object),
+    });
+  });
 });