Staging back merge

services/export/tdei.ts

@@ -289,7 +289,7 @@ export class TdeiExporter {
     //
     await Promise.all(changesets.map(async (cs) => {
       const osc = await this._osmClient.downloadOsmChange(workspace.id, cs.id);
-      const osmChange = parseOsmChangeXml(osc);
+      const osmChange = await parseOsmChangeXml(osc);
 
       files.set(`changesets/${cs.id}.json`, JSON.stringify(osmChange));
 

services/osm.ts

@@ -407,7 +407,7 @@ export class OsmApiClient extends BaseHttpClient implements ICancelableClient {
   }
 
   async getOsmChange(workspaceId: WorkspaceId, changesetId: number): Promise<OsmChange> {
-    const osmChange = parseOsmChangeXml(await this.downloadOsmChange(workspaceId, changesetId));
+    const osmChange = await parseOsmChangeXml(await this.downloadOsmChange(workspaceId, changesetId));
 
     for (const type of OSMCHANGE_ACTION_TYPES) {
       for (const element of osmChange[type] ?? []) {

test/unit/services/osm.test.ts

@@ -0,0 +1,72 @@
+import { http, HttpResponse } from 'msw';
+import { describe, expect, it } from 'vitest';
+import { OsmApiClient } from '~/services/osm';
+import { server } from '../../mocks/server';
+
+import type { TdeiClient } from '~/services/tdei';
+
+// getOsmChange only needs its tdei collaborator for auth: a no-op refresh and an
+// `auth` object whose `complete` flag gates the Authorization header. The real
+// BaseHttpClient runs end to end — MSW intercepts at fetch, so URL building and
+// the async XML parse are exercised.
+const tdeiClient = {
+  tryRefreshAuth: async () => {},
+  auth: { complete: false, accessToken: '' }
+} as unknown as TdeiClient;
+
+const OSM_WEB_BASE = 'http://api.test/osm/';
+const OSM_API_BASE = 'http://api.test/osm/api/0.6/';
+
+// A minimal but real osmChange document: one created node carrying a tag and a
+// timestamp, so we can assert both the parsed structure and the Date coercion.
+const OSM_CHANGE_XML = `<osmChange version="0.6">
+  <create>
+    <node id="1" lat="47.6" lon="-122.3" version="1" changeset="42" timestamp="2026-07-01T00:00:00Z" user="tester" uid="9">
+      <tag k="highway" v="crossing"/>
+    </node>
+  </create>
+</osmChange>`;
+
+function makeClient() {
+  return new OsmApiClient(OSM_WEB_BASE, OSM_API_BASE, tdeiClient);
+}
+
+function stubDownload(xml: string = OSM_CHANGE_XML) {
+  server.use(
+    http.get(`${OSM_API_BASE}changeset/:id/download`, () =>
+      HttpResponse.text(xml, { headers: { 'Content-Type': 'application/xml' } })
+    )
+  );
+}
+
+describe('OsmApiClient.getOsmChange', () => {
+  // Regression: parseOsmChangeXml is async (it resolves a Promise once the
+  // streaming sax parse completes). Using it without `await` left a Promise
+  // here, which JSON.stringify's to "{}" — the bug that made the exported
+  // changesets/{id}.json empty even when the .osc had content.
+  it('parses the downloaded osmChange XML into a populated object', async () => {
+    stubDownload();
+
+    const osmChange = await makeClient().getOsmChange(1, 777);
+
+    expect(JSON.stringify(osmChange)).not.toBe('{}');
+    expect(osmChange.create).toHaveLength(1);
+
+    const element = osmChange.create![0]!;
+    expect(element.type).toBe('node');
+    expect(element.tags).toEqual({ highway: 'crossing' });
+  });
+
+  // The same missing `await` also silently skipped getOsmChange's normalization
+  // loop (it iterated the Promise, not the elements), so timestamps stayed raw
+  // strings. With the await, each element.timestamp is coerced to a Date.
+  it('normalizes each element timestamp into a Date', async () => {
+    stubDownload();
+
+    const osmChange = await makeClient().getOsmChange(1, 777);
+
+    const element = osmChange.create![0]!;
+    expect(element.timestamp).toBeInstanceOf(Date);
+    expect(element.timestamp.toISOString()).toBe('2026-07-01T00:00:00.000Z');
+  });
+});

types/osmchange-parser.d.ts

@@ -1 +1,9 @@
-declare module '@osmcha/osmchange-parser';
+declare module '@osmcha/osmchange-parser' {
+  import type { OsmChange } from './osm';
+
+  // The parser is async (built on the streaming `sax` parser); it resolves once
+  // parsing completes. Typing it as a Promise prevents callers from using the
+  // result without awaiting — doing so yields a Promise that JSON-stringifies to
+  // "{}" and whose `create`/`modify`/`delete` reads are silently undefined.
+  export default function parseOsmChangeXml(xmlString: string): Promise<OsmChange>;
+}