Testing export/import of Olm devices in the browser

Inspired by examples/browser

• Make sure you built the current version of the Matrix JS SDK (yarn build)
• make sure there is matrix.js, olm.js and olm.wasm in directory lib/
• start a local Matrix homeserver (on port 8008, or change the port in the code)
• Serve this HTML file (e.g. python3 -m http.server) and go to it through your browser
• in the JS console, do:

  aliceMatrixClient = await newMatrixClient("alice-"+randomHex());
  await aliceMatrixClient.exportDevice();
  await aliceMatrixClient.getAccessToken();
              

• copy the result of exportDevice and getAccessToken somewhere (not in a JS variable as it will be destroyed when you refresh the page)
• refresh the page (F5) to make sure the client is destroyed
• Do the following, replacing ALICE_ID with the user ID of Alice (you can find it in the exported data)

  bobMatrixClient = await newMatrixClient("bob-"+randomHex());
  roomId = await bobMatrixClient.createEncryptedRoom([ALICE_ID]);
  await bobMatrixClient.sendTextMessage('Hi Alice!', roomId);
              

• Again, refresh the page (F5). You may want to clear your console as well.
• Now do the following, using the exported data and the access token you saved previously:

  aliceMatrixClient = await importMatrixClient(EXPORTED_DATA, ACCESS_TOKEN);
              

• You should see the message sent by Bob printed in the console.