devtools 0.0.1

Performance tools for Dart and Flutter.

What is this?

This repo is a companion repo to the main flutter repo. It contains the source code for a suite of performance tools for Dart and Flutter.

But there's not much here?

It's still very early in development - stay tuned.

Development

• git clone https://github.com/flutter/devtools
• cd devtools
• pub get

From a separate terminal:

• cd <path/to/flutter-sdk>/examples/flutter_gallery
• ensure the iOS Simulator is open (or a physical device is connected)
• flutter run

From the devtools directory:

• pub run webdev serve web

Then, open a browser window to the local url specified by webdev. After the page has loaded, append ?port=xxx to the url, where xxx is the port number of the service protocol port, as specified by the flutter run output.

For more productive development, launch your flutter application specifying --observatory-port so the observatory is available on a fixed port. This lets you avoid manually entering the observatory port parameter each time you launch the application.

• flutter run --observatory-port=8888
• open http://localhost:8080/?port=8888

pub run webdev provides a fast development server that incrementally rebuilds the portion of the application that was edited each time you reload the page in the browser. If initial app load times become slow as this tool grows, we can integrate with the hot restart support in webdev.

Testing

Running tests that depend on the Flutter SDK

Make sure your flutter SDK matches the tip of trunk before running these tests.

pub run test --tags useFlutterSdk

Run all other tests

pub run test --exclude-tags useFlutterSdk
pub run test --exclude-tags useFlutterSdk --platform chrome-no-sandbox

Updating golden files:

Some of the golden file tests will fail if Flutter changes the implementation or diagnostic properties of widgets used by the inspector tests. If this happens, make sure the golden file output still looks reasonable and execute the following command to update the golden files.

tool/update_goldens.sh

Deployment

The general deployment strategy for this tool has not yet been finalized.

Currently the application is built using dartdevc, which provides a productive development experience. The application, however, will be deployed using the Dart2Js compiler, which generates significantly faster JS. Before optimizing slow code, make sure there is still a performance issue when running the application with Dart2js.