This repository showcases how to build a Flutter application for different desktop platforms. Flutter only allows building for the host platform, i.e. macOS builds are only possible when building on macOS. Moreover, it requires the macos or windows folders, which can be found in this repo.

The location of the application installers on the CI machine is $project-dir/build/macos/Build/Products/Release/sample.dmg for macOS and $project-dir\sample_app-SetupFiles for Windows.

The instructions that are used to build the installer can be found in the appveyor.yml file.

Summary

1. Install Flutter.
2. Run flutter channel master and flutter upgrade, as desktop requires the most recent Flutter version.
3. Run flutter config --enable-<windows|macos|linux>-desktop.
4. Run flutter doctor and fix whatever complaints it has. It looks like this:

[X] Visual Studio - develop for Windows
    X Visual Studio not installed; this is necessary for Windows development.
      Download at https://visualstudio.microsoft.com/downloads/.
      Please install the "Desktop development with C++" workload, including the following components:
        MSBuild
        MSVC v142 - VS 2019 C++ x64/x86 build tools
         - If there are multiple build tool versions available, install the latest
        Windows 10 SDK (10.0.17763.0)

Instructions are straightforward and following them lets you build desktop applications.

After doing this, flutter build <windws|macos|linux> produces a native application:

A directory like this for Windows

 Directory of C:\projects\sample-dart-project\build\windows\x64\Release\Runner
05/15/2020  11:12 AM    <DIR>          .
05/15/2020  11:12 AM    <DIR>          ..
05/15/2020  11:12 AM    <DIR>          data
05/15/2020  11:11 AM        29,130,752 flutter_windows.dll
05/15/2020  11:12 AM            68,608 sample_project.exe
05/15/2020  11:12 AM           963,701 sample_project.iobj
05/15/2020  11:12 AM           530,640 sample_project.ipdb
05/15/2020  11:12 AM         1,208,320 sample_project.pdb
               5 File(s)     31,902,021 bytes

Or a directory this for macOS:

$> pwd
/home/dev/sample_project/build/macos/Build/Products/Release
$> ls -l
sample_project.app
sample_project.app.dSYM
sample_project.swiftmodule

Notes on Windows

As per the Flutter desktop documentation, building a Windows application is possible, but not in a stable state. Moreover, Flutter calls Windows builds "debug" builds, producing the following warning:

Warning: Only debug is currently implemented for Windows. This is effectively a debug build.
See https://github.com/flutter/flutter/issues/38477 for details and updates.

Notes on CI choice

I have chosen to use Appveyor, because of its Windows support.

Namely, it provides a Visual Studio 2019 image out of the box. Windows builds require Visual Studio and its additional components: MSBuild, MSVC v142 - VS 2019 C++ x64/x86 build tools and Windows 10 SDK (10.0.17763.0).

Using Travis with Windows requires more os-specific configuration, same goes for GitHub Actions CI.

Notes on installer creation tools

For macOS, a script from the create-dmg NPM package was used. It is MIT licensed.

For Windows, an Advanced Installer choco package was used. Its free version is enough to create a necessary installer.