Tasks
Dart Code adds a number of tasks under the Run Task command in the command palette (Ctrl+Shift+P or Cmd+Shift+P).
These tasks can also be copied to tasks.json to allow customisation of arguments by clicking the cog icon next to the task. Tasks can be referenced in a launch.json launch config (for example in the preLaunchTask field to run a task prior to launching an app). Tasks can also be configured to run at folder open using the folderOpen field in tasks.json.
The Run Build Task command in VS Code (Ctrl+Shift+B or Cmd+Shift+B) can be used to quickly execute a task designated as a build task.
pub get, pub upgrade, flutter pub get, flutter pub upgrade, dartdoc
These tasks are the same as using the equivilent named commands and just execute pub/flutter to fetch/upgrade packages.
flutter build
Build tasks are available for Flutter projects to build common app types (apk, ios, web). These run the flutter build [type] and can be further customised by copying them to tasks.json using the cog icon.
build_runner
build_runner provides a way of generating files using Dart code, outside of tools like pub. Unlike pub serve/build, files are always generated directly on disk and rebuilds are incremental.
The build_runner tasks appear if your project(s) reference the build_runner package in pubspec.yaml. Supported commands are watch, build, serve and test. For more information on each of these commands, see the build_runner documentation.