Grinder is a task runner for Dart, helping to define and automate common project workflows.



Dart pub package

Dart workflows, automated.

Grinder consists of a library to define project tasks (e.g. test, build, doc) and a command-line tool to run them.

Getting Started

To start using grinder, add it to your dev_dependencies.

Defining Tasks

Tasks are defined entirely by Dart code allowing you to take advantage of the whole Dart ecosystem to write and debug them. Task definitions reside in a tool/grind.dart script. To create a simple grinder script, run:

pub run grinder:init

In general, grinder scripts look something like this:

import 'package:grinder/grinder.dart';

main(args) => grind(args);

@DefaultTask('Build the project.')
build() {

@Task('Test stuff.')
test() {
  new PubApp.local('test').run([]);

@Task('Generate docs.')
doc() {
  log("Generating docs...");

@Task('Deploy built app.')
@Depends(build, test, doc)
deploy() {

Any task dependencies (see @Depends above), are run before the dependent task.

Grinder contains a variety of convenience APIs for common task definitions, such as PubApp referenced above. See the API Documentation for full details.

Running Tasks

First install the grind executable:

pub global activate grinder

then use it to run desired tasks:

grind test
grind build doc

or to run a default task (see @DefaultTask above):


or to display a list of available tasks and their dependencies:

grind -h

You can also bypass installing grind and instead use pub run grinder.

Passing parameters to tasks

In order to pass parameters to tasks from the command-line, you query the TaskArgs instance for your task invocation. For example:

grind build --release --mode=topaz


build() {
  TaskArgs args = context.invocation.arguments;
  bool isRelease = args.getFlag('release'); // will be set to true
  String mode = args.getOption('mode'); // will be set to topaz

would pass the flag release and the option mode to the build task.

You can pass flags and options to multiple tasks. The following command-line would pass separate flags and options to two different tasks:

grind build --release generate-docs --header=small


This is not an official Google product.

Publishing automation

For information about our publishing automation and release process, see