Workspace scripts can be executed with
melos run or will be executed as hooks
before/after some specific Melos commands.
With the simple syntax, only the name of the script and the command to execute needs to be specified:
scripts: hello: echo 'Hello World'
The extends syntax allows for a more complex configuration of a script:
scripts: hello: name: hey description: 'Greet the world' run: echo '$GREETING World' env: GREETING: 'Hey'
Scripts are executed in a shell. On Windows the shell is
cmd.exe and on all
other platforms it is
If multiple commands are being executed in a script and no further commands
should be executed after a command has failed, connect the commands with
scripts: prepare: melos bootstrap && melos run build
A unique identifier for the script.
A short description, shown when using
melos run with no argument.
The command to execute.
Execute a script in multiple packages through
This options must either contain the command to execute in multiple packages or
the options for the
melos exec command.
When using the default options for
melos exec, it's easiest to specify the
command in the
scripts: hello: exec: echo 'Hello $(dirname $PWD)'
If you need to provide options for the
exec command, specify them in the
exec option and specify the command in the
scripts: hello: run: echo 'Hello $(dirname $PWD)' exec: concurrency: 1
for filtering the packages to execute the command in.
Defines the max concurrency value of how many packages will execute the command
in at any one time. Defaults to
exec should fail fast and not execute the script in further packages
if the script fails in an individual package. Defaults to
exec should order the execution of the script in multiple packages
based on the dependency graph of the packages. The script will be executed in
leaf packages first and then in packages that depend on them and so on. This is
useful for example, for a script that generates code in multiple packages, which
depend on each other. Defaults to
A map of environment variables that will be passed to the executed command.
melos exec command allows you to execute a command for
multiple packages. When used in a script, you can declare filter options in the
hello_flutter script below is only executed in Flutter packages:
scripts: hello_flutter: exec: echo 'Hello $(dirname $PWD)' select-package: flutter: true
See the global options for a list of supported filters.
When running a script that uses
select-package, you will be prompted to select
the package to execute the script in. If you want to skip this prompt and run
the script in all packages, use the
Certain Melos commands support running scripts before and after the command is executed, as well as at other interstring points in the command's execution.
All commands that support hooks at least support
post hook. Pre
hooks have the captialized name of the command prefixed with
pre. Post hooks
have the captialized name of the command prefixed with
scripts: preBootstrap: echo `bootstrap command is running...` postBootstrap: echo `bootstrap command is done`
Currently, the following Melos commands support hooks: