The `fmt` command

The fmt command formats a given Alloy configuration file.

Usage

alloy fmt [<FLAG> ...] <FILE_NAME>

Replace the following:

<FLAG>: One or more flags that define the input and output of the command.
<FILE_NAME>: The Alloy configuration file.

If the <FILE_NAME> argument isn’t provided or if the <FILE_NAME> argument is equal to -, fmt formats the contents of standard input. Otherwise, fmt reads and formats the file from disk specified by the argument.

The --write flag can be specified to replace the contents of the original file on disk with the formatted results. --write can only be provided when fmt isn’t reading from standard input.

The --test flag can be specified to test if the contents of the file are formatted correctly.

The --write and --test flags are mutually exclusive.

The command fails if the file being formatted has syntactically incorrect Alloy configuration, but doesn’t validate whether Alloy components are configured properly.

The following flags are supported:

--write, -w: Write the formatted file back to disk when not reading from standard input.
--test, -t: Only test the input and return a non-zero exit code if changes would have been made.