fauxcli

FauxCLI (pronounced foak-ley) mocks a command line client from a given YAML file.

Quickstart

Install:

$ go get github.com/nextrevision/fauxcli

Create a cli.yml file in your current directory (or init one with FAUXCLI_INIT=1 fauxcli):

name: spiderpig
help: does whatever a spiderpig does
commands:
  - name: swing
    help: swings from a web
    output: |
      I can't do that, I'm a pig!
  - name: plop
    help: super secret maneuver
    output: |
      Look out!

Run fauxcli:

$ fauxcli
does whatever a spiderpig does

Usage:
  spiderpig [command]

Available Commands:
  swing       swings from a web
  plop        super secret maneuver

Flags:
  -h, --help   help for spiderpig

Use "spiderpig [command] --help" for more information about a command.

With a subcommand:

$ fauxcli swing
I can't do that, I'm a pig!

Aliasing:

$ alias spiderpig='fauxcli'
$ spiderpig plop
Look out!

Installation

With go:

go get github.com/nextrevision/fauxcli

Using GitHub releases:

# OSX
curl -s -o /usr/local/bin/fauxcli https://github.com/nextrevision/fauxcli/releases/download/1.1.0/fauxcli_darwin_amd64

# Linux
curl -s -o /usr/local/bin/fauxcli https://github.com/nextrevision/fauxcli/releases/download/1.1.0/fauxcli_linux_amd64

chmod +x /usr/local/bin/fauxcli

cli.yml

The cli.yml file holds all the details required in order to mock a CLI application. By default, fauxcli will look in your current directory for this file. You can override this setting with the FAUXCLI_FILE environment variable pointing to a different YAML file of your choosing.

---
# (required) name of the command
name: mycliapp

# (required) the help text for the command (displayed with -h)
help: does something cool

# additional command aliases
aliases: ["myapp", "app"]

# output to print when the command is run
# if this key is omitted, the command will act as a
# parent to any subcommands, essentially doing nothing
# but printing the help text
output: |
  Hello, World!

# flags available to the command
flags:
    # (required) long name of the flag (--debug)
  - name: debug

    # (required) help text for the flag
    help: enables debugging

    # short name for the flag (-d)
    short: d

    # default value of the flag
    default: false

    # make the flag globally available
    global: true

    # the type of the value (default string)
    # available types:
    #   - string
    #   - bool
    #   - int
    #   - float
    type: bool

# subcommands (nested from all the options above)
commands:
  - name: subcommand1
    help: a subcommand
    flags:
      - name: upper
        help: converts output to uppercase
        short: u
        type: bool
    output: |
      {{ if .Flags.upper.Bool -}}
      HELLO FROM SC1!
      {{ else -}}
      Hello from SC1!
      {{ end -}}
  - name: subcommand2
    help: another subcommand with children
    commands:
      - name: child1
        help: the first child command
        output: |
          Hello from child1
      - name: child2
        help: the second child command
        output: |
          Hello from child2

Initializing a cli.yml

Run fauxcli with the environment variable FAUXCLI_INIT set to 1 to create a sample cli.yml.

$ FAXUCLI_INIT=1 fauxcli
Hello, World!

Output

The output section of a command uses the Golang template syntax (also see https://gohugo.io/templates/go-templates/). There are two main variables exposed to you:

1. Flags, the list of flags defined in your cli.yaml.
2. Args, a list of additional string arguments passed to the command.

Flags

Flags can be accessed using the following syntax in the output section: {{ .Flags.flagname }}. This, however, is not very useful on its own. If you want to retrieve the genericly typed value of a flag, you can use {{ .Flags.flagname.Value }}. This is useful for just dumping the value, regardless of type. If you are doing a comparison, like checking if a string flag's value is empty, you need to retrieve the typed value instead, so for a string {{ .Flags.flagname.String }}, bools {{ .Flags.flagname.Bool }}, ints {{ .Flags.flagname.Int }}, and floats {{ .Flags.flagname.Float }}.

Args

Additional arguments passed to the command can be accessed via the {{ .Args }} variable. Useful functions related to args are:

• Checking if args are passed (or empty): {{ .Args | lengthis 0 }}
• Retrieving the first arg: {{ .Args | first }}
• Looping over the args:

{{ range $i, $v := .Args -}}
arg{{ $i }} value: {{ $v }}
{{ end -}}

Pipelines/Filters (methods available in functions)

A number of methods are made available to use in the functions, taken primarily from Pallinder/go-randomdata and leekchan/gtf:

Random Data Functions

Sometimes is useful to mix up the output type you will receive. Also "foo" and "bar" get a little boring compared to "sargentbrindle" and "fishhail". Here are some functions to generate random values in your output templates (from Pallinder/go-randomdata):

Function	Description	Example	Usage
name	returns a silly, random, one-word name	Apeflannel	{{ name }}
fullname	returns a capitalized, first and last name	Natalie White	{{ fullname }}
email	returns a random email address	[email protected]	{{ email }}
city	returns the name of a random city	Skidaway Island	{{ city }}
street	returns the name of a random street	Wilson Ct	{{ street }}
address	returns a random street address (two lines)	48 Lincoln Circle,\nBurrton, MS, 85910	{{ address }}
number	returns a random number for a given range	4	{{ number 1 10 }}
paragraph	returns a random paragraph	One dog rolled before him...snip	{{ paragraph }}
ipaddress	returns a random IPv4 address	32.254.96.245	{{ ipaddress }}
day	returns a random day	Sunday	{{ day }}
month	returns a random month	November	{{ month }}
date	returns a random date	Wednesday 8 Apr 2016	{{ date }}

Imported from GTF

Again, see the reference here for additional details.

• replace
• default
• length
• lower
• upper
• truncatechars
• urlencode
• wordcount
• divisibleby
• lengthis
• trim
• capfirst
• pluralize
• yesno
• rjust
• ljust
• center
• filesizeformat
• apnumber
• intcomma
• ordinal
• first
• last
• join
• slice
• random
• striptags

Custom

Function	Description	Usage
string	type casts value as a string	`{{ .Flags.flagname.Value
bool	type casts value as a bool	`{{ .Flags.flagname.Value
int	type casts value as a int	`{{ .Flags.flagname.Value
float	type casts value as a float (float64)	`{{ .Flags.flagname.Value
count	returns an iterator with the specified size	{{ range $i, $_ := count 3 }}

Examples

Check out the examples directory for some sample apps.