subcommands.md
In Rapp: Easily Build Command Line Applications

missing literal command switch prints help

Code
  yaml12::write_yaml(snapshot)
Output
  ---
  app: |-
    #!/usr/bin/env Rapp
    #| name: required-command-test
    #| description: Exercise missing command help.

    switch('',
      #| title: List entries
      list = { cat('list called\n') }
    )
  invocation:
    - usage: $ required-command-test
      output: |-
        Usage: required-command-test <COMMAND>

        Exercise missing command help.

        Commands:
          list  List entries

        For help with a specific command, run: `required-command-test <command> --help`.
    - usage: $ required-command-test list
      output: list called
  ...

missing command assignment prints help by default

Code
  yaml12::write_yaml(snapshot)
Output
  ---
  app: |-
    #!/usr/bin/env Rapp
    #| name: assigned-command-test
    #| description: Exercise missing command help.

    switch(command <- '',
      #| title: List entries
      list = { cat(command, '\n', sep = '') }
    )
  invocation:
    - usage: $ assigned-command-test
      output: |-
        Usage: assigned-command-test <COMMAND>

        Exercise missing command help.

        Commands:
          list  List entries

        For help with a specific command, run: `assigned-command-test <command> --help`.
    - usage: $ assigned-command-test list
      output: list
  ...

required false command switch allows missing command

Code
  yaml12::write_yaml(snapshot)
Output
  ---
  app: |-
    #!/usr/bin/env Rapp
    #| name: optional-command-test

    #| required: false
    switch(command <- '',
      #| title: List entries
      list = { cat(command, '\n', sep = '') }
    )
    cat('no command\n')
  invocation:
    - usage: $ optional-command-test
      output: no command
    - usage: $ optional-command-test list
      output: |-
        list
        no command
    - usage: $ optional-command-test --help
      output: |-
        Usage: optional-command-test [<COMMAND>]

        optional-command-test

        Commands:
          list  List entries

        For help with a specific command, run: `optional-command-test <command> --help`.
  ...

missing command prints help before matching positionals

Code
  yaml12::write_yaml(snapshot)
Output
  ---
  app: |-
    #!/usr/bin/env Rapp
    #| name: command-with-positional-test

    #| description: Input path.
    input <- NULL

    switch('',
      #| title: Run command
      run = { cat('run ', input, '\n', sep = '') }
    )
    cat('no command\n')
  invocation:
    - usage: $ command-with-positional-test data.csv
      output: |-
        Usage: command-with-positional-test <COMMAND> <INPUT>

        command-with-positional-test

        Commands:
          run  Run command

        Arguments:
          <INPUT>  Input path.

        For help with a specific command, run: `command-with-positional-test <command> --help`.
    - usage: $ command-with-positional-test run data.csv
      output: |-
        run data.csv
        no command
  ...

missing nested command prints scoped help

Code
  yaml12::write_yaml(snapshot)
Output
  ---
  app: |-
    #!/usr/bin/env Rapp
    #| name: nested-required-command-test

    switch('',
      #| title: Parent command
      parent = {
        switch('',
          #| title: Child command
          child = { cat('child called\n') }
        )
      }
    )
  invocation:
    - usage: $ nested-required-command-test parent
      output: |-
        Parent command

        Usage: nested-required-command-test parent <COMMAND>

        Commands:
          child  Child command

        For help with a specific command, run: `nested-required-command-test parent <command> --help`.
    - usage: $ nested-required-command-test parent child
      output: child called
  ...

optional parent command preserves required child help

Code
  yaml12::write_yaml(snapshot)
Output
  ---
  app: |-
    #!/usr/bin/env Rapp
    #| name: optional-parent-required-child-test

    #| required: false
    switch(parent_cmd <- '',
      #| title: Parent command
      parent = {
        switch(child_cmd <- NULL,
          #| title: Child command
          child = { cat('child called\n') }
        )
      }
    )
  invocation:
    - usage: $ optional-parent-required-child-test parent
      output: |-
        Parent command

        Usage: optional-parent-required-child-test parent <COMMAND>

        Commands:
          child  Child command

        For help with a specific command, run: `optional-parent-required-child-test parent <command> --help`.
    - usage: $ optional-parent-required-child-test parent child
      output: child called
  ...