Add show_examples_on_error setting

[DannyBen]

cc #526, #527

This PR adds the ability to specify show_examples_on_error: true. When set, the usage message will include the configured examples whenever the user misses a required argument.

$ ./cli
missing required argument: SOURCE
usage: cli [download] SOURCE TARGET [OPTIONS]
examples:
  cli download example.com
  cli download example.com ./output -f

Relevant settings:

# settings.yml
show_examples_on_error: true

# strings.yml
examples_caption_on_error: 'examples:'

[codevogel]

❌ I did find a small bug in this:

If I list no examples section when show_examples_on_error: true, then bashly generate seems to fail. This could possibly be intended behavior (maybe you want show_examples_on_error users to have this as a failcheck so they provide examples for all commands? In that case, a better error message is necessary ).

I think it would probably make more sense to have the examples section optional though.

with bashly.yml

name: pls
help: "Project Level Shortcuts - A simple tool to manage project specific aliases."
version: 0.1.0

environment_variables:
- name: pls_default
  help: Path to the root configuration file (The fallback .pls file if is is not found in the current working directory or any of its parents)
  default: $HOME/.pls

commands:
  - name: do
    help: Executes the command associated with the given alias
    default: force
    args:
      - name: alias
        help: The alias to execute
        required: true

I get

❯ bashly generate
creating user files in src
skipped src/do_command.sh (exists)
 NoMethodError
undefined method `any?' for nil

Otherwise the functionality seems great:

• ✔️ The examples are listed when I enable the setting.
• ✔️ The setting is also added to the defaults generated by bashly add settings.
• ✔️ The custom string for examples_caption_on_error adjusts the output as needed.
• ✔️ If I don't have a custom strings file, it just outputs as examples: which is the correct casing.

[DannyBen]

Excellent report, thanks.
I will fix it and add a test case.

[DannyBen]

Fixed.