Top Level Namespace

Defined Under Namespace

Modules: ShellMock

Instance Method Summary collapse

Instance Method Details

#SpawnArguments(*args) ⇒ Object

The method signatures for exec, system, & spawn are identical and complicated. This is a helper method that extracts the env vars hash, command, and options hash components. I’ve called it SpawnArguments even though it’s the same signature for exec, spawn, and system because the Ruby docs for exec and system refer to the docs for spawn, indicating that Ruby considers spawn the “origin” of the signature.

Raises:

  • (ArgumentError) 


6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
 
# File 'lib/shell_mock/spawn_arguments.rb', line 6

def SpawnArguments(*args)
  # the env vars hash is either the first argument, or empty
  env = if args.first.is_a?(Hash)
          args.shift
        else
          {}
        end

  # the options hash is either the last argument, or empty
  options = if args.last.is_a?(Hash)
              args.pop
            else
              {}
            end

  raise(ArgumentError, "You must provide a command to run.") if args.empty?

  command = args.shift

  raise(
    ArgumentError,
    "Unable to recognize first command component. Expected String or Array, got #{args.first.class}."
  ) unless command.is_a?(String) || command.is_a?(Array)

  raise(
    ArgumentError,
    "Each command component after the first must be strings."
  ) unless args.all? { |arg| arg.is_a?(String) }

  if args.empty?
    if command.is_a?(String) # single commandline string
      [env, command, options]
    elsif command.is_a?(Array)
      [env, [command], options] # [command, argv0] pair with no other command arguments
    end
  else
    # this covers
    #   a command with multiple string arguments
    # and
    #   a [command, argv0] pair with multiple string arguments
    [env, [command, *args], options]
  end
end