================================================================================
Single if statement
================================================================================

if foo
  Bar
endif

--------------------------------------------------------------------------------

(script_file
  (if_statement
    condition: (identifier)
    (body
      (user_command
        (command_name)))))

================================================================================
If - else statement
================================================================================

if foo
  Bar
else
  Baz
end

--------------------------------------------------------------------------------

(script_file
  (if_statement
    condition: (identifier)
    (body
      (user_command
        (command_name)))
    (else_statement
      (body
        (user_command
          (command_name))))))

================================================================================
If - elseif - else statement
================================================================================

if foo
  Bar
elseif baz
  Bux
else
  Quux
end

--------------------------------------------------------------------------------

(script_file
  (if_statement
    condition: (identifier)
    (body
      (user_command
        (command_name)))
    (elseif_statement
      condition: (identifier)
      (body
        (user_command
          (command_name))))
    (else_statement
      (body
        (user_command
          (command_name))))))

================================================================================
If - elseif statement
================================================================================

if foo
  Bar
elseif bar
  Baz
  Qux
end

--------------------------------------------------------------------------------

(script_file
  (if_statement
    condition: (identifier)
    (body
      (user_command
        (command_name)))
    (elseif_statement
      condition: (identifier)
      (body
        (user_command
          (command_name))
        (user_command
          (command_name))))))

================================================================================
If - elseif statement with a:var
================================================================================

if a:foo == 0
  Bar
elseif a:bar == 1
  Baz
  Qux
end

--------------------------------------------------------------------------------

(script_file
  (if_statement
    condition: (binary_operation
      left: (argument
        (identifier))
      right: (integer_literal))
    (body
      (user_command
        (command_name)))
    (elseif_statement
      condition: (binary_operation
        left: (argument
          (identifier))
        right: (integer_literal))
      (body
        (user_command
          (command_name))
        (user_command
          (command_name))))))