Module: Roby::App::CucumberHelpers

Defined in:
lib/roby/app/cucumber/helpers.rb

Overview

Module with helpers to be used in cucumber specifications

Defined Under Namespace

Classes: InvalidSyntax, InvalidUnit, MissingArgument, MixingOrderAndNames, UnexpectedArgument

Constant Summary collapse

KNOWN_UNITS = 
{
    length: %w[m],
    angle: %w[deg],
    time: %w[h min s]
}.freeze

Class Method Summary collapse

Class Method Details

.apply_unit(value, unit) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Helper that converts a value with unit into the corresponding normalized value (e.g. degrees to radians)

Raises:

  • InvalidUnit if the unit parameter is unknown



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# File 'lib/roby/app/cucumber/helpers.rb', line 296

def self.apply_unit(value, unit)
    case unit
    when "deg"
        value * Math::PI / 180
    when "m"
        value
    when "h"
        value * 3600
    when "min"
        value * 60
    when "s"
        value
    else
        raise InvalidUnit,
              "unknown unit #{unit}, known units are deg, m (meters), "\
              "h (hour), min (minute) and s (seconds)"
    end
end

.parse_argument_text_to_hash(raw_arguments) ⇒ Object 



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# File 'lib/roby/app/cucumber/helpers.rb', line 100

def self.parse_argument_text_to_hash(raw_arguments)
    current = {}
    stack   = []
    scanner = StringScanner.new(raw_arguments)
    until scanner.eos?
        arg_name = scanner.scan_until(/=/)
        unless arg_name
            raise InvalidSyntax,
                  "expected to find '=' in #{raw_arguments}\n"\
                  "#{' ' * (24 + scanner.pos)}^"
        end
        arg_name = arg_name[0, arg_name.size - 1].to_sym

        if scanner.peek(1) == "{"
            scanner.getch
            stack << current
            current[arg_name] = child = {}
            current = child
        else
            match = scanner.scan_until(/(\s*,\s*|\s+and\s+|\s*}\s*)/)
            if match && (scanner[1].strip == "}")
                current[arg_name] = match[0, match.size - scanner[1].size]

                loop do
                    current = stack.pop
                    unless current
                        raise InvalidSyntax, "unbalanced closed hash"
                    end
                    break unless scanner.scan(/\s*}\s*/)
                end

                if !scanner.eos? && !scanner.scan(/\s*,\s*|\s+and\s+/)
                    raise InvalidSyntax, "expected comma or 'and' after }"
                end
            elsif match
                current[arg_name] = match[0, match.size - scanner[1].size]
            else
                current[arg_name] = scanner.rest
                scanner.terminate
            end
        end
    end

    unless stack.empty?
        raise InvalidSyntax, "expected closing } at the end of string"
    end

    current
end

.parse_arguments(raw_arguments, expected = {}, strict: true) ⇒ Object

Parsing of a set of quantities, in the form

x=VAL, y=VAL and z=VAL

The value can be specified as a numerical value with unit, in which case the value is converted into the corresponding SI unit, as e.g.

yaw=10deg

will be converted to

Hash[yaw: 0.1745] # 10 degrees in radians



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# File 'lib/roby/app/cucumber/helpers.rb', line 36

def self.parse_arguments(raw_arguments, expected = {}, strict: true)
    hash = parse_argument_text_to_hash(raw_arguments)
    parse_hash_numerical_values(hash, expected, strict: strict)
end

.parse_arguments_respectively(reference, raw_arguments, expected = {}, strict: true) ⇒ Object

Parsing of a set of quantities that follow another already given set

Examples:

pose with tolerance

the pose x=10m and y=20m with tolerance 1m and 1m


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# File 'lib/roby/app/cucumber/helpers.rb', line 156

def self.parse_arguments_respectively(
    reference, raw_arguments, expected = {}, strict: true
)
    arguments = {}
    has_implicit = false
    has_explicit = false
    raw_arguments = raw_arguments.split(/(?:\s*,\s*|\s+and\s+)/)

    # Same value for all keys
    if raw_arguments.size == 1 && (raw_arguments.first !~ /=/)
        arg_value = raw_arguments.first

        if strict
            reference.each do |key|
                unless expected[key]
                    raise UnexpectedArgument,
                          "unexpected argument found #{key}"
                end
            end
        end

        if (value_with_unit = try_numerical_value_with_unit(arg_value))
            reference.each do |key|
                if (expectation = expected[key])
                    validate_unit(key, *value_with_unit, expectation)
                end
            end
            arg_value = apply_unit(*value_with_unit)
        else
            reference.each do |key|
                is_numeric = Float(arg_value) rescue nil
                next unless (expectation = expected[key])

                msg = if is_numeric
                          "but it got no unit"
                      else
                          "but it is not even a number"
                      end
                raise InvalidUnit,
                      "expected #{key}=#{arg_value} to be "\
                      "a #{expectation}, #{msg}"
            end
        end
        reference.each do |key|
            arguments[key] = arg_value
        end
        return arguments
    end

    raw_arguments.each_with_index do |arg, arg_i|
        arg_name, arg_value = arg.split("=")

        if arg_value
            if has_implicit
                raise MixingOrderAndNames,
                      "cannot mix order-based syntax and explicit names"
            end
            has_explicit = true
        else
            if has_explicit
                raise MixingOrderAndNames,
                      "cannot mix order-based syntax and explicit names"
            end
            arg_value = arg_name
            arg_name = reference[arg_i]
            unless arg_name
                raise UnexpectedArgument,
                      "too many implicit values given, expected "\
                      "#{reference.size} (#{reference.join(', ')})"
            end
            has_implicit = true
        end

        expected_quantity = expected[arg_name.to_sym]
        if strict && !expected_quantity
            raise UnexpectedArgument, "unexpected argument found #{arg_name}"
        elsif (value_with_unit = try_numerical_value_with_unit(arg_value))
            if expected_quantity
                validate_unit(arg_name, *value_with_unit, expected_quantity)
            end
            arg_value = apply_unit(*value_with_unit)
        elsif expected_quantity
            raise InvalidUnit,
                  "expected #{arg_name}=#{arg_value} to be "\
                  "a #{expected_quantity}"
        end

        unless reference.include?(arg_name.to_sym)
            raise UnexpectedArgument,
                  "got '#{arg_name}' but was expecting one of "\
                  "#{reference.map(&:to_s).sort.join(', ')}"
        end
        arguments[arg_name.to_sym] = arg_value
    end

    if arguments.keys.to_set != reference.to_set
        missing = reference.to_set - arguments.keys
        raise MissingArgument,
              "missing #{missing.size} argument(s) "\
              "(for #{missing.map(&:to_s).sort.join(', ')})"
    end
    arguments
end

.parse_hash_numerical_entry(key, value, expected, strict: true) ⇒ Object 



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# File 'lib/roby/app/cucumber/helpers.rb', line 49

def self.parse_hash_numerical_entry(key, value, expected, strict: true)
    if strict && !expected
        raise UnexpectedArgument, "unexpected argument found #{key}"
    end

    if value.kind_of?(Hash)
        parse_hash_numerical_values(value, expected || {}, strict: strict)
    elsif (value_with_unit = try_numerical_value_with_unit(value))
        validate_unit(key, *value_with_unit, expected) if expected
        apply_unit(*value_with_unit)
    elsif expected
        raise InvalidUnit,
              "expected #{key}=#{value} to be a #{expected}, "\
              "but it got no unit"
    else
        begin
            Integer(value)
        rescue ArgumentError
            begin
                Float(value)
            rescue ArgumentError
                value
            end
        end
    end
end

.parse_hash_numerical_values(hash, expected = {}, strict: true) ⇒ Object 



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# File 'lib/roby/app/cucumber/helpers.rb', line 41

def self.parse_hash_numerical_values(hash, expected = {}, strict: true)
    hash.each_with_object({}) do |(key, value), h|
        h[key] = parse_hash_numerical_entry(
            key, value, expected[key], strict: strict
        )
    end
end

.parse_numerical_value(text, expected_quantity = nil) ⇒ (Float,String)

Parses a numerical value, possibly with a unit, in which case it is converted to the corresponding “natural” unit (e.g. meters, seconds, …)

Returns:

  • ((Float,String)) —

    the normalized value and the unit



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# File 'lib/roby/app/cucumber/helpers.rb', line 265

def self.parse_numerical_value(text, expected_quantity = nil)
    value, unit = try_numerical_value_with_unit(text)
    if unit
        if expected_quantity
            validate_unit(nil, value, unit, expected_quantity)
        end
        [apply_unit(value, unit), unit]
    elsif expected_quantity
        raise InvalidUnit, "expected a #{expected_quantity}, but got #{text}"
    else
        Float(text)
    end
end

.try_numerical_value_with_unit(string) ⇒ (Numeric,String)?

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Helper that identifies a value which looks like a numerical value with unit and returns it as (numeric, unit)

Returns:

  • ((Numeric,String), nil) 


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# File 'lib/roby/app/cucumber/helpers.rb', line 285

def self.try_numerical_value_with_unit(string)
    m = /^(-?\.\d+|-?\d+(?:\.\d+)?)([^\d.]\w*)$/.match(string)
    [Float(m[1]), m[2]] if m
end

.validate_unit(name, value, unit, quantity) ⇒ Object 



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# File 'lib/roby/app/cucumber/helpers.rb', line 85

def self.validate_unit(name, value, unit, quantity)
    unless (valid_units = KNOWN_UNITS[quantity])
        raise ArgumentError,
              "unknown quantity definition '#{quantity}', "\
              "expected one of #{KNOWN_UNITS.keys.map(&:inspect).join(', ')}"
    end

    unless valid_units.include?(unit)
        raise InvalidUnit,
              "expected a #{quantity} in place of #{name}=#{value}#{unit}"
    end

    nil
end