Module: Modulation::Paths

Defined in:
lib/modulation/paths.rb

Overview

Implements methods for expanding relative or incomplete module file names

Constant Summary collapse

CALLER_FILE_REGEXP =

Regexp for extracting filename from caller reference

/^([^\:]+)\:?/.freeze
TAGGED_REGEXP = 
/^@([^\/]+)(\/.+)?$/.freeze
RE_TAG = 
/^@([^\/]+)/.freeze
GEM_NAME_RE = 
/^([^\/]+)/.freeze

Class Method Summary collapse

Class Method Details

.absolute_dir_path(path, caller_location) ⇒ String

Computes and verifies the absolute directory path

Parameters:

  • path —

    String] unqualified path

  • caller_location (String) —

    caller location

Returns:

  • (String) —

    absolute directory path



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# File 'lib/modulation/paths.rb', line 58

def absolute_dir_path(path, caller_location)
  path = expand_tag(path)
  caller_file = caller_location[CALLER_FILE_REGEXP, 1]
  return nil unless caller_file

  path = File.expand_path(path, File.dirname(caller_file))
  File.directory?(path) ? path : (raise "Invalid directory #{path}")
end

.absolute_path(path, caller_location) ⇒ String

Resolves the absolute path to the provided reference. If the file is not found, will try to resolve to a gem

Parameters:

  • path (String) —

    unqualified file name

  • caller_location (String) —

    caller location

Returns:

  • (String) —

    absolute file name



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# File 'lib/modulation/paths.rb', line 46

def absolute_path(path, caller_location)
  caller_file = caller_location[CALLER_FILE_REGEXP, 1]
  return nil unless caller_file

  path = File.expand_path(path, File.dirname(caller_file))
  check_path(path)
end

.add_tags(new_tags, caller_location) ⇒ Object 



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# File 'lib/modulation/paths.rb', line 23

def add_tags(new_tags, caller_location)
  caller_file = caller_location[CALLER_FILE_REGEXP, 1]
  caller_dir = caller_file ? File.dirname(caller_file) : nil

  new_tags.each do |k, path|
    tags[k.to_s] = caller_dir ? File.expand_path(path, caller_dir) : path
  end
end

.check_path(path) ⇒ String?

Checks that the given path references an existing file, adding the .rb extension if needed

Parameters:

  • path (String) —

    absolute file path (with/without .rb extension)

Returns:

  • (String, nil) —

    path of file or nil if not found



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# File 'lib/modulation/paths.rb', line 71

def check_path(path)
  if File.file?("#{path}.rb")
    path + '.rb'
  elsif File.file?(path)
    path
  end
end

.expand_tag(path) ⇒ Object 



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# File 'lib/modulation/paths.rb', line 34

def expand_tag(path)
  path.sub RE_TAG do
    tag = Regexp.last_match[1]
    tags[tag] || (raise "Invalid tag #{tag}")
  end
end

.find_gem_based_path(gemspec, path) ⇒ String

Finds full path for gem file based on gem’s require paths

Parameters:

  • gemspec (Gem::Specification) —

    gem spec

  • path (String) —

    given import path

Returns:

  • (String) —

    full path



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# File 'lib/modulation/paths.rb', line 111

def find_gem_based_path(gemspec, path)
  gemspec.full_require_paths.each do |p|
    full_path = check_path(File.join(p, path))
    return full_path if full_path
  end
  nil
end

.gem_uses_modulation?(gemspec) ⇒ Boolean

Returns true if given gemspec depends on modulation, which means it can be loaded using import

Parameters:

  • gemspec (Gem::Specification) —

    gem spec

Returns:

  • (Boolean) —

    does gem depend on modulation?



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# File 'lib/modulation/paths.rb', line 103

def gem_uses_modulation?(gemspec)
  gemspec.dependencies.map(&:name).include?('modulation')
end

.lookup_gem_path(name) ⇒ String, Symbol

Resolves the provided path by looking for a corresponding gem. If no gem is found, returns nil. If the corresponding gem does not use modulation, returns :require_gem, which signals that the gem must be required.

Parameters:

  • name (String) —

    gem name

Returns:

  • (String, Symbol) —

    absolute path or :require_gem



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# File 'lib/modulation/paths.rb', line 86

def lookup_gem_path(name)
  gem = name[GEM_NAME_RE, 1] || name
  spec = Gem::Specification.find_by_name(gem)

  if gem_uses_modulation?(spec)
    find_gem_based_path(spec, name)
  else
    :require_gem
  end
rescue Gem::MissingSpecError
  nil
end

.process(path, caller_location) ⇒ Object 



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# File 'lib/modulation/paths.rb', line 7

def process(path, caller_location)
  path = expand_tag(path)
  absolute_path(path, caller_location) ||
    lookup_gem_path(path)
end

.tags ⇒ Object 



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# File 'lib/modulation/paths.rb', line 17

def tags
  @tags ||= {
    'modulation' =>  File.join(Modulation::DIR, 'modulation/modules')
  }
end