lib/guard/watcher.rb
# frozen_string_literal: true
require "guard/ui"
require "guard/watcher/pattern"
require "guard/watcher/pattern/match_result"
module Guard
# The watcher defines a RegExp that will be matched against file system
# modifications.
# When a watcher matches a change, an optional action block is executed to
# enable processing the file system change result.
#
class Watcher
attr_accessor :pattern, :action
# Initializes a file watcher.
#
# @param [String, Regexp] pattern the pattern to be watched by the Guard
# plugin
# @param [Block] action the action to execute before passing the result to
# the Guard plugin
#
def initialize(pattern, action = nil)
@action = action
@pattern = Pattern.create(pattern)
end
# Compare with other watcher
# @param other [Guard::Watcher] other watcher for comparing
# @return [true, false] equal or not
def ==(other)
action == other.action && pattern == other.pattern
end
# Finds the files that matches a Guard plugin.
#
# @param [Guard::Plugin] guard the Guard plugin which watchers are used
# @param [Array<String>] files the changed files
# @return [Array<Object>] the matched watcher response
#
def self.match_files(guard, files)
return [] if files.empty?
files.inject([]) do |paths, file|
guard.watchers.each do |watcher|
matches = watcher.match(file)
next(paths) unless matches
if watcher.action
result = watcher.call_action(matches)
if guard.options[:any_return]
paths << result
elsif result.respond_to?(:empty?) && !result.empty?
paths << Array(result)
else
next(paths)
end
else
paths << matches[0]
end
break if guard.options[:first_match]
end
guard.options[:any_return] ? paths : paths.flatten.map(&:to_s)
end
end
def match(string_or_pathname)
m = pattern.match(string_or_pathname)
m ? Pattern::MatchResult.new(m, string_or_pathname) : nil
end
# @private
# Executes a watcher action.
#
# @param [String, MatchData] matches the matched path or the match from the
# Regex
# @return [String] the final paths
#
def call_action(matches)
@action.arity.positive? ? @action.call(matches) : @action.call
rescue StandardError => e
UI.error "Problem with watch action!\n#{e.message}"
UI.error e.backtrace.join("\n")
end
def to_s
pattern
end
alias_method :inspect, :to_s
end
end