A script which counts lines of code in Swift and Objective-C projects. It ignores blank lines and counts production code and test code separately. It provides the average number of lines per file and the standard deviation.

LineCounter.rb

# Usage: ruby LineCounter.rb <directory to search>

class LineCounter

	def initialize(lineCounts)
		@lineCounts = lineCountsFromString(lineCounts)
	end

	def lineCountsFromString(string)
		lineCountsStrings = string.split("\n")
		return lineCountsStrings.map { |e| e.to_i }
	end
	
	def standardDeviation
		variance = @lineCounts.reduce(0) { |v, e| v + (mean - e)**2 }
		variance = variance / (entries - 1).to_f
		standardDeviation = Math.sqrt(variance)
	end

	def mean
		fileCount = @lineCounts.length
		meanLineCount = sum / fileCount
	end

	def sum
		return @lineCounts.reduce(:+)
	end

	def entries
		@lineCounts.length
	end
end

directory = ARGV.last
excludeDependencies = "--exclude-dir=Carthage --exclude-dir=Pods"
includeFiles = "--include=*.swift --include=*.m"
excludeTests = "--exclude-dir=*Tests"
emptyLinePattern = "'^[[:space:]]*$'"
includeTestFiles = "--include=*Tests.swift --include=*Tests.m"

productionLineCounter = LineCounter.new(`grep #{includeFiles} #{excludeTests} #{excludeDependencies} --no-filename -cvr -e #{emptyLinePattern} #{directory}`)
testLineCounter = LineCounter.new(`grep #{includeTestFiles}  #{excludeDependencies} --no-filename -cvr -e #{emptyLinePattern} #{directory}`)

puts "There are #{productionLineCounter.sum} lines of production code."
puts "There are #{testLineCounter.sum} lines of test code."
puts "There are #{productionLineCounter.entries} production files."
puts "The mean line count for production code is #{productionLineCounter.mean}."
puts "The standard deviation for production code is #{productionLineCounter.standardDeviation}."