Console application for filtering CSV

bin/csv-filter

@@ -0,0 +1,26 @@
+#!/usr/bin/env ruby
+
+require 'optparse'
+require 'csv'
+
+options = {}
+
+parser = OptionParser.new
+
+parser.version = CSV::VERSION
+parser.banner = <<-BANNER
+Usage: #{parser.program_name} [options]
+
+  Reads and parses the CSV text content of the standard input per the given input options.
+  From that content, generates CSV text per the given output options
+  and writes that text to the standard output.
+
+BANNER
+
+parser.separator('Generic Options')
+parser.separator(nil)
+
+parser.parse!
+
+CSV.filter(**options) do |row|
+end

test/csv/csv-filter/test_csv_filter.rb

@@ -0,0 +1,92 @@
+# frozen_string_literal: false
+
+require_relative "../helper"
+
+class TestFilter < Test::Unit::TestCase
+
+  def setup
+    @input = [
+      %w[aaa bbb ccc].join(","),
+      %w[ddd eee fff].join(","),
+      "" # Force trailing newline.
+    ].join("\n")
+  end
+
+  # Return filepath of file containing CSV data.
+  def csv_filepath(input, dirpath, option)
+    filename = "#{option}.csv"
+    filepath = File.join(dirpath, filename)
+    File.write(filepath, input)
+    filepath
+  end
+
+  # Return stdout and stderr from CLI execution.
+  def run_csv_filter(filepath, *cli_option_names)
+    top_dir = File.join(__dir__, "..", "..", "..")
+    command_line = [
+      Gem.ruby,
+      "-I",
+      File.join(top_dir, "lib"), 
+      File.join(top_dir, "bin", "csv-filter"),
+      *cli_option_names,
+      filepath,
+    ].join(" ")
+    Tempfile.create("stdout", mode: File::RDWR) do |stdout|
+      Tempfile.create("stderr", mode: File::RDWR) do |stderr|
+        system(command_line, {1 => stdout, 2 => stderr})
+        stdout.rewind
+        stderr.rewind
+        [stdout.read, stderr.read]
+      end
+    end
+  end
+
+  # Return results for CLI-only option (or invalid option).
+  def results_for_cli_option(option_name)
+    output = ""
+    error = ""
+    Dir.mktmpdir do |dirpath|
+      sym = option_name.to_sym
+      filepath = csv_filepath("", dirpath, sym)
+      output, error = run_csv_filter(filepath, [option_name])
+    end
+    [output, error]
+  end
+
+  # Get and return the actual output from the API.
+  def api_output(input, **api_options)
+    output = ""
+    CSV.filter(input, output, **api_options) {|row| }
+    output
+  end
+
+  # Test for invalid option.
+
+  def test_invalid_option
+    output, error = results_for_cli_option("-Z")
+    assert_equal("", output)
+    assert_match(/OptionParser::InvalidOption/, error)
+  end
+
+  # Test for no options.
+
+  def test_no_options
+    output = api_output(@input)
+    assert_equal(@input, output)
+  end
+
+  # Tests for general options.
+
+  def test_option_h
+    output, error = results_for_cli_option("-h")
+    assert_equal("Usage: csv-filter [options]\n", output.lines.first)
+    assert_equal("", error)
+  end
+
+  def test_option_v
+    output, error = results_for_cli_option("-v")
+    assert_match(/\d+\.\d+\.\d+/, output)
+    assert_equal("", error)
+  end
+
+end