Refactor CLI to use thor

* Use `thor` gem for the CLI
* Add quiet/verbose/debug options to the CLI
* Bump minimum required Ruby version to 2.7.0 (oldest version we're
  testing with)
* Accept `String` arguments to `new()`

- Fixes #23
- Fixes #24

exe/scelint

@@ -1,38 +1,6 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
 
-require 'scelint'
+require 'scelint/cli'
 
-to_check = ARGV.empty? ? ['.'] : ARGV
-lint = Scelint::Lint.new(to_check)
-
-count = lint.files.count
-
-if count.zero?
-  warn 'No SCE data found.'
-  exit 0
-end
-
-lint.errors.each do |error|
-  warn error
-end
-
-lint.warnings.each do |warning|
-  warn warning
-end
-
-message = "Checked #{count} files."
-if lint.errors.count == 0
-  message += '  No errors.'
-  exit_code = 0
-else
-  message += "  #{lint.errors.count} errors."
-  exit_code = 1
-end
-
-if lint.warnings.count > 0
-  message += "  #{lint.warnings.count} warnings."
-end
-
-puts message
-exit exit_code
+Scelint::CLI.start(['lint'] + ARGV)

lib/scelint.rb

@@ -26,7 +26,7 @@ def initialize(paths = ['.'])
 
       merged_data = {}
 
-      paths.each do |path|
+      Array(paths).each do |path|
         if File.directory?(path)
           [
             'SIMP/compliance_profiles',

lib/scelint/cli.rb

@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+require 'scelint'
+require 'thor'
+require 'logger'
+
+# SCELint CLI
+class Scelint::CLI < Thor
+  class_option :quiet, type: :boolean, aliases: '-q', default: false
+  class_option :verbose, type: :boolean, aliases: '-v', default: false
+  class_option :debug, type: :boolean, aliases: '-d', default: false
+
+  desc 'lint PATH', 'Lint all files in PATH'
+  def lint(*paths)
+    paths = ['.'] if paths.nil? || paths.empty?
+    lint = Scelint::Lint.new(paths)
+
+    count = lint.files.count
+
+    if count.zero?
+      logger.error 'No SCE data found.'
+      exit 0
+    end
+
+    lint.errors.each do |error|
+      logger.error error
+    end
+
+    lint.warnings.each do |warning|
+      logger.warn warning
+    end
+
+    message = "Checked #{count} files."
+    if lint.errors.count == 0
+      message += '  No errors.'
+      exit_code = 0
+    else
+      message += "  #{lint.errors.count} errors."
+      exit_code = 1
+    end
+
+    if lint.warnings.count > 0
+      message += "  #{lint.warnings.count} warnings."
+    end
+
+    logger.info message
+    exit exit_code
+  rescue => e
+    logger.fatal e.message
+  end
+  default_task :lint
+
+  private
+
+  def logger
+    return @logger if @logger
+    @logger = Logger.new(STDOUT)
+    if options[:quiet]
+      @logger.level = Logger::FATAL
+    elsif options[:debug]
+      @logger.level = Logger::DEBUG
+    elsif options[:verbose]
+      @logger.level = Logger::INFO
+    else
+      @logger.level = Logger::INFO
+      @logger.formatter = proc do |_severity, _datetime, _progname, msg|
+        "#{msg}\n"
+      end
+    end
+    @logger
+  end
+end

scelint.gemspec

@@ -9,7 +9,7 @@ Gem::Specification.new do |spec|
 
   spec.summary       = %q{Linter SIMP Compliance Engine data}
   spec.homepage      = 'https://github.com/simp/rubygem-simp-scelint'
-  spec.required_ruby_version = Gem::Requirement.new('>= 2.5.0')
+  spec.required_ruby_version = Gem::Requirement.new('>= 2.7.0')
 
   spec.metadata['homepage_uri'] = spec.homepage
   spec.metadata['source_code_uri'] = spec.homepage
@@ -24,5 +24,6 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ['lib']
 
-  spec.add_runtime_dependency 'deep_merge'
+  spec.add_runtime_dependency 'deep_merge', '~> 1.2'
+  spec.add_runtime_dependency 'thor', '~> 1.3'
 end