brew cask audit

for a given cask:
 - checks required fields
 - checks URL responds successfully
 - checks content_length specified

lib/cask/audit.rb

@@ -0,0 +1,128 @@
+class Cask::Audit
+  attr_reader :cask, :errors, :warnings, :headers, :response_status
+
+  def initialize(cask)
+    @cask = cask
+    @errors = []
+    @warnings = []
+    @headers = {}
+  end
+
+  def run!
+    _check_required_fields
+    return if errors?
+    _get_data_from_request
+    return if errors?
+    _check_response_status
+    return if errors?
+    _check_content_length
+  end
+
+  def add_error(message)
+    @errors << message
+  end
+
+  def add_warning(message)
+    @warnings << message
+  end
+
+  def errors?
+    !@errors.empty?
+  end
+
+  def warnings?
+    !@warnings.empty?
+  end
+
+  def result
+    if errors?
+      "#{Tty.red}failed#{Tty.reset}"
+    elsif warnings?
+      "#{Tty.yellow}warning#{Tty.reset}"
+    else
+      "#{Tty.green}passed#{Tty.reset}"
+    end
+  end
+
+  def summary
+    summary = ["audit for #{cask}: #{result}"]
+
+    @errors.each do |error|
+      summary << " #{Tty.red}-#{Tty.reset} #{error}"
+    end
+
+    @warnings.each do |warning|
+      summary << " #{Tty.yellow}-#{Tty.reset} #{warning}"
+    end
+
+    summary.join("\n")
+  end
+
+  def _check_required_fields
+    add_error "url is required" unless cask.url
+    add_error "version is required" unless cask.version
+    add_error "homepage is required" unless cask.homepage
+  end
+
+  http_responses = [
+    'HTTP/1.0 200 OK',
+    'HTTP/1.1 200 OK'
+  ]
+
+  OK_RESPONSES = {
+    'http'  => http_responses,
+    'https' => http_responses,
+    'ftp'   => [ 'OK' ]
+  }
+
+  def _check_response_status
+    ok = OK_RESPONSES[cask.url.scheme]
+    unless ok.include?(@response_status)
+      add_error "unexpected http response, expecting #{ok.map(&:inspect).join(' or ')}, got #{@response_status.inspect}"
+    end
+  end
+
+  def _check_content_length
+    remote_content_length = @headers['Content-Length']
+    if cask.content_length.nil?
+      add_warning "specify content_length so we can check against URL, currently: content_length '#{remote_content_length}'"
+    else
+      unless cask.content_length == remote_content_length
+        add_warning "unexpected content_length for #{cask}; specified #{cask.content_length.inspect}, but got #{remote_content_length.inspect}"
+      end
+    end
+  end
+
+  def _get_data_from_request
+    response = _curl(cask.url)
+
+    if response.empty?
+      add_error "timeout while requesting #{cask.url}"
+      return
+    end
+
+    response_lines = response.split("\n").map(&:chomp)
+
+    case cask.url.scheme
+    when 'http', 'https' then
+      @response_status = response_lines.grep(/^HTTP/).last
+      http_headers = response_lines[(response_lines.index(@response_status)+1)..-1]
+      http_headers.each { |line|
+        header_name, header_value = line.split(': ')
+        @headers[header_name] = header_value
+      }
+    when 'ftp' then
+      @response_status = 'OK'
+      response_lines.each { |line|
+        header_name, header_value = line.split(': ')
+        @headers[header_name] = header_value
+      }
+    else
+      add_error "unknown scheme for #{cask.url}"
+    end
+  end
+
+  def _curl(url)
+    `curl --max-time 5 --silent --location --head '#{url}'`
+  end
+end

lib/cask/auditor.rb

@@ -0,0 +1,7 @@
+class Cask::Auditor
+  def self.audit(cask)
+    audit = Cask::Audit.new(cask)
+    audit.run!
+    puts audit.summary
+  end
+end

lib/cask/cli/audit.rb

@@ -0,0 +1,12 @@
+class Cask::CLI::Audit
+  def self.run(*args)
+    casks_to_audit = args.empty? ? Cask.all : args.map { |arg| Cask.load(arg) }
+    casks_to_audit.each do |cask|
+      Cask::Auditor.audit(cask)
+    end
+  end
+
+  def self.help
+    "verifies installability of casks"
+  end
+end

lib/cask/dsl.rb

@@ -3,6 +3,8 @@ module Cask::DSL
     base.extend(ClassMethods)
   end
 
+  def content_length; self.class.content_length; end
+
   def homepage; self.class.homepage; end
 
   def url; self.class.url; end
@@ -10,6 +12,10 @@ module Cask::DSL
   def version; self.class.version; end
 
   module ClassMethods
+    def content_length(content_length=nil)
+      @content_length ||= content_length
+    end
+
     def homepage(homepage=nil)
       @homepage ||= homepage
     end

test/cask/audit_test.rb

@@ -0,0 +1,78 @@
+require 'test_helper'
+
+describe Cask::Audit do
+  describe "result" do
+    it "is 'failed' if there are have been any errors added" do
+      audit = Cask::Audit.new(mock())
+      audit.add_error 'bad'
+      audit.add_warning 'eh'
+      audit.result.must_match /failed/
+    end
+
+    it "is 'warning' if there are no errors, but there are warnings" do
+      audit = Cask::Audit.new(mock())
+      audit.add_warning 'eh'
+      audit.result.must_match /warning/
+    end
+
+    it "is 'passed' if there are no errors or warning" do
+      audit = Cask::Audit.new(mock())
+      audit.result.must_match /passed/
+    end
+  end
+
+  describe "run!" do
+    describe "required fields" do
+      it "adds an error if url is missing" do
+        audit = Cask::Audit.new(stub(:url => nil, :version => 'something', :homepage => 'something'))
+        audit.run!
+        audit.errors.must_include 'url is required'
+      end
+
+      it "adds an error if version is missing" do
+        audit = Cask::Audit.new(stub(:url => 'something', :version => nil, :homepage => 'something'))
+        audit.run!
+        audit.errors.must_include 'version is required'
+      end
+
+      it "adds an error if homepage is missing" do
+        audit = Cask::Audit.new(stub(:url => 'something', :version => 'something', :homepage => nil))
+        audit.run!
+        audit.errors.must_include 'homepage is required'
+      end
+    end
+
+    describe "request processing" do
+      it "adds an error if response is empty" do
+        audit = Cask::Audit.new(stub(:url => 'something', :version => 'something', :homepage => 'something'))
+        audit.stubs(:_curl).returns('')
+        audit.run!
+        audit.errors.must_include 'timeout while requesting something'
+      end
+
+      it "properly populates the response code and headers from an http response" do
+        audit = Cask::Audit.new(stub(
+          :url => URI('http://something/file.zip'),
+          :version => 'something',
+          :homepage => 'something',
+          :content_length => '123'
+        ))
+        audit.stubs(:_curl).returns(<<-RESPONSE.gsub(/^          /, ''))
+          HTTP/1.1 200 OK
+          Content-Type: application/x-apple-diskimage
+          ETag: "b4208f3e84967be4b078ecaa03fba941"
+          Content-Length: 23726161
+          Last-Modified: Sun, 12 Aug 2012 21:17:21 GMT
+        RESPONSE
+        audit.run!
+        audit.response_status.must_equal 'HTTP/1.1 200 OK'
+        audit.headers.must_equal({
+          'Content-Type' => 'application/x-apple-diskimage',
+          'ETag' => '"b4208f3e84967be4b078ecaa03fba941"',
+          'Content-Length' => '23726161',
+          'Last-Modified' => 'Sun, 12 Aug 2012 21:17:21 GMT'
+        })
+      end
+    end
+  end
+end