Merge branch 'raphink-validate_cmd'

* raphink-validate_cmd:
  Add validate_cmd function

This merge commit closes #113

lib/puppet/parser/functions/validate_cmd.rb

@@ -0,0 +1,41 @@
+module Puppet::Parser::Functions
+  newfunction(:validate_cmd, :doc => <<-'ENDHEREDOC') do |args|
+    Perform validation of a string with an external command.
+    The first argument of this function should be a string to
+    test, and the second argument should be a path to a test command
+    taking a file as last argument. If the command, launched against
+    a tempfile containing the passed string, returns a non-null value,
+    compilation will abort with a parse error.
+
+    If a third argument is specified, this will be the error message raised and
+    seen by the user.
+
+    A helpful error message can be returned like this:
+
+    Example:
+
+        validate_cmd($sudoerscontent, '/usr/sbin/visudo -c -f', 'Visudo failed to validate sudoers content')
+
+    ENDHEREDOC
+    if (args.length < 2) or (args.length > 3) then
+      raise Puppet::ParseError, ("validate_cmd(): wrong number of arguments (#{args.length}; must be 2 or 3)")
+    end
+
+    msg = args[2] || "validate_cmd(): failed to validate content with command #{args[1].inspect}"
+
+    content = args[0]
+    checkscript = args[1]
+
+    # Test content in a temporary file
+    tmpfile = Tempfile.new("validate_cmd")
+    tmpfile.write(content)
+    tmpfile.close
+    output = `#{checkscript} #{tmpfile.path} 2>&1 1>/dev/null`
+    r = $?
+    File.delete(tmpfile.path)
+    if output
+      msg += "\nOutput is:\n#{output}"
+    end
+    raise Puppet::ParseError, (msg) unless r == 0
+  end
+end

spec/unit/puppet/parser/functions/validate_cmd_spec.rb

@@ -0,0 +1,81 @@
+require 'spec_helper'
+
+describe Puppet::Parser::Functions.function(:validate_cmd) do
+  let(:scope) { PuppetlabsSpec::PuppetInternals.scope }
+
+  # The subject of these examplres is the method itself.
+  subject do
+    # This makes sure the function is loaded within each test
+    function_name = Puppet::Parser::Functions.function(:validate_cmd)
+    scope.method(function_name)
+  end
+
+  context 'Using Puppet::Parser::Scope.new' do
+
+    describe 'Garbage inputs' do
+      inputs = [
+        [ nil ],
+        [ [ nil ] ],
+        [ { 'foo' => 'bar' } ],
+        [ { } ],
+        [ '' ],
+        [ "one", "one", "MSG to User", "4th arg" ],
+      ]
+
+      inputs.each do |input|
+        it "validate_cmd(#{input.inspect}) should fail" do
+          expect { subject.call [input] }.to raise_error Puppet::ParseError
+        end
+      end
+    end
+
+    describe 'Valid inputs' do
+      inputs = [
+        [ '/full/path/to/something', '/bin/echo' ],
+        [ '/full/path/to/something', '/bin/cat' ],
+      ]
+
+      inputs.each do |input|
+        it "validate_cmd(#{input.inspect}) should not fail" do
+          expect { subject.call input }.not_to raise_error
+        end
+      end
+    end
+
+    describe "Valid inputs which should raise an exception without a message" do
+      # The intent here is to make sure valid inputs raise exceptions when they
+      # don't specify an error message to display.  This is the behvior in
+      # 2.2.x and prior.
+      inputs = [
+        [ "hello", "/bin/false" ],
+      ]
+
+      inputs.each do |input|
+        it "validate_cmd(#{input.inspect}) should fail" do
+          expect { subject.call input }.to raise_error /validate_cmd.*?failed to validate content with command/
+        end
+      end
+    end
+
+    describe "Nicer Error Messages" do
+      # The intent here is to make sure the function returns the 3rd argument
+      # in the exception thrown
+      inputs = [
+        [ "hello", [ "bye", "later", "adios" ], "MSG to User" ],
+        [ "greetings", "salutations", "Error, greetings does not match salutations" ],
+      ]
+
+      inputs.each do |input|
+        it "validate_cmd(#{input.inspect}) should fail" do
+          expect { subject.call input }.to raise_error /#{input[2]}/
+        end
+      end
+    end
+
+    describe "Test output message" do
+      it "validate_cmd('whatever', 'kthnksbye') should fail" do
+          expect { subject.call ['whatever', 'kthnksbye'] }.to raise_error /kthnksbye.*not found/
+      end
+    end
+  end
+end