Convert tests to use plain rspec-puppet

Tests in the new style produces the following documentation output:

abs
  should not eq nil
  should run abs() and raise an Puppet::ParseError
  should run abs(-34) and return 34
  should run abs("-34") and return 34
  should run abs(34) and return 34
  should run abs("34") and return 34

1 files changed, 10 insertions, 35 deletions

diff --git a/spec/functions/dirname_spec.rb b/spec/functions/dirname_spec.rb
index 4261144..46c4c35 100755
--- a/spec/functions/dirname_spec.rb
+++ b/spec/functions/dirname_spec.rb
@@ -1,38 +1,13 @@
-#! /usr/bin/env ruby -S rspec
 require 'spec_helper'
 
-describe "the dirname function" do
-  let(:scope) { PuppetlabsSpec::PuppetInternals.scope }
-
-  it "should exist" do
-    expect(Puppet::Parser::Functions.function("dirname")).to eq("function_dirname")
-  end
-
-  it "should raise a ParseError if there is less than 1 arguments" do
-    expect { scope.function_dirname([]) }.to( raise_error(Puppet::ParseError))
-  end
-
-  it "should raise a ParseError if there is more than 1 argument" do
-    expect { scope.function_dirname(['a', 'b']) }.to( raise_error(Puppet::ParseError))
-  end
-
-  it "should return dirname for an absolute path" do
-    result = scope.function_dirname(['/path/to/a/file.ext'])
-    expect(result).to(eq('/path/to/a'))
-  end
-
-  it "should return dirname for a relative path" do
-    result = scope.function_dirname(['path/to/a/file.ext'])
-    expect(result).to(eq('path/to/a'))
-  end
-
-  it "should complain about hash argument" do
-    expect { scope.function_dirname([{}]) }.to( raise_error(Puppet::ParseError))
-  end
-  it "should complain about list argument" do
-    expect { scope.function_dirname([[]]) }.to( raise_error(Puppet::ParseError))
-  end
-  it "should complain about numeric argument" do
-    expect { scope.function_dirname([2112]) }.to( raise_error(Puppet::ParseError))
-  end
+describe 'dirname' do
+  it { is_expected.not_to eq(nil) }
+  it { is_expected.to run.with_params().and_raise_error(Puppet::ParseError) }
+  it { is_expected.to run.with_params('one', 'two').and_raise_error(Puppet::ParseError) }
+  it { is_expected.to run.with_params([]).and_raise_error(Puppet::ParseError) }
+  it { is_expected.to run.with_params({}).and_raise_error(Puppet::ParseError) }
+  it { is_expected.to run.with_params(1).and_raise_error(Puppet::ParseError) }
+  it { is_expected.to run.with_params('/path/to/a/file.ext', []).and_raise_error(Puppet::ParseError) }
+  it { is_expected.to run.with_params('/path/to/a/file.ext').and_return('/path/to/a') }
+  it { is_expected.to run.with_params('relative_path/to/a/file.ext').and_return('relative_path/to/a') }
 end