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, 7 insertions, 42 deletions

diff --git a/spec/functions/bool2str_spec.rb b/spec/functions/bool2str_spec.rb
index b878891..8d35598 100755
--- a/spec/functions/bool2str_spec.rb
+++ b/spec/functions/bool2str_spec.rb
@@ -1,46 +1,11 @@
-#! /usr/bin/env ruby -S rspec
 require 'spec_helper'
 
-describe "the bool2str function" do
-  let(:scope) { PuppetlabsSpec::PuppetInternals.scope }
-
-  it "should exist" do
-    expect(Puppet::Parser::Functions.function("bool2str")).to eq("function_bool2str")
-  end
-
-  it "should raise a ParseError if there is less than 1 arguments" do
-    expect { scope.function_bool2str([]) }.to( raise_error(Puppet::ParseError))
-  end
-
-  it "should convert true to 'true'" do
-    result = scope.function_bool2str([true])
-    expect(result).to(eq('true'))
-  end
-
-  it "should convert true to a string" do
-    result = scope.function_bool2str([true])
-    expect(result.class).to(eq(String))
-  end
-
-  it "should convert false to 'false'" do
-    result = scope.function_bool2str([false])
-    expect(result).to(eq('false'))
-  end
-
-  it "should convert false to a string" do
-    result = scope.function_bool2str([false])
-    expect(result.class).to(eq(String))
-  end
-
-  it "should not accept a string" do
-    expect { scope.function_bool2str(["false"]) }.to( raise_error(Puppet::ParseError))
-  end
-
-  it "should not accept a nil value" do
-    expect { scope.function_bool2str([nil]) }.to( raise_error(Puppet::ParseError))
-  end
-
-  it "should not accept an undef" do
-    expect { scope.function_bool2str([:undef]) }.to( raise_error(Puppet::ParseError))
+describe 'bool2str' do
+  it { is_expected.not_to eq(nil) }
+  it { is_expected.to run.with_params().and_raise_error(Puppet::ParseError) }
+  [ 'true', 'false', nil, :undef, ''].each do |invalid|
+    it { is_expected.to run.with_params(invalid).and_raise_error(Puppet::ParseError) }
   end
+  it { is_expected.to run.with_params(true).and_return("true") }
+  it { is_expected.to run.with_params(false).and_return("false") }
 end