Fix filenames of two function spec tests

The tests weren't being run.  Total tests increase from 2742 to 2769.

Also fix 'when using a class extending String' test.
It had been failing with...
```
RuntimeError:
       can't modify frozen AlsoString
```

3 files changed, 2 insertions, 6 deletions

diff --git a/lib/puppet/functions/length.rb b/lib/puppet/functions/length.rb
index 86e735c..5ebd455 100644
--- a/lib/puppet/functions/length.rb
+++ b/lib/puppet/functions/length.rb
@@ -3,7 +3,7 @@ Puppet::Functions.create_function(:length) do
   dispatch :length do
     param 'Variant[String,Array,Hash]', :value
   end
-  def	length(value)
+  def length(value)
     if value.is_a?(String)
       result = value.length
     elsif value.is_a?(Array) || value.is_a?(Hash)
diff --git a/spec/functions/is_function_available.rb b/spec/functions/is_function_available_spec.rb
index 44f08c0..44f08c0 100755
--- a/spec/functions/is_function_available.rb
+++ b/spec/functions/is_function_available_spec.rb
diff --git a/spec/functions/length.rb b/spec/functions/length_spec.rb
index d1ab003..487cf21 100755
--- a/spec/functions/length.rb
+++ b/spec/functions/length_spec.rb
@@ -26,10 +26,6 @@ describe 'length' do
   it { is_expected.to run.with_params('āβćđ').and_return(4) }
 
   context 'when using a class extending String' do
-    it 'should call its size method' do
-      value = AlsoString.new('asdfghjkl')
-      value.expects(:length).returns('foo')
-      expect(subject).to run.with_params(value).and_return('foo')
-    end
+    it { is_expected.to run.with_params(AlsoString.new('asdfghjkl')).and_return(9) }
   end
 end