Catch parse failures in PuppetStrings::Json tests

Previously, the tests for `PuppetStrings::Json` (in json_spec.rb) parsed
a variety of code samples and then queried YARD to test the results. If
a sample failed to parse, an error might be outputted (see [issue
#307][#307]), but no failure was registered by the testing harness.

This adds simple checks to verify that the parses actually succeed.

Unfortunately, one of the samples currently fails to parse, so this
commit introduces a testing error. The subbsequent commit will fix it.

[#307]: #307

Author: danielparks

spec/unit/puppet-strings/json_spec.rb

@@ -7,7 +7,7 @@
 describe PuppetStrings::Json do
   before :each do
     # Populate the YARD registry with both Puppet and Ruby source
-    YARD::Parser::SourceParser.parse_string(<<-SOURCE, :puppet)
+    expect(YARD::Parser::SourceParser.parse_string(<<-SOURCE, :puppet).enumerator.length).to eq(2)
 # A simple class.
 # @todo Do a thing
 # @note Some note
@@ -25,7 +25,7 @@ class klass(Integer $param1, $param2, String $param3 = hi) inherits foo::bar {
 }
     SOURCE
 
-    YARD::Parser::SourceParser.parse_string(<<-SOURCE, :puppet) if TEST_PUPPET_PLANS
+    expect(YARD::Parser::SourceParser.parse_string(<<-SOURCE, :puppet).enumerator.length).to eq(1) if TEST_PUPPET_PLANS
 # A simple plan.
 # @param param1 First param.
 # @param param2 Second param.
@@ -35,7 +35,7 @@ class klass(Integer $param1, $param2, String $param3 = hi) inherits foo::bar {
     SOURCE
 
     # Only include Puppet functions for 4.1+
-    YARD::Parser::SourceParser.parse_string(<<-SOURCE, :puppet) if TEST_PUPPET_FUNCTIONS
+    expect(YARD::Parser::SourceParser.parse_string(<<-SOURCE, :puppet).enumerator.length).to eq(1) if TEST_PUPPET_FUNCTIONS
 # A simple function.
 # @param param1 First param.
 # @param param2 Second param.
@@ -46,7 +46,7 @@ class klass(Integer $param1, $param2, String $param3 = hi) inherits foo::bar {
     SOURCE
 
     # Only include Puppet types for 5.0+
-    YARD::Parser::SourceParser.parse_string(<<-SOURCE, :ruby) if TEST_PUPPET_DATATYPES
+    expect(YARD::Parser::SourceParser.parse_string(<<-SOURCE, :ruby).enumerator.length).to eq(1) if TEST_PUPPET_DATATYPES
 # Basic Puppet Data Type in Ruby
 #
 # @param msg A message parameter
@@ -67,7 +67,7 @@ class klass(Integer $param1, $param2, String $param3 = hi) inherits foo::bar {
 end
 SOURCE
 
-    YARD::Parser::SourceParser.parse_string(<<-SOURCE, :json)
+    expect(YARD::Parser::SourceParser.parse_string(<<-SOURCE, :json).enumerator.length).to eq(1)
 {
   "description": "Allows you to backup your database to local file.",
   "input_method": "stdin",
@@ -92,7 +92,7 @@ class klass(Integer $param1, $param2, String $param3 = hi) inherits foo::bar {
 }
     SOURCE
 
-    YARD::Parser::SourceParser.parse_string(<<-SOURCE, :ruby)
+    expect(YARD::Parser::SourceParser.parse_string(<<-SOURCE, :ruby).enumerator.length).to eq(6)
 Puppet::Parser::Functions.newfunction(:func3x, doc: <<-DOC
 An example 3.x function.
 @param [String] first The first parameter.