Add a delete_regex function

To maintain backwards compatibility, add a delete_regex function instead
of modifying delete itself.

Author: Joseph Yaworski

README.markdown

@@ -263,16 +263,24 @@ Takes a resource reference and an optional hash of attributes. Returns 'true' if
 
 #### `delete`
 
-Deletes all instances of a given element from an array, substring from a string, or key from a hash. Arrays and hashes may also match on regular expressions by providing a full regular expression.
+Deletes all instances of a given element from an array, substring from a string, or key from a hash.
 
-For example, `delete(['a','b','c','b'], 'b')` returns ['a','c']; `delete('abracadabra', 'bra')` returns 'acada'. `delete({'a' => 1,'b' => 2,'c' => 3},['b','c'])` returns {'a'=> 1}, `delete(['abf', 'ab', 'ac'], '^ab.*')` returns ['ac']. `delete(['ab', 'b'], 'b')` returns ['ab'].
+For example, `delete(['a','b','c','b'], 'b')` returns ['a','c']; `delete('abracadabra', 'bra')` returns 'acada'. `delete({'a' => 1,'b' => 2,'c' => 3},['b','c'])` returns {'a'=> 1}, `delete(['ab', 'b'], 'b')` returns ['ab'].
 
 *Type*: rvalue.
 
 #### `delete_at`
 
 Deletes a determined indexed value from an array. For example, `delete_at(['a','b','c'], 1)` returns ['a','c']. *Type*: rvalue.
 
+#### `delete_regex`
+
+Deletes all instances of a given element from an array or hash that match a provided regular expression. A string will be treated as a one-item array.
+
+For example, `delete_regex(['a','b','c','b'], 'b')` returns ['a','c']; `delete_regex({'a' => 1,'b' => 2,'c' => 3},['b','c'])` returns {'a'=> 1}, `delete_regex(['abf', 'ab', 'ac'], '^ab.*')` returns ['ac']. `delete_regex(['ab', 'b'], 'b')` returns ['ab'].
+
+*Type*: rvalue.
+
 #### `delete_values`
 
 Deletes all instances of a given value from a hash. For example, `delete_values({'a'=>'A','b'=>'B','c'=>'C','B'=>'D'}, 'B')` returns {'a'=>'A','c'=>'C','B'=>'D'} *Type*: rvalue.

lib/puppet/parser/functions/delete.rb

@@ -20,12 +20,6 @@ module Puppet::Parser::Functions
 
     delete('abracadabra', 'bra')
     Would return: 'acada'
-
-    delete(['abracadabra'], '^.*bra.*$')
-    Would return: []
-
-    delete(['abracadabra'], '^.*jimbob.*$')
-    Would return: ['abracadabra']
   EOS
   ) do |arguments|
 
@@ -36,7 +30,7 @@ module Puppet::Parser::Functions
     Array(arguments[1]).each do |item|
       case collection
         when Array, Hash
-          collection.reject! { |coll_item| (coll_item =~ %r{\b#{item}\b}) }
+          collection.delete item
         when String
           collection.gsub! item, ''
         else

lib/puppet/parser/functions/delete_regex.rb

@@ -0,0 +1,45 @@
+#
+# delete_regex.rb
+#
+
+module Puppet::Parser::Functions
+  newfunction(:delete_regex, :type => :rvalue, :doc => <<-EOS
+deletes all instances of a given element that match a regular expression
+from an array or key from a hash. Multiple regular expressions are assumed
+to be matched as an OR.
+
+*Examples:*
+
+    delete_regex(['a','b','c','b'], 'b')
+    Would return: ['a','c']
+    
+    delete_regex(['a','b','c','b'], ['b', 'c'])
+    Would return: ['a']
+
+    delete_regex({'a'=>1,'b'=>2,'c'=>3}, 'b')
+    Would return: {'a'=>1,'c'=>3}
+
+    delete_regex({'a'=>1,'b'=>2,'c'=>3}, '^a$')
+    Would return: {'b'=>2,'c'=>3}
+
+  EOS
+  ) do |arguments|
+
+    raise(Puppet::ParseError, "delete_regex(): Wrong number of arguments "+
+                              "given #{arguments.size} for 2") unless arguments.size == 2
+
+    collection = arguments[0].dup
+    Array(arguments[1]).each do |item|
+      case collection
+        when Array, Hash, String
+          collection.reject! { |coll_item| (coll_item =~ %r{\b#{item}\b}) }
+        else
+          raise(TypeError, "delete_regex(): First argument must be an Array, " +
+                             "Hash, or String. Given an argument of class #{collection.class}.")
+      end
+    end
+    collection
+  end
+end
+
+# vim: set ts=2 sw=2 et :

spec/functions/delete_regex_spec.rb

@@ -0,0 +1,54 @@
+require 'spec_helper'
+
+describe 'delete_regex' 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([]).and_raise_error(Puppet::ParseError) }
+  it { is_expected.to run.with_params([], 'two') }
+  it { is_expected.to run.with_params({}, 'two') }
+  it { is_expected.to run.with_params([], 'two', 'three').and_raise_error(Puppet::ParseError) }
+  it { is_expected.to run.with_params([], 'two', 'three', 'four').and_raise_error(Puppet::ParseError) }
+  it { is_expected.to run.with_params(1, 'two').and_raise_error(TypeError) }
+
+  describe 'deleting from an array' do
+    it { is_expected.to run.with_params([], '').and_return([]) }
+    it { is_expected.to run.with_params([], 'two').and_return([]) }
+    it { is_expected.to run.with_params(['two'], 'two').and_return([]) }
+    it { is_expected.to run.with_params(['two', 'two'], 'two').and_return([]) }
+    it { is_expected.to run.with_params(['one', 'two', 'three'], '^t.*').and_return(['one']) }
+    it { is_expected.to run.with_params(['ab', 'b', 'c', 'b'], 'b').and_return(['ab', 'c']) }
+    it { is_expected.to run.with_params(['one', 'two', 'three'], 'four').and_return(['one', 'two', 'three']) }
+    it { is_expected.to run.with_params(['one', 'two', 'three'], 'e').and_return(['one', 'two', 'three']) }
+    it { is_expected.to run.with_params(['one', 'two', 'three'], 'two').and_return(['one', 'three']) }
+    it { is_expected.to run.with_params(['two', 'one', 'two', 'three', 'two'], 'two').and_return(['one', 'three']) }
+    it { is_expected.to run.with_params(['abracadabra'], 'abr').and_return(['abracadabra']) }
+    it { is_expected.to run.with_params(['abracadabra'], '^.*jimbob.*$').and_return(['abracadabra']) }
+  end
+
+  describe 'deleting from an array' do
+    it { is_expected.to run.with_params({}, '').and_return({}) }
+    it { is_expected.to run.with_params({}, 'key').and_return({}) }
+    it { is_expected.to run.with_params({'key' => 'value'}, 'key').and_return({}) }
+    it { is_expected.to run \
+      .with_params({'key1' => 'value1', 'key2' => 'value2', 'key3' => 'value3'}, 'key2') \
+      .and_return( {'key1' => 'value1', 'key3' => 'value3'})
+    }
+    it { is_expected.to run \
+      .with_params({'key1' => 'value1', 'key2' => 'value2', 'key3' => 'value3'}, ['key1', 'key2']) \
+      .and_return( {'key3' => 'value3'})
+    }
+  end
+
+  it "should leave the original array intact" do
+    argument1 = ['one','two','three']
+    original1 = argument1.dup
+    subject.call([argument1,'two'])
+    expect(argument1).to eq(original1)
+  end
+  it "should leave the original hash intact" do
+    argument1 = {'key1' => 'value1', 'key2' => 'value2', 'key3' => 'value3'}
+    original1 = argument1.dup
+    subject.call([argument1,'key2'])
+    expect(argument1).to eq(original1)
+  end
+end

spec/functions/delete_spec.rb

@@ -13,15 +13,12 @@
     it { is_expected.to run.with_params([], 'two').and_return([]) }
     it { is_expected.to run.with_params(['two'], 'two').and_return([]) }
     it { is_expected.to run.with_params(['two', 'two'], 'two').and_return([]) }
-    it { is_expected.to run.with_params(['one', 'two', 'three'], '^t.*').and_return(['one']) }
     it { is_expected.to run.with_params(['ab', 'b', 'c', 'b'], 'b').and_return(['ab', 'c']) }
     it { is_expected.to run.with_params(['one', 'two', 'three'], 'four').and_return(['one', 'two', 'three']) }
     it { is_expected.to run.with_params(['one', 'two', 'three'], 'e').and_return(['one', 'two', 'three']) }
     it { is_expected.to run.with_params(['one', 'two', 'three'], 'two').and_return(['one', 'three']) }
     it { is_expected.to run.with_params(['two', 'one', 'two', 'three', 'two'], 'two').and_return(['one', 'three']) }
     it { is_expected.to run.with_params(['one', 'two', 'three', 'two'], ['one', 'two']).and_return(['three']) }
-    it { is_expected.to run.with_params(['abracadabra'], 'abr').and_return(['abracadabra']) }
-    it { is_expected.to run.with_params(['abracadabra'], '^.*jimbob.*$').and_return(['abracadabra']) }
   end
 
   describe 'deleting from a string' do