(#19272) Add has_element() function

It is exceptionally difficult to determine if an array contains an element matching a specific value without an iteration or loop construct.

This function is the Puppet equivalent of Array.includes?(foo) in Ruby.  The implementation is a verbatim copy of has_key() with the minor modifications needed to support arrays instead of hashes.

1 files changed, 42 insertions, 0 deletions

diff --git a/spec/unit/puppet/parser/functions/has_element_spec.rb b/spec/unit/puppet/parser/functions/has_element_spec.rb
new file mode 100644
index 0000000..b5270d2
--- /dev/null
+++ b/spec/unit/puppet/parser/functions/has_element_spec.rb
@@ -0,0 +1,42 @@
+#! /usr/bin/env ruby -S rspec
+require 'spec_helper'
+
+describe Puppet::Parser::Functions.function(:has_element) do
+  let(:scope) { PuppetlabsSpec::PuppetInternals.scope }
+
+  describe 'when calling has_element from puppet' do
+    it "should not compile when no arguments are passed" do
+      pending("Fails on 2.6.x, see bug #15912") if Puppet.version =~ /^2\.6\./
+      Puppet[:code] = '$x = has_element()'
+      expect {
+        scope.compiler.compile
+      }.to raise_error(Puppet::ParseError, /wrong number of arguments/)
+    end
+
+    it "should not compile when 1 argument is passed" do
+      pending("Fails on 2.6.x, see bug #15912") if Puppet.version =~ /^2\.6\./
+      Puppet[:code] = "$x = has_element('foo')"
+      expect {
+        scope.compiler.compile
+      }.to raise_error(Puppet::ParseError, /wrong number of arguments/)
+    end
+
+    it "should require the first value to be an Array" do
+      pending("Fails on 2.6.x, see bug #15912") if Puppet.version =~ /^2\.6\./
+      Puppet[:code] = "$x = has_element('foo', 'bar')"
+      expect {
+        scope.compiler.compile
+      }.to raise_error(Puppet::ParseError, /expects the first argument to be an array/)
+    end
+  end
+
+  describe 'when calling the function has_element from a scope instance' do
+    it 'should detect existing elements' do
+      scope.function_has_element([['one'], 'one']).should be_true
+    end
+
+    it 'should detect existing elements' do
+      scope.function_has_element([['one'], 'two']).should be_false
+    end
+  end
+end