diff options
-rw-r--r-- | lib/puppet/parser/functions/deep_merge.rb | 44 | ||||
-rw-r--r-- | spec/unit/puppet/parser/functions/deep_merge_spec.rb | 77 |
2 files changed, 121 insertions, 0 deletions
diff --git a/lib/puppet/parser/functions/deep_merge.rb b/lib/puppet/parser/functions/deep_merge.rb new file mode 100644 index 0000000..94677b8 --- /dev/null +++ b/lib/puppet/parser/functions/deep_merge.rb @@ -0,0 +1,44 @@ +module Puppet::Parser::Functions + newfunction(:deep_merge, :type => :rvalue, :doc => <<-'ENDHEREDOC') do |args| + Recursively merges two or more hashes together and returns the resulting hash. + + For example: + + $hash1 = {'one' => 1, 'two' => 2, 'three' => { 'four' => 4 } } + $hash2 = {'two' => 'dos', 'three' => { 'five' => 5 } } + $merged_hash = deep_merge($hash1, $hash2) + # The resulting hash is equivalent to: + # $merged_hash = { 'one' => 1, 'two' => 'dos', 'three' => { 'four' => 4, 'five' => 5 } } + + When there is a duplicate key that is a hash, they are recursively merged. + When there is a duplicate key that is not a hash, the key in the rightmost hash will "win." + + ENDHEREDOC + + if args.length < 2 + raise Puppet::ParseError, ("deep_merge(): wrong number of arguments (#{args.length}; must be at least 2)") + end + + deep_merge = Proc.new do |hash1,hash2| + hash1.merge!(hash2) do |key,old_value,new_value| + if old_value.is_a?(Hash) && new_value.is_a?(Hash) + deep_merge.call(old_value, new_value) + else + new_value + end + end + end + + result = Hash.new + args.each do |arg| + next if arg.is_a? String and arg.empty? # empty string is synonym for puppet's undef + # If the argument was not a hash, skip it. + unless arg.is_a?(Hash) + raise Puppet::ParseError, "deep_merge: unexpected argument type #{arg.class}, only expects hash arguments" + end + + deep_merge.call(result, arg) + end + return( result ) + end +end diff --git a/spec/unit/puppet/parser/functions/deep_merge_spec.rb b/spec/unit/puppet/parser/functions/deep_merge_spec.rb new file mode 100644 index 0000000..fffb7f7 --- /dev/null +++ b/spec/unit/puppet/parser/functions/deep_merge_spec.rb @@ -0,0 +1,77 @@ +#! /usr/bin/env ruby -S rspec + +require 'spec_helper' + +describe Puppet::Parser::Functions.function(:deep_merge) do + let(:scope) { PuppetlabsSpec::PuppetInternals.scope } + + describe 'when calling deep_merge from puppet' do + it "should not compile when no arguments are passed" do + pending("Fails on 2.6.x, see bug #15912") if Puppet.version =~ /^2\.6\./ + Puppet[:code] = '$x = deep_merge()' + 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] = "$my_hash={'one' => 1}\n$x = deep_merge($my_hash)" + expect { + scope.compiler.compile + }.to raise_error(Puppet::ParseError, /wrong number of arguments/) + end + end + + describe 'when calling deep_merge on the scope instance' do + it 'should require all parameters are hashes' do + expect { new_hash = scope.function_deep_merge([{}, '2'])}.to raise_error(Puppet::ParseError, /unexpected argument type String/) + expect { new_hash = scope.function_deep_merge([{}, 2])}.to raise_error(Puppet::ParseError, /unexpected argument type Fixnum/) + end + + it 'should accept empty strings as puppet undef' do + expect { new_hash = scope.function_deep_merge([{}, ''])}.not_to raise_error(Puppet::ParseError, /unexpected argument type String/) + end + + it 'should be able to deep_merge two hashes' do + new_hash = scope.function_deep_merge([{'one' => '1', 'two' => '1'}, {'two' => '2', 'three' => '2'}]) + new_hash['one'].should == '1' + new_hash['two'].should == '2' + new_hash['three'].should == '2' + end + + it 'should deep_merge multiple hashes' do + hash = scope.function_deep_merge([{'one' => 1}, {'one' => '2'}, {'one' => '3'}]) + hash['one'].should == '3' + end + + it 'should accept empty hashes' do + scope.function_deep_merge([{},{},{}]).should == {} + end + + it 'should deep_merge subhashes' do + hash = scope.function_deep_merge([{'one' => 1}, {'two' => 2, 'three' => { 'four' => 4 } }]) + hash['one'].should == 1 + hash['two'].should == 2 + hash['three'].should == { 'four' => 4 } + end + + it 'should append to subhashes' do + hash = scope.function_deep_merge([{'one' => { 'two' => 2 } }, { 'one' => { 'three' => 3 } }]) + hash['one'].should == { 'two' => 2, 'three' => 3 } + end + + it 'should append to subhashes 2' do + hash = scope.function_deep_merge([{'one' => 1, 'two' => 2, 'three' => { 'four' => 4 } }, {'two' => 'dos', 'three' => { 'five' => 5 } }]) + hash['one'].should == 1 + hash['two'].should == 'dos' + hash['three'].should == { 'four' => 4, 'five' => 5 } + end + + it 'should append to subhashes 3' do + hash = scope.function_deep_merge([{ 'key1' => { 'a' => 1, 'b' => 2 }, 'key2' => { 'c' => 3 } }, { 'key1' => { 'b' => 99 } }]) + hash['key1'].should == { 'a' => 1, 'b' => 99 } + hash['key2'].should == { 'c' => 3 } + end + end +end |