Fix #2033 - Allow regexp in if expression

This changeset introduces regexp in if expression with the use of the
=~ (match) and !~ (not match) operator.

Usage:

if $uname =~ /Linux|Debian/ {
  ...
}

Moreover this patch creates ephemeral variables ($0 to $9) in the current
scope which contains the regex captures:
if $uname =~ /(Linux|Debian)/ {
  notice("this is a $1 system")
}

Signed-off-by: Brice Figureau <brice-puppet@daysofwonder.com>

2 files changed, 125 insertions, 0 deletions

diff --git a/spec/unit/parser/ast/ifstatement.rb b/spec/unit/parser/ast/ifstatement.rb
new file mode 100755
index 000000000..10d877a4b
--- /dev/null
+++ b/spec/unit/parser/ast/ifstatement.rb
@@ -0,0 +1,75 @@
+#!/usr/bin/env ruby
+
+require File.dirname(__FILE__) + '/../../../spec_helper'
+
+describe Puppet::Parser::AST::IfStatement do
+    before :each do
+        @scope = Puppet::Parser::Scope.new()
+    end
+
+    describe "when evaluating" do
+
+        before :each do
+            @test = stub 'test'
+            @test.stubs(:safeevaluate).with(@scope)
+
+            @stmt = stub 'stmt'
+            @stmt.stubs(:safeevaluate).with(@scope)
+
+            @else = stub 'else'
+            @else.stubs(:safeevaluate).with(@scope)
+
+            @ifstmt = Puppet::Parser::AST::IfStatement.new :test => @test, :statements => @stmt
+            @ifelsestmt = Puppet::Parser::AST::IfStatement.new :test => @test, :statements => @stmt, :else => @else
+        end
+
+        it "should evaluate test" do
+            Puppet::Parser::Scope.stubs(:true?).returns(false)
+
+            @test.expects(:safeevaluate).with(@scope)
+
+            @ifstmt.evaluate(@scope)
+        end
+
+        it "should evaluate if statements if test is true" do
+            Puppet::Parser::Scope.stubs(:true?).returns(true)
+
+            @stmt.expects(:safeevaluate).with(@scope)
+
+            @ifstmt.evaluate(@scope)
+        end
+
+        it "should not evaluate if statements if test is false" do
+            Puppet::Parser::Scope.stubs(:true?).returns(false)
+
+            @stmt.expects(:safeevaluate).with(@scope).never
+
+            @ifstmt.evaluate(@scope)
+        end
+
+        it "should evaluate the else branch if test is false" do
+            Puppet::Parser::Scope.stubs(:true?).returns(false)
+
+            @else.expects(:safeevaluate).with(@scope)
+
+            @ifelsestmt.evaluate(@scope)
+        end
+
+        it "should not evaluate the else branch if test is true" do
+            Puppet::Parser::Scope.stubs(:true?).returns(true)
+
+            @else.expects(:safeevaluate).with(@scope).never
+
+            @ifelsestmt.evaluate(@scope)
+        end
+
+        it "should reset ephemeral statements after evaluation" do
+            Puppet::Parser::Scope.stubs(:true?).returns(true)
+
+            @stmt.expects(:safeevaluate).with(@scope)
+            @scope.expects(:unset_ephemeral_var)
+
+            @ifstmt.evaluate(@scope)
+        end
+    end
+end
diff --git a/spec/unit/parser/ast/match_operator.rb b/spec/unit/parser/ast/match_operator.rb
new file mode 100755
index 000000000..985cf60d5
--- /dev/null
+++ b/spec/unit/parser/ast/match_operator.rb
@@ -0,0 +1,50 @@
+#!/usr/bin/env ruby
+
+require File.dirname(__FILE__) + '/../../../spec_helper'
+
+describe Puppet::Parser::AST::MatchOperator do
+    before :each do
+        @scope = Puppet::Parser::Scope.new()
+
+        @lval = stub 'lval'
+        @lval.stubs(:safeevaluate).with(@scope).returns("this is a string")
+
+        @rval = stub 'rval'
+        @rval.stubs(:evaluate_match)
+
+        @operator = Puppet::Parser::AST::MatchOperator.new :lval => @lval, :rval => @rval, :operator => "=~"
+    end
+
+    it "should evaluate the left operand" do
+        @lval.expects(:safeevaluate).with(@scope)
+
+        @operator.evaluate(@scope)
+    end
+
+    it "should fail for an unknown operator" do
+        lambda { operator = Puppet::Parser::AST::MatchOperator.new :lval => @lval, :operator => "unknown", :rval => @rval }.should raise_error
+    end
+
+    it "should evaluate_match the left operand" do
+        @rval.expects(:evaluate_match).with("this is a string", @scope).returns(:match)
+
+        @operator.evaluate(@scope)
+    end
+
+    { "=~" => true, "!~" => false }.each do |op, res|
+        it "should return #{res} if the regexp matches with #{op}" do
+            match = stub 'match'
+            @rval.stubs(:evaluate_match).with("this is a string", @scope).returns(match)
+
+            operator = Puppet::Parser::AST::MatchOperator.new :lval => @lval, :rval => @rval, :operator => op
+            operator.evaluate(@scope).should == res
+        end
+
+        it "should return #{!res} if the regexp doesn't match" do
+            @rval.stubs(:evaluate_match).with("this is a string", @scope).returns(nil)
+
+            operator = Puppet::Parser::AST::MatchOperator.new :lval => @lval, :rval => @rval, :operator => op
+            operator.evaluate(@scope).should == !res
+        end
+    end
+end