raise error if multiple constraints are met

2 files changed, 36 insertions, 32 deletions

diff --git a/lib/chef/dsl/platform_introspection.rb b/lib/chef/dsl/platform_introspection.rb
index 2e22662ca2..ff48cc16d2 100644
--- a/lib/chef/dsl/platform_introspection.rb
+++ b/lib/chef/dsl/platform_introspection.rb
@@ -70,20 +70,29 @@ class Chef
         def match_versions(node)
           begin
             platform, version = node[:platform].to_s, node[:platform_version].to_s
-            return unless @values.key?(platform)
+            return nil unless @values.key?(platform)
             node_version = Chef::Version::Platform.new(version)
+            key_matches = []
             keys = @values[platform].keys
             keys.each do |k|
               begin
-              if Chef::VersionConstraint.new(k).include?(node_version)
-                return @values[platform][k]
-              end
+                if Chef::VersionConstraint.new(k).include?(node_version)
+                  key_matches << k
+                end
               rescue Chef::Exceptions::InvalidVersionConstraint => e
                 Chef::Log.debug "Caught InvalidVersionConstraint. This means that a key in value_for_platform cannot be interpreted as a Chef::VersionConstraint."
                 Chef::Log.debug(e)
               end
             end
-            return nil
+            return @values[platform][version] if key_matches.include?(version)
+            case key_matches.length
+            when 0
+              return nil
+            when 1
+              return @values[platform][key_matches.first]
+            else
+              fail "Multiple matches detected for #{platform} with values #{@values}. The matches are: #{key_matches}"
+            end
           rescue Chef::Exceptions::InvalidCookbookVersion => e
             # Lets not break because someone passes a weird string like 'default' :)
             Chef::Log.debug(e)
diff --git a/spec/support/shared/unit/platform_introspector.rb b/spec/support/shared/unit/platform_introspector.rb
index 45dbff7dae..f76ddbdf9e 100644
--- a/spec/support/shared/unit/platform_introspector.rb
+++ b/spec/support/shared/unit/platform_introspector.rb
@@ -28,9 +28,11 @@ shared_examples_for "a platform introspector" do
       }
     end
     @platform_hash["debian"] = {["5", "6"] => "debian-5/6", "default" => "debian"}
-    @platform_hash["centos"] = {"~> 6.0" => "centos-6", ">= 7.0" => "centos-7", "6.5" => "centos-6.5" }
-    @platform_hash["pessimistic"] = {"~> 1.2.3" => "12", "~> 1.2" => "1", "default" => "2"}
     @platform_hash["default"] = "default"
+    # The following @platform_hash keys are used for testing version constraints
+    @platform_hash['exact_match'] = { '1.2.3' => 'exact', '>= 1.0' => 'not exact'}
+    @platform_hash['multiple_matches'] = { '~> 2.3.4' => 'matched ~> 2.3.4', '>= 2.3' => 'matched >=2.3' }
+    @platform_hash['successful_matches'] = { '< 3.0' => 'matched < 3.0', '>= 3.0' => 'matched >= 3.0' }
 
     @platform_family_hash = {
       "debian" => "debian value",
@@ -81,6 +83,24 @@ shared_examples_for "a platform introspector" do
     platform_introspector.value_for_platform(@platform_hash).should == "openbsd"
   end
 
+  it 'returns the exact match' do
+    node.automatic_attrs[:platform] = 'exact_match'
+    node.automatic_attrs[:platform_version] = '1.2.3'
+    platform_introspector.value_for_platform(@platform_hash).should == 'exact'
+  end
+
+  it 'raises RuntimeError' do
+    node.automatic_attrs[:platform] = 'multiple_matches'
+    node.automatic_attrs[:platform_version] = '2.3.4'
+    expect {platform_introspector.value_for_platform(@platform_hash)}.to raise_error(RuntimeError)
+  end
+
+  it 'should return the value for that match' do
+    node.automatic_attrs[:platform] = 'successful_matches'
+    node.automatic_attrs[:platform_version] = '2.9'
+    platform_introspector.value_for_platform(@platform_hash).should == 'matched < 3.0'
+  end
+
   describe "when platform versions is an array" do
     it "returns a version-specific value based on the current platform" do
       node.automatic_attrs[:platform] = "debian"
@@ -93,31 +113,6 @@ shared_examples_for "a platform introspector" do
       node.automatic_attrs[:platform_version] = "0.0.0"
       platform_introspector.value_for_platform(@platform_hash).should == "debian"
     end
-    it "returns a value when given a version constraint key" do
-      node.automatic_attrs[:platform] = "centos"
-      node.automatic_attrs[:platform_version] = "7.0.1406"
-      platform_introspector.value_for_platform(@platform_hash).should == "centos-7"
-    end
-    it "returns the value for a specific key over a constrained key" do
-      node.automatic_attrs[:platform] = "centos"
-      node.automatic_attrs[:platform_version] = "6.5"
-      platform_introspector.value_for_platform(@platform_hash).should == "centos-6.5"
-    end
-    it "pessimistic depends on x.y.z looks at x.y" do
-      node.automatic_attrs[:platform] = "pessimistic"
-      node.automatic_attrs[:platform_version] = "1.2.17"
-      platform_introspector.value_for_platform(@platform_hash).should == "12"
-    end
-    it "pessismistic depends on x.y looks at x" do
-      node.automatic_attrs[:platform] = "pessimistic"
-      node.automatic_attrs[:platform_version] = "1.8.14"
-      platform_introspector.value_for_platform(@platform_hash).should == "1"
-    end
-    it "pessismistic depends on x.y won't match x+1" do
-      node.automatic_attrs[:platform] = "pessimistic"
-      node.automatic_attrs[:platform_version] = "2.8.14"
-      platform_introspector.value_for_platform(@platform_hash).should == "2"
-    end
   end
 
   describe "when checking platform?" do