Merge pull request #4869 from chef/lcg/package-lazy-monads

Lazy'ing candidate_version in package provider

5 files changed, 285 insertions, 9 deletions

diff --git a/spec/unit/decorator/lazy_array_spec.rb b/spec/unit/decorator/lazy_array_spec.rb
new file mode 100644
index 0000000000..0c5c2eeee0
--- /dev/null
+++ b/spec/unit/decorator/lazy_array_spec.rb
@@ -0,0 +1,58 @@
+#
+# Author:: Lamont Granquist (<lamont@chef.io>)
+# Copyright:: Copyright 2015-2016, Chef Software Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require "spec_helper"
+
+describe Chef::Decorator::LazyArray do
+  def foo
+    @foo ||= 1
+  end
+
+  def bar
+    @bar ||= 2
+  end
+
+  let(:decorator) do
+    Chef::Decorator::LazyArray.new { [ foo, bar ] }
+  end
+
+  it "behaves like an array" do
+    expect(decorator[0]).to eql(1)
+    expect(decorator[1]).to eql(2)
+  end
+
+  it "accessing the array elements is lazy" do
+    expect(decorator[0].class).to eql(Chef::Decorator::Lazy)
+    expect(decorator[1].class).to eql(Chef::Decorator::Lazy)
+    expect(@foo).to be nil
+    expect(@bar).to be nil
+  end
+
+  it "calling a method on the array element runs the proc (and both elements are autovivified)" do
+    expect(decorator[0].nil?).to be false
+    expect(@foo).to equal(1)
+    expect(@bar).to equal(2)
+  end
+
+  it "if we loop over the elements and do nothing then its not lazy" do
+    # we don't know how many elements there are unless we evaluate the proc
+    decorator.each { |i| }
+    expect(@foo).to equal(1)
+    expect(@bar).to equal(2)
+  end
+end
diff --git a/spec/unit/decorator/lazy_spec.rb b/spec/unit/decorator/lazy_spec.rb
new file mode 100644
index 0000000000..4ea8301b63
--- /dev/null
+++ b/spec/unit/decorator/lazy_spec.rb
@@ -0,0 +1,39 @@
+#
+# Author:: Lamont Granquist (<lamont@chef.io>)
+# Copyright:: Copyright 2015-2016, Chef Software Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require "spec_helper"
+
+describe Chef::Decorator::Lazy do
+  let(:decorator) do
+    @a = 0
+    Chef::Decorator::Lazy.new { @a = @a + 1 }
+  end
+
+  it "decorates an object" do
+    expect(decorator.even?).to be false
+  end
+
+  it "the proc runs and does work" do
+    expect(decorator).to eql(1)
+  end
+
+  it "creating the decorator does not cause the proc to run" do
+    decorator
+    expect(@a).to eql(0)
+  end
+end
diff --git a/spec/unit/decorator_spec.rb b/spec/unit/decorator_spec.rb
new file mode 100644
index 0000000000..6d73db2cc4
--- /dev/null
+++ b/spec/unit/decorator_spec.rb
@@ -0,0 +1,142 @@
+#
+# Author:: Lamont Granquist (<lamont@chef.io>)
+# Copyright:: Copyright 2015-2016, Chef Software Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require "spec_helper"
+
+def impersonates_a(klass)
+  it "#is_a?(#{klass}) is true" do
+    expect(decorator.is_a?(klass)).to be true
+  end
+
+  it "#is_a?(Chef::Decorator) is true" do
+    expect(decorator.is_a?(Chef::Decorator)).to be true
+  end
+
+  it "#kind_of?(#{klass}) is true" do
+    expect(decorator.kind_of?(klass)).to be true
+  end
+
+  it "#kind_of?(Chef::Decorator) is true" do
+    expect(decorator.kind_of?(Chef::Decorator)).to be true
+  end
+
+  it "#instance_of?(#{klass}) is false" do
+    expect(decorator.instance_of?(klass)).to be false
+  end
+
+  it "#instance_of?(Chef::Decorator) is true" do
+    expect(decorator.instance_of?(Chef::Decorator)).to be true
+  end
+
+  it "#class is Chef::Decorator" do
+    expect(decorator.class).to eql(Chef::Decorator)
+  end
+end
+
+describe Chef::Decorator do
+  let(:obj) {}
+  let(:decorator) { Chef::Decorator.new(obj) }
+
+  context "when the obj is a string" do
+    let(:obj) { "STRING" }
+
+    impersonates_a(String)
+
+    it "#nil? is false" do
+      expect(decorator.nil?).to be false
+    end
+
+    it "!! is true" do
+      expect(!!decorator).to be true
+    end
+
+    it "dup returns a decorator" do
+      expect(decorator.dup.class).to be Chef::Decorator
+    end
+
+    it "dup dup's the underlying thing" do
+      expect(decorator.dup.__getobj__).not_to equal(decorator.__getobj__)
+    end
+  end
+
+  context "when the obj is a nil" do
+    let(:obj) { nil }
+
+    it "#nil? is true" do
+      expect(decorator.nil?).to be true
+    end
+
+    it "!! is false" do
+      expect(!!decorator).to be false
+    end
+
+    impersonates_a(NilClass)
+  end
+
+  context "when the obj is an empty Hash" do
+    let(:obj) { {} }
+
+    impersonates_a(Hash)
+
+    it "formats it correctly through ffi-yajl and not the JSON gem" do
+      # this relies on a quirk of pretty formatting whitespace between yajl and ruby's JSON
+      expect(FFI_Yajl::Encoder.encode(decorator, pretty: true)).to eql("{\n\n}\n")
+    end
+  end
+
+  context "whent he obj is a Hash with elements" do
+    let(:obj) { { foo: "bar", baz: "qux" } }
+
+    impersonates_a(Hash)
+
+    it "dup is shallow on the Hash" do
+      expect(decorator.dup[:baz]).to equal(decorator[:baz])
+    end
+
+    it "deep mutating the dup'd hash mutates the origin" do
+      decorator.dup[:baz] << "qux"
+      expect(decorator[:baz]).to eql("quxqux")
+    end
+  end
+
+  context "memoizing methods" do
+    let(:obj) { {} }
+
+    it "calls method_missing only once" do
+      expect(decorator).to receive(:method_missing).once.and_call_original
+      expect(decorator.keys).to eql([])
+      expect(decorator.keys).to eql([])
+    end
+
+    it "switching a Hash to an Array responds to keys then does not" do
+      expect(decorator.respond_to?(:keys)).to be true
+      expect(decorator.keys).to eql([])
+      decorator.__setobj__([])
+      expect(decorator.respond_to?(:keys)).to be false
+      expect { decorator.keys }.to raise_error(NoMethodError)
+    end
+
+    it "memoization of methods happens on the instances, not the classes" do
+      decorator2 = Chef::Decorator.new([])
+      expect(decorator.respond_to?(:keys)).to be true
+      expect(decorator.keys).to eql([])
+      expect(decorator2.respond_to?(:keys)).to be false
+      expect { decorator2.keys }.to raise_error(NoMethodError)
+    end
+  end
+end
diff --git a/spec/unit/provider/package/rubygems_spec.rb b/spec/unit/provider/package/rubygems_spec.rb
index 6e77e7c112..f87c261ec0 100644
--- a/spec/unit/provider/package/rubygems_spec.rb
+++ b/spec/unit/provider/package/rubygems_spec.rb
@@ -496,12 +496,36 @@ describe Chef::Provider::Package::Rubygems do
         provider.load_current_resource
       end
 
-      it "does not query for available versions when the current version is the target version" do
-        expect(provider.candidate_version).to be_nil
+      context "when the current version is the target version" do
+        it "does not query for available versions" do
+          # NOTE: odd use case -- we've equality pinned a version, but are calling :upgrade
+          expect(provider.gem_env).not_to receive(:candidate_version_from_remote)
+          expect(provider.gem_env).not_to receive(:install)
+          provider.run_action(:upgrade)
+          expect(new_resource).not_to be_updated_by_last_action
+        end
       end
 
-      context "when the current version is not the target version" do
-        let(:target_version) { "9000.0.2" }
+      context "when the current version satisfies the target version requirement" do
+        let(:target_version) { ">= 0" }
+
+        it "does not query for available versions on install" do
+          expect(provider.gem_env).not_to receive(:candidate_version_from_remote)
+          expect(provider.gem_env).not_to receive(:install)
+          provider.run_action(:install)
+          expect(new_resource).not_to be_updated_by_last_action
+        end
+
+        it "queries for available versions on upgrade" do
+          expect(provider.gem_env).to receive(:candidate_version_from_remote).
+            and_return(Gem::Version.new("9000.0.2"))
+          expect(provider.gem_env).to receive(:install)
+          provider.run_action(:upgrade)
+          expect(new_resource).to be_updated_by_last_action
+        end
+      end
+
+      context "when the requested source is a remote server" do
         let(:source) { "http://mygems.example.com" }
 
         it "determines the candidate version by querying the remote gem servers" do
@@ -669,6 +693,11 @@ describe Chef::Provider::Package::Rubygems do
               expect(provider.gem_env).not_to receive(:install)
               provider.run_action(:install)
             end
+
+            it "performs the upgrade" do
+              expect(provider.gem_env).to receive(:install)
+              provider.run_action(:upgrade)
+            end
           end
 
           context "if the fuzzy operator is used" do
@@ -679,6 +708,11 @@ describe Chef::Provider::Package::Rubygems do
               expect(provider.gem_env).not_to receive(:install)
               provider.run_action(:install)
             end
+
+            it "it upgrades an existing gem" do
+              expect(provider.gem_env).to receive(:install)
+              provider.run_action(:upgrade)
+            end
           end
         end
       end
diff --git a/spec/unit/provider/package_spec.rb b/spec/unit/provider/package_spec.rb
index abf0322868..e4354d0db4 100644
--- a/spec/unit/provider/package_spec.rb
+++ b/spec/unit/provider/package_spec.rb
@@ -566,8 +566,11 @@ describe "Chef::Provider::Package - Multi" do
   let(:new_resource) { Chef::Resource::Package.new(%w{emacs vi}) }
   let(:current_resource) { Chef::Resource::Package.new(%w{emacs vi}) }
   let(:candidate_version) { [ "1.0", "6.2" ] }
+  class MyPackageProvider < Chef::Provider::Package
+    use_multipackage_api
+  end
   let(:provider) do
-    provider = Chef::Provider::Package.new(new_resource, run_context)
+    provider = MyPackageProvider.new(new_resource, run_context)
     provider.current_resource = current_resource
     provider.candidate_version = candidate_version
     provider
@@ -731,7 +734,7 @@ describe "Chef::Provider::Package - Multi" do
 
     it "should remove the packages if all are installed" do
       expect(provider).to be_removing_package
-      expect(provider).to receive(:remove_package).with(%w{emacs vi}, nil)
+      expect(provider).to receive(:remove_package).with(%w{emacs vi}, [nil])
       provider.run_action(:remove)
       expect(new_resource).to be_updated
       expect(new_resource).to be_updated_by_last_action
@@ -740,7 +743,7 @@ describe "Chef::Provider::Package - Multi" do
     it "should remove the packages if some are installed" do
       current_resource.version ["1.0", nil]
       expect(provider).to be_removing_package
-      expect(provider).to receive(:remove_package).with(%w{emacs vi}, nil)
+      expect(provider).to receive(:remove_package).with(%w{emacs vi}, [nil])
       provider.run_action(:remove)
       expect(new_resource).to be_updated
       expect(new_resource).to be_updated_by_last_action
@@ -787,7 +790,7 @@ describe "Chef::Provider::Package - Multi" do
 
     it "should purge the packages if all are installed" do
       expect(provider).to be_removing_package
-      expect(provider).to receive(:purge_package).with(%w{emacs vi}, nil)
+      expect(provider).to receive(:purge_package).with(%w{emacs vi}, [nil])
       provider.run_action(:purge)
       expect(new_resource).to be_updated
       expect(new_resource).to be_updated_by_last_action
@@ -796,7 +799,7 @@ describe "Chef::Provider::Package - Multi" do
     it "should purge the packages if some are installed" do
       current_resource.version ["1.0", nil]
       expect(provider).to be_removing_package
-      expect(provider).to receive(:purge_package).with(%w{emacs vi}, nil)
+      expect(provider).to receive(:purge_package).with(%w{emacs vi}, [nil])
       provider.run_action(:purge)
       expect(new_resource).to be_updated
       expect(new_resource).to be_updated_by_last_action