Detect changes in path specs by comparing locked specs to source specs

Previously, we'd wrongly conclude there are no path changes when there are
changes. We'd parse the Gemfile.lock and compare the source.specs, the
gemspecs currently in the path, to what's in the Gemfile.lock's locked.specs.
Unfortunately, locked.specs for Path sources creates an Index with the specs
from the filesystem and NOT what we already parsed from the Gemfile.lock!  In
other words, we compare the filesystems specs for a path to itself and always
conclude "No changes detected!"

Instead, we build an index with specs for the source we want from the
already parsed Gemfile.lock.  We use this index to compare to the current
source.specs index from the filesystem.

Ironically, this issue was masked by the bug from our prior fix, namely that
dependencies_for_source_changed? always would conclude that there were changes.
Because of that bug, it would short circuit out of the nothing_changed? method
and force a re-resolve with path gems, which would properly build the
Gemfile.lock from the prior parsed one.

Undo some test changes needed to get the first fix to pass.

3 files changed, 117 insertions, 10 deletions

diff --git a/lib/bundler/definition.rb b/lib/bundler/definition.rb
index 852f343509..efc249be91 100644
--- a/lib/bundler/definition.rb
+++ b/lib/bundler/definition.rb
@@ -482,7 +482,7 @@ module Bundler
         end
       end
 
-      !locked || unlocking || dependencies_for_source_changed?(locked) || source.specs != locked.specs
+      !locked || unlocking || dependencies_for_source_changed?(source) || specs_for_source_changed?(source)
     end
 
     def dependencies_for_source_changed?(source)
@@ -492,6 +492,13 @@ module Bundler
       Set.new(deps_for_source) != Set.new(locked_deps_for_source)
     end
 
+    def specs_for_source_changed?(source)
+      locked_index = Index.new
+      locked_index.use(@locked_specs.select {|s| source.can_lock?(s) })
+
+      source.specs != locked_index
+    end
+
     # Get all locals and override their matching sources.
     # Return true if any of the locals changed (for example,
     # they point to a new revision) or depend on new specs.
diff --git a/spec/bundler/definition_spec.rb b/spec/bundler/definition_spec.rb
index 6e347dbdc2..02049b557a 100644
--- a/spec/bundler/definition_spec.rb
+++ b/spec/bundler/definition_spec.rb
@@ -3,13 +3,12 @@ require "spec_helper"
 require "bundler/definition"
 
 describe Bundler::Definition do
-  before do
-    allow(Bundler).to receive(:settings) { Bundler::Settings.new(".") }
-    allow(Bundler).to receive(:default_gemfile) { Pathname.new("Gemfile") }
-    allow(Bundler).to receive(:ui) { double("UI", :info => "", :debug => "") }
-  end
-
   describe "#lock" do
+    before do
+      allow(Bundler).to receive(:settings) { Bundler::Settings.new(".") }
+      allow(Bundler).to receive(:default_gemfile) { Pathname.new("Gemfile") }
+      allow(Bundler).to receive(:ui) { double("UI", :info => "", :debug => "") }
+    end
     context "when it's not possible to write to the file" do
       subject { Bundler::Definition.new(nil, [], Bundler::SourceList.new, []) }
 
@@ -31,4 +30,106 @@ describe Bundler::Definition do
       end
     end
   end
+
+  describe "detects changes" do
+    it "for a path gem with changes" do
+      build_lib "foo", "1.0", :path => lib_path("foo")
+
+      install_gemfile <<-G
+        source "file://#{gem_repo1}"
+        gem "foo", :path => "#{lib_path("foo")}"
+      G
+
+      build_lib "foo", "1.0", :path => lib_path("foo") do |s|
+        s.add_dependency "rack", "1.0"
+      end
+
+      bundle :install, :env => { "DEBUG" => 1 }
+
+      expect(out).to match(/re-resolving dependencies/)
+      lockfile_should_be <<-G
+        PATH
+          remote: #{lib_path("foo")}
+          specs:
+            foo (1.0)
+              rack (= 1.0)
+
+        GEM
+          remote: file:#{gem_repo1}/
+          specs:
+            rack (1.0.0)
+
+        PLATFORMS
+          ruby
+
+        DEPENDENCIES
+          foo!
+
+        BUNDLED WITH
+           #{Bundler::VERSION}
+      G
+    end
+
+    it "for a path gem with deps and no changes" do
+      build_lib "foo", "1.0", :path => lib_path("foo") do |s|
+        s.add_dependency "rack", "1.0"
+      end
+
+      install_gemfile <<-G
+        source "file://#{gem_repo1}"
+        gem "foo", :path => "#{lib_path("foo")}"
+      G
+
+      bundle :check, :env => { "DEBUG" => 1 }
+
+      expect(out).to match(/using resolution from the lockfile/)
+      lockfile_should_be <<-G
+        PATH
+          remote: #{lib_path("foo")}
+          specs:
+            foo (1.0)
+              rack (= 1.0)
+
+        GEM
+          remote: file:#{gem_repo1}/
+          specs:
+            rack (1.0.0)
+
+        PLATFORMS
+          ruby
+
+        DEPENDENCIES
+          foo!
+
+        BUNDLED WITH
+           #{Bundler::VERSION}
+      G
+    end
+
+    it "for a rubygems gem" do
+      install_gemfile <<-G
+        source "file://#{gem_repo1}"
+        gem "foo"
+      G
+
+      bundle :check, :env => { "DEBUG" => 1 }
+
+      expect(out).to match(/using resolution from the lockfile/)
+      lockfile_should_be <<-G
+        GEM
+          remote: file:#{gem_repo1}/
+          specs:
+            foo (1.0)
+
+        PLATFORMS
+          ruby
+
+        DEPENDENCIES
+          foo
+
+        BUNDLED WITH
+           #{Bundler::VERSION}
+      G
+    end
+  end
 end
diff --git a/spec/install/gemfile/path_spec.rb b/spec/install/gemfile/path_spec.rb
index de4e80cb6a..39b0aed788 100644
--- a/spec/install/gemfile/path_spec.rb
+++ b/spec/install/gemfile/path_spec.rb
@@ -415,7 +415,7 @@ describe "bundle install with explicit source paths" do
       build_lib "foo", "1.0", :path => lib_path("foo") do |s|
         s.add_dependency "bar"
       end
-      build_lib "bar", "1.0", :path => lib_path("foo")
+      build_lib "bar", "1.0", :path => lib_path("foo/bar")
 
       install_gemfile <<-G
         gem "foo", :path => "#{lib_path("foo")}"
@@ -433,7 +433,7 @@ describe "bundle install with explicit source paths" do
     end
 
     it "unlocks all gems when a child dependency gem is updated" do
-      build_lib "bar", "2.0", :path => lib_path("foo")
+      build_lib "bar", "2.0", :path => lib_path("foo/bar")
 
       bundle "install"
 
@@ -452,7 +452,6 @@ describe "bundle install with explicit source paths" do
     end
 
     it "gets dependencies that are updated in the path" do
-      build_lib "rack", "1.0.0", :path => lib_path("foo")
       build_lib "foo", "1.0", :path => lib_path("foo") do |s|
         s.add_dependency "rack"
       end