1 files changed, 110 insertions, 7 deletions
diff --git a/spec/commands/binstubs_spec.rb b/spec/commands/binstubs_spec.rb
index 89fc3866f7..eb14db4f6f 100644
--- a/spec/commands/binstubs_spec.rb
+++ b/spec/commands/binstubs_spec.rb
@@ -50,15 +50,118 @@ RSpec.describe "bundle binstubs <gem>" do
       expect(out).to include("`bundle binstubs` needs at least one gem to run.")
     end
 
-    it "does not bundle the bundler binary" do
-      install_gemfile <<-G
-        source "file://#{gem_repo1}"
-      G
+    context "the bundle binstub" do
+      before do
+        if system_bundler_version == :bundler
+          system_gems :bundler
+        elsif system_bundler_version
+          build_repo4 do
+            build_gem "bundler", system_bundler_version do |s|
+              s.executables = "bundle"
+              s.bindir = "exe"
+              s.write "exe/bundle", "puts %(system bundler #{system_bundler_version}\\n\#{ARGV.inspect})"
+            end
+          end
+          system_gems "bundler-#{system_bundler_version}", :gem_repo => gem_repo4
+        end
+        build_repo2 do
+          build_gem "prints_loaded_gems", "1.0" do |s|
+            s.executables = "print_loaded_gems"
+            s.write "bin/print_loaded_gems", 'puts "#{Gem.loaded_specs.values.reject(&:default_gem?).map(&:full_name).sort.inspect}"'
+          end
+        end
+        install_gemfile! <<-G
+          source "file://#{gem_repo2}"
+          gem "rack"
+          gem "prints_loaded_gems"
+        G
+        bundle! "binstubs bundler rack prints_loaded_gems"
+      end
+
+      let(:system_bundler_version) { Bundler::VERSION }
+
+      it "runs bundler" do
+        sys_exec! "#{bundled_app("bin/bundle")} install"
+        expect(out).to eq %(system bundler #{system_bundler_version}\n["install"])
+      end
+
+      context "when BUNDLER_VERSION is set" do
+        it "runs the correct version of bundler" do
+          sys_exec "BUNDLER_VERSION=999.999.999 #{bundled_app("bin/bundle")} install"
+          expect(exitstatus).to eq(42) if exitstatus
+          expect(last_command.stderr).to include("Activating bundler (999.999.999) failed:").
+            and include("To install the version of bundler this project requires, run `gem install bundler -v '999.999.999'`")
+        end
+      end
+
+      context "when a lockfile exists with a locked bundler version" do
+        it "runs the correct version of bundler when the version is newer" do
+          lockfile lockfile.gsub(system_bundler_version, "999.999.999")
+          sys_exec "#{bundled_app("bin/bundle")} install"
+          expect(exitstatus).to eq(42) if exitstatus
+          expect(last_command.stderr).to include("Activating bundler (999.999.999) failed:").
+            and include("To install the version of bundler this project requires, run `gem install bundler -v '999.999.999'`")
+        end
+
+        it "runs the correct version of bundler when the version is older" do
+          lockfile lockfile.gsub(system_bundler_version, "1.0")
+          sys_exec "#{bundled_app("bin/bundle")} install"
+          expect(exitstatus).to eq(42) if exitstatus
+          expect(last_command.stderr).to include("Activating bundler (1.0) failed:").
+            and include("To install the version of bundler this project requires, run `gem install bundler -v '1.0'`")
+        end
+
+        it "runs the correct version of bundler when the version is a pre-release" do
+          lockfile lockfile.gsub(system_bundler_version, "1.12.0.a")
+          sys_exec "#{bundled_app("bin/bundle")} install"
+          expect(exitstatus).to eq(42) if exitstatus
+          expect(last_command.stderr).to include("Activating bundler (1.12.0.a) failed:").
+            and include("To install the version of bundler this project requires, run `gem install bundler -v '1.12.0.a'`")
+        end
+      end
+
+      context "when update --bundler is called" do
+        before { lockfile.gsub(system_bundler_version, "1.1.1") }
 
-      bundle "binstubs bundler"
+        it "calls through to the latest bundler version" do
+          sys_exec! "#{bundled_app("bin/bundle")} update --bundler"
+          expect(last_command.stdout).to eq %(system bundler #{system_bundler_version}\n["update", "--bundler"])
+        end
+
+        it "calls through to the explicit bundler version" do
+          sys_exec "#{bundled_app("bin/bundle")} update --bundler=999.999.999"
+          expect(exitstatus).to eq(42) if exitstatus
+          expect(last_command.stderr).to include("Activating bundler (999.999.999) failed:").
+            and include("To install the version of bundler this project requires, run `gem install bundler -v '999.999.999'`")
+        end
+      end
 
-      expect(bundled_app("bin/bundle")).not_to exist
-      expect(out).to include("Sorry, Bundler can only be run via RubyGems.")
+      context "without a lockfile" do
+        it "falls back to the latest installed bundler" do
+          FileUtils.rm bundled_app("Gemfile.lock")
+          sys_exec! bundled_app("bin/bundle").to_s
+          expect(out).to eq "system bundler #{system_bundler_version}\n[]"
+        end
+      end
+
+      context "using another binstub" do
+        let(:system_bundler_version) { :bundler }
+        it "loads all gems" do
+          sys_exec! bundled_app("bin/print_loaded_gems").to_s
+          expect(out).to eq %(["bundler-#{Bundler::VERSION}", "prints_loaded_gems-1.0", "rack-1.2"])
+        end
+
+        context "when requesting a different bundler version" do
+          before { lockfile lockfile.gsub(Bundler::VERSION, "999.999.999") }
+
+          it "attempts to load that version" do
+            sys_exec bundled_app("bin/rackup").to_s
+            expect(exitstatus).to eq(42) if exitstatus
+            expect(last_command.stderr).to include("Activating bundler (999.999.999) failed:").
+              and include("To install the version of bundler this project requires, run `gem install bundler -v '999.999.999'`")
+          end
+        end
+      end
     end
 
     it "installs binstubs from git gems" do