Merge #6730

6730: Print errors to stderr by default, and remove configuration option r=greysteil a=greysteil

### What was the end-user problem that led to this PR?

The problem was #6729 - Bundler unexpectedly outputs error and warning messages to STDOUT.

### What was your diagnosis of the problem?

My diagnosis was that whilst very minorly breaking, this is essentially a bug fix, and should be considered for inclusion for Bundler 2.0 even if very few other breaking changes are.

### What is your fix for the problem, implemented in this PR?

My fix was so switch output for warning and error messages to STDERR, and remove the configuration option (as is redundant once the setup is flipped - anyone wanting to redirect those message to STDOUT could do so in their shell).

### Why did you choose this fix out of the possible options?

I chose this fix because I think the new behaviour is what everyone would expect, and we should get it out from behind its feature switch sooner rather than later.

Alternatively, we might want to keep the Bundler 2.0 release "purer" by only dropping Ruby versions in it - that's totally fine too, but I figured we should have the code to discus #6729, rather than doing it in abstract.

Co-authored-by: Grey Baker <greysteil@gmail.com>
Co-authored-by: David Rodríguez <deivid.rodriguez@riseup.net>

3 files changed, 13 insertions, 27 deletions

diff --git a/spec/bundler/cli_spec.rb b/spec/bundler/cli_spec.rb
index 6a505358d1..2e12fbfc6b 100644
--- a/spec/bundler/cli_spec.rb
+++ b/spec/bundler/cli_spec.rb
@@ -30,8 +30,8 @@ RSpec.describe "bundle executable" do
   context "with no arguments" do
     it "prints a concise help message", :bundler => "3" do
       bundle! ""
-      expect(last_command.stderr).to be_empty
-      expect(last_command.stdout).to include("Bundler version #{Bundler::VERSION}").
+      expect(err).to be_empty
+      expect(out).to include("Bundler version #{Bundler::VERSION}").
         and include("\n\nBundler commands:\n\n").
         and include("\n\n  Primary commands:\n").
         and include("\n\n  Utilities:\n").
@@ -72,17 +72,17 @@ RSpec.describe "bundle executable" do
     it "prints the running command" do
       gemfile ""
       bundle! "info bundler", :verbose => true
-      expect(last_command.stdout).to start_with("Running `bundle info bundler --verbose` with bundler #{Bundler::VERSION}")
+      expect(out).to start_with("Running `bundle info bundler --verbose` with bundler #{Bundler::VERSION}")
     end
 
     it "doesn't print defaults" do
       install_gemfile! "", :verbose => true
-      expect(last_command.stdout).to start_with("Running `bundle install --retry 0 --verbose` with bundler #{Bundler::VERSION}")
+      expect(out).to start_with("Running `bundle install --retry 0 --verbose` with bundler #{Bundler::VERSION}")
     end
 
     it "doesn't print defaults" do
       install_gemfile! "", :verbose => true
-      expect(last_command.stdout).to start_with("Running `bundle install --retry 0 --verbose` with bundler #{Bundler::VERSION}")
+      expect(out).to start_with("Running `bundle install --retry 0 --verbose` with bundler #{Bundler::VERSION}")
     end
   end
 
@@ -125,7 +125,7 @@ RSpec.describe "bundle executable" do
       let(:latest_version) { "222.0" }
       it "prints the version warning" do
         bundle "fail"
-        expect(last_command.stdout).to start_with(<<-EOS.strip)
+        expect(err).to start_with(<<-EOS.strip)
 The latest bundler is #{latest_version}, but you are currently running #{bundler_version}.
 To install the latest version, run `gem install bundler`
         EOS
@@ -150,7 +150,7 @@ To install the latest version, run `gem install bundler`
         let(:latest_version) { "222.0.0.pre.4" }
         it "prints the version warning" do
           bundle "fail"
-          expect(last_command.stdout).to start_with(<<-EOS.strip)
+          expect(err).to start_with(<<-EOS.strip)
 The latest bundler is #{latest_version}, but you are currently running #{bundler_version}.
 To install the latest version, run `gem install bundler --pre`
           EOS
diff --git a/spec/bundler/friendly_errors_spec.rb b/spec/bundler/friendly_errors_spec.rb
index 4ca1e543c1..07ec196b86 100644
--- a/spec/bundler/friendly_errors_spec.rb
+++ b/spec/bundler/friendly_errors_spec.rb
@@ -24,7 +24,7 @@ RSpec.describe Bundler, "friendly errors" do
 
       bundle :install, :env => { "DEBUG" => true }
 
-      expect(last_command.stderr).to include("Failed to load #{home(".gemrc")}")
+      expect(err).to include("Failed to load #{home(".gemrc")}")
       expect(exitstatus).to eq(0) if exitstatus
     end
   end
diff --git a/spec/bundler/ui/shell_spec.rb b/spec/bundler/ui/shell_spec.rb
index 23a7670dd1..632477096e 100644
--- a/spec/bundler/ui/shell_spec.rb
+++ b/spec/bundler/ui/shell_spec.rb
@@ -24,13 +24,6 @@ RSpec.describe Bundler::UI::Shell do
     it "prints to stderr" do
       expect { subject.warn("warning") }.to output("warning\n").to_stderr
     end
-
-    context "when stderr flag is enabled" do
-      before { Bundler.settings.temporary(:error_on_stderr => true) }
-      it "prints to stderr" do
-        expect { subject.warn("warning!") }.to output("warning!\n").to_stderr
-      end
-    end
   end
 
   describe "#debug" do
@@ -46,19 +39,12 @@ RSpec.describe Bundler::UI::Shell do
       expect { subject.error("error!!!") }.to output("error!!!\n").to_stderr
     end
 
-    context "when stderr flag is enabled" do
-      before { Bundler.settings.temporary(:error_on_stderr => true) }
-      it "prints to stderr" do
-        expect { subject.error("error!!!") }.to output("error!!!\n").to_stderr
-      end
-
-      context "when stderr is closed" do
-        it "doesn't report anything" do
-          output = capture(:stderr, :closed => true) do
-            subject.error("Something went wrong")
-          end
-          expect(output).to_not eq("Something went wrong\n")
+    context "when stderr is closed" do
+      it "doesn't report anything" do
+        output = capture(:stderr, :closed => true) do
+          subject.error("Something went wrong")
         end
+        expect(output).to_not eq("Something went wrong\n")
       end
     end
   end