config: add `rc_file` that allows specifying `pryrc` file

Keeping this in a constant makes it really hard to test. Moving it to the config
and making it configurable seems to be sensible. Now we have a new option and a
lot of tests.

3 files changed, 44 insertions, 3 deletions

diff --git a/spec/config_spec.rb b/spec/config_spec.rb
index 1cd9cdb2..a3d38043 100644
--- a/spec/config_spec.rb
+++ b/spec/config_spec.rb
@@ -40,6 +40,46 @@ RSpec.describe Pry::Config do
   specify { expect(subject.history_load).to eq(true).or be(false) }
   specify { expect(subject.history_file).to be_a(String) }
   specify { expect(subject.exec_string).to be_a(String) }
+  specify { expect(subject.rc_file).to be_a(String) }
+
+  describe "#rc_file" do
+    context "when $PRYRC env variable is set" do
+      before { ENV['PRYRC'] = '/foo/pryrc' }
+      after { ENV.delete('PRYRC') }
+
+      it "defaults to the value of PRYRC env variable" do
+        expect(subject.rc_file).to eq('/foo/pryrc')
+      end
+    end
+
+    context "when ~/.pryrc exists" do
+      before do
+        allow(File).to receive(:exist?)
+        expect(File).to receive(:exist?)
+          .with(File.expand_path('~/.pryrc')).and_return(true)
+      end
+
+      it "defaults ~/.pryrc" do
+        expect(subject.rc_file).to eq('~/.pryrc')
+      end
+    end
+
+    context "when $XDG_CONFIG_HOME is defined" do
+      before do
+        allow(File).to receive(:exist?)
+        expect(File).to receive(:exist?)
+          .with(File.expand_path('~/.pryrc')).and_return(false)
+
+        ENV['XDG_CONFIG_HOME'] = '/xdg_home'
+      end
+
+      after { ENV.delete('XDG_CONFIG_HOME') }
+
+      it "defaults $XDG_CONFIG_HOME/pry/pryrc" do
+        expect(subject.rc_file).to eq('/xdg_home/pry/pryrc')
+      end
+    end
+  end
 
   describe "#merge!" do
     it "merges given hash with the config instance" do
diff --git a/spec/history_spec.rb b/spec/history_spec.rb
index 0e3f4b6e..43bf55a2 100644
--- a/spec/history_spec.rb
+++ b/spec/history_spec.rb
@@ -27,6 +27,7 @@ RSpec.describe Pry::History do
     context "when ~/.pry_history exists" do
       before do
         allow(File).to receive(:exist?)
+        expect(File).to receive(:exist?)
           .with(File.expand_path('~/.pry_history')).and_return(true)
       end
 
diff --git a/spec/pryrc_spec.rb b/spec/pryrc_spec.rb
index 7bcd8a1f..338f6b7e 100644
--- a/spec/pryrc_spec.rb
+++ b/spec/pryrc_spec.rb
@@ -1,7 +1,7 @@
 describe Pry do
   describe 'loading rc files' do
     before do
-      stub_const('Pry::HOME_RC_FILE', 'spec/fixtures/testrc')
+      Pry.config.rc_file = 'spec/fixtures/testrc'
       stub_const('Pry::LOCAL_RC_FILE', 'spec/fixtures/testrc/../testrc')
 
       Pry.instance_variable_set(:@initial_session, true)
@@ -25,7 +25,7 @@ describe Pry do
     # Resolving symlinks doesn't work on jruby 1.9 [jruby issue #538]
     unless Pry::Helpers::Platform.jruby_19?
       it "should not load the rc file twice if it's symlinked differently" do
-        stub_const('Pry::HOME_RC_FILE', 'spec/fixtures/testrc')
+        Pry.config.rc_file = 'spec/fixtures/testrc'
         stub_const('Pry::LOCAL_RC_FILE', 'spec/fixtures/testlinkrc')
 
         Pry.start(self, input: StringIO.new("exit-all\n"), output: StringIO.new)
@@ -66,7 +66,7 @@ describe Pry do
 
     describe "that raise exceptions" do
       before do
-        Pry::HOME_RC_FILE.replace "spec/fixtures/testrcbad"
+        Pry.config.rc_file = 'spec/fixtures/testrcbad'
         Pry.config.should_load_local_rc = false
 
         putsed = nil