Don't abort if repo is in a detached HEAD state

When HEAD is detached (e.g., during an interactive rebase) Fit Commit
should still run. Since the branch name is unknown, validators that
specify branch name will not get run.

Fixes #21

Author: Mike Foley

lib/fit_commit.rb

@@ -17,7 +17,6 @@ def self.message_path
   end
 
   def self.branch_name
-    ENV["GIT_BRANCH_NAME"] ||
-      fail("Git branch not found. You might need to re-run `fit-commit install`")
+    ENV.fetch("GIT_BRANCH_NAME")
   end
 end

templates/hooks/commit-msg

@@ -18,13 +18,7 @@ if [ ! -r "$COMMIT_MESSAGE_PATH" ]; then
   exit 0
 fi
 
-export GIT_BRANCH_NAME=`git symbolic-ref --short HEAD`
-if [ -z "$GIT_BRANCH_NAME" ]; then
-  >&2 echo "fit-commit: WARNING: Skipping checks because the Git branch cannot be determined."
-  >&2 echo "fit-commit: Please submit a bug report with the project:"
-  >&2 echo "fit-commit: https://github.com/m1foley/fit-commit/issues"
-  exit 0
-fi
+export GIT_BRANCH_NAME=`git symbolic-ref --short HEAD 2> /dev/null`
 
 # find appropriate Ruby command
 if which rbenv > /dev/null 2>&1; then

test/unit/runner_test.rb

@@ -101,6 +101,13 @@ def stringio.tty?
         assert_equal FitCommit::Runner::EXIT_CODE_REJECT_COMMIT, call_runner
         assert_error_output
       end
+      describe "empty branch name" do
+        let(:branch_name) { "" }
+        it "prints errors to stderr and rejects commit" do
+          assert_equal FitCommit::Runner::EXIT_CODE_REJECT_COMMIT, call_runner
+          assert_error_output
+        end
+      end
     end
     describe "user forces commit" do
       let(:stdin) { fake_tty("y") }

test/unit/validator_loader_test.rb

@@ -23,30 +23,45 @@
   end
 
   it "loads enabled validators" do
-    assert validators.any? { |v| v.is_a? FitCommit::Validators::Wip }
+    assert validators.one? { |v| v.is_a? FitCommit::Validators::Wip }
   end
 
   it "doesn't load disabled validators" do
     assert validators.none? { |v| v.is_a? FitCommit::Validators::LineLength }
   end
 
   describe "non-boolean options for Enabled" do
-    it "doesn't load validators with a non-matching string/regex Enabled values" do
-      assert validators.none? { |v| v.is_a? FitCommit::Validators::Frathouse }
+    describe "branch_name does not match validator" do
+      it "doesn't load validator" do
+        assert validators.none? { |v| v.is_a? FitCommit::Validators::Frathouse }
+      end
     end
 
-    describe "validator has a matching string Enabled value" do
+    describe "branch_name matches validator via String" do
       let(:branch_name) { "bar" }
       it "loads validator" do
-        assert validators.any? { |v| v.is_a? FitCommit::Validators::Frathouse }
+        assert validators.one? { |v| v.is_a? FitCommit::Validators::Frathouse }
       end
     end
 
-    describe "validator has a matching regex Enabled value" do
+    describe "branch_name matches validator via regex" do
       let(:branch_name) { "bazzz" }
       it "loads validator" do
-        assert validators.any? { |v| v.is_a? FitCommit::Validators::Frathouse }
+        assert validators.one? { |v| v.is_a? FitCommit::Validators::Frathouse }
       end
     end
   end
+
+  describe "branch_name is blank" do
+    let(:branch_name) { "" }
+    it "loads enabled validators" do
+      assert validators.one? { |v| v.is_a? FitCommit::Validators::Wip }
+    end
+    it "doesn't load disabled validators" do
+      assert validators.none? { |v| v.is_a? FitCommit::Validators::LineLength }
+    end
+    it "doesn't load validators that have non-boolean options for Enabled" do
+      assert validators.none? { |v| v.is_a? FitCommit::Validators::Frathouse }
+    end
+  end
 end