add more specs, try to fix release spec with forcing encoding for git…

… ls-files output

spec/datadog/ci/cov/cov_spec.rb

@@ -107,6 +107,24 @@ def absolute_path(path)
         expect(coverage.keys).to include(absolute_path("calculator/operations/multiply.rb"))
       end
 
+      it "does not fail if start called several times" do
+        subject.start
+        expect(calculator.add(1, 2)).to eq(3)
+
+        subject.start
+        coverage = subject.stop
+        expect(coverage.size).to eq(1)
+      end
+
+      it "does not fail if stop called several times" do
+        subject.start
+        expect(calculator.add(1, 2)).to eq(3)
+        coverage = subject.stop
+        expect(coverage.size).to eq(1)
+
+        expect(subject.stop).to eq({})
+      end
+
       it "tracks coverage in mixins" do
         subject.start
         expect(calculator.divide(6, 3)).to eq(2)

spec/datadog/ci/release_gem_spec.rb

@@ -51,6 +51,7 @@
         expect(files)
           .to match_array(
             `git ls-files -z`
+              .force_encoding(Encoding::UTF_8)
               .split("\x0")
               .reject { |f| f.match(directories_excluded) }
               .reject { |f| f.match(single_files_excluded) }