Teach Scalastyle hook to fail in exceptional conditions

Author: jawshooah

lib/overcommit/hook/pre_commit/scalastyle.rb

@@ -12,9 +12,10 @@ class Scalastyle < Base
 
     def run
       result = execute(command, args: applicable_files)
-      output = result.stdout.chomp
+      output = result.stdout.chomp + result.stderr.chomp
       messages = output.split("\n").grep(MESSAGE_REGEX)
-      return :pass if result.success? && messages.empty?
+
+      return [:fail, output] unless result.success? || messages.any?
 
       # example message:
       #   error file=/path/to/file.scala message=Error message line=1 column=1

spec/overcommit/hook/pre_commit/scalastyle_spec.rb

@@ -19,33 +19,33 @@
 
     context 'with no errors or warnings' do
       before do
-        result.stub(:stdout).and_return([
-          'Processed 1 file(s)',
-          'Found 0 errors',
-          'Found 0 warnings',
-          'Finished in 490 ms'
-        ].join("\n"))
+        result.stub(stderr: '', stdout: normalize_indent(<<-OUT))
+          Processed 1 file(s)
+          Found 0 errors
+          Found 0 warnings
+          Finished in 490 ms
+        OUT
       end
 
       it { should pass }
     end
 
     context 'and it reports a warning' do
       before do
-        result.stub(:stdout).and_return([
-          'warning file=file1.scala message=Use : Unit = for procedures line=1 column=15',
-          'Processed 1 file(s)',
-          'Found 0 errors',
-          'Found 1 warnings',
-          'Finished in 490 ms'
-        ].join("\n"))
+        result.stub(stderr: '', stdout: normalize_indent(<<-OUT))
+          warning file=file1.scala message=Use : Unit = for procedures line=1 column=15
+          Processed 1 file(s)
+          Found 0 errors
+          Found 1 warnings
+          Finished in 490 ms
+        OUT
       end
 
       it { should warn }
     end
   end
 
-  context 'when scalastyle exits unsucessfully' do
+  context 'when scalastyle exits unsuccessfully' do
     let(:result) { double('result') }
 
     before do
@@ -55,13 +55,55 @@
 
     context 'and it reports an error' do
       before do
-        result.stub(:stdout).and_return([
-          'error file=file1.scala message=Use : Unit = for procedures line=1 column=15',
-          'Processed 1 file(s)',
-          'Found 1 errors',
-          'Found 0 warnings',
-          'Finished in 490 ms'
-        ].join("\n"))
+        result.stub(stderr: '', stdout: normalize_indent(<<-OUT))
+          error file=file1.scala message=Use : Unit = for procedures line=1 column=15
+          Processed 1 file(s)
+          Found 1 errors
+          Found 0 warnings
+          Finished in 490 ms
+        OUT
+      end
+
+      it { should fail_hook }
+    end
+
+    context 'with a usage message' do
+      before do
+        result.stub(stderr: '', stdout: normalize_indent(<<-OUT))
+          scalastyle 0.7.0
+          Usage: scalastyle [options] <source directory>
+           -c, --config FILE               configuration file (required)
+           -v, --verbose true|false        verbose output
+           -q, --quiet true|false          be quiet
+               --xmlOutput FILE            write checkstyle format output to this file
+               --xmlEncoding STRING        encoding to use for the xml file
+               --inputEncoding STRING      encoding for the source files
+           -w, --warnings true|false       fail if there are warnings
+           -e, --externalJar FILE          jar containing custom rules
+        OUT
+      end
+
+      it { should fail_hook }
+    end
+
+    context 'with a runtime error' do
+      before do
+        # rubocop:disable Metrics/LineLength
+        result.stub(stdout: '', stderr: normalize_indent(<<-ERR))
+          Exception in thread "main" java.io.FileNotFoundException: scalastyle-config.xml (No such file or directory)
+                  at java.io.FileInputStream.open0(Native Method)
+                  at java.io.FileInputStream.open(FileInputStream.java:195)
+                  at java.io.FileInputStream.<init>(FileInputStream.java:138)
+                  at java.io.FileInputStream.<init>(FileInputStream.java:93)
+                  at scala.xml.Source$.fromFile(XML.scala:22)
+                  at scala.xml.factory.XMLLoader$class.loadFile(XMLLoader.scala:50)
+                  at scala.xml.XML$.loadFile(XML.scala:60)
+                  at org.scalastyle.ScalastyleConfiguration$.readFromXml(ScalastyleConfiguration.scala:87)
+                  at org.scalastyle.Main$.execute(Main.scala:106)
+                  at org.scalastyle.Main$.main(Main.scala:95)
+                  at org.scalastyle.Main.main(Main.scala)
+        ERR
+        # rubocop:enable Metrics/LineLength
       end
 
       it { should fail_hook }