Make the configuration more testable

Author: jeffgbutler

src/main/java/org/mybatis/dynamic/sql/configuration/GlobalConfiguration.java

@@ -18,6 +18,8 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Properties;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 public class GlobalConfiguration {
     public static final String CONFIGURATION_FILE_PROPERTY = "mybatis-dynamic-sql.configurationFile"; //$NON-NLS-1$
@@ -35,9 +37,10 @@ private void initialize() {
     }
 
     private void initializeProperties(){
-        InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream(getConfigurationFileName());
+        String configFileName = getConfigurationFileName();
+        InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream(configFileName);
         if (inputStream != null) {
-            loadProperties(inputStream);
+            loadProperties(inputStream, configFileName);
         }
     }
 
@@ -50,11 +53,12 @@ private String getConfigurationFileName() {
         }
     }
 
-    private void loadProperties(InputStream inputStream) {
+    void loadProperties(InputStream inputStream, String propertyFile) {
         try {
             properties.load(inputStream);
         } catch (IOException e) {
-            throw new RuntimeException(e);
+            Logger logger = Logger.getLogger(GlobalConfiguration.class.getName());
+            logger.log(Level.SEVERE, e, () -> "IOException reading property file \"" + propertyFile + "\"");
         }
     }
 

src/test/java/org/mybatis/dynamic/sql/configuration/GlobalConfigurationTest.java

@@ -17,6 +17,14 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.logging.Handler;
+import java.util.logging.LogRecord;
+import java.util.logging.Logger;
+
 import org.junit.jupiter.api.Test;
 
 class GlobalConfigurationTest {
@@ -46,4 +54,43 @@ void testMissingPropertyFileUsesDefaults() {
 
         assertThat(configuration.isIsNonRenderingWhereClauseAllowed()).isFalse();
     }
+
+    @Test
+    void testBadPropertyFile() throws IOException {
+        GlobalConfiguration configuration = new GlobalConfiguration();
+        InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream("empty.properties");
+        assert inputStream != null;
+        inputStream.close();
+
+        TestLogHandler testLogHandler = new TestLogHandler();
+        Logger logger = Logger.getLogger(GlobalConfiguration.class.getName());
+        // we only want to use our handler for this test, so we don't pollute the test output
+        logger.setUseParentHandlers(false);
+        logger.addHandler(testLogHandler);
+
+        configuration.loadProperties(inputStream, "empty.properties");
+        assertThat(testLogHandler.records).hasSize(1);
+        assertThat(testLogHandler.getRecords().get(0).getMessage())
+                .isEqualTo("IOException reading property file \"empty.properties\"");
+    }
+
+    public static class TestLogHandler extends Handler {
+
+        private final List<LogRecord> records = new ArrayList<>();
+
+        public List<LogRecord> getRecords() {
+            return records;
+        }
+
+        @Override
+        public void publish(LogRecord record) {
+            records.add(record);
+        }
+
+        @Override
+        public void flush() {}
+
+        @Override
+        public void close() {}
+    }
 }