Use SAXException for parse method

Signed-off-by: Jarno Elovirta <jarno@elovirta.com>

src/main/java/com/elovirta/dita/markdown/MarkdownParser.java

@@ -4,6 +4,7 @@
 import java.net.URI;
 import org.xml.sax.ContentHandler;
 import org.xml.sax.ErrorHandler;
+import org.xml.sax.SAXException;
 
 /**
  * Interface for Markdown parser that produces SAX events for a DITA document.
@@ -16,7 +17,7 @@ public interface MarkdownParser {
    * @param input    Markdown document URI.
    * @throws ParseException if parsing failed
    */
-  void convert(BasedSequence sequence, URI input) throws ParseException;
+  void convert(BasedSequence sequence, URI input) throws SAXException;
 
   /**
    * Set the content event handler.

src/main/java/com/elovirta/dita/markdown/MarkdownParserImpl.java

@@ -10,6 +10,7 @@
 import com.vladsch.flexmark.util.ast.Node;
 import com.vladsch.flexmark.util.data.DataSet;
 import com.vladsch.flexmark.util.sequence.BasedSequence;
+import java.io.IOException;
 import java.net.URI;
 import java.util.List;
 import java.util.Map;
@@ -33,15 +34,20 @@ public MarkdownParserImpl(DataSet options) {
   }
 
   @Override
-  public void convert(BasedSequence sequence, URI input) throws ParseException {
+  public void convert(BasedSequence sequence, URI input) throws SAXException {
     final Parser parser = Parser.builder(options).build();
     final Document root = parser.parse(sequence);
     try {
       final Document cleaned = preprocess(root, input);
       validate(cleaned);
       render(cleaned);
-    } catch (SAXException e) {
-      throw new ParseException(e);
+    } catch (ParseException e) {
+      final Throwable cause = e.getCause();
+      if (cause != null && cause instanceof SAXException) {
+        throw (SAXException) cause;
+      } else {
+        throw new SAXException(e);
+      }
     }
   }
 

src/main/java/com/elovirta/dita/markdown/MarkdownReader.java

@@ -258,7 +258,7 @@ public void parse(final InputSource input) throws IOException, SAXException {
     try {
       markdownParser.convert(sequence, Optional.ofNullable(input.getSystemId()).map(URI::create).orElse(null));
     } catch (ParseException e) {
-      throw new SAXException(e);
+      throw new SAXException("Failed to parse: " + e.getMessage(), e);
     }
   }
 

src/main/java/com/elovirta/dita/markdown/ParseException.java

@@ -1,24 +1,23 @@
 package com.elovirta.dita.markdown;
 
+import org.xml.sax.SAXException;
+import org.xml.sax.SAXParseException;
+
 /**
  * Markdown parsing exception. Extends RuntimeException because underlying
  * parser framework doesn't allow throwing checked exceptions.
  */
 public class ParseException extends RuntimeException {
 
-  ParseException() {
-    super();
-  }
-
   public ParseException(final String msg) {
-    super(msg);
+    super(new SAXException(msg));
   }
 
-  ParseException(final Throwable cause) {
+  ParseException(final SAXException cause) {
     super(cause);
   }
 
-  public ParseException(String msg, Throwable cause) {
-    super(msg, cause);
+  public ParseException(String msg, Exception cause) {
+    super(new SAXException(msg, cause));
   }
 }

src/test/java/com/elovirta/dita/markdown/MDitaReaderCoreTest.java

@@ -1,11 +1,12 @@
 package com.elovirta.dita.markdown;
 
-import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.*;
 
 import com.elovirta.dita.utils.AbstractReaderTest;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ValueSource;
 import org.opentest4j.AssertionFailedError;
+import org.xml.sax.SAXException;
 
 public class MDitaReaderCoreTest extends AbstractReaderTest {
 
@@ -79,6 +80,11 @@ public void test_unsupported(String file) {
   @ParameterizedTest
   @ValueSource(strings = { "header.md", "invalid_header.md", "invalid_header_third.md" })
   public void test_fail(String file) {
-    assertThrows(ParseException.class, () -> run(file));
+    try {
+      run(file);
+      fail();
+    } catch (Exception e) {
+      assertEquals(SAXException.class, e.getCause().getClass());
+    }
   }
 }

src/test/java/com/elovirta/dita/markdown/MDitaReaderExtendedTest.java

@@ -1,6 +1,6 @@
 package com.elovirta.dita.markdown;
 
-import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.*;
 
 import com.elovirta.dita.utils.AbstractReaderTest;
 import java.io.IOException;
@@ -79,7 +79,12 @@ public void test(String file) throws Exception {
   @ParameterizedTest
   @ValueSource(strings = { "header.md", "invalid_header.md", "invalid_header_third.md" })
   public void test_fail(String file) {
-    assertThrows(ParseException.class, () -> run(file));
+    try {
+      run(file);
+      fail();
+    } catch (Exception e) {
+      assertEquals(SAXException.class, e.getCause().getClass());
+    }
   }
 
   @Test

src/test/java/com/elovirta/dita/markdown/MarkdownReaderTest.java

@@ -175,7 +175,12 @@ public void test_schemaParseFailure_withoutErrorHandler() throws Exception {
   @ParameterizedTest
   @ValueSource(strings = { "invalid_header.md" })
   public void test_fail(String file) {
-    assertThrows(RuntimeException.class, () -> run(file));
+    try {
+      run(file);
+      fail();
+    } catch (Exception e) {
+      assertEquals(SAXException.class, e.getCause().getClass());
+    }
   }
 
   @Test