DASHBUILDE-172: Fail fast on invalid CSV data

dashbuilder-backend/dashbuilder-dataset-csv/src/main/java/org/dashbuilder/dataprovider/csv/CSVParser.java

@@ -73,7 +73,12 @@ protected DataSet load() throws Exception {
             if (header == null) throw new IOException("CSV has no header: " + dataSetDef);
 
             String[] firstRow = csvReader.readNext();
-            if (firstRow == null || firstRow.length < header.length) firstRow = null;
+            if (firstRow != null && firstRow.length < header.length) {
+                String exceptionMessage = String.format("CSV parse error : The first row has fewer columns (%d) than the header (%d)"
+                        , firstRow.length, header.length);
+                // Fail fast - see DASHBUILDE-172
+                throw new IllegalArgumentException(exceptionMessage);
+            }
 
             // Build the data set structure
             List<Integer> _columnIdxs = new ArrayList<Integer>();

dashbuilder-backend/dashbuilder-dataset-csv/src/test/java/org/dashbuilder/dataprovider/csv/CSVParserTest.java

@@ -0,0 +1,88 @@
+package org.dashbuilder.dataprovider.csv;
+
+
+import org.dashbuilder.dataset.ColumnType;
+import org.dashbuilder.dataset.DataSet;
+import org.dashbuilder.dataset.def.CSVDataSetDef;
+import org.dashbuilder.dataset.def.DataSetDefFactory;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+
+import static org.junit.Assert.assertEquals;
+
+public class CSVParserTest {
+
+    //Dummy DataSetDef just to get separator/quote/escape char definition for the parser
+    private final CSVDataSetDef csvDataSet = (CSVDataSetDef) DataSetDefFactory.newCSVDataSetDef()
+            .separatorChar(',')
+            .quoteChar('\'')
+            .escapeChar('\\')
+            .datePattern("YYYY-MM-dd")
+            .numberPattern("###.##")
+            .buildDef();
+
+
+    /* Reproducer of DASHBUILDE-172 */
+    @Test
+    public void exceptionThrown_whenFirstLineHasLessFieldsThanHeader() throws Exception {
+        //Header with 2 fields, 1st row missing comma -> has only 1 field
+        final String CSV_DATA = "'Name','Age'\n'Jan''15'";
+
+        CSVFileStorage mockStorage = new MockCSVFileStorage(CSV_DATA);
+        CSVParser testedParser = new CSVParser(csvDataSet, mockStorage);
+        try {
+            DataSet dataSetShouldNotLoad = testedParser.load();
+            Assert.fail("IllegalArgumentException should be thrown when 1st row of CSV data has less fields than the header");
+        } catch (IllegalArgumentException iae) {
+            String expectedExceptionMessage = "CSV parse error : The first row has fewer columns (1) than the header (2)";
+            assertEquals(expectedExceptionMessage, iae.getMessage());
+        }
+    }
+
+    @Test
+    public void dataSetCreated_whenCsvDataValid() throws Exception {
+        final String CSV_DATA = "'Name','Weight','Date of birth'\n'Jan','75.64','1950-01-20'";
+
+        CSVFileStorage mockStorage = new MockCSVFileStorage(CSV_DATA);
+        CSVParser testedParser = new CSVParser(csvDataSet, mockStorage);
+        DataSet dset = testedParser.load();
+
+        assertEquals(1, dset.getRowCount());
+        assertEquals(ColumnType.LABEL, dset.getColumnById("Name").getColumnType());
+        assertEquals(ColumnType.NUMBER, dset.getColumnById("Weight").getColumnType());
+        assertEquals(ColumnType.DATE, dset.getColumnById("Date of birth").getColumnType());
+    }
+
+
+    static class MockCSVFileStorage implements CSVFileStorage {
+
+        private final String csvData;
+
+        MockCSVFileStorage(String csvData) {
+            this.csvData = csvData;
+        }
+
+        @Override
+        public InputStream getCSVInputStream(CSVDataSetDef ignored) {
+            return new ByteArrayInputStream(csvData.getBytes(StandardCharsets.UTF_8));
+        }
+
+        @Override
+        public String getCSVString(CSVDataSetDef def) {
+            return null;
+        }
+
+        @Override
+        public void saveCSVFile(CSVDataSetDef def) {
+        }
+
+        @Override
+        public void deleteCSVFile(CSVDataSetDef def) {
+        }
+    }
+}