fix: treat numRows(0) as no row limit when reading (#1149)

fesod-sheet/src/main/java/org/apache/fesod/sheet/read/listener/ReadListener.java

@@ -102,7 +102,8 @@ default boolean hasNext(AnalysisContext context) {
         if (limit == null) {
             limit = context.readWorkbookHolder().getReadWorkbook().getNumRows();
         }
-        if (limit != null && index >= limit) {
+        // Zero is documented as "no limit", so only a positive limit stops the read.
+        if (limit != null && limit > 0 && index >= limit) {
             return false;
         }
         return true;

fesod-sheet/src/test/java/org/apache/fesod/sheet/read/listener/NumRowsReadLimitTest.java

@@ -0,0 +1,104 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.fesod.sheet.read.listener;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+import lombok.Getter;
+import lombok.Setter;
+import org.apache.fesod.sheet.FesodSheet;
+import org.apache.fesod.sheet.annotation.ExcelProperty;
+import org.apache.fesod.sheet.testkit.Tags;
+import org.apache.fesod.sheet.testkit.base.AbstractExcelTest;
+import org.apache.fesod.sheet.testkit.enums.ExcelFormat;
+import org.apache.fesod.sheet.testkit.listeners.CollectingReadListener;
+import org.apache.fesod.sheet.testkit.params.ExcelFormatSource;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Tag;
+import org.junit.jupiter.params.ParameterizedTest;
+
+/**
+ * The documented {@code numRows} sentinel: zero means no row limit, so all rows are read, while a
+ * positive limit still stops the read early.
+ */
+@Tag(Tags.ROUND_TRIP)
+public class NumRowsReadLimitTest extends AbstractExcelTest {
+
+    private static final int TOTAL_ROWS = 3;
+
+    @ParameterizedTest
+    @ExcelFormatSource
+    void numRowsZeroReadsAllRowsLikeNoLimit(ExcelFormat format) throws IOException {
+        File file = createTempFile(format);
+        writeHeadless(file);
+
+        Assertions.assertEquals(TOTAL_ROWS, readRows(file, 0));
+    }
+
+    @ParameterizedTest
+    @ExcelFormatSource
+    void omittedNumRowsReadsAllRows(ExcelFormat format) throws IOException {
+        File file = createTempFile(format);
+        writeHeadless(file);
+
+        Assertions.assertEquals(TOTAL_ROWS, readRows(file, null));
+    }
+
+    @ParameterizedTest
+    @ExcelFormatSource
+    void positiveNumRowsStillStopsEarly(ExcelFormat format) throws IOException {
+        File file = createTempFile(format);
+        writeHeadless(file);
+
+        Assertions.assertEquals(1, readRows(file, 1));
+    }
+
+    /**
+     * Writes rows without a header row, so the numRows limit maps one-to-one onto data rows
+     * regardless of the head row numbering.
+     */
+    private void writeHeadless(File file) {
+        List<List<String>> rows = new java.util.ArrayList<>();
+        for (int i = 1; i <= TOTAL_ROWS; i++) {
+            rows.add(Arrays.asList("row-" + i));
+        }
+        FesodSheet.write(file).sheet().doWrite(rows);
+    }
+
+    private int readRows(File file, Integer numRows) {
+        CollectingReadListener<RowData> listener = new CollectingReadListener<>();
+        FesodSheet.read(file, RowData.class, listener)
+                .sheet()
+                .headRowNumber(0)
+                .numRows(numRows)
+                .doRead();
+        return listener.getRows().size();
+    }
+
+    @Getter
+    @Setter
+    public static class RowData {
+
+        @ExcelProperty("name")
+        private String name;
+    }
+}