datatable/java: all asX should behave consistently

Fixes: cucumber/cucumber-jvm#2262

datatable/src/main/java/io/cucumber/datatable/DataTable.java

@@ -166,16 +166,30 @@ public void unorderedDiff(DataTable actual) throws TableDiffException {
      *
      * @return the cells of the table
      */
-    public List<String> asList() {
+    List<String> toList() {
         return new ListView();
     }
 
+    /**
+     * Converts the table to a list of {@code String}s. Contains the cells
+     * ordered from left to right, top to bottom starting at the top left.
+     *
+     * @return a list of strings
+     *
+     * @see TableConverter#toList(DataTable, Type)
+     */
+    public List<String> asList() {
+        return asList(String.class);
+    }
+
     /**
      * Converts the table to a list of {@code itemType}.
      *
      * @param itemType the type of the list items
      * @param <T>      the type of the list items
-     * @return a List of objects
+     * @return a list of objects
+     *
+     * @see TableConverter#toList(DataTable, Type)
      */
     public <T> List<T> asList(Type itemType) {
         return tableConverter.toList(this, itemType);
@@ -186,7 +200,7 @@ public <T> List<T> asList(Type itemType) {
      *
      * @return the cells of the table
      */
-    public List<List<String>> asLists() {
+    List<List<String>> toLists() {
         return cells();
     }
 
@@ -195,8 +209,8 @@ public List<List<String>> asLists() {
      *
      * @return the cells of the table
      */
-    public List<List<String>> cells() {
-        return raw;
+    public List<List<String>> asLists() {
+        return asLists(String.class);
     }
 
     /**
@@ -227,14 +241,7 @@ public <K, V> Map<K, V> asMap(Type keyType, Type valueType) {
         return tableConverter.toMap(this, keyType, valueType);
     }
 
-    /**
-     * Converts the table to a list of maps of strings. For each row in the body
-     * of the table a map is created containing a mapping of column headers to
-     * the column cell of that row.
-     *
-     * @return a list of maps
-     */
-    public List<Map<String, String>> asMaps() {
+    List<Map<String, String>> toMaps() {
         if (raw.isEmpty()) return emptyList();
 
         List<String> headers = raw.get(0);
@@ -258,6 +265,20 @@ public List<Map<String, String>> asMaps() {
         return unmodifiableList(headersAndRows);
     }
 
+    /**
+     * Converts the table to a list of maps of strings. For each row in the body
+     * of the table a map is created containing a mapping of column headers to
+     * the column cell of that row.
+     *
+     * @return a list of maps
+     */
+    public List<Map<String, String>> asMaps() {
+        if (!hasConverter()) {
+            return toMaps();
+        }
+        return asMaps(String.class, String.class);
+    }
+
     /**
      * Converts the table to a list of maps of {@code keyType} to {@code valueType}.
      * For each row in the body of the table a map is created containing a mapping
@@ -273,6 +294,19 @@ public <K, V> List<Map<K, V>> asMaps(Type keyType, Type valueType) {
         return tableConverter.toMaps(this, keyType, valueType);
     }
 
+    private boolean hasConverter() {
+        return !(tableConverter instanceof NoConverterDefined);
+    }
+
+    /**
+     * Returns the cells of the table.
+     *
+     * @return the cells of the table
+     */
+    public List<List<String>> cells() {
+        return raw;
+    }
+
     /**
      * Returns a single table cell.
      *

datatable/src/main/java/io/cucumber/datatable/DataTableType.java

@@ -328,7 +328,7 @@ public Class<?> getOriginalTransformerType() {
         public List<T> transform(List<List<String>> raw) throws Throwable {
             DataTable table = DataTable.create(raw, CONVERSION_REQUIRED);
             List<T> list = new ArrayList<>();
-            for (Map<String, String> entry : table.asMaps()) {
+            for (Map<String, String> entry : table.toMaps()) {
                 list.add(transformer.transform(entry));
             }
 

datatable/src/test/java/io/cucumber/datatable/DataTableTest.java

@@ -313,7 +313,7 @@ void columns_should_view_sub_table() {
     void as_lists_should_equal_raw() {
         List<List<String>> raw = asList(asList("hundred", "100"), asList("thousand", "1000"));
         DataTable table = DataTable.create(raw);
-        assertEquals(raw, table.asLists());
+        assertEquals(raw, table.toLists());
     }
 
     @Test
@@ -414,7 +414,7 @@ void asLists_returns_raw_rows_in_order() {
                 asList("2", "1000")
         );
         DataTable table = DataTable.create(raw);
-        assertEquals(asList("1", "100", "2", "1000"), table.asList());
+        assertEquals(asList("1", "100", "2", "1000"), table.toList());
     }
 
     @Test
@@ -424,7 +424,7 @@ void asLists_throws_for_large_index() {
                 asList("2", "1000")
         );
         DataTable table = DataTable.create(raw);
-        assertThrows(IndexOutOfBoundsException.class, () -> table.asList().get(5));
+        assertThrows(IndexOutOfBoundsException.class, () -> table.toList().get(5));
     }
 
     @Test
@@ -434,7 +434,7 @@ void asLists_throws_for_negative_index() {
                 asList("2", "1000")
         );
         DataTable table = DataTable.create(raw);
-        assertThrows(IndexOutOfBoundsException.class, () -> table.asList().get(-1));
+        assertThrows(IndexOutOfBoundsException.class, () -> table.toList().get(-1));
     }
 
     @Test
@@ -458,7 +458,7 @@ void asLists_returns_raw() {
                 asList("2", "1000")
         );
         DataTable table = DataTable.create(raw);
-        assertEquals(raw, table.asLists());
+        assertEquals(raw, table.toLists());
     }
 
     @Test
@@ -477,7 +477,7 @@ void asMaps_returns_maps_of_raw() {
             put("100", "1000");
         }};
 
-        assertEquals(singletonList(expected), table.asMaps());
+        assertEquals(singletonList(expected), table.toMaps());
     }
 
     @Test
@@ -492,7 +492,7 @@ void asMaps_can_convert_table_with_null_values() {
             put("2", null);
         }};
 
-        assertEquals(singletonList(expected), table.asMaps());
+        assertEquals(singletonList(expected), table.toMaps());
     }
 
     @Test
@@ -505,7 +505,7 @@ void asMaps_cant_convert_table_with_duplicate_keys() {
 
         CucumberDataTableException exception = assertThrows(
                 CucumberDataTableException.class,
-                table::asMaps
+                table::toMaps
         );
 
         assertThat(exception.getMessage(), is(format("" +
@@ -523,7 +523,7 @@ void asMaps_cant_convert_table_with_duplicate_null_keys() {
 
         CucumberDataTableException exception = assertThrows(
                 CucumberDataTableException.class,
-                table::asMaps
+                table::toMaps
         );
         assertThat(exception.getMessage(), is(format("" +
                         "Can't convert DataTable to Map<%s, %s>.\n" +
@@ -538,7 +538,7 @@ void asMaps_with_nulls_returns_maps_of_raw() {
             put(null, null);
         }};
 
-        assertEquals(singletonList(expected), table.asMaps());
+        assertEquals(singletonList(expected), table.toMaps());
     }
 
     @Test

datatable/src/test/java/io/cucumber/datatable/DataTableTypeRegistryTableConverterTest.java

@@ -95,7 +95,7 @@ class DataTableTypeRegistryTableConverterTest {
     }.getType();
     public static final Type OPTIONAL_CHESS_BOARD_TYPE = new TypeReference<Optional<ChessBoard>>() {
     }.getType();
-    private static final TableTransformer<ChessBoard> CHESS_BOARD_TABLE_TRANSFORMER = table -> new ChessBoard(table.subTable(1, 1).asList());
+    private static final TableTransformer<ChessBoard> CHESS_BOARD_TABLE_TRANSFORMER = table -> new ChessBoard(table.subTable(1, 1).toList());
     private static final TableCellTransformer<Piece> PIECE_TABLE_CELL_TRANSFORMER = Piece::fromString;
     private static final TableCellTransformer<AirPortCode> AIR_PORT_CODE_TABLE_CELL_TRANSFORMER = AirPortCode::new;
     private static final SimpleDateFormat SIMPLE_DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd");