[vividus] Add ability to keep all columns in DISTINCTING transformer (

#4959)

docs/modules/commons/pages/table-transformers.adoc

@@ -360,16 +360,24 @@ in the exampe above we select only those rows that do not contain `bbb` string i
 
 `DISTINCTING` transformer generates xref:ROOT:glossary.adoc#_examplestable[ExamplesTable] from the specified columns, deleting the rows with repeating values.
 
-[cols="1,3", options="header"]
+[cols="1,1,4", options="header"]
 |===
 |Parameter
+|Default value
 |Description
 
-|`byColumnNames`
-|the names of the columns to keep separated by semicolon
+|[subs=+quotes]`*byColumnNames*`
+|
+|The names of the columns to keep (separated by semicolon).
+
+|`keepAllColumns`
+|`false`
+|If `false`, only the columns specified in `byColumnNames` will appear in the resulting table. Otherwise, all columns
+ from the initial table will be included in the resulting table. If the initial table has rows with repeated values,
+the value from the first row will be retained in the resulting table.
 |===
 
-The following `DISTINCTING` transformer:
+This `DISTINCTING` transformer:
 
 [source,gherkin]
 ----
@@ -391,6 +399,28 @@ will result in the following xref:ROOT:glossary.adoc#_examplestable[ExamplesTabl
 |B      |D      |
 ----
 
+This `DISTINCTING` transformer keeping all columns:
+
+[source,gherkin]
+----
+{transformer=DISTINCTING, byColumnNames=column1;column2, keepAllColumns=true}
+|column1|column2|column3|
+|A      |C      |0      |
+|B      |D      |1      |
+|A      |C      |1      |
+|A      |C      |0      |
+|B      |D      |0      |
+----
+
+will result in the following xref:ROOT:glossary.adoc#_examplestable[ExamplesTable]:
+
+[source,gherkin]
+----
+|column1|column2|column3|
+|A      |C      |0      |
+|B      |D      |1      |
+----
+
 == MERGING
 
 `MERGING` transformer merges several tables into one.

vividus-tests/src/main/resources/story/integration/TableTransformers.story

@@ -201,7 +201,7 @@ Examples:
 }
 {transformer=FILTERING, column.col1=.+}
 
-Scenario: Verify DISTINCTING transformer
+Scenario: Validate DISTINCTING transformer
 Meta:
     @requirementId 992
 Then `<column1>` is equal to `a a b b`
@@ -219,6 +219,25 @@ Examples:
 |b      |x      |b      |
 |b      |y      |b      |
 
+Scenario: Validate DISTINCTING transformer keeping all columns
+Meta:
+    @requirementId 992
+Then `<column1>` is equal to `a a b b`
+Then `<column2>` is equal to `x x x x`
+Then `<column3>` is equal to `a b a b`
+Examples:
+{transformer=DISTINCTING, byColumnNames=column1;column3, keepAllColumns=true}
+{transformer=JOINING, joinMode=rows}
+|column1|column2|column3|
+|a      |x      |a      |
+|a      |y      |a      |
+|a      |x      |b      |
+|a      |y      |b      |
+|b      |x      |a      |
+|b      |y      |a      |
+|b      |x      |b      |
+|b      |y      |b      |
+
 Scenario: Verify possibility to use the range of ALL cells
 Meta:
     @requirementId 919

vividus/src/main/java/org/vividus/transformer/DistinctingTableTransformer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2022 the original author or authors.
+ * Copyright 2019-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,9 +16,13 @@
 
 package org.vividus.transformer;
 
+import java.util.Collection;
+import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
 import java.util.List;
-import java.util.Set;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
 
 import org.jbehave.core.model.ExamplesTable.TableProperties;
 import org.jbehave.core.model.ExamplesTable.TableRows;
@@ -31,14 +35,36 @@ public class DistinctingTableTransformer extends AbstractFilteringTableTransform
     public String transform(String tableAsString, TableParsers tableParsers, TableProperties tableProperties)
     {
         String byColumnNames = tableProperties.getMandatoryNonBlankProperty(BY_COLUMNS_NAMES_PROPERTY, String.class);
+        String keepAllColumns = tableProperties.getProperties().getProperty("keepAllColumns");
+
         TableRows tableRows = tableParsers.parseRows(tableAsString, tableProperties);
         List<String> allColumnNames = tableRows.getHeaders();
         List<String> filteredColumnNames = filterColumnNames(allColumnNames, byColumnNames);
         List<List<String>> rows = tableRows.getRows();
-        filterRowsByColumnNames(allColumnNames, rows, filteredColumnNames);
 
-        Set<List<String>> distinctRows = new LinkedHashSet<>(rows);
+        Collection<String> headers;
+        Collection<List<String>> distinctRows;
+        if (Boolean.parseBoolean(keepAllColumns))
+        {
+            int[] indexesToDistinct = IntStream.range(0, allColumnNames.size())
+                    .filter(i -> filteredColumnNames.contains(allColumnNames.get(i)))
+                    .sorted()
+                    .toArray();
 
-        return ExamplesTableProcessor.buildExamplesTable(filteredColumnNames, distinctRows, tableProperties);
+            distinctRows = rows.stream().collect(Collectors.toMap(
+                    r -> IntStream.of(indexesToDistinct).mapToObj(r::get).toList(),
+                    Function.identity(),
+                    (r1, r2) -> r1,
+                    LinkedHashMap::new
+            )).values();
+            headers = allColumnNames;
+        }
+        else
+        {
+            filterRowsByColumnNames(allColumnNames, rows, filteredColumnNames);
+            distinctRows = new LinkedHashSet<>(rows);
+            headers = filteredColumnNames;
+        }
+        return ExamplesTableProcessor.buildExamplesTable(headers, distinctRows, tableProperties);
     }
 }

vividus/src/test/java/org/vividus/transformer/DistinctingTableTransformerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2023 the original author or authors.
+ * Copyright 2019-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,23 +26,24 @@
 
 class DistinctingTableTransformerTests
 {
+    private static final String INPUT_TABLE = """
+            |key1|key2|key3|
+            |a   |x   |a   |
+            |a   |y   |a   |
+            |b   |x   |a   |
+            |b   |y   |a   |
+            |b   |x   |b   |
+            |b   |y   |b   |
+            |a   |x   |b   |
+            |a   |y   |b   |""";
+
     @Test
     void testDistinct()
     {
         var parameterConverters = new ParameterConverters();
         var tableParsers = new TableParsers(parameterConverters);
         var tableProperties = new TableProperties("byColumnNames=key1;key3", new Keywords(), parameterConverters);
-        var inputTable = """
-                |key1|key2|key3|
-                |a   |x   |a   |
-                |a   |y   |a   |
-                |b   |x   |a   |
-                |b   |y   |a   |
-                |b   |x   |b   |
-                |b   |y   |b   |
-                |a   |x   |b   |
-                |a   |y   |b   |""";
-        String result = new DistinctingTableTransformer().transform(inputTable, tableParsers, tableProperties);
+        String result = new DistinctingTableTransformer().transform(INPUT_TABLE, tableParsers, tableProperties);
         var distinctTable = """
                 |key1|key3|
                 |a|a|
@@ -51,4 +52,21 @@ void testDistinct()
                 |a|b|""";
         assertEquals(distinctTable, result);
     }
+
+    @Test
+    void shouldReturnDistinctTableKeepingAllColumns()
+    {
+        var parameterConverters = new ParameterConverters();
+        var tableParsers = new TableParsers(parameterConverters);
+        var tableProperties = new TableProperties("byColumnNames=key1;key3, keepAllColumns=true", new Keywords(),
+                parameterConverters);
+        String result = new DistinctingTableTransformer().transform(INPUT_TABLE, tableParsers, tableProperties);
+        var distinctTable = """
+            |key1|key2|key3|
+            |a|x|a|
+            |b|x|a|
+            |b|x|b|
+            |a|x|b|""";
+        assertEquals(distinctTable, result);
+    }
 }