Fix default value handling in REGEXP_EXTRACT transform function (#14489)

apache · Nov 21, 2024 · 87ea7c8 · 87ea7c8
1 parent c5e00bb
commit 87ea7c8
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Showing 2 changed files with 17 additions and 5 deletions.
diff --git a/...ava/org/apache/pinot/core/operator/transform/function/RegexpExtractTransformFunction.java b/...ava/org/apache/pinot/core/operator/transform/function/RegexpExtractTransformFunction.java
@@ -81,10 +81,10 @@ public void init(List<TransformFunction> arguments, Map<String, ColumnContext> c
     }
 
     if (arguments.size() == 4) {
-      TransformFunction positionFunction = arguments.get(3);
-      Preconditions.checkState(positionFunction instanceof LiteralTransformFunction,
+      TransformFunction defaultValueTransformFunction = arguments.get(3);
+      Preconditions.checkState(defaultValueTransformFunction instanceof LiteralTransformFunction,
           "`default_value` must be a literal expression.");
-      _defaultValue = ((LiteralTransformFunction) regexpFunction).getStringLiteral();
+      _defaultValue = ((LiteralTransformFunction) defaultValueTransformFunction).getStringLiteral();
     } else {
       _defaultValue = "";
     }

diff --git a/...t/java/org/apache/pinot/core/operator/transform/function/RegexpTransformFunctionTest.java b/...t/java/org/apache/pinot/core/operator/transform/function/RegexpTransformFunctionTest.java
@@ -41,8 +41,20 @@ public void testRegexpExtractLegalArguments(String expressionStr, int group, Str
     for (int i = 0; i < NUM_ROWS; i++) {
       Matcher matcher = PATTERN.matcher(_stringSVValues[i]);
       Assert.assertEquals(
-          matcher.find() && matcher.groupCount() >= group ? matcher.group(group) : defaultValue,
-          actualValues[i]);
+          actualValues[i],
+          matcher.find() && matcher.groupCount() >= group ? matcher.group(group) : defaultValue
+      );
+    }
+  }
+
+  @Test
+  public void testDefaultValue() {
+    String expressionStr = String.format("REGEXP_EXTRACT(%s, '%s', 1, 'null')", STRING_SV_COLUMN, "nonMatchingRegex");
+    ExpressionContext expression = RequestContextUtils.getExpression(expressionStr);
+    TransformFunction transformFunction = TransformFunctionFactory.get(expression, _dataSourceMap);
+    String[] actualValues = transformFunction.transformToStringValuesSV(_projectionBlock);
+    for (int i = 0; i < NUM_ROWS; i++) {
+      Assert.assertEquals(actualValues[i], "null");
     }
   }