fixed opensearch-project#266

Signed-off-by: chloe-zh <chloezh1102@gmail.com>
chloe-zh · Nov 13, 2021 · 0cf5c8a · 0cf5c8a
1 parent 603d953
commit 0cf5c8a
Show file tree

Hide file tree

Showing 3 changed files with 39 additions and 3 deletions.
diff --git a/core/src/main/java/org/opensearch/sql/expression/text/TextFunction.java b/core/src/main/java/org/opensearch/sql/expression/text/TextFunction.java
@@ -286,12 +286,18 @@ private static ExprValue exprSubStr(String str, int start, int len) {
   }
 
   private static ExprValue exprRight(ExprValue str, ExprValue len) {
-    return new ExprStringValue(str.stringValue().substring(
-            str.stringValue().length() - len.integerValue()));
+    if (len.integerValue() <= 0) {
+      return new ExprStringValue("");
+    }
+    String stringValue = str.stringValue();
+    int left = Math.max(stringValue.length() - len.integerValue(), 0);
+    return new ExprStringValue(str.stringValue().substring(left));
   }
 
   private static ExprValue exprLeft(ExprValue expr, ExprValue length) {
-    return new ExprStringValue(expr.stringValue().substring(0, length.integerValue()));
+    String stringValue = expr.stringValue();
+    int right = length.integerValue();
+    return new ExprStringValue(stringValue.substring(0, Math.min(right, stringValue.length())));
   }
 
   private static ExprValue exprAscii(ExprValue expr) {

diff --git a/core/src/test/java/org/opensearch/sql/expression/text/TextFunctionTest.java b/core/src/test/java/org/opensearch/sql/expression/text/TextFunctionTest.java
@@ -291,6 +291,18 @@ void right() {
     assertEquals(STRING, expression.type());
     assertEquals("rbar", eval(expression).stringValue());
 
+    expression = dsl.right(DSL.literal("foo"), DSL.literal(10));
+    assertEquals(STRING, expression.type());
+    assertEquals("foo", eval(expression).value());
+
+    expression = dsl.right(DSL.literal("foo"), DSL.literal(0));
+    assertEquals(STRING, expression.type());
+    assertEquals("", eval(expression).value());
+
+    expression = dsl.right(DSL.literal(""), DSL.literal(10));
+    assertEquals(STRING, expression.type());
+    assertEquals("", eval(expression).value());
+
     when(nullRef.type()).thenReturn(STRING);
     when(missingRef.type()).thenReturn(INTEGER);
     assertEquals(missingValue(), eval(dsl.right(nullRef, missingRef)));
@@ -308,6 +320,18 @@ void left() {
     assertEquals(STRING, expression.type());
     assertEquals("hello", eval(expression).stringValue());
 
+    expression = dsl.left(DSL.literal("hello"), DSL.literal(10));
+    assertEquals(STRING, expression.type());
+    assertEquals("hello", eval(expression).value());
+
+    expression = dsl.left(DSL.literal("hello"), DSL.literal(0));
+    assertEquals(STRING, expression.type());
+    assertEquals("", eval(expression).value());
+
+    expression = dsl.left(DSL.literal(""), DSL.literal(10));
+    assertEquals(STRING, expression.type());
+    assertEquals("", eval(expression).value());
+
     when(nullRef.type()).thenReturn(STRING);
     when(missingRef.type()).thenReturn(INTEGER);
     assertEquals(missingValue(), eval(dsl.left(nullRef, missingRef)));

diff --git a/integ-test/src/test/resources/correctness/expressions/text_functions.txt b/integ-test/src/test/resources/correctness/expressions/text_functions.txt
@@ -1,5 +1,11 @@
 RIGHT('Hello World', 5) as column
+RIGHT('Hello World', 20) as column
+RIGHT('Hello World', 0) as column
+RIGHT('', 5) as column
 LEFT('Hello World', 5) as column
+LEFT('Hello World', 20) as column
+LEFT('Hello World', 0) as column
+LEFT('', 5) as column
 ASCII('hello') as column
 LOCATE('world', 'helloworld') as column
 LOCATE('world', 'hello') as column