adds new function STR_TRIM (#486)

docs/references/functions.md

@@ -40,6 +40,7 @@ Available through the _ExpressionConfiguration.StandardFunctionsDictionary_ cons
 | STR_FORMAT(format [,argument, ...]) | Returns a formatted string using the specified format string and arguments, using the configured locale |
 | STR_LOWER(value)                    | Converts the given value to lower case                                                                  |
 | STR_STARTS_WITH(string, substring)  | Returns true if the string starts with the substring (case-sensitive)                                   |
+| STR_TRIM(string)                    | Returns the given string with all leading and trailing space removed.                                   |
 | STR_UPPER(value)                    | Converts the given value to upper case                                                                  |
 
 ### Trigonometric Functions

src/main/java/com/ezylang/evalex/config/ExpressionConfiguration.java

@@ -185,6 +185,7 @@ public class ExpressionConfiguration {
           Map.entry("STR_FORMAT", new StringFormatFunction()),
           Map.entry("STR_LOWER", new StringLowerFunction()),
           Map.entry("STR_STARTS_WITH", new StringStartsWithFunction()),
+          Map.entry("STR_TRIM", new StringTrimFunction()),
           Map.entry("STR_UPPER", new StringUpperFunction()),
           // date time functions
           Map.entry("DT_DATE_NEW", new DateTimeNewFunction()),

src/main/java/com/ezylang/evalex/functions/string/StringTrimFunction.java

@@ -0,0 +1,38 @@
+/*
+  Copyright 2012-2024 Udo Klimaschewski
+
+  Licensed 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 com.ezylang.evalex.functions.string;
+
+import com.ezylang.evalex.EvaluationException;
+import com.ezylang.evalex.Expression;
+import com.ezylang.evalex.data.EvaluationValue;
+import com.ezylang.evalex.functions.AbstractFunction;
+import com.ezylang.evalex.functions.FunctionParameter;
+import com.ezylang.evalex.parser.Token;
+
+/**
+ * Returns the given string with all leading and trailing space removed.
+ *
+ * @author LeonardoSoaresDev
+ */
+@FunctionParameter(name = "string")
+public class StringTrimFunction extends AbstractFunction {
+  @Override
+  public EvaluationValue evaluate(
+      Expression expression, Token functionToken, EvaluationValue... parameterValues)
+      throws EvaluationException {
+    return expression.convertValue(parameterValues[0].getStringValue().trim());
+  }
+}

src/test/java/com/ezylang/evalex/functions/string/StringFunctionsTest.java

@@ -151,4 +151,18 @@ void testFormatChicago(String expression, String expectedResult)
     assertExpressionHasExpectedResult(
         expression, expectedResult, TestConfigurationProvider.ChicagoConfiguration);
   }
+
+  @ParameterizedTest
+  @CsvSource(
+      delimiter = ':',
+      value = {
+        "STR_TRIM(\" Two whitespace \") : Two whitespace",
+        "STR_TRIM(\" Left whitespace\") : Left whitespace",
+        "STR_TRIM(\"Right whitespace  \") : Right whitespace",
+        "STR_TRIM(\"No whitespace\") : No whitespace"
+      })
+  void testTrimString(String expression, String expectedResult)
+      throws EvaluationException, ParseException {
+    assertExpressionHasExpectedResult(expression, expectedResult);
+  }
 }