test: add tests for the builtin function %chr

_[TODO: fix `%chr` to allow Unicode chars, the corresponding tests are here.]_

test/net/sourceforge/plantuml/tim/stdlib/ChrTest.java

@@ -0,0 +1,46 @@
+package net.sourceforge.plantuml.tim.stdlib;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.Collections;
+import java.util.List;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+import net.sourceforge.plantuml.tim.EaterException;
+import net.sourceforge.plantuml.tim.EaterExceptionLocated;
+import net.sourceforge.plantuml.tim.expression.TValue;
+
+/**
+ * Tests the builtin function %chr.
+ */
+class ChrTest {
+
+	/**
+	 * Tests chr according to a list of input / expected output 
+	 *
+	 * @throws EaterException should not
+	 * @throws EaterExceptionLocated should not
+	 */
+	@ParameterizedTest
+	@CsvSource(nullValues = "null", value = {
+			" 65   , A ",
+			" 9    , '\t' ",
+			" 32   , ' ' ",
+			" 33   , '!' ",
+			" 34   , '\"' ",
+			" 224  , à ",
+			" 233  , é ",
+// TODO: fix `%chr` to allow Unicode chars, the corresponding tests are here:
+//			" 128512 , 😀 ",
+//			" 128512 , \uD83D\uDE00 ",
+	})
+	void executeReturnFunctionChrTest(Integer input, String expected) throws EaterException, EaterExceptionLocated {
+		Chr cut = new Chr();
+
+		List<TValue> values = Collections.singletonList(TValue.fromInt(input));
+		TValue tValue = cut.executeReturnFunction(null, null, null, values, null);
+		assertEquals(expected, tValue.toString());
+	}
+}