spanish errors (#167)

anilang-parser/src/main/java/com/anilang/parser/ListErrorListener.java

@@ -42,7 +42,7 @@ public void syntaxError(
             new ParseError(
                 line,
                 column,
-                msg
+                new SyntaxError(exception).message()
             )
         );
     }

anilang-parser/src/main/java/com/anilang/parser/SyntaxError.java

@@ -0,0 +1,23 @@
+/*
+ * Property of ani-lang project.
+ */
+
+package com.anilang.parser;
+
+import org.antlr.v4.runtime.NoViableAltException;
+import org.antlr.v4.runtime.RecognitionException;
+
+final class SyntaxError {
+    private final RecognitionException exception;
+
+    public SyntaxError(final RecognitionException exception) {
+        this.exception = exception;
+    }
+
+    String message() {
+        if(exception instanceof NoViableAltException) {
+            return "Token no esperado.";
+        }
+        return exception.getMessage();
+    }
+}

anilang-parser/src/test/java/com/anilang/parser/AniParserCheckTest.java

@@ -29,6 +29,19 @@ void invalidCharacterAssignation() throws IOException {
         );
     }
 
+    @Test
+    void spanishDefaultError() throws IOException {
+        Assertions.assertEquals(
+            "[1:4]: Token no esperado.",
+            new AniParserCheck(
+                new ExampleFile(
+                    ExampleCode.INVALID_ASSIGNATION
+                ).inputStream()
+            ).errors().get(0).getError(),
+            "spanish default"
+        );
+    }
+
     @Test
     void validCharacterAssignation() throws IOException {
         Assertions.assertEquals(