chore: add tests and update README.md

Author: Pedro Pablo Bustamante Barrera

README.md

@@ -19,6 +19,7 @@ Currently, this package supports the following formats:
 - CURP (Clave Única de Registro de Población, Mexican personal ID.)
 - DNI (Documento Nacional de Identidad, Argentinian national identity number).
 - EAN (International Article Number).
+- ISBN (International Standard Book Number).
 - NIT (Número De Identificación Tributaria, Colombian identity code).
 - RFC (Registro Federal de Contribuyentes, Mexican tax number).
 - RIF (Registro de Identificación Fiscal, Venezuelan VAT number).

src/test/scala/CurpSuite.scala

@@ -17,8 +17,8 @@ class CURPSuite extends munit.FunSuite {
   }
 
   test("validate invalid CURP") {
-    val validCurp = CURP.validate("BOXW310820HNERXN08")
-    assert(validCurp.isLeft)
+    val invalidCurp = CURP.validate("BOXW310820HNERXN08")
+    assert(invalidCurp.isLeft)
   }
 
   test("isValid valid CURP") {

src/test/scala/RfcSuite.scala

@@ -21,8 +21,8 @@ class RFCSuite extends munit.FunSuite {
   }
 
   test("validate invalid RFC") {
-    val validRfc = RFC.validate("VACE-460910-SX6")
-    assert(validRfc.isLeft)
+    val invalidRfc = RFC.validate("VACE-460910-SX6")
+    assert(invalidRfc.isLeft)
   }
 
   test("isValid valid RFC") {

src/test/scala/RutSuite.scala

@@ -17,8 +17,8 @@ class RUTSuite extends munit.FunSuite {
   }
 
   test("validate invalid RUT") {
-    val validRut = RUT.validate("30.866.497-5")
-    assert(validRut.isLeft)
+    val invalidRut = RUT.validate("30.866.497-5")
+    assert(invalidRut.isLeft)
   }
 
   test("isValid valid RUT") {