Thank you, now all cleared :-)

I wrote

console.log('pattern = ' + pattern + ' / str = ' + str);

and got

pattern = aafggiilp / str = cow cow fly pig pig sheep sheep chicken aardvark
Expected: true, instead got: false

aaffggiilp != ccfppssca
but test expected true answer

in Javascript 10th test looks like

Test.assertEquals(wordPattern('aafggiilp', 'cow cow fly pig pig sheep sheep chicken aardvark'), true);

it's wrong
please fix it