When people describe their true friends, they say "he was with me when I was sad, he was with me on my bad days". A true friend is the one who is with us in our good times. Not people who get jealous when we're good and want us to fail inwardly. It is actually very easy to understand people who want us to be successful and rejoice with us. Tell them about a dream and see their reaction. So you will know if he is your true friend or not.