Is the theme of love fulfilled by deception or tests?
Let us begin with the caskets. Portia's father knew his world well. Despite her brains, Portia lived in as male dominated world. Portia was a like a bird in a guilded cage. He did not want his daughter caught like Penelope with suitors plaguing her. He devised the caskets as a test and it worked. Probably many were turned away because of the terms. The two we do see before Bassanio, go for the glitter, proving themselves unworthy of such a treasure as Portia who is greater than either silver or gold. Bassanio has the breeding if not the fortune necessary to risk the challenge. He needs Antonio's help. He is also Portia's choice.
The ring is also a test since rings are traditionally the symbol of marriage. Portia warns him not to lose or give away the ring.
Her disguise is the only way Portia can appear in the court due to the male dominated society. That Bassanio does not recognise her is credible since as far as he knew, his wife was at Belmont. We often don't recognise people outside their normal environment.
You must admit that the disguised Portia who has just saved Bassiano's best friend's life just won't take no for an answer. Bassanio does try but yields to Antonio who persuades him to give the young lawyer the ring.
Perhaps it is only through these tests or deceptions that Bassanio realizes exactly what love is. When he has the chance to help out Bassanio concerning the ring, Antonio says nothing. Love of wife supersedes best friend. A good lesson.
A better question, do they live happily ever after?