Context

• node version: N/A
• joi version: HEAD
• environment (node, browser): N/A
• used with (hapi, standalone, ...): N/A
• any other relevant information:

const result = joi.validate(value, schema);

result is a thennable, despite validate being synchronous. It seems like the callback has been removed from the upcoming v16, and it seems like the 'thennable' should be removed too.

validate already returns its result synchronously (via result.error and result.value), so going genuinely async would be a breaking change anyway.