What deal this was

Brd:  Who Care’s
Dlr:  N                North
Vul: E/W          
 - Q74
- KT62
- AQJ6
 - KJ
   West                                                East
 -  ??                                              
 - ????

 - KJ98                
 -  864          
 - K83
 - T42

A one over one response bid in bridge requires very special conditions and even more rarely promises a 5 card or longer
holding in the suit bid.  The term bidding up the line means that the the responder bids a higher suit on the one level in response to Partner’s 1 level opening in a MINOR suit.  The only time this promises a 5 card or longer suit is when Partner
has  opened specifically 1 Heart and the Responder bids 1 Spade. 

So if the opening bid by Partner is 1 of a minor, they very rarely can possess a major suit of 5 cards or longer or that would
have been the opening bid.

Opener must not raise partner’s one over one response until they have been the suit twice or have freely bid a lower suit at the Two(2) level.  So in the case above the auction sez:  If north opens 1 Diamond and hears Partner respond 1 Spade, Openers
rebid must be 1NT and allow Partner to continue the auction as they see fit.

The following might be an acceptable immediate raise:
Dealer is just shy of a 2NT opening bid and not good enough to open with 2C’s.  They have a maximun raise in Partner’s 1st
suit Spades and can reasonably expect Partner to be able to control the trump suit to include at least one ruffing trick in the hand with only three trump cards and a semi solid side suit Diamonds as a source of game going tricks.  Having their super
hand on the table will provide many lead problems for either opponent that will help declarer.  If partner has 13+ in HCP’s they should consider 3NT or greater as the final contract.

Seeya when we seeya