Nicki Minaj isn't going to the cops after Cardi B went after her at a New York Fashion Week party Friday night ... because it really didn't bother her at all.

Sources close to "Chun-Li" rapper tell TMZ ... even though Cardi's shoe-throwing attack at the Harper's Bazaar party Friday night was a shock -- her security handled it and Nicki was totally fine.

We're told Minaj was unscathed and nobody on her team was injured either ... so she sees no reason to file a police report and carry on with the drama.

As for Cardi -- who was left with a lump on her head after the ruckus she started -- law enforcement tells us she hasn't filed a police report either. People connected to Cardi told us they believe she got the lump from being elbowed by someone on Nicki's security.

CARDI BEASTMODE
TMZ.com

We broke the story ... Cardi reached a breaking point after Nicki making comments about her fitness as a mom. Judging from Cardi's own words, she was looking for a fight. She never made contact, either with her fists or her shoe.

Nicki played it super cool later while leaving the Plaza hotel ... and it seems she's still not letting it affect her ... at least outwardly.