the direction of bond polarity for the Cl-F bond?

F atom has a higher electronegativity than Cl atom. Therefore, in Cl-F bond, Cl atom carries partial positive charge and F atom carries partial negative charge.

As the polarity of covalent bond is from the positive end to the negative end, the bond polarity of Cl-F bond is from Cl atom to F atom.

North is up, South is down

Electronegativity measures the relative force of attraction for bonding electrons. Since Fluorine has a higher electronegativity, it will be the negative end of the molecule.

Fluorine has a higher electronegativity and will end up with the electrons around it for a greater percentage of time, or you could say that an electron density cloud would center near the fluorine and give it a more negative charge. The electron density will distort toward the fluorine and away from the chlorine. Chlorine becomes the "positive" charge of the asymmetric bond.

An electron donor that is brought into contact will be seen to give an electron to chlorine, to reduce the chlorine atom, and not the fluorine atom.

F- Cl+