Can the Thorn Whip cantrip fulfill the requirement for the third benefit of the Mobile feat? [duplicate]

Question

As stated in the description for the thorn whip cantrip (PHB, p. 282), the caster makes a "melee spell attack" against the target.

You create a long, vine-like whip covered in thorns that lashes out at your command toward a creature in range. Make a melee spell attack against the target.

The third benefit of the Mobile feat says (PHB, p. 168):

When you make a melee attack against a creature, you don’t provoke opportunity attacks from that creature for the rest of the turn, whether you hit or not.

Given that the third benefit of the Mobile feat only requires a melee attack to be made to avoid provoking opportunity attacks (without specifying the type of melee attack), would that cantrip fulfill the trigger for Mobile?

In other words:
Is a spell melee attack considered a "melee attack" for the purpose of the Mobile feat?

Answer 1

Yes.

Besides seeming obvious, Jeremy Crawford also answered a question about this in regard to Cleric's Touch of Death.

A melee spell attack is, indeed, a melee attack

Answer 2

A melee spell attack is considered a melee attack, even if it is done via a spell. The PHB/basic rules describe melee attacks as follows (emphasis mine):

Used in hand-to-hand combat, a melee attack allows you to attack a foe within your reach. A melee attack typically uses a handheld weapon such as a sword, a warhammer, or an axe. A typical monster makes a melee attack when it strikes with its claws, horns, teeth, tentacles, or other body part. A few spells also involve making a melee attack.

This is confirmed by the Sage Advice Compendium, which says:

Does a melee spell attack count as a melee attack for Touch of Death? A melee spell attack is, indeed, a melee attack and can qualify for the Death cleric’s Touch of Death feature.

Hence, the Thorn Whip spell (as any other spell involving a melee attack) completely fulfills the requirement for the Mobile feat.

Answer 3

A melee spell attack is a melee attack

The Player's Handbook and Basic Rules have the following description in the Combat section on melee attacks (emphasis mine):

Used in hand-to-hand combat, a melee attack allows you to attack a foe within your reach. A melee attack typically uses a handheld weapon such as a sword, a warhammer, or an ax. A typical monster makes a melee attack when it strikes with its claws, horns, teeth, tentacles, or other body part. A few spells also involve making a melee attack.

Moreover, when the rules choose to distinguish between a "spell attack" and a "weapon attack", they do so explicitly. This is seen in a few other feats; one example is the Charger feat (PHB, p. 165; emphasis mine):

When you use your action to Dash, you can use a bonus action to make one melee weapon attack or to shove a creature.

The Mobile feat does not choose to distinguish in this way, so any melee attack applies, including melee spell attacks.

Answer 4

Yup. The feat mentions just melee attack, and melee spell attacks are melee attacks. For it not to work it must have specified melee WEAPON attack. In that case it would also exclude unarmed strikes as well