Method trackActivity

app/models/User.js:644–655

(activityName, increment = 1)

    }

    trackActivity (activityName, increment = 1) {
      return $.ajax({
        method: 'POST',
        url: `/db/user/${this.id}/track/${activityName}/${increment}`,
        success: attributes => {
          return this.set(attributes)
        },
        error () {
          return console.error(`Couldn't save activity ${activityName}`)
        },
      })
    }

    /**
     * Pure read — local cache first, then me.activity. Never writes.