  Pulsars have been invoked to explain the origin of recently observed
high-energy Galactic cosmic-ray positrons. Since the positron propagation
distance decreases with energy, the number of pulsars that can contribute to
the observed positrons decreases from $O(10^3)$ for positron energies
$E\gtrsim10$ GeV to only a few for $E \gtrsim 500$ GeV. Thus, if pulsars
explain these positrons, the positron energy spectrum should become
increasingly bumpy at higher energies. Here we present a power-spectrum
analysis that can be applied to seek such spectral features in the energy
spectrum for cosmic-ray positrons and for the energy spectrum of the combined
electron/positron flux. We account for uncertainties in the pulsar distribution
by generating hundreds of simulated spectra from pulsar distributions
consistent with current observational constraints. Although the current AMS-02
data do not exhibit evidence for spectral features, we find that such features
would be detectable in $\simeq 10\%$ of our simulations, with 20 years of
AMS-02 data or three years of DAMPE measurements on the electron-plus-positron
flux.
