message: adding portamento tests
diff: @@ -218,5 +218,17 @@ export function InstrumentTest(Constr, note, constrArg?, optionsIndex?): void {
  }
  }, 3);
  });
  +
  + it("can do portamento glide between notes", () => {
  + return Offline(() => {
  + const instance = new Constr(constrArg);
  + if (instance instanceof Monophonic) {
  + instance.portamento = 0.5;
  + instance.triggerAttackRelease("C4", 0.2, 0);
  + expect(instance.getLevelAtTime(0.4)).to.be.greaterThan(0);
  + instance.triggerAttackRelease("C2", 0.2, 0.4);
  + }
  + }, 0.5);
  + });
  });
  }
  