Added getDuration, need to fix failing test

packages/superdough/superdough.mjs

@@ -25,7 +25,7 @@ import {
 import { map } from 'nanostores';
 import { logger } from './logger.mjs';
 import { connectLFO, connectEnvelope, connectBusModulator } from './modulators.mjs';
-import { loadBuffer } from './sampler.mjs';
+import { getSampleBufferSource, loadBuffer } from './sampler.mjs';
 import { getAudioContext } from './audioContext.mjs';
 import { SuperdoughAudioController } from './superdoughoutput.mjs';
 import { resetSeenKeys } from './wavetable.mjs';
@@ -85,6 +85,26 @@ export function setGainCurve(newGainCurveFunc) {
   gainCurveFunc = newGainCurveFunc;
 }
 
+/**
+ * Returns the duration, in seconds, of the given sample.
+ * Has optional param `n` (for instance, the `2` in `s("casio:2")`)
+ *
+ * Note: `must` be called with await, otherwise you'll get a pending Promise object.
+ *
+ * @name getDuration
+ * @param {string} sampleName
+ * @param {number} (optional) n
+ *
+ * @example
+ * // Set a patterns cycle length to exactly the length of the sample
+ * samples('github:tidalcycles/dirt-samples')
+ * let k = await getDuration('sax')
+ * s("sax").cps(1/k)
+ */
+export const getDuration = (s, n = 0) => {
+  return getSampleBufferSource({ s, n }, soundMap.get(s)[s].data.samples).then((x) => x.bufferDuration);
+};
+
 function aliasBankMap(aliasMap) {
   // Make all bank keys lower case for case insensitivity
   for (const key in aliasMap) {