chore(cu): cleanup loadMessages pipeline

servers/cu/src/domain/lib/loadMessages.js

@@ -277,41 +277,6 @@ function loadCronMessagesWith ({ loadTimestamp, locateScheduler, loadBlocksMeta,
   loadTimestamp = fromPromise(loadTimestampSchema.implement(loadTimestamp))
   loadBlocksMeta = fromPromise(loadBlocksMetaSchema.implement(loadBlocksMeta))
 
-  /**
-   * Given a left-most and right-most boundary, return an async generator,
-   * that given a list of values, emits sequential binary tuples dervied from those values,
-   * with an additional element appended and prepended to the list of values.
-   *
-   * This effectively places an tuple aperture on the incoming stream of single values,
-   * and with andditional element at the beginning and end of the list
-   *
-   * Since we added our left and right bounds, there should always
-   * be at least one tuple emitted, which will account for any time
-   * we have <2 cron messages to use as boundaries.
-   *
-   * If our leftMost and rightMost boundary are the only boundaries, this effectively means
-   * that we have no cron messages to merge and evaluate, and only cron messages to generate
-   *
-   * [b1, b2, b3] -> [ [b1, b2], [b2, b3] ]
-   */
-  function genTuplesWithBoundaries ({ left: first, right: last }) {
-    return async function * genTuples (boundaries) {
-      /**
-       * the initial prev is the left-most boundary
-       */
-      let prev = first
-      for await (const boundary of boundaries) {
-        yield [prev, boundary]
-        prev = boundary
-      }
-
-      /**
-       * Emit the last boundary
-       */
-      yield [prev, last]
-    }
-  }
-
   return (ctx) => of(ctx)
     .chain(parseCrons)
     .bimap(
@@ -390,20 +355,54 @@ function loadCronMessagesWith ({ loadTimestamp, locateScheduler, loadBlocksMeta,
           return ctx
         })
         .map(({ leftMost, rightMost, $scheduled, genCronMessages }) => {
-          /**
-           * Each set of cron messages will be generated between a left and right boundary,
-           * So we need to procure a set of boundaries to use, while ALSO merging with the scheduled messages
-           * from the SU.
-           *
-           * Our messages retrieved from the SU are perfect boundaries, as they each have a
-           * block height and timestamp
-           *
-           * This will allow the CU to generate cron messages with monotonically increasing timestamp and accurate block metadata,
-           * at least w.r.t the SU's claims.
-           */
           return pipeline(
+            /**
+             * Each set of cron messages will be generated between a left and right boundary,
+             * So we need to procure a set of boundaries to use, while ALSO merging with the scheduled messages
+             * from the SU.
+             *
+             * Our messages retrieved from the SU are perfect boundaries, as they each have a
+             * block height and timestamp
+             *
+             * This will allow the CU to generate cron messages with monotonically increasing timestamp and accurate block metadata,
+             * at least w.r.t the SU's claims.
+             */
             $scheduled,
-            Transform.from(genTuplesWithBoundaries({ left: leftMost, right: rightMost })),
+            /**
+             * Given a left-most and right-most boundary, return an async generator,
+             * that given a list of values, emits sequential binary tuples dervied from those values,
+             * with an additional element appended and prepended to the list of values.
+             *
+             * This effectively places an tuple aperture on the incoming stream of single values,
+             * and with andditional element at the beginning and end of the list
+             *
+             * Since we added our left and right bounds, there should always
+             * be at least one tuple emitted, which will account for any time
+             * we have <2 cron messages to use as boundaries.
+             *
+             * If our leftMost and rightMost boundary are the only boundaries, this effectively means
+             * that we have no cron messages to merge and evaluate, and only cron messages to generate
+             *
+             * [b1, b2, b3] -> [ [b1, b2], [b2, b3] ]
+             */
+            Transform.from(
+              async function * genBoundariesAsTuples (boundaries) {
+                /**
+                 * the initial prev is the left-most boundary
+                 */
+                let prev = leftMost
+
+                for await (const boundary of boundaries) {
+                  yield [prev, boundary]
+                  prev = boundary
+                }
+
+                /**
+                 * Emit the last boundary
+                 */
+                yield [prev, rightMost]
+              }
+            ),
             Transform.from(async function * (boundaries) {
               let tuple = await boundaries.next()
               while (!tuple.done) {