Improve readability

Signed-off-by: Ryan Russell <ryanrussell@users.noreply.github.com>

replica.go

@@ -105,7 +105,7 @@ func (r *Replica) Client() ReplicaClient { return r.client }
 
 // Starts replicating in a background goroutine.
 func (r *Replica) Start(ctx context.Context) {
-	// Ignore if replica is being used sychronously.
+	// Ignore if replica is being used synchronously.
 	if !r.MonitorEnabled {
 		return
 	}

wal_downloader.go

@@ -15,12 +15,12 @@ import (
 // WALDownloader represents a parallel downloader of WAL files from a replica client.
 //
 // It works on a per-index level so WAL files are always downloaded in their
-// entirety and are not segmented. WAL files are downloaded from minIndex to
+// entiretry and are not segmented. WAL files are downloaded from minIndex to
 // maxIndex, inclusively, and are written to a path prefix. WAL files are named
 // with the prefix and suffixed with the WAL index. It is the responsibility of
 // the caller to clean up these WAL files.
 //
-// The purpose of the parallization is that RTT & WAL apply time can consume
+// The purpose of the parallelization is that RTT & WAL apply time can consume
 // much of the restore time so it's useful to download multiple WAL files in
 // the background to minimize the latency. While some WAL indexes may be
 // downloaded out of order, the WALDownloader ensures that Next() always

wal_downloader_test.go

@@ -383,7 +383,7 @@ func testWALDownloader(t *testing.T, parallelism int) {
 		}
 	})
 
-	// Ensure a gap in indicies returns an error.
+	// Ensure a gap in indices returns an error.
 	t.Run("ErrMissingMiddleIndex", func(t *testing.T) {
 		testDir := filepath.Join("testdata", "wal-downloader", "missing-middle-index")
 		tempDir := t.TempDir()