From 9868a72faed2a31d390e28365070d2e27db53c64 Mon Sep 17 00:00:00 2001
From: Bryan White <bryanchriswhite@gmail.com>
Date: Thu, 26 Oct 2023 11:53:23 +0200
Subject: [PATCH 1/2] feat: add either.AsyncErr type & helpers

---
 pkg/either/errors.go | 35 +++++++++++++++++++++++++++++++++++
 pkg/either/types.go  |  6 ++++++
 2 files changed, 41 insertions(+)
 create mode 100644 pkg/either/errors.go
 create mode 100644 pkg/either/types.go

diff --git a/pkg/either/errors.go b/pkg/either/errors.go
new file mode 100644
index 000000000..888258e3a
--- /dev/null
+++ b/pkg/either/errors.go
@@ -0,0 +1,35 @@
+package either
+
+// SyncErr creates an AsyncError either from a synchronous error.
+// It wraps the Error into the left field (conventionally associated with  the
+// error value in the Either pattern) of the Either type. It casts the result
+// to the AsyncError type.
+func SyncErr(err error) AsyncError {
+	return AsyncError(Error[chan error](err))
+}
+
+// AsyncErr creates an AsyncError from an error channel.
+// It wraps the error channel into the right field (conventionally associated with
+// successful values in the Either pattern) of the Either type.
+func AsyncErr(errCh chan error) AsyncError {
+	return AsyncError(Success[chan error](errCh))
+}
+
+// SyncOrAsyncError decomposes the AsyncError into its components, returning
+// a synchronous error and an error channel. If the AsyncError represents a
+// synchronous error, the error channel will be nil and vice versa.
+func (soaErr AsyncError) SyncOrAsyncError() (error, chan error) {
+	errCh, err := Either[chan error](soaErr).ValueOrError()
+	return err, errCh
+}
+
+// IsSyncError checks if the AsyncError represents a synchronous error.
+func (soaErr AsyncError) IsSyncError() bool {
+	return Either[chan error](soaErr).IsError()
+}
+
+// IsAsyncError checks if the AsyncError represents an asynchronous error
+// (sent through a channel).
+func (soaErr AsyncError) IsAsyncError() bool {
+	return Either[chan error](soaErr).IsSuccess()
+}
diff --git a/pkg/either/types.go b/pkg/either/types.go
new file mode 100644
index 000000000..2d08f7945
--- /dev/null
+++ b/pkg/either/types.go
@@ -0,0 +1,6 @@
+package either
+
+// AsyncError represents a value which could either be a synchronous error or
+// an asynchronous error (sent through a channel). It wraps the more generic
+// `Either` type specific for error channels.
+type AsyncError Either[chan error]

From 369bcf297d7588ebbba728f282d13f7496377510 Mon Sep 17 00:00:00 2001
From: Bryan White <bryanchriswhite@gmail.com>
Date: Mon, 30 Oct 2023 23:36:55 +0100
Subject: [PATCH 2/2] fix: comment typo

Co-authored-by: Daniel Olshansky <olshansky.daniel@gmail.com>
---
 pkg/either/errors.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkg/either/errors.go b/pkg/either/errors.go
index 888258e3a..f464b8886 100644
--- a/pkg/either/errors.go
+++ b/pkg/either/errors.go
@@ -1,7 +1,7 @@
 package either
 
 // SyncErr creates an AsyncError either from a synchronous error.
-// It wraps the Error into the left field (conventionally associated with  the
+// It wraps the Error into the left field (conventionally associated with the
 // error value in the Either pattern) of the Either type. It casts the result
 // to the AsyncError type.
 func SyncErr(err error) AsyncError {