From fc261d7dcd0b6109c866cda9f6b21426b1742ed1 Mon Sep 17 00:00:00 2001
From: "R.I.Pienaar" <rip@devco.net>
Date: Mon, 11 Oct 2021 13:02:30 +0200
Subject: [PATCH] ensure get returns a nil and key not found as per spec

Signed-off-by: R.I.Pienaar <rip@devco.net>
---
 js.go           |  9 +++++++++
 kv.go           | 17 ++++++++++++++++-
 test/kv_test.go |  9 ++++-----
 3 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/js.go b/js.go
index 361c15a6c..e61d92151 100644
--- a/js.go
+++ b/js.go
@@ -254,16 +254,25 @@ func (opt jsOptFn) configureJSContext(opts *jsOpts) error {
 
 // Domain changes the domain part of JetSteam API prefix.
 func Domain(domain string) JSOpt {
+	if domain == "" {
+		return APIPrefix("")
+	}
+
 	return APIPrefix(fmt.Sprintf(jsDomainT, domain))
 }
 
 // APIPrefix changes the default prefix used for the JetStream API.
 func APIPrefix(pre string) JSOpt {
 	return jsOptFn(func(js *jsOpts) error {
+		if pre == "" {
+			return nil
+		}
+
 		js.pre = pre
 		if !strings.HasSuffix(js.pre, ".") {
 			js.pre = js.pre + "."
 		}
+
 		return nil
 	})
 }
diff --git a/kv.go b/kv.go
index cf5468bce..30ea14208 100644
--- a/kv.go
+++ b/kv.go
@@ -333,6 +333,18 @@ func keyValid(key string) bool {
 
 // Get returns the latest value for the key.
 func (kv *kvs) Get(key string) (KeyValueEntry, error) {
+	e, err := kv.get(key)
+	if err == ErrKeyDeleted {
+		return nil, ErrKeyNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	return e, nil
+}
+
+func (kv *kvs) get(key string) (KeyValueEntry, error) {
 	if !keyValid(key) {
 		return nil, ErrInvalidKey
 	}
@@ -367,6 +379,7 @@ func (kv *kvs) Get(key string) (KeyValueEntry, error) {
 			entry.op = KeyValuePurge
 			return entry, ErrKeyDeleted
 		}
+
 	}
 
 	return entry, nil
@@ -400,11 +413,13 @@ func (kv *kvs) Create(key string, value []byte) (revision uint64, err error) {
 	if err == nil {
 		return v, nil
 	}
+
 	// TODO(dlc) - Since we have tombstones for DEL ops for watchers, this could be from that
 	// so we need to double check.
-	if e, err := kv.Get(key); err == ErrKeyDeleted {
+	if e, err := kv.get(key); err == ErrKeyDeleted {
 		return kv.Update(key, value, e.Revision())
 	}
+
 	return 0, err
 }
 
diff --git a/test/kv_test.go b/test/kv_test.go
index 01934ba48..f2f75bae5 100644
--- a/test/kv_test.go
+++ b/test/kv_test.go
@@ -60,7 +60,7 @@ func TestKeyValueBasics(t *testing.T) {
 	err = kv.Delete("name")
 	expectOk(t, err)
 	_, err = kv.Get("name")
-	expectErr(t, err, nats.ErrKeyDeleted)
+	expectErr(t, err, nats.ErrKeyNotFound)
 	r, err = kv.Create("name", []byte("derek"))
 	expectOk(t, err)
 	if r != 3 {
@@ -284,10 +284,9 @@ func TestKeyValueDeleteVsPurge(t *testing.T) {
 	expectOk(t, err)
 	// Check marker
 	e, err := kv.Get("name")
-	expectErr(t, err, nats.ErrKeyDeleted)
-	// Also make sure op is purge
-	if e.Operation() != nats.KeyValuePurge {
-		t.Fatalf("Expected a purge operation but got %v", e.Operation())
+	expectErr(t, err, nats.ErrKeyNotFound)
+	if e != nil {
+		t.Fatalf("Expected a nil entry but got %v", e)
 	}
 	entries, err = kv.History("name")
 	expectOk(t, err)