From 26399de7e959c3d7eda0639ec291d8181bacfd43 Mon Sep 17 00:00:00 2001
From: Florin Braghis <florin.braghis@gmail.com>
Date: Wed, 13 Aug 2025 17:00:52 +0200
Subject: [PATCH 1/3] Fix return value for keys Add keys test

---
 src/xitdb/hash_map.clj  |  9 ++++-----
 src/xitdb/hash_set.clj  | 10 ++++++----
 test/xitdb/map_test.clj | 15 ++++++++++++++-
 3 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/src/xitdb/hash_map.clj b/src/xitdb/hash_map.clj
index df01503..b253356 100644
--- a/src/xitdb/hash_map.clj
+++ b/src/xitdb/hash_map.clj
@@ -57,7 +57,8 @@
 
   clojure.lang.Seqable
   (seq [this]
-    (map-seq rhm))
+    (when (pos? (operations/map-item-count rhm))
+      (map-seq rhm)))
 
   clojure.lang.IFn
   (invoke [this k]
@@ -162,7 +163,8 @@
 
   clojure.lang.Seqable
   (seq [this]
-    (map-seq whm))
+    (when (pos? (operations/map-item-count whm))
+      (map-seq whm)))
 
   clojure.core.protocols/IKVReduce
   (kv-reduce [this f init]
@@ -192,6 +194,3 @@
 
 (defn xhash-map-counted [^ReadCursor read-cursor]
   (->XITDBHashMap (ReadCountedHashMap. read-cursor)))
-
-
-
diff --git a/src/xitdb/hash_set.clj b/src/xitdb/hash_set.clj
index 6d2da8b..a5c1ccb 100644
--- a/src/xitdb/hash_set.clj
+++ b/src/xitdb/hash_set.clj
@@ -41,8 +41,9 @@
     (operations/set-item-count rhs))
 
   clojure.lang.Seqable
-  (seq [_]
-    (set-seq rhs))
+  (seq [this]
+    (when (pos? (operations/set-item-count rhs))
+      (set-seq rhs)))
 
   clojure.lang.ILookup
   (valAt [this k]
@@ -117,8 +118,9 @@
     (operations/set-item-count whs))
 
   clojure.lang.Seqable
-  (seq [_]
-    (set-seq whs))
+  (seq [this]
+    (when (pos? (operations/set-item-count whs))
+      (set-seq whs)))
 
   clojure.lang.ILookup
   (valAt [this k]
diff --git a/test/xitdb/map_test.clj b/test/xitdb/map_test.clj
index 976690f..e2c8f3e 100644
--- a/test/xitdb/map_test.clj
+++ b/test/xitdb/map_test.clj
@@ -1,6 +1,7 @@
 (ns xitdb.map-test
   (:require
     [clojure.test :refer :all]
+    [xitdb.db :as xdb]
     [xitdb.test-utils :as tu :refer [with-db]]))
 
 (deftest map-with-complex-keys
@@ -19,4 +20,16 @@
       (swap! db update :foo dissoc [2 :baz])
       
       (is (= {:foo {[1 :bar] 31}}
-             (tu/materialize @db))))))
\ No newline at end of file
+             (tu/materialize @db))))))
+
+(deftest KeysTest
+  (with-open [db (xitdb.db/xit-db :memory)]
+    (reset! db {})
+    (is (= nil (keys @db)))
+    (is (= 0 (count (keys @db))))))
+
+(deftest KeysTestSet
+  (with-open [db (xitdb.db/xit-db :memory)]
+    (reset! db #{})
+    (is (= 0 (count (keys @db))))
+    (is (= nil (keys @db)))))

From 1ae2d62cf17a9bb5eedf227685f18a20a5acae76 Mon Sep 17 00:00:00 2001
From: Florin Braghis <florin.braghis@gmail.com>
Date: Wed, 13 Aug 2025 17:04:00 +0200
Subject: [PATCH 2/3] Fix the map-seq and hash-set to return nil

---
 src/xitdb/hash_map.clj        |  6 ++----
 src/xitdb/hash_set.clj        |  6 ++----
 src/xitdb/util/operations.clj | 40 ++++++++++++++++++-----------------
 3 files changed, 25 insertions(+), 27 deletions(-)

diff --git a/src/xitdb/hash_map.clj b/src/xitdb/hash_map.clj
index b253356..badeaea 100644
--- a/src/xitdb/hash_map.clj
+++ b/src/xitdb/hash_map.clj
@@ -57,8 +57,7 @@
 
   clojure.lang.Seqable
   (seq [this]
-    (when (pos? (operations/map-item-count rhm))
-      (map-seq rhm)))
+    (map-seq rhm))
 
   clojure.lang.IFn
   (invoke [this k]
@@ -163,8 +162,7 @@
 
   clojure.lang.Seqable
   (seq [this]
-    (when (pos? (operations/map-item-count whm))
-      (map-seq whm)))
+    (map-seq whm))
 
   clojure.core.protocols/IKVReduce
   (kv-reduce [this f init]
diff --git a/src/xitdb/hash_set.clj b/src/xitdb/hash_set.clj
index a5c1ccb..ff1110d 100644
--- a/src/xitdb/hash_set.clj
+++ b/src/xitdb/hash_set.clj
@@ -42,8 +42,7 @@
 
   clojure.lang.Seqable
   (seq [this]
-    (when (pos? (operations/set-item-count rhs))
-      (set-seq rhs)))
+    (set-seq rhs))
 
   clojure.lang.ILookup
   (valAt [this k]
@@ -119,8 +118,7 @@
 
   clojure.lang.Seqable
   (seq [this]
-    (when (pos? (operations/set-item-count whs))
-      (set-seq whs)))
+    (set-seq whs))
 
   clojure.lang.ILookup
   (valAt [this k]
diff --git a/src/xitdb/util/operations.clj b/src/xitdb/util/operations.clj
index 410bf78..848c858 100644
--- a/src/xitdb/util/operations.clj
+++ b/src/xitdb/util/operations.clj
@@ -197,31 +197,33 @@
 ;; ============================================================================
 
 (defn map-seq
-  "Return a lazy seq of key-value MapEntry pairs."
+  "Return a lazy seq of key-value MapEntry pairs, or nil if empty."
   [^ReadHashMap rhm read-from-cursor]
   (let [it (.iterator rhm)]
-    (letfn [(step []
-              (lazy-seq
-                (when (.hasNext it)
-                  (let [cursor (.next it)
-                        kv     (.readKeyValuePair cursor)
-                        k      (read-from-cursor (.-keyCursor kv))]
-                    (let [v (read-from-cursor (.-valueCursor kv))]
-                      (cons (clojure.lang.MapEntry. k v) (step)))))))]
-      (step))))
+    (when (.hasNext it)
+      (letfn [(step []
+                (lazy-seq
+                  (when (.hasNext it)
+                    (let [cursor (.next it)
+                          kv     (.readKeyValuePair cursor)
+                          k      (read-from-cursor (.-keyCursor kv))]
+                      (let [v (read-from-cursor (.-valueCursor kv))]
+                        (cons (clojure.lang.MapEntry. k v) (step)))))))]
+        (step)))))
 
 (defn set-seq
-  "Return a lazy seq values from the set."
+  "Return a lazy seq values from the set, or nil if empty."
   [rhm read-from-cursor]
   (let [it (.iterator rhm)]
-    (letfn [(step []
-              (lazy-seq
-                (when (.hasNext it)
-                  (let [cursor (.next it)
-                        kv     (.readKeyValuePair cursor)
-                        v      (read-from-cursor (.-keyCursor kv))]
-                    (cons v (step))))))]
-      (step))))
+    (when (.hasNext it)
+      (letfn [(step []
+                (lazy-seq
+                  (when (.hasNext it)
+                    (let [cursor (.next it)
+                          kv     (.readKeyValuePair cursor)
+                          v      (read-from-cursor (.-keyCursor kv))]
+                      (cons v (step))))))]
+        (step)))))
 
 (defn array-seq
   "Creates a lazy sequence from a ReadArrayList.

From 300e02e0e00668b0fad3ce9eb64bee0c3f8d4eba Mon Sep 17 00:00:00 2001
From: Florin Braghis <florin.braghis@gmail.com>
Date: Wed, 13 Aug 2025 17:14:47 +0200
Subject: [PATCH 3/3] Cosmetic fixes

---
 src/xitdb/hash_map.clj  | 4 ++--
 test/xitdb/map_test.clj | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/xitdb/hash_map.clj b/src/xitdb/hash_map.clj
index badeaea..8be3add 100644
--- a/src/xitdb/hash_map.clj
+++ b/src/xitdb/hash_map.clj
@@ -56,7 +56,7 @@
          (= (into {} this) (into {} other))))
 
   clojure.lang.Seqable
-  (seq [this]
+  (seq [_]
     (map-seq rhm))
 
   clojure.lang.IFn
@@ -161,7 +161,7 @@
         (common/-read-from-cursor (conversion/map-write-cursor whm key)))))
 
   clojure.lang.Seqable
-  (seq [this]
+  (seq [_]
     (map-seq whm))
 
   clojure.core.protocols/IKVReduce
diff --git a/test/xitdb/map_test.clj b/test/xitdb/map_test.clj
index e2c8f3e..c7276e5 100644
--- a/test/xitdb/map_test.clj
+++ b/test/xitdb/map_test.clj
@@ -23,13 +23,13 @@
              (tu/materialize @db))))))
 
 (deftest KeysTest
-  (with-open [db (xitdb.db/xit-db :memory)]
+  (with-open [db (xdb/xit-db :memory)]
     (reset! db {})
     (is (= nil (keys @db)))
     (is (= 0 (count (keys @db))))))
 
 (deftest KeysTestSet
-  (with-open [db (xitdb.db/xit-db :memory)]
+  (with-open [db (xdb/xit-db :memory)]
     (reset! db #{})
     (is (= 0 (count (keys @db))))
     (is (= nil (keys @db)))))