diff --git a/test/datomish/db_test.cljc b/test/datomish/db_test.cljc
index 91222a25..7d541a70 100644
--- a/test/datomish/db_test.cljc
+++ b/test/datomish/db_test.cljc
@@ -40,7 +40,7 @@
   (let [entids (zipmap (vals (dm/idents db)) (keys (dm/idents db)))]
     (go-pair
       (->>
-        (s/all-rows (:sqlite-connection db) ["SELECT e, a, v, tx FROM datoms WHERE tx >= ?" tx])
+        (s/all-rows (:sqlite-connection db) ["SELECT e, a, v, tx FROM datoms WHERE tx > ?" tx])
         (<?)
         (mapv #(vector (:e %) (get entids (:a %) (str "fail" (:a %))) (:v %)))
         (filter #(not (= :db/txInstant (second %))))
@@ -62,7 +62,7 @@
   (let [entids (zipmap (vals (dm/idents db)) (keys (dm/idents db)))]
     (go-pair
       (->>
-        (s/all-rows (:sqlite-connection db) ["SELECT e, a, v, tx, added FROM transactions WHERE tx >= ? ORDER BY tx ASC, e, a, v, added" tx])
+        (s/all-rows (:sqlite-connection db) ["SELECT e, a, v, tx, added FROM transactions WHERE tx > ? ORDER BY tx ASC, e, a, v, added" tx])
         (<?)
         (mapv #(vector (:e %) (entids (:a %)) (:v %) (:tx %) (:added %)))))))
 
@@ -117,16 +117,15 @@
           conn (dm/connection-with-db db)
           now  0xdeadbeef]
       (try
-        (is (not (= nil (<? (dm/<transact! conn test-schema now)))))
-
-        (let [;; TODO: drop now, allow to set :db/txInstant.
-              report (<? (dm/<transact! conn [[:db/add 0 :name "valuex"]] now))
-              tx     (tx report)]
-          (is (= (<? (<datoms-after (dm/db conn) tx))
-                 #{[0 :name "valuex"]}))
-          (is (= (<? (<transactions-after (dm/db conn) tx))
-                 [[0 :name "valuex" tx 1] ;; TODO: true, not 1.
-                  [tx :db/txInstant now tx 1]])))
+        (let [tx0 (tx (<? (dm/<transact! conn test-schema now)))]
+          (let [;; TODO: drop now, allow to set :db/txInstant.
+                report (<? (dm/<transact! conn [[:db/add 0 :name "valuex"]] now))
+                tx     (tx report)]
+            (is (= (<? (<datoms-after (dm/db conn) tx0))
+                   #{[0 :name "valuex"]}))
+            (is (= (<? (<transactions-after (dm/db conn) tx0))
+                   [[0 :name "valuex" tx 1] ;; TODO: true, not 1.
+                    [tx :db/txInstant now tx 1]]))))
         (finally
           (<? (dm/close-db db)))))))
 
@@ -137,18 +136,17 @@
           conn (dm/connection-with-db db)
           now  0xdeadbeef]
       (try
-        (is (not (= nil (<? (dm/<transact! conn test-schema now)))))
-
-        (let [tx1 (tx (<? (dm/<transact! conn [[:db/add 1 :name "Ivan"]] now)))
+        (let [tx0 (tx (<? (dm/<transact! conn test-schema now)))
+              tx1 (tx (<? (dm/<transact! conn [[:db/add 1 :name "Ivan"]] now)))
               tx2 (tx (<? (dm/<transact! conn [[:db/add 1 :name "Petr"]] now)))
               tx3 (tx (<? (dm/<transact! conn [[:db/add 1 :aka "Tupen"]] now)))
               tx4 (tx (<? (dm/<transact! conn [[:db/add 1 :aka "Devil"]] now)))]
-          (is (= (<? (<datoms-after (dm/db conn) tx1))
+          (is (= (<? (<datoms-after (dm/db conn) tx0))
                  #{[1 :name "Petr"]
                    [1 :aka  "Tupen"]
                    [1 :aka  "Devil"]}))
 
-          (is (= (<? (<transactions-after (dm/db conn) tx1))
+          (is (= (<? (<transactions-after (dm/db conn) tx0))
                  [[1 :name "Ivan" tx1 1] ;; TODO: true, not 1.
                   [tx1 :db/txInstant now tx1 1]
                   [1 :name "Ivan" tx2 0]
@@ -158,6 +156,7 @@
                   [tx3 :db/txInstant now tx3 1]
                   [1 :aka "Devil" tx4 1]
                   [tx4 :db/txInstant now tx4 1]])))
+
         (finally
           (<? (dm/close-db db)))))))
 
@@ -169,13 +168,12 @@
           conn (dm/connection-with-db db)
           now  0xdeadbeef]
       (try
-        (is (not (= nil (<? (dm/<transact! conn test-schema now)))))
-
-        (let [txa (tx (<? (dm/<transact! conn [[:db/add     0 :x 123]] now)))
+        (let [tx0 (tx (<? (dm/<transact! conn test-schema now)))
+              txa (tx (<? (dm/<transact! conn [[:db/add     0 :x 123]] now)))
               txb (tx (<? (dm/<transact! conn [[:db/retract 0 :x 123]] now)))]
-          (is (= (<? (<datoms-after (dm/db conn) txa))
+          (is (= (<? (<datoms-after (dm/db conn) tx0))
                  #{}))
-          (is (= (<? (<transactions-after (dm/db conn) txa))
+          (is (= (<? (<transactions-after (dm/db conn) tx0))
                  [[0 :x 123 txa 1] ;; TODO: true, not 1.
                   [txa :db/txInstant now txa 1]
                   [0 :x 123 txb 0]
@@ -190,9 +188,8 @@
           conn (dm/connection-with-db db)
           now  -1]
       (try
-        (is (not (= nil (<? (dm/<transact! conn test-schema now)))))
-
-        (let [report (<? (dm/<transact! conn [[:db/add (dm/id-literal :db.part/user -1) :x 0]
+        (let [tx0 (tx (<? (dm/<transact! conn test-schema now)))
+              report (<? (dm/<transact! conn [[:db/add (dm/id-literal :db.part/user -1) :x 0]
                                               [:db/add (dm/id-literal :db.part/user -1) :y 1]
                                               [:db/add (dm/id-literal :db.part/user -2) :y 2]
                                               [:db/add (dm/id-literal :db.part/user -2) :y 3]] now))]
@@ -200,10 +197,9 @@
                  [(dm/id-literal :db.part/user -1)
                   (dm/id-literal :db.part/user -2)]))
 
-          (let [tx   (get-in report [:db-after :current-tx])
-                eid1 (get-in report [:tempids (dm/id-literal :db.part/user -1)])
+          (let [eid1 (get-in report [:tempids (dm/id-literal :db.part/user -1)])
                 eid2 (get-in report [:tempids (dm/id-literal :db.part/user -2)])]
-            (is (= (<? (<datoms-after (dm/db conn) tx))
+            (is (= (<? (<datoms-after (dm/db conn) tx0))
                    #{[eid1 :x 0]
                      [eid1 :y 1]
                      [eid2 :y 2]
@@ -219,19 +215,18 @@
           conn (dm/connection-with-db db)
           now  -1]
       (try
-        (is (not (= nil (<? (dm/<transact! conn test-schema now)))))
+        (let [tx0 (tx (<? (dm/<transact! conn test-schema now)))]
+          (testing "Multiple :db/unique values in tx-data violate unique constraint, no tempid"
+            (is (thrown-with-msg?
+                  ExceptionInfo #"unique constraint"
+                  (<? (dm/<transact! conn [[:db/add 1 :x 0]
+                                           [:db/add 2 :x 0]] now)))))
 
-        (testing "Multiple :db/unique values in tx-data violate unique constraint, no tempid"
-          (is (thrown-with-msg?
-                ExceptionInfo #"unique constraint"
-                (<? (dm/<transact! conn [[:db/add 1 :x 0]
-                                         [:db/add 2 :x 0]] now)))))
-
-        (testing "Multiple :db/unique values in tx-data violate unique constraint, tempid"
-          (is (thrown-with-msg?
-                ExceptionInfo #"unique constraint"
-                (<? (dm/<transact! conn [[:db/add (dm/id-literal :db.part/user -1) :spouse "Dana"]
-                                         [:db/add (dm/id-literal :db.part/user -2) :spouse "Dana"]] now)))))
+          (testing "Multiple :db/unique values in tx-data violate unique constraint, tempid"
+            (is (thrown-with-msg?
+                  ExceptionInfo #"unique constraint"
+                  (<? (dm/<transact! conn [[:db/add (dm/id-literal :db.part/user -1) :spouse "Dana"]
+                                           [:db/add (dm/id-literal :db.part/user -2) :spouse "Dana"]] now))))))
 
         (finally
           (<? (dm/close-db db)))))))
@@ -243,32 +238,31 @@
           conn (dm/connection-with-db db)
           now  -1]
       (try
-        (<? (dm/<transact! conn [{:db/id        (dm/id-literal :db.part/user -1)
-                                  :db/ident     :test/kw
-                                  :db/unique    :db.unique/identity
-                                  :db/valueType :db.type/keyword}
-                                 {:db/id :db.part/db :db.install/attribute (dm/id-literal :db.part/user -1)}] now))
+        (let [tx0 (tx (<? (dm/<transact! conn [{:db/id        (dm/id-literal :db.part/user -1)
+                                                :db/ident     :test/kw
+                                                :db/unique    :db.unique/identity
+                                                :db/valueType :db.type/keyword}
+                                               {:db/id :db.part/db :db.install/attribute (dm/id-literal :db.part/user -1)}] now)))]
 
-        (let [report (<? (dm/<transact! conn [[:db/add (dm/id-literal :db.part/user -1) :test/kw :test/kw1]] now))
-              tx     (get-in report [:db-after :current-tx])
-              eid    (get-in report [:tempids (dm/id-literal :db.part/user -1)])]
-          (is (= (<? (<datoms-after (dm/db conn) tx))
-                 #{[eid :test/kw ":test/kw1"]})) ;; Value is raw.
+          (let [report (<? (dm/<transact! conn [[:db/add (dm/id-literal :db.part/user -1) :test/kw :test/kw1]] now))
+                eid    (get-in report [:tempids (dm/id-literal :db.part/user -1)])]
+            (is (= (<? (<datoms-after (dm/db conn) tx0))
+                   #{[eid :test/kw ":test/kw1"]})) ;; Value is raw.
 
-          (testing "Adding the same value compares existing values correctly."
-            (<? (dm/<transact! conn [[:db/add eid :test/kw :test/kw1]] now))
-            (is (= (<? (<datoms-after (dm/db conn) tx))
-                   #{[eid :test/kw ":test/kw1"]}))) ;; Value is raw.
+            (testing "Adding the same value compares existing values correctly."
+              (<? (dm/<transact! conn [[:db/add eid :test/kw :test/kw1]] now))
+              (is (= (<? (<datoms-after (dm/db conn) tx0))
+                     #{[eid :test/kw ":test/kw1"]}))) ;; Value is raw.
 
-          (testing "Upserting retracts existing value correctly."
-            (<? (dm/<transact! conn [[:db/add eid :test/kw :test/kw2]] now))
-            (is (= (<? (<datoms-after (dm/db conn) tx))
-                   #{[eid :test/kw ":test/kw2"]}))) ;; Value is raw.
+            (testing "Upserting retracts existing value correctly."
+              (<? (dm/<transact! conn [[:db/add eid :test/kw :test/kw2]] now))
+              (is (= (<? (<datoms-after (dm/db conn) tx0))
+                     #{[eid :test/kw ":test/kw2"]}))) ;; Value is raw.
 
-          (testing "Retracting compares values correctly."
-            (<? (dm/<transact! conn [[:db/retract eid :test/kw :test/kw2]] now))
-            (is (= (<? (<datoms-after (dm/db conn) tx))
-                   #{}))))
+            (testing "Retracting compares values correctly."
+              (<? (dm/<transact! conn [[:db/retract eid :test/kw :test/kw2]] now))
+              (is (= (<? (<datoms-after (dm/db conn) tx0))
+                     #{})))))
 
         (finally
           (<? (dm/close-db db)))))))
@@ -281,36 +275,34 @@
           now  0xdeadbeef
           tempids (fn [tx] (into {} (map (juxt (comp :idx first) second) (:tempids tx))))]
       (try
-        (is (not (= nil (<? (dm/<transact! conn test-schema now)))))
-
         ;; Not having DB-as-value really hurts us here.  This test only works because all upserts
         ;; succeed on top of each other, so we never need to reset the underlying store.
         (<? (dm/<transact! conn test-schema now))
-        (<? (dm/<transact! conn [{:db/id 101 :name "Ivan" :email "@1"}
-                                 {:db/id 102 :name "Petr" :email "@2"}] now))
+        (let [tx0 (tx (<? (dm/<transact! conn [{:db/id 101 :name "Ivan" :email "@1"}
+                                               {:db/id 102 :name "Petr" :email "@2"}] now)))]
 
-        (testing "upsert with tempid"
-          (let [report (<? (dm/<transact! conn [[:db/add (dm/id-literal :db.part/user -1) :name "Ivan"]
-                                                [:db/add (dm/id-literal :db.part/user -1) :age 12]] now))]
-            (is (= (<? (<shallow-entity (dm/db conn) 101))
-                   {:name "Ivan" :age 12 :email "@1"}))
-            (is (= (tempids report)
-                   {-1 101}))))
+          (testing "upsert with tempid"
+            (let [report (<? (dm/<transact! conn [[:db/add (dm/id-literal :db.part/user -1) :name "Ivan"]
+                                                  [:db/add (dm/id-literal :db.part/user -1) :age 12]] now))]
+              (is (= (<? (<shallow-entity (dm/db conn) 101))
+                     {:name "Ivan" :age 12 :email "@1"}))
+              (is (= (tempids report)
+                     {-1 101}))))
 
-        (testing "upsert with tempid, order does not matter"
-          (let [report (<? (dm/<transact! conn [[:db/add (dm/id-literal :db.part/user -1) :age 13]
-                                                [:db/add (dm/id-literal :db.part/user -1) :name "Petr"]] now))]
-            (is (= (<? (<shallow-entity (dm/db conn) 102))
-                   {:name "Petr" :age 13 :email "@2"}))
-            (is (= (tempids report)
-                   {-1 102}))))
+          (testing "upsert with tempid, order does not matter"
+            (let [report (<? (dm/<transact! conn [[:db/add (dm/id-literal :db.part/user -1) :age 13]
+                                                  [:db/add (dm/id-literal :db.part/user -1) :name "Petr"]] now))]
+              (is (= (<? (<shallow-entity (dm/db conn) 102))
+                     {:name "Petr" :age 13 :email "@2"}))
+              (is (= (tempids report)
+                     {-1 102}))))
 
-        (testing "Conflicting upserts fail"
-          (is (thrown-with-msg? Throwable #"Conflicting upsert: #datomish.db.TempId\{:part :db.part/user, :idx -\d+\} resolves both to \d+ and \d+"
-                                (<? (dm/<transact! conn [[:db/add (dm/id-literal :db.part/user -1) :name "Ivan"]
-                                                         [:db/add (dm/id-literal :db.part/user -1) :age 35]
-                                                         [:db/add (dm/id-literal :db.part/user -1) :name "Petr"]
-                                                         [:db/add (dm/id-literal :db.part/user -1) :age 36]] now)))))
+          (testing "Conflicting upserts fail"
+            (is (thrown-with-msg? Throwable #"Conflicting upsert: #datomish.db.TempId\{:part :db.part/user, :idx -\d+\} resolves both to \d+ and \d+"
+                                  (<? (dm/<transact! conn [[:db/add (dm/id-literal :db.part/user -1) :name "Ivan"]
+                                                           [:db/add (dm/id-literal :db.part/user -1) :age 35]
+                                                           [:db/add (dm/id-literal :db.part/user -1) :name "Petr"]
+                                                           [:db/add (dm/id-literal :db.part/user -1) :age 36]] now))))))
         (finally
           (<? (dm/close-db db)))))))
 
@@ -325,46 +317,46 @@
         ;; Not having DB-as-value really hurts us here.  This test only works because all upserts
         ;; succeed on top of each other, so we never need to reset the underlying store.
         (<? (dm/<transact! conn test-schema now))
-        (<? (dm/<transact! conn [{:db/id 101 :name "Ivan" :email "@1"}
-                                 {:db/id 102 :name "Petr" :email "@2"}] now))
+        (let [tx0 (tx (<? (dm/<transact! conn [{:db/id 101 :name "Ivan" :email "@1"}
+                                               {:db/id 102 :name "Petr" :email "@2"}] now)))]
 
-        (testing "upsert with tempid"
-          (let [tx (<? (dm/<transact! conn [{:db/id (dm/id-literal :db.part/user -1) :name "Ivan" :age 35}] now))]
-            (is (= (<? (<shallow-entity (dm/db conn) 101))
-                   {:name "Ivan" :email "@1" :age 35}))
-            (is (= (tempids tx)
-                   {-1 101}))))
+          (testing "upsert with tempid"
+            (let [tx (<? (dm/<transact! conn [{:db/id (dm/id-literal :db.part/user -1) :name "Ivan" :age 35}] now))]
+              (is (= (<? (<shallow-entity (dm/db conn) 101))
+                     {:name "Ivan" :email "@1" :age 35}))
+              (is (= (tempids tx)
+                     {-1 101}))))
 
-        (testing "upsert by 2 attrs with tempid"
-          (let [tx (<? (dm/<transact! conn [{:db/id (dm/id-literal :db.part/user -1) :name "Ivan" :email "@1" :age 35}] now))]
-            (is (= (<? (<shallow-entity (dm/db conn) 101))
-                   {:name "Ivan" :email "@1" :age 35}))
-            (is (= (tempids tx)
-                   {-1 101}))))
+          (testing "upsert by 2 attrs with tempid"
+            (let [tx (<? (dm/<transact! conn [{:db/id (dm/id-literal :db.part/user -1) :name "Ivan" :email "@1" :age 35}] now))]
+              (is (= (<? (<shallow-entity (dm/db conn) 101))
+                     {:name "Ivan" :email "@1" :age 35}))
+              (is (= (tempids tx)
+                     {-1 101}))))
 
-        (testing "upsert with existing id"
-          (let [tx (<? (dm/<transact! conn [{:db/id 101 :name "Ivan" :age 36}] now))]
-            (is (= (<? (<shallow-entity (dm/db conn) 101))
-                   {:name "Ivan" :email "@1" :age 36}))
-            (is (= (tempids tx)
-                   {}))))
+          (testing "upsert with existing id"
+            (let [tx (<? (dm/<transact! conn [{:db/id 101 :name "Ivan" :age 36}] now))]
+              (is (= (<? (<shallow-entity (dm/db conn) 101))
+                     {:name "Ivan" :email "@1" :age 36}))
+              (is (= (tempids tx)
+                     {}))))
 
-        (testing "upsert by 2 attrs with existing id"
-          (let [tx (<? (dm/<transact! conn [{:db/id 101 :name "Ivan" :email "@1" :age 37}] now))]
-            (is (= (<? (<shallow-entity (dm/db conn) 101))
-                   {:name "Ivan" :email "@1" :age 37}))
-            (is (= (tempids tx)
-                   {}))))
+          (testing "upsert by 2 attrs with existing id"
+            (let [tx (<? (dm/<transact! conn [{:db/id 101 :name "Ivan" :email "@1" :age 37}] now))]
+              (is (= (<? (<shallow-entity (dm/db conn) 101))
+                     {:name "Ivan" :email "@1" :age 37}))
+              (is (= (tempids tx)
+                     {}))))
 
-        (testing "upsert to two entities, resolve to same tempid, fails due to overlapping writes"
-          (is (thrown-with-msg? Throwable #"cardinality constraint"
-                                (<? (dm/<transact! conn [{:db/id (dm/id-literal :db.part/user -1) :name "Ivan" :age 35}
-                                                         {:db/id (dm/id-literal :db.part/user -1) :name "Ivan" :age 36}] now)))))
+          (testing "upsert to two entities, resolve to same tempid, fails due to overlapping writes"
+            (is (thrown-with-msg? Throwable #"cardinality constraint"
+                                  (<? (dm/<transact! conn [{:db/id (dm/id-literal :db.part/user -1) :name "Ivan" :age 35}
+                                                           {:db/id (dm/id-literal :db.part/user -1) :name "Ivan" :age 36}] now)))))
 
-        (testing "upsert to two entities, two tempids, fails due to overlapping writes"
-          (is (thrown-with-msg? Throwable #"cardinality constraint"
-                                (<? (dm/<transact! conn [{:db/id (dm/id-literal :db.part/user -1) :name "Ivan" :age 35}
-                                                         {:db/id (dm/id-literal :db.part/user -2) :name "Ivan" :age 36}] now)))))
+          (testing "upsert to two entities, two tempids, fails due to overlapping writes"
+            (is (thrown-with-msg? Throwable #"cardinality constraint"
+                                  (<? (dm/<transact! conn [{:db/id (dm/id-literal :db.part/user -1) :name "Ivan" :age 35}
+                                                           {:db/id (dm/id-literal :db.part/user -2) :name "Ivan" :age 36}] now))))))
 
         (finally
           (<? (dm/close-db db)))))))
@@ -380,30 +372,30 @@
         ;; Not having DB-as-value really hurts us here.  This test only works because all upserts
         ;; fail until the final one, so we never need to reset the underlying store.
         (<? (dm/<transact! conn test-schema now))
-        (<? (dm/<transact! conn [{:db/id 101 :name "Ivan" :email "@1"}
-                                 {:db/id 102 :name "Petr" :email "@2"}] now))
+        (let [tx0 (tx (<? (dm/<transact! conn [{:db/id 101 :name "Ivan" :email "@1"}
+                                               {:db/id 102 :name "Petr" :email "@2"}] now)))]
 
-        ;; TODO: improve error message to refer to upsert inputs.
-        (testing "upsert conficts with existing id"
-          (is (thrown-with-msg? Throwable #"unique constraint"
-                                (<? (dm/<transact! conn [{:db/id 102 :name "Ivan" :age 36}] now)))))
+          ;; TODO: improve error message to refer to upsert inputs.
+          (testing "upsert conficts with existing id"
+            (is (thrown-with-msg? Throwable #"unique constraint"
+                                  (<? (dm/<transact! conn [{:db/id 102 :name "Ivan" :age 36}] now)))))
 
-        ;; TODO: improve error message to refer to upsert inputs.
-        (testing "upsert conficts with non-existing id"
-          (is (thrown-with-msg? Throwable #"unique constraint"
-                                (<? (dm/<transact! conn [{:db/id 103 :name "Ivan" :age 36}] now)))))
+          ;; TODO: improve error message to refer to upsert inputs.
+          (testing "upsert conficts with non-existing id"
+            (is (thrown-with-msg? Throwable #"unique constraint"
+                                  (<? (dm/<transact! conn [{:db/id 103 :name "Ivan" :age 36}] now)))))
 
-        ;; TODO: improve error message to refer to upsert inputs.
-        (testing "upsert by 2 conflicting fields"
-          (is (thrown-with-msg? Throwable #"Conflicting upsert: #datomish.db.TempId\{:part :db.part/user, :idx -\d+\} resolves both to \d+ and \d+"
-                                (<? (dm/<transact! conn [{:db/id (dm/id-literal :db.part/user -1) :name "Ivan" :email "@2" :age 35}] now)))))
+          ;; TODO: improve error message to refer to upsert inputs.
+          (testing "upsert by 2 conflicting fields"
+            (is (thrown-with-msg? Throwable #"Conflicting upsert: #datomish.db.TempId\{:part :db.part/user, :idx -\d+\} resolves both to \d+ and \d+"
+                                  (<? (dm/<transact! conn [{:db/id (dm/id-literal :db.part/user -1) :name "Ivan" :email "@2" :age 35}] now)))))
 
-        (testing "upsert by non-existing value resolves as update"
-          (let [report (<? (dm/<transact! conn [{:db/id (dm/id-literal :db.part/user -1) :name "Ivan" :email "@3" :age 35}] now))]
-            (is (= (<? (<shallow-entity (dm/db conn) 101))
-                   {:name "Ivan" :email "@3" :age 35}))
-            (is (= (tempids report)
-                   {-1 101}))))
+          (testing "upsert by non-existing value resolves as update"
+            (let [report (<? (dm/<transact! conn [{:db/id (dm/id-literal :db.part/user -1) :name "Ivan" :email "@3" :age 35}] now))]
+              (is (= (<? (<shallow-entity (dm/db conn) 101))
+                     {:name "Ivan" :email "@3" :age 35}))
+              (is (= (tempids report)
+                     {-1 101})))))
 
         (finally
           (<? (dm/close-db db)))))))