diff --git a/test/monger/test/multi/atomic_modifiers_test.clj b/test/monger/test/multi/atomic_modifiers_test.clj
new file mode 100644
index 0000000..28247f7
--- /dev/null
+++ b/test/monger/test/multi/atomic_modifiers_test.clj
@@ -0,0 +1,407 @@
+(set! *warn-on-reflection* true)
+
+(ns monger.test.multi.atomic-modifiers-test
+  (:import  [com.mongodb WriteResult WriteConcern DBCursor DBObject]
+            [org.bson.types ObjectId]
+            [java.util Date])
+  (:require [monger.core        :as mg]
+            [monger core util]
+            [monger.multi.collection :as mgcol]
+            [monger.result     :as mgres]
+            [monger.test.helper :as helper])
+  (:use [clojure.test]
+        [monger.operators]
+        [monger.test.fixtures]))
+
+(helper/connect!)
+
+(defn drop-altdb
+  [f]
+  (mg/drop-db "altdb")
+  (f))
+
+(use-fixtures :each drop-altdb)
+
+;;
+;; $inc
+;;
+
+(deftest increment-a-single-existing-field-using-$inc-modifier
+  (let [db (mg/get-db "altdb")
+        coll "scores"
+        oid  (ObjectId.)]
+    (mgcol/insert db coll { :_id oid :username "l33r0y" :score 100 })
+    (mgcol/update db coll { :_id oid } { $inc { :score 20 } })
+    (is (= 120 (:score (mgcol/find-map-by-id db coll oid))))))
+
+(deftest set-a-single-non-existing-field-using-$inc-modifier
+  (let [db (mg/get-db "altdb")
+        coll "scores"
+        oid  (ObjectId.)]
+    (mgcol/insert db coll { :_id oid :username "l33r0y" })
+    (mgcol/update db coll { :_id oid } { $inc { :score 30 } })
+    (is (= 30 (:score (mgcol/find-map-by-id db coll oid))))))
+
+
+(deftest increment-multiple-existing-fields-using-$inc-modifier
+  (let [db (mg/get-db "altdb")
+        coll "scores"
+        oid  (ObjectId.)]
+    (mgcol/insert db coll { :_id oid :username "l33r0y" :score 100 :bonus 0 })
+    (mgcol/update db coll { :_id oid } {$inc { :score 20 :bonus 10 } })
+    (is (= { :_id oid :score 120 :bonus 10 :username "l33r0y" } (mgcol/find-map-by-id db coll oid)))))
+
+
+(deftest increment-and-set-multiple-existing-fields-using-$inc-modifier
+  (let [db (mg/get-db "altdb")
+        coll "scores"
+        oid  (ObjectId.)]
+    (mgcol/insert db coll { :_id oid :username "l33r0y" :score 100 })
+    (mgcol/update db coll { :_id oid } { $inc { :score 20 :bonus 10 } })
+    (is (= { :_id oid :score 120 :bonus 10 :username "l33r0y" } (mgcol/find-map-by-id db coll oid)))))
+
+
+
+;;
+;; $set
+;;
+
+(deftest update-a-single-existing-field-using-$set-modifier
+  (let [db (mg/get-db "altdb")
+        coll "things"
+        oid  (ObjectId.)]
+    (mgcol/insert db coll { :_id oid :weight 10.0 })
+    (mgcol/update db coll { :_id oid } { $set { :weight 20.5 } })
+    (is (= 20.5 (:weight (mgcol/find-map-by-id db coll oid [:weight]))))))
+
+(deftest set-a-single-non-existing-field-using-$set-modifier
+  (let [db (mg/get-db "altdb")
+        coll "things"
+        oid  (ObjectId.)]
+    (mgcol/insert db coll { :_id oid :weight 10.0 })
+    (mgcol/update db coll { :_id oid } { $set { :height 17.2 } })
+    (is (= 17.2 (:height (mgcol/find-map-by-id db coll oid [:height]))))))
+
+(deftest update-multiple-existing-fields-using-$set-modifier
+  (let [db (mg/get-db "altdb")
+        coll "things"
+        oid  (ObjectId.)]
+    (mgcol/insert db coll { :_id oid :weight 10.0 :height 15.2 })
+    (mgcol/update db coll { :_id oid } { $set { :weight 20.5 :height 25.6 } })
+    (is (= { :_id oid :weight 20.5 :height 25.6 } (mgcol/find-map-by-id db coll oid [:weight :height])))))
+
+
+(deftest update-and-set-multiple-fields-using-$set-modifier
+  (let [db (mg/get-db "altdb")
+        coll "things"
+        oid  (ObjectId.)]
+    (mgcol/insert db coll { :_id oid :weight 10.0 })
+    (mgcol/update db coll { :_id oid } {$set { :weight 20.5 :height 25.6 } })
+    (is (= { :_id oid :weight 20.5 :height 25.6 } (mgcol/find-map-by-id db coll oid [:weight :height])))))
+
+
+;;
+;; $unset
+;;
+
+(deftest unset-a-single-existing-field-using-$unset-modifier
+  (let [db (mg/get-db "altdb")
+        coll "docs"
+        oid  (ObjectId.)]
+    (mgcol/insert db coll { :_id oid :title "Document 1" :published true })
+    (mgcol/update db coll { :_id oid } { $unset { :published 1 } })
+    (is (= { :_id oid :title "Document 1" } (mgcol/find-map-by-id db coll oid)))))
+
+
+(deftest unset-multiple-existing-fields-using-$unset-modifier
+  (let [db (mg/get-db "altdb")
+        coll "docs"
+        oid  (ObjectId.)]
+    (mgcol/insert db coll { :_id oid :title "Document 1" :published true :featured true })
+    (mgcol/update db coll { :_id oid } { $unset { :published 1 :featured true } })
+    (is (= { :_id oid :title "Document 1" } (mgcol/find-map-by-id db coll oid)))))
+
+
+(deftest unsetting-an-unexisting-field-using-$unset-modifier-is-not-considered-an-issue
+  (let [db (mg/get-db "altdb")
+        coll "docs"
+        oid  (ObjectId.)]
+    (mgcol/insert db coll { :_id oid :title "Document 1" :published true })
+    (is (mgres/ok? (mgcol/update db coll { :_id oid } { $unset { :published 1 :featured true } })))
+    (is (= { :_id oid :title "Document 1" } (mgcol/find-map-by-id db coll oid)))))
+
+;;
+;; $setOnInsert
+;;
+
+(deftest setOnInsert-in-upsert-for-non-existing-document
+  (let [db (mg/get-db "altdb")
+        coll "docs"
+        now  456
+        oid  (ObjectId.)]
+    (mgcol/find-and-modify db coll {:_id oid} {$set {:lastseen now} $setOnInsert {:firstseen now}} :upsert true)
+    (is (= { :_id oid :lastseen now :firstseen now} (mgcol/find-map-by-id db coll oid)))))
+
+(deftest setOnInsert-in-upsert-for-existing-document
+  (let [db (mg/get-db "altdb")
+        coll   "docs"
+        before 123
+        now    456
+        oid    (ObjectId.)]
+    (mgcol/insert db coll { :_id oid :firstseen before :lastseen before})
+    (mgcol/find-and-modify db coll {:_id oid} {$set {:lastseen now} $setOnInsert {:firstseen now}} :upsert true)
+    (is (= { :_id oid :lastseen now :firstseen before} (mgcol/find-map-by-id db coll oid)))))
+
+;;
+;; $push
+;;
+
+(deftest initialize-an-array-using-$push-modifier
+  (let [db (mg/get-db "altdb")
+        coll  "docs"
+        oid   (ObjectId.)
+        title "$push modifier appends value to field"]
+    (mgcol/insert db coll { :_id oid :title title })
+    (mgcol/update db coll { :_id oid } { $push { :tags "modifiers" } })
+    (is (= { :_id oid :title title :tags ["modifiers"] } (mgcol/find-map-by-id db coll oid)))))
+
+(deftest add-value-to-an-existing-array-using-$push-modifier
+  (let [db (mg/get-db "altdb")
+        coll  "docs"
+        oid   (ObjectId.)
+        title "$push modifier appends value to field"]
+    (mgcol/insert db coll { :_id oid :title title :tags ["mongodb"] })
+    (mgcol/update db coll { :_id oid } { $push { :tags "modifiers" } })
+    (is (= { :_id oid :title title :tags ["mongodb" "modifiers"] } (mgcol/find-map-by-id db coll oid)))))
+
+
+;; this is a common mistake, I leave it here to demonstrate it. You almost never
+;; actually want to do this! What you really want is to use $pushAll instead of $push. MK.
+(deftest add-array-value-to-an-existing-array-using-$push-modifier
+  (let [db (mg/get-db "altdb")
+        coll  "docs"
+        oid   (ObjectId.)
+        title "$push modifier appends value to field"]
+    (mgcol/insert db coll { :_id oid :title title :tags ["mongodb"] })
+    (mgcol/update db coll { :_id oid } { $push { :tags ["modifiers" "operators"] } })
+    (is (= { :_id oid :title title :tags ["mongodb" ["modifiers" "operators"]] } (mgcol/find-map-by-id db coll oid)))))
+
+
+
+(deftest double-add-value-to-an-existing-array-using-$push-modifier
+  (let [db (mg/get-db "altdb")
+        coll  "docs"
+        oid   (ObjectId.)
+        title "$push modifier appends value to field"]
+    (mgcol/insert db coll { :_id oid :title title :tags ["mongodb"] })
+    (mgcol/update db coll { :_id oid } { $push { :tags "modifiers" } })
+    (mgcol/update db coll { :_id oid } { $push { :tags "modifiers" } })
+    (is (= { :_id oid :title title :tags ["mongodb" "modifiers" "modifiers"] } (mgcol/find-map-by-id db coll oid)))))
+
+;;
+;; $pushAll
+;;
+
+(deftest initialize-an-array-using-$pushAll-modifier
+  (let [db (mg/get-db "altdb")
+        coll  "docs"
+        oid   (ObjectId.)
+        title "$pushAll modifier appends multiple values to field"]
+    (mgcol/insert db coll { :_id oid :title title })
+    (mgcol/update db coll { :_id oid } { $pushAll { :tags ["mongodb" "docs"] } })
+    (is (= { :_id oid :title title :tags ["mongodb" "docs"] } (mgcol/find-map-by-id db coll oid)))))
+
+(deftest add-value-to-an-existing-array-using-$pushAll-modifier
+  (let [db (mg/get-db "altdb")
+        coll  "docs"
+        oid   (ObjectId.)
+        title "$pushAll modifier appends multiple values to field"]
+    (mgcol/insert db coll { :_id oid :title title :tags ["mongodb"] })
+    (mgcol/update db coll { :_id oid } { $pushAll { :tags ["modifiers" "docs"] } })
+    (is (= { :_id oid :title title :tags ["mongodb" "modifiers" "docs"] } (mgcol/find-map-by-id db coll oid)))))
+
+
+(deftest double-add-value-to-an-existing-array-using-$pushAll-modifier
+  (let [db (mg/get-db "altdb")
+        coll  "docs"
+        oid   (ObjectId.)
+        title "$pushAll modifier appends multiple values to field"]
+    (mgcol/insert db coll { :_id oid :title title :tags ["mongodb" "docs"] })
+    (mgcol/update db coll { :_id oid } { $pushAll { :tags ["modifiers" "docs"] } })
+    (is (= { :_id oid :title title :tags ["mongodb" "docs" "modifiers" "docs"] } (mgcol/find-map-by-id db coll oid)))))
+
+
+;;
+;; $addToSet
+;;
+
+(deftest initialize-an-array-using-$addToSet-modifier
+  (let [db (mg/get-db "altdb")
+        coll  "docs"
+        oid   (ObjectId.)
+        title "$addToSet modifier appends value to field unless it is already there"]
+    (mgcol/insert db coll { :_id oid :title title })
+    (mgcol/update db coll { :_id oid } { $addToSet { :tags "modifiers" } })
+    (is (= { :_id oid :title title :tags ["modifiers"] } (mgcol/find-map-by-id db coll oid)))))
+
+(deftest add-value-to-an-existing-array-using-$addToSet-modifier
+  (let [db (mg/get-db "altdb")
+        coll  "docs"
+        oid   (ObjectId.)
+        title "$addToSet modifier appends value to field unless it is already there"]
+    (mgcol/insert db coll { :_id oid :title title :tags ["mongodb"] })
+    (mgcol/update db coll { :_id oid } { $addToSet { :tags "modifiers" } })
+    (is (= { :_id oid :title title :tags ["mongodb" "modifiers"] } (mgcol/find-map-by-id db coll oid)))))
+
+
+(deftest double-add-value-to-an-existing-array-using-$addToSet-modifier
+  (let [db (mg/get-db "altdb")
+        coll  "docs"
+        oid   (ObjectId.)
+        title "$addToSet modifier appends value to field unless it is already there"]
+    (mgcol/insert db coll { :_id oid :title title :tags ["mongodb"] })
+    (mgcol/update db coll { :_id oid } { $addToSet { :tags "modifiers" } })
+    (mgcol/update db coll { :_id oid } { $addToSet { :tags "modifiers" } })
+    (is (= { :_id oid :title title :tags ["mongodb" "modifiers"] } (mgcol/find-map-by-id db coll oid)))))
+
+
+;;
+;; $pop
+;;
+
+(deftest pop-last-value-in-the-array-using-$pop-modifier
+  (let [db (mg/get-db "altdb")
+        coll   "docs"
+        oid    (ObjectId.)
+        title "$pop modifier removes last or first value in the array"]
+    (mgcol/insert db coll { :_id oid :title title :tags ["products" "apple" "reviews"] })
+    (mgcol/update db coll { :_id oid } { $pop { :tags 1 } })
+    (is (= { :_id oid :title title :tags ["products" "apple"] } (mgcol/find-map-by-id db coll oid)))))
+
+(deftest unshift-first-value-in-the-array-using-$pop-modifier
+  (let [db (mg/get-db "altdb")
+        coll   "docs"
+        oid    (ObjectId.)
+        title "$pop modifier removes last or first value in the array"]
+    (mgcol/insert db coll { :_id oid :title title :tags ["products" "apple" "reviews"] })
+    (mgcol/update db coll { :_id oid } { $pop { :tags -1 } })
+    (is (= { :_id oid :title title :tags ["apple" "reviews"] } (mgcol/find-map-by-id db coll oid)))))
+
+(deftest pop-last-values-from-multiple-arrays-using-$pop-modifier
+  (let [db (mg/get-db "altdb")
+        coll   "docs"
+        oid    (ObjectId.)
+        title "$pop modifier removes last or first value in the array"]
+    (mgcol/insert db coll { :_id oid :title title :tags ["products" "apple" "reviews"] :categories ["apple" "reviews" "drafts"] })
+    (mgcol/update db coll { :_id oid } { $pop { :tags 1 :categories 1 } })
+    (is (= { :_id oid :title title :tags ["products" "apple"] :categories ["apple" "reviews"] } (mgcol/find-map-by-id db coll oid)))))
+
+
+;;
+;; $pull
+;;
+
+(deftest remove-all-value-entries-from-array-using-$pull-modifier
+  (let [db (mg/get-db "altdb")
+        coll   "docs"
+        oid    (ObjectId.)
+        title "$pull modifier removes all value entries in the array"]
+    (mgcol/insert db coll { :_id oid :title title :measurements [1.0 1.2 1.2 1.2 1.1 1.1 1.2 1.3 1.0] })
+    (mgcol/update db coll { :_id oid } { $pull { :measurements 1.2 } })
+    (is (= { :_id oid :title title :measurements [1.0 1.1 1.1 1.3 1.0] } (mgcol/find-map-by-id db coll oid)))))
+
+(deftest remove-all-value-entries-from-array-using-$pull-modifier-based-on-a-condition
+  (let [db (mg/get-db "altdb")
+        coll   "docs"
+        oid    (ObjectId.)
+        title "$pull modifier removes all value entries in the array"]
+    (mgcol/insert db coll { :_id oid :title title :measurements [1.0 1.2 1.2 1.2 1.1 1.1 1.2 1.3 1.0] })
+    (mgcol/update db coll { :_id oid } { $pull { :measurements { $gte 1.2 } } })
+    (is (= { :_id oid :title title :measurements [1.0 1.1 1.1 1.0] } (mgcol/find-map-by-id db coll oid)))))
+;;
+;; $pullAll
+;;
+
+(deftest remove-all-value-entries-from-array-using-$pullAll-modifier
+  (let [db (mg/get-db "altdb")
+        coll   "docs"
+        oid    (ObjectId.)
+        title "$pullAll modifier removes entries of multiple values in the array"]
+    (mgcol/insert db coll { :_id oid :title title :measurements [1.0 1.2 1.2 1.2 1.1 1.1 1.2 1.3 1.0] })
+    (mgcol/update db coll { :_id oid } { $pullAll { :measurements [1.0 1.1 1.2] } })
+    (is (= { :_id oid :title title :measurements [1.3] } (mgcol/find-map-by-id db coll oid)))))
+
+
+;;
+;; $rename
+;;
+
+(deftest rename-a-single-field-using-$rename-modifier
+  (let [db (mg/get-db "altdb")
+        coll   "docs"
+        oid    (ObjectId.)
+        title "$rename renames fields"
+        v     [1.0 1.2 1.2 1.2 1.1 1.1 1.2 1.3 1.0]]
+    (mgcol/insert db coll { :_id oid :title title :measurements v })
+    (mgcol/update db coll { :_id oid } { $rename { :measurements "results" } })
+    (is (= { :_id oid :title title :results v } (mgcol/find-map-by-id db coll oid)))))
+
+
+;;
+;; find-and-modify
+;;
+
+(deftest find-and-modify-a-single-document
+  (let [db (mg/get-db "altdb")
+        coll "docs"
+        oid (ObjectId.)
+        doc {:_id oid :name "Sophie Bangs" :level 42}
+        conditions {:name "Sophie Bangs"}
+        update {$inc {:level 1}}]
+    (mgcol/insert db coll doc)
+    (let [res (mgcol/find-and-modify db coll conditions update :return-new true)]
+      (is (= (select-keys res [:name :level]) {:name "Sophie Bangs" :level 43})))))
+
+
+(deftest find-and-modify-remove-a-document
+  (let [db (mg/get-db "altdb")
+        coll "docs"
+        oid (ObjectId.)
+        doc {:_id oid :name "Sophie Bangs" :level 42}
+        conditions {:name "Sophie Bangs"}]
+    (mgcol/insert db coll doc)
+    (let [res (mgcol/find-and-modify db coll conditions {} :remove true)]
+      (is (= (select-keys res [:name :level]) {:name "Sophie Bangs" :level 42}))
+      (is (empty? (mgcol/find-maps db coll conditions))))))
+
+
+(deftest find-and-modify-upsert-a-document
+  (testing "case 1"
+    (let [db (mg/get-db "altdb")
+          coll "docs"
+          oid (ObjectId.)
+          doc {:_id oid :name "Sophie Bangs" :level 42}]
+      (let [res (mgcol/find-and-modify db coll doc doc :upsert true)]
+        (is (empty? res))
+        (is (select-keys (mgcol/find-map-by-id db coll oid) [:name :level]) (dissoc doc :_id)))))
+  (testing "case 2"
+    (let [db (mg/get-db "altdb")
+          coll  "docs"
+          query {:name "Sophie Bangs"}
+          doc   (merge query {:level 42})]
+      (let [res (mgcol/find-and-modify db coll query doc :upsert true :return-new true)]
+        (is (:_id res))
+        (is (select-keys (mgcol/find-map-by-id db coll (:_id res)) [:name :level]) doc)))))
+
+
+(deftest find-and-modify-after-sort
+  (let [db (mg/get-db "altdb")
+        coll "docs"
+        oid (ObjectId.)
+        oid2 (ObjectId.)
+        doc {:name "Sophie Bangs"}
+        doc1 (assoc doc :_id oid :level 42)
+        doc2 (assoc doc :_id oid2 :level 0)]
+    (mgcol/insert-batch db coll [doc1 doc2])
+    (let [res (mgcol/find-and-modify db coll doc {$inc {:level 1}} :sort {:level -1})]
+      (is (= (select-keys res [:name :level]) {:name "Sophie Bangs" :level 42})))))
diff --git a/test/monger/test/multi/indexing_test.clj b/test/monger/test/multi/indexing_test.clj
new file mode 100644
index 0000000..38540ac
--- /dev/null
+++ b/test/monger/test/multi/indexing_test.clj
@@ -0,0 +1,57 @@
+(ns monger.test.multi.indexing-test
+  (:import  org.bson.types.ObjectId
+            java.util.Date)
+  (:require [monger.core        :as mg]
+            [monger.multi.collection :as mc]
+            [monger.test.helper :as helper]
+            monger.joda-time)
+  (:use clojure.test
+        monger.test.fixtures
+        [clj-time.core :only [now secs ago from-now]]))
+
+(helper/connect!)
+
+(defn drop-altdb
+  [f]
+  (mg/drop-db "altdb")
+  (f))
+
+(use-fixtures :each drop-altdb)
+
+(deftest ^{:indexing true} test-creating-and-dropping-indexes
+  (let [db (mg/get-db "altdb")
+        collection "libraries"]
+    (mc/drop-indexes db collection)
+    (mc/create-index db collection { "language" 1 })
+    (is (= "language_1"
+           (:name (second (mc/indexes-on db collection)))))
+    (mc/drop-index db collection "language_1")
+    (mc/create-index db collection ["language"])
+    (mc/drop-index db collection "language_1")
+    (is (nil? (second (mc/indexes-on db collection))))
+    (mc/ensure-index db collection (array-map "language" 1) {:unique true})
+    (is (= "language_1"
+           (:name (second (mc/indexes-on db collection)))))
+    (mc/ensure-index db collection (array-map "language" 1))
+    (mc/ensure-index db collection (array-map "language" 1) { :unique true })
+    (mc/drop-indexes db collection)))
+
+(deftest ^{:indexing true :edge-features true :time-consuming true} test-ttl-collections
+  (let [db (mg/get-db "altdb")
+        coll  "recent_events"
+        ttl   30
+        sleep 120]
+    (mc/remove db coll)
+    (mc/ensure-index db coll (array-map :created-at 1) {:expireAfterSeconds ttl})
+    (dotimes [i 100]
+      (mc/insert db coll {:type "signup" :created-at (-> i secs ago) :i i}))
+    (dotimes [i 100]
+      (mc/insert db coll {:type "signup" :created-at (-> i secs from-now) :i i}))
+    (is (= 200 (mc/count db coll {:type "signup"})))
+    ;; sleep for 65 seconds. MongoDB 2.1.2 seems to run TTLMonitor once per minute, according to
+    ;; the log. MK.
+    (println (format "Now sleeping for %d seconds to test TTL collections!" sleep))
+    (Thread/sleep (* sleep 1000))
+    (println (format "Documents in the TTL collection: %d" (mc/count db coll {:type "signup"})))
+    (is (< (mc/count db coll {:type "signup"}) 100))
+    (mc/remove db coll)))
diff --git a/test/monger/test/multi/updating_test.clj b/test/monger/test/multi/updating_test.clj
new file mode 100644
index 0000000..6c4f37c
--- /dev/null
+++ b/test/monger/test/multi/updating_test.clj
@@ -0,0 +1,183 @@
+(set! *warn-on-reflection* true)
+
+(ns monger.test.multi.updating-test
+  (:import  [com.mongodb WriteResult WriteConcern DBCursor DBObject]
+            org.bson.types.ObjectId
+            java.util.Date)
+  (:require [monger.core        :as mg]
+            [monger core util]
+            [monger.multi.collection :as mc]
+            [monger.result     :as mr]
+            [monger.test.helper :as helper])
+  (:use clojure.test
+        monger.operators
+        monger.test.fixtures
+        [monger.conversion :only [to-db-object]]))
+
+(helper/connect!)
+
+(defn drop-altdb
+  [f]
+  (mg/drop-db "altdb")
+  (f))
+
+(use-fixtures :each drop-altdb)
+
+;;
+;; update, save
+;;
+
+(deftest ^{:updating true} update-document-by-id-without-upsert
+  (let [db (mg/get-db "altdb")
+        collection "libraries"
+        doc-id       (monger.util/random-uuid)
+        date         (Date.)
+        doc          { :created-at date, :data-store "MongoDB", :language "Clojure", :_id doc-id }
+        modified-doc { :created-at date, :data-store "MongoDB", :language "Erlang",  :_id doc-id }]
+    (mc/insert db collection doc)
+    (is (= (doc (mc/find-by-id db collection doc-id))))
+    (mc/update db collection { :_id doc-id } { :language "Erlang" })
+    (is (= (modified-doc (mc/find-by-id db collection doc-id))))))
+
+(deftest ^{:updating true} update-document-by-id-without-upsert-using-update-by-id
+  (let [db (mg/get-db "altdb")
+        collection "libraries"
+        doc-id       (monger.util/random-uuid)
+        date         (Date.)
+        doc          { :created-at date, :data-store "MongoDB", :language "Clojure", :_id doc-id }
+        modified-doc { :created-at date, :data-store "MongoDB", :language "Erlang",  :_id doc-id }]
+    (mc/insert db collection doc)
+    (is (= (doc (mc/find-by-id db collection doc-id))))
+    (mc/update-by-id db collection doc-id { :language "Erlang" })
+    (is (= (modified-doc (mc/find-by-id db collection doc-id))))))
+
+(deftest ^{:updating true} update-nested-document-fields-without-upsert-using-update-by-id
+  (let [db (mg/get-db "altdb")
+        collection "libraries"
+        doc-id       (ObjectId.)
+        date         (Date.)
+        doc          { :created-at date :data-store "MongoDB" :language { :primary "Clojure" } :_id doc-id }
+        modified-doc { :created-at date :data-store "MongoDB" :language { :primary "Erlang"  } :_id doc-id }]
+    (mc/insert db collection doc)
+    (is (= (doc (mc/find-by-id db collection doc-id))))
+    (mc/update-by-id db collection doc-id { $set { "language.primary" "Erlang" }})
+    (is (= (modified-doc (mc/find-by-id db collection doc-id))))))
+
+
+(deftest ^{:updating true} update-multiple-documents
+  (let [db (mg/get-db "altdb")
+        collection "libraries"]
+    (mc/insert db collection { :language "Clojure", :name "monger" })
+    (mc/insert db collection { :language "Clojure", :name "langohr" })
+    (mc/insert db collection { :language "Clojure", :name "incanter" })
+    (mc/insert db collection { :language "Scala",   :name "akka" })
+    (is (= 3 (mc/count db collection { :language "Clojure" })))
+    (is (= 1 (mc/count db collection { :language "Scala"   })))
+    (is (= 0 (mc/count db collection { :language "Python"  })))
+    (mc/update db collection { :language "Clojure" } { $set { :language "Python" } } :multi true)
+    (is (= 0 (mc/count db collection { :language "Clojure" })))
+    (is (= 1 (mc/count db collection { :language "Scala"   })))
+    (is (= 3 (mc/count db collection { :language "Python"  })))))
+
+
+(deftest ^{:updating true} save-a-new-document
+  (let [db (mg/get-db "altdb")
+        collection "people"
+        document       {:name "Joe" :age 30}]
+    (is (mr/ok? (mc/save db "people" document)))
+    (is (= 1 (mc/count db collection)))))
+
+(deftest ^{:updating true} save-and-return-a-new-document
+  (let [db (mg/get-db "altdb")
+        collection "people"
+        document       {:name "Joe" :age 30}
+        returned   (mc/save-and-return db "people" document)]
+    (is (:_id returned))
+    (is (= document (dissoc returned :_id)))
+    (is (= 1 (mc/count db collection)))))
+
+
+(deftest ^{:updating true} save-a-new-basic-db-object
+  (let [db (mg/get-db "altdb")
+        collection "people"
+        doc        (to-db-object {:name "Joe" :age 30})]
+    (is (nil? (monger.util/get-id doc)))
+    (mc/save db "people" doc WriteConcern/SAFE)
+    (is (not (nil? (monger.util/get-id doc))))))
+
+
+
+(deftest ^{:updating true} update-an-existing-document-using-save
+  (let [db (mg/get-db "altdb")
+        collection "people"
+        doc-id            "people-1"
+        document          { :_id doc-id, :name "Joe",   :age 30 }]
+    (is (mr/ok? (mc/insert db "people" document)))
+    (is (= 1 (mc/count db collection)))
+    (mc/save db collection { :_id doc-id, :name "Alan", :age 40 })
+    (is (= 1 (mc/count db collection { :name "Alan", :age 40 })))))
+
+(deftest ^{:updating true} update-an-existing-document-using-save-and-return
+  (let [db (mg/get-db "altdb")
+        collection "people"
+        document   (mc/insert-and-return db "people" {:name "Joe" :age 30})
+        doc-id     (:_id document)
+        updated    (mc/save-and-return db collection {:_id doc-id :name "Alan" :age 40})]
+    (is (= {:_id doc-id :name "Alan" :age 40} updated))
+    (is (= 1 (mc/count db collection)))
+    (is (= 1 (mc/count db collection {:name "Alan" :age 40})))))
+
+
+(deftest ^{:updating true} set-an-attribute-on-existing-document-using-update
+  (let [db (mg/get-db "altdb")
+        collection "people"
+        doc-id            (monger.util/object-id)
+        document          { :_id doc-id, :name "Joe",   :age 30 }]
+    (is (mr/ok? (mc/insert db "people" document)))
+    (is (= 1 (mc/count db collection)))
+    (is (= 0 (mc/count db collection { :has_kids true })))
+    (mc/update db collection { :_id doc-id } { $set { :has_kids true } })
+    (is (= 1 (mc/count db collection { :has_kids true })))))
+
+
+(deftest ^{:updating true}  increment-multiple-fields-using-exists-operator-and-update
+  (let [db (mg/get-db "altdb")
+        collection "matches"
+        doc-id     (monger.util/object-id)
+        document   { :_id doc-id :abc 0 :def 10 }]
+    (mc/remove db collection)
+    (is (mr/ok? (mc/insert db collection document)))
+    (is (= 1 (mc/count db collection {:abc {$exists true} :def {$exists true}})))
+    (mc/update db collection {:abc {$exists true} :def {$exists true}} {$inc {:abc 1 :def 0}})
+    (is (= 1 (mc/count db collection { :abc 1 })))))
+
+
+
+(deftest ^{:updating true} upsert-a-document-using-update
+  (let [db (mg/get-db "altdb")
+        collection "libraries"
+        doc-id       (monger.util/random-uuid)
+        date         (Date.)
+        doc          { :created-at date, :data-store "MongoDB", :language "Clojure", :_id doc-id }
+        modified-doc { :created-at date, :data-store "MongoDB", :language "Erlang",  :_id doc-id }]
+    (is (not (mr/updated-existing? (mc/update db collection { :language "Clojure" } doc :upsert true))))
+    (is (= 1 (mc/count db collection)))
+    (is (mr/updated-existing? (mc/update db collection { :language "Clojure" } modified-doc :multi false :upsert true)))
+    (is (= 1 (mc/count db collection)))
+    (is (= (modified-doc (mc/find-by-id db collection doc-id))))
+    (mc/remove db collection)))
+
+(deftest ^{:updating true} upsert-a-document-using-upsert
+  (let [db (mg/get-db "altdb")
+        collection "libraries"
+        doc-id       (monger.util/random-uuid)
+        date         (Date.)
+        doc          {:created-at date :data-store "MongoDB" :language "Clojure" :_id doc-id}
+        modified-doc {:created-at date :data-store "MongoDB" :language "Erlang"  :_id doc-id}]
+    (mc/remove db collection)
+    (is (not (mr/updated-existing? (mc/upsert db collection {:language "Clojure"} doc))))
+    (is (= 1 (mc/count db collection)))
+    (is (mr/updated-existing? (mc/upsert db collection {:language "Clojure"} modified-doc :multi false)))
+    (is (= 1 (mc/count db collection)))
+    (is (= (modified-doc (mc/find-by-id db collection doc-id))))
+    (mc/remove db collection)))