diff --git a/cms/themes/rise/src/systems/bread/alpha/cms/theme/rise.cljc b/cms/themes/rise/src/systems/bread/alpha/cms/theme/rise.cljc
index a3828f2e..467c41bf 100644
--- a/cms/themes/rise/src/systems/bread/alpha/cms/theme/rise.cljc
+++ b/cms/themes/rise/src/systems/bread/alpha/cms/theme/rise.cljc
@@ -666,7 +666,7 @@
      (ErrorMessage {:message (i18n/t i18n error-key)}))])
 
 (defmethod Section :save [{:keys [i18n]} _]
-  (Submit (:account/save i18n) :name :action :value "update"))
+  (Submit (:account/save i18n) :name :action :value "update-details"))
 
 (defn- CustomizingSection [_]
   {:id :customizing
diff --git a/plugins/auth/account.i18n.edn b/plugins/auth/account.i18n.edn
index f20ca0f4..4706d914 100644
--- a/plugins/auth/account.i18n.edn
+++ b/plugins/auth/account.i18n.edn
@@ -8,6 +8,7 @@
            :account-updated "Account details have been updated."
            :datetime-format-default "EEE, LLL d 'at' h:mm a"
            :date-format-default "EEE, LLL d"
+           :invalid-action "Invalid action."
            :leave-passwords-blank "Leave password fields blank to keep your current password."
            :name "Name"
            :email "Email"
@@ -15,6 +16,7 @@
            :pronouns "Pronouns"
            :pronouns-example "they/them/theirs"
            :save "Save"
+           :session-deleted "Session deleted."
            :timezone "Timezone"
            :your-sessions "Your login sessions"
            }
diff --git a/plugins/auth/systems/bread/alpha/plugin/account.cljc b/plugins/auth/systems/bread/alpha/plugin/account.cljc
index dc10f033..b65dad3b 100644
--- a/plugins/auth/systems/bread/alpha/plugin/account.cljc
+++ b/plugins/auth/systems/bread/alpha/plugin/account.cljc
@@ -155,14 +155,20 @@
       (update $ :user/preferences edn/read-string)
       (s/transform [:user/sessions s/ALL :session/data] edn/read-string $))))
 
-(defmulti account-action (fn [{:keys [params]}] (keyword (:action params))))
+(defmulti effects (fn [{:keys [params]}] (keyword (:action params))))
 
-(defmethod account-action :delete-session [{:keys [params]}]
-  (when-let [id (try (Integer. (:dbid params)) (catch Throwable _ nil))]
-    [[:db/retract id :session/id]
-     [:db/retract id :session/data]
-     [:db/retract id :thing/created-at]
-     [:db/retract id :thing/updated-at]]))
+(defmethod effects :default [_]
+  ;; TODO standardize generic error-key?
+  (throw (ex-info "Invalid action" {:error-key :account/invalid-action})))
+
+(defmethod effects :delete-session [{:as req :keys [params]}]
+  (when (try (Integer. (:dbid params)) (catch Throwable _ nil))
+    [{:effect/name [::update :delete-session]
+      :effect/description "Update account state"
+      :effect/key :delete-session
+      :success-key :account/session-deleted
+      :params params
+      :conn (db/connection req)}]))
 
 (defn validate-password-fields
   [{:auth/keys [min-password-length max-password-length]}
@@ -170,6 +176,9 @@
   "Returns an error code as a keyword if the :password and/or :password-confirmation
   params are invalid."
   (cond
+    ;; If the user submitted only the password confirmation, assume they intended
+    ;; to update password but forgot to fill out both fields.
+    (and (seq password-confirmation) (empty? password)) :auth/passwords-must-match
     (empty? password) :auth/password-required
     (not= password password-confirmation) :auth/passwords-must-match
     (< (count password) min-password-length)
@@ -180,65 +189,83 @@
 (defn- hook-preference [req [k v]]
   [k (bread/hook req [::preference k] v)])
 
-(defmethod account-action :update [{:as req :keys [params session] ::bread/keys [config]}]
+(defmethod effects :update-details
+  [{:as req :keys [params session] ::bread/keys [config]}]
   (let [{:keys [password password-confirmation]} params
-        update-password? (seq password)
+        update-password? (or (seq password) (seq password-confirmation))
         error-key (when update-password? (validate-password-fields config params))
         hash-algo (when update-password? (:auth/hash-algorithm config))
         preferences (dissoc params :action :name :lang :password :password-confirmation)]
     (when error-key (throw (ex-info "Invalid password" {:error-key error-key})))
-    [(cond-> {:db/id (:db/id (:user session)) :user/name (:name params)}
-       (:lang params) (assoc :user/lang (keyword (:lang params)))
-       update-password? (assoc :user/password
-                               (hashers/derive password {:alg hash-algo}))
-       (seq preferences)  (assoc :user/preferences (->> preferences
-                                                        (map (partial hook-preference req))
-                                                        (into {})
-                                                        pr-str)))]))
+    [{:effect/name ::db/transact
+      :effect/description "Update account details"
+      :effect/key :update-details
+      :success-key :account/account-updated
+      :conn (db/connection req)
+      :txs
+      [(cond-> {:db/id (:db/id (:user session)) :user/name (:name params)}
+         (:lang params) (assoc :user/lang (keyword (:lang params)))
+         update-password? (assoc :user/password
+                                 (hashers/derive password {:alg hash-algo}))
+         (seq preferences)  (assoc :user/preferences (->> preferences
+                                                          (map (partial hook-preference req))
+                                                          (into {})
+                                                          pr-str)))]}]))
+
+(defmethod bread/effect [::update :delete-session]
+  [{k :effect/key :keys [conn params success-key]} {user :user}]
+  (let [session-id (try (Integer. (:dbid params)) (catch Throwable _ nil))
+        valid-ids (set (map :db/id (:user/sessions user)))
+        valid? (contains? valid-ids session-id)]
+    (when valid?
+      {:effects
+       [{:effect/name ::db/transact
+         :effect/description "Delete a user session."
+         :effect/key k
+         :success-key success-key
+         :conn conn
+         :txs [[:db/retractEntity session-id]]}]})))
 
 (defmethod bread/dispatch ::account=>
-  [{:as req :keys [params request-method session] ::bread/keys [config dispatcher]}]
-  (if (= :post request-method)
-    ;; Account update.
-    (let [action (keyword (:action params))
-          account-update? (= :update action)
-          [txs error-key] (try
-                            [(account-action req) nil]
-                            (catch clojure.lang.ExceptionInfo e
-                              [nil (-> e ex-data :error-key)]))
-          success-key (cond
-                        account-update? :account-updated)]
-      (if txs
-        {:effects
-         [(db/txs->effect req txs :effect/description "Update account details")]
-         :hooks
-         {::bread/expand
-          [{:action/name ::ring/redirect
-            :to (bread/config req :account/account-uri)
-            :flash (when account-update? {:success-key :account/account-updated})
-            :action/description
-            "Redirect to account page after taking an account action"}]}}
-        {:hooks
-         {::bread/expand
-          [{:action/name ::ring/redirect
-            :to (bread/config req :account/account-uri)
-            :flash (when account-update? {:error-key error-key})
-            :action/description
-            "Redirect to account page after an error"}]}}))
-    ;; Rendering the account page.
-    (let [id (:db/id (:user session))
-          pull (:dispatcher/pull dispatcher)]
+  [{:as req :keys [params request-method session] ::bread/keys [dispatcher]}]
+  (let [id (:db/id (:user session))
+        pull (:dispatcher/pull dispatcher)
+        user-pull {:find [(list 'pull '?e pull) '.] :in '[$ ?e]}
+        query-user {:expansion/key :user
+                    :expansion/name ::db/query
+                    :expansion/description "Query for all user account data"
+                    :expansion/db (db/database req)
+                    :expansion/args [user-pull id]}
+        expand-user {:expansion/key :user
+                     :expansion/name ::user
+                     :expansion/description "Expand user data"}]
+    (if (= :post request-method)
+      ;; Account update.
+      (let [[effects error-key] (try
+                                  [(effects req) nil]
+                                  (catch clojure.lang.ExceptionInfo e
+                                    [nil (-> e ex-data :error-key)]))]
+        (if error-key
+          {:hooks
+           {::bread/render
+            [{:action/name ::ring/redirect
+              :to (bread/config req :account/account-uri)
+              :flash (when error-key {:error-key error-key})
+              :action/description
+              "Redirect to account page after an error"}]}}
+          {:expansions [query-user expand-user]
+           :effects effects
+           :hooks
+           {::bread/render
+            [{:action/name ::ring/effect-redirect
+              :to (bread/config req :account/account-uri)
+              :effect/key (keyword (:action params))
+              :action/description
+              "Redirect to account page after taking an account action"}]}}))
+      ;; Rendering the account page.
       {:expansions
-       [{:expansion/key :user
-         :expansion/name ::db/query
-         :expansion/description "Query for all user account data"
-         :expansion/db (db/database req)
-         :expansion/args [{:find [(list 'pull '?e pull) '.]
-                           :in '[$ ?e]}
-                          id]}
-        {:expansion/key :user
-         :expansion/name ::user
-         :expansion/description "Expand user data"}
+       [query-user
+        expand-user
         {;; TODO => i18n
          :expansion/key :supported-langs
          :expansion/name ::bread/value
@@ -247,6 +274,7 @@
         {;; TODO => i18n
          :expansion/key :lang-names
          :expansion/name ::bread/value
+         :expansion/description "Language names for display"
          :expansion/value (bread/config req :i18n/lang-names)}]})))
 
 (defn plugin [{:keys [account-uri html-account-header html-account-form
diff --git a/src/systems/bread/alpha/component.cljc b/src/systems/bread/alpha/component.cljc
index e6c97a37..eeb73d91 100644
--- a/src/systems/bread/alpha/component.cljc
+++ b/src/systems/bread/alpha/component.cljc
@@ -130,10 +130,10 @@
 (defmethod bread/action ::render
   [{:keys [::bread/data body] :as res} _ _]
   (if body
-   res
-   (let [component (match res)
-         body (render component data)]
-     (assoc res :body body))))
+    res
+    (let [component (match res)
+          body (render component data)]
+      (assoc res :body body))))
 
 (defmethod bread/action ::hook-fn
   [req _ _]
diff --git a/src/systems/bread/alpha/database.cljc b/src/systems/bread/alpha/database.cljc
index 95261b67..3ddd3e64 100644
--- a/src/systems/bread/alpha/database.cljc
+++ b/src/systems/bread/alpha/database.cljc
@@ -118,8 +118,13 @@
     (contains? ks (migration-key migration))))
 
 (defmethod bread/effect ::transact
-  [{:keys [conn txs]} _]
-  (transact conn {:tx-data txs}))
+  [{:keys [conn txs success-key error-key]} _]
+  (try
+    {:db (transact conn {:tx-data txs})
+     :flash {:success-key success-key}}
+    (catch Throwable e
+      {:ex e
+       :flash {:error-key error-key}})))
 
 (defn txs->effect [req txs & {desc :effect/description
                               k :effect/key
diff --git a/test/cms/systems/bread/alpha/plugin/account_test.clj b/test/cms/systems/bread/alpha/plugin/account_test.clj
new file mode 100644
index 00000000..bf05d791
--- /dev/null
+++ b/test/cms/systems/bread/alpha/plugin/account_test.clj
@@ -0,0 +1,475 @@
+(ns systems.bread.alpha.plugin.account-test
+  (:require
+    [buddy.hashers :as hashers]
+    [clojure.test :refer [deftest are]]
+
+    [systems.bread.alpha.test-helpers :refer [db->plugin
+                                              plugins->loaded
+                                              use-db]]
+    [systems.bread.alpha.core :as bread]
+    [systems.bread.alpha.database :as db]
+    [systems.bread.alpha.dispatcher :as dispatcher]
+    [systems.bread.alpha.i18n :as i18n]
+    [systems.bread.alpha.plugin.account :as account]
+    [systems.bread.alpha.plugin.auth :as auth]
+    [systems.bread.alpha.ring :as ring]
+    [systems.bread.alpha.schema :as schema]))
+
+(def db-config
+  {:db/type :datahike
+   :db/migrations schema/initial
+   :db/config {:store {:backend :mem :id "account-test-db"}}})
+
+(use-db :each db-config)
+
+(deftest test-account=>
+  (let [db-plugin (db->plugin ::FAKEDB)
+        db-conn (:db/connection (:config db-plugin))
+        query-user
+        {:expansion/args ['{:find [(pull ?e [:user/attrs]) .]
+                            :in [$ ?e]}
+                          123]
+         :expansion/db ::FAKEDB
+         :expansion/description "Query for all user account data"
+         :expansion/key :user
+         :expansion/name ::db/query}
+        expand-user
+        {:expansion/description "Expand user data"
+         :expansion/key :user
+         :expansion/name ::account/user}
+        success-hook
+        {:action/name ::ring/effect-redirect
+         :action/description "Redirect to account page after taking an account action"
+         :effect/key :update-details
+         :to "/account"}]
+    (are
+      [expected config req]
+      (= expected (let [dispatcher {:dispatcher/type ::account/account=>
+                                    :dispatcher/pull [:user/attrs]}
+                        {:keys [account-config auth-config]} config
+                        app (plugins->loaded [db-plugin
+                                              (i18n/plugin
+                                                {:supported-langs [:be :de]
+                                                 :lang-names {:be "Belarusian"
+                                                              :de "Deutsche"}})
+                                              (auth/plugin auth-config)
+                                              (account/plugin account-config)])
+                        req* (merge app req {::bread/dispatcher dispatcher})]
+                    (with-redefs [hashers/derive (fn [pw {:keys [alg]}]
+                                                   (str "[" alg "+" pw "]"))]
+                      (bread/dispatch req*))))
+
+      ;; Just loading the account page.
+      {:expansions [query-user
+                    expand-user
+                    {:expansion/description "Supported languages"
+                     :expansion/key :supported-langs
+                     :expansion/name ::bread/value
+                     :expansion/value [:be :de]}
+                    {:expansion/key :lang-names
+                     :expansion/name ::bread/value
+                     :expansion/description "Language names for display"
+                     :expansion/value {:be "Belarusian"
+                                       :de "Deutsche"}}]}
+      {}
+      {:request-method :get
+       :session {:user {:db/id 123}}}
+
+      ;; Updating name.
+      {:expansions
+       [query-user expand-user]
+       :effects
+       [{:effect/name ::db/transact
+         :effect/key :update-details
+         :effect/description "Update account details"
+         :success-key :account/account-updated
+         :txs [{:db/id 123 :user/name "Spongebob Squarepants"}]
+         :conn db-conn}]
+       :hooks
+       {::bread/render [success-hook]}}
+      {}
+      {:request-method :post
+       :params {:action "update-details"
+                :name "Spongebob Squarepants"}
+       :session {:user {:db/id 123}}}
+
+      ;; Updating preferences.
+      {:expansions [query-user expand-user]
+       :effects [{:effect/name ::db/transact
+                  :effect/key :update-details
+                  :effect/description "Update account details"
+                  :success-key :account/account-updated
+                  :txs [{:db/id 123
+                         :user/name "Spongebob Squarepants"
+                         :user/preferences (pr-str {:pronouns "he/they"
+                                                    :timezone "America/Los_Angeles"})}]
+                  :conn db-conn}]
+       :hooks {::bread/render [success-hook]}}
+      {}
+      {:request-method :post
+       :params {:action "update-details"
+                :name "Spongebob Squarepants"
+                :pronouns "he/they"
+                :timezone "America/Los_Angeles"}
+       :session {:user {:db/id 123}}}
+
+      ;; Updating preferences; custom account-uri.
+      {:expansions [query-user expand-user]
+       :effects [{:effect/name ::db/transact
+                  :effect/key :update-details
+                  :effect/description "Update account details"
+                  :success-key :account/account-updated
+                  :txs [{:db/id 123
+                         :user/name "Spongebob Squarepants"
+                         :user/preferences (pr-str {:pronouns "he/they"
+                                                    :timezone "America/Los_Angeles"})}]
+                  :conn db-conn}]
+       :hooks {::bread/render [(assoc success-hook :to "/custom")]}}
+      {:account-config {:account-uri "/custom"}}
+      {:request-method :post
+       :params {:action "update-details"
+                :name "Spongebob Squarepants"
+                :pronouns "he/they"
+                :timezone "America/Los_Angeles"}
+       :session {:user {:db/id 123}}}
+
+      ;; Invalid action.
+      {:hooks {::bread/render [{:action/name ::ring/redirect
+                                :action/description
+                                "Redirect to account page after an error"
+                                :flash {:error-key :account/invalid-action}
+                                :to "/account"}]}}
+      {}
+      {:request-method :post
+       :params {:action "booboo"
+                :name "Spongebob Squarepants"
+                :pronouns "he/they"
+                :timezone "America/Los_Angeles"}
+       :session {:user {:db/id 123}}}
+
+      ;; Invalid action; custom URI.
+      {:hooks {::bread/render [{:action/name ::ring/redirect
+                                :action/description
+                                "Redirect to account page after an error"
+                                :flash {:error-key :account/invalid-action}
+                                :to "/custom"}]}}
+      {:account-config {:account-uri "/custom"}}
+      {:request-method :post
+       :params {:action "booboo"
+                :name "Spongebob Squarepants"
+                :pronouns "he/they"
+                :timezone "America/Los_Angeles"}
+       :session {:user {:db/id 123}}}
+
+      ;; Any custom fields on the account form are treated as preferences.
+      {:expansions [query-user expand-user]
+       :effects [{:effect/name ::db/transact
+                  :effect/key :update-details
+                  :effect/description "Update account details"
+                  :success-key :account/account-updated
+                  :txs [{:db/id 123
+                         :user/name "Spongebob Squarepants"
+                         :user/preferences (pr-str {:custom "something"
+                                                    :other "something else"})}]
+                  :conn db-conn}]
+       :hooks {::bread/render [success-hook]}}
+      {}
+      {:request-method :post
+       :params {:action "update-details"
+                :name "Spongebob Squarepants"
+                :custom "something"
+                :other "something else"}
+       :session {:user {:db/id 123}}}
+
+      ;; Updating password - mismatched passwords error.
+      {:hooks {::bread/render [{:action/name ::ring/redirect
+                                :action/description
+                                "Redirect to account page after an error"
+                                :flash {:error-key :auth/passwords-must-match}
+                                :to "/account"}]}}
+      {}
+      {:request-method :post
+       :params {:action "update-details"
+                :name "Spongebob Squarepants"
+                :password "xyz"
+                :password-confirmation ""}
+       :session {:user {:db/id 123}}}
+
+      ;; Updating password - only confirmation submitted.
+      {:hooks {::bread/render [{:action/name ::ring/redirect
+                                :action/description
+                                "Redirect to account page after an error"
+                                :flash {:error-key :auth/passwords-must-match}
+                                :to "/account"}]}}
+      {}
+      {:request-method :post
+       :params {:action "update-details"
+                :name "Spongebob Squarepants"
+                :password ""
+                :password-confirmation "xyz"}
+       :session {:user {:db/id 123}}}
+
+      ;; Updating password - both fields submitted, but still mismatched
+      {:hooks {::bread/render [{:action/name ::ring/redirect
+                                :action/description
+                                "Redirect to account page after an error"
+                                :flash {:error-key :auth/passwords-must-match}
+                                :to "/account"}]}}
+      {}
+      {:request-method :post
+       :params {:action "update-details"
+                :name "Spongebob Squarepants"
+                :password "abc"
+                :password-confirmation "xyz"}
+       :session {:user {:db/id 123}}}
+
+      ;; Updating password - too short.
+      {:hooks {::bread/render [{:action/name ::ring/redirect
+                                :action/description
+                                "Redirect to account page after an error"
+                                ;; 12 is the default from auth
+                                :flash {:error-key [:auth/password-must-be-at-least 12]}
+                                :to "/account"}]}}
+      {}
+      {:request-method :post
+       :params {:action "update-details"
+                :name "Spongebob Squarepants"
+                :password "tooshort"
+                :password-confirmation "tooshort"}
+       :session {:user {:db/id 123}}}
+
+      ;; Updating password - too short with custom auth config.
+      {:hooks {::bread/render [{:action/name ::ring/redirect
+                                :action/description
+                                "Redirect to account page after an error"
+                                ;; 12 is the default from auth
+                                :flash {:error-key [:auth/password-must-be-at-least 8]}
+                                :to "/account"}]}}
+      {:auth-config {:min-password-length 8}}
+      {:request-method :post
+       :params {:action "update-details"
+                :name "Spongebob Squarepants"
+                :password "2shrt"
+                :password-confirmation "2shrt"}
+       :session {:user {:db/id 123}}}
+
+      ;; Updating password - just long enough with custom config.
+      {:expansions [query-user expand-user]
+       :effects [{:effect/name ::db/transact
+                  :effect/description "Update account details"
+                  :effect/key :update-details
+                  :success-key :account/account-updated
+                  :txs [{:db/id 123
+                         :user/name "Spongebob Squarepants"
+                         :user/password "[:bcrypt+blake2b-512+password]"}]
+                  :conn db-conn}]
+       :hooks {::bread/render [success-hook]}}
+      {:auth-config {:min-password-length 8}}
+      {:request-method :post
+       :params {:action "update-details"
+                :name "Spongebob Squarepants"
+                :password "password"
+                :password-confirmation "password"}
+       :session {:user {:db/id 123}}}
+
+      ;; Updating password - meets default 12-char minimum.
+      {:expansions [query-user expand-user]
+       :effects [{:effect/name ::db/transact
+                  :effect/description "Update account details"
+                  :effect/key :update-details
+                  :success-key :account/account-updated
+                  :txs [{:db/id 123
+                         :user/name "Spongebob Squarepants"
+                         :user/password "[:bcrypt+blake2b-512+password1234]"}]
+                  :conn db-conn}]
+       :hooks {::bread/render [success-hook]}}
+      {}
+      {:request-method :post
+       :params {:action "update-details"
+                :name "Spongebob Squarepants"
+                :password "password1234"
+                :password-confirmation "password1234"}
+       :session {:user {:db/id 123}}}
+
+      ;; Updating password - meets default 12-char minimum.
+      {:expansions [query-user expand-user]
+       :effects [{:effect/name ::db/transact
+                  :effect/description "Update account details"
+                  :effect/key :update-details
+                  :success-key :account/account-updated
+                  :txs [{:db/id 123
+                         :user/name "Spongebob Squarepants"
+                         :user/password (str
+                                          "[:bcrypt+blake2b-512+"
+                                          "twelve_chars"
+                                          "twelve_chars"
+                                          "twelve_chars"
+                                          "twelve_chars"
+                                          "twelve_chars"
+                                          "twelve_chars"
+                                          "]")}]
+                  :conn db-conn}]
+       :hooks {::bread/render [success-hook]}}
+      {}
+      (let [;; 6 * 12 = 72
+            long-password (apply str (repeat 6 "twelve_chars"))]
+        {:request-method :post
+         :params {:action "update-details"
+                  :name "Spongebob Squarepants"
+                  :password long-password
+                  :password-confirmation long-password}
+         :session {:user {:db/id 123}}})
+
+      ;; Updating password - too long!
+      {:hooks {::bread/render [{:action/name ::ring/redirect
+                                :action/description
+                                "Redirect to account page after an error"
+                                ;; 12 is the default from auth
+                                :flash {:error-key [:auth/password-must-be-at-most 72]}
+                                :to "/account"}]}}
+      {}
+      (let [;; 1 + 6 * 12 = 73
+            long-password (apply str "x" (repeat 6 "twelve_chars"))]
+        {:request-method :post
+         :params {:action "update-details"
+                  :name "Spongebob Squarepants"
+                  :password long-password
+                  :password-confirmation long-password}
+         :session {:user {:db/id 123}}})
+
+      ;; Updating password - too long with custom auth config.
+      {:hooks {::bread/render [{:action/name ::ring/redirect
+                                :action/description
+                                "Redirect to account page after an error"
+                                ;; 12 is the default from auth
+                                :flash {:error-key [:auth/password-must-be-at-most 71]}
+                                :to "/account"}]}}
+      {:auth-config {:max-password-length 71}}
+      (let [;; 6 * 12 = 72
+            long-password (apply str (repeat 6 "twelve_chars"))]
+        {:request-method :post
+         :params {:action "update-details"
+                  :name "Spongebob Squarepants"
+                  :password long-password
+                  :password-confirmation long-password}
+         :session {:user {:db/id 123}}})
+
+      ;; Deleting a session.
+      {:expansions [query-user expand-user]
+       :effects [{:effect/name [::account/update :delete-session]
+                  :effect/description "Update account state"
+                  :effect/key :delete-session
+                  :success-key :account/session-deleted
+                  :params {:action "delete-session" :dbid "456"}
+                  :conn db-conn}]
+       :hooks {::bread/render [(assoc success-hook :effect/key :delete-session)]}}
+      {}
+      {:request-method :post
+       :params {:action "delete-session"
+                :dbid "456"}
+       :session {:user {:db/id 123}}}
+
+      ,)))
+
+(deftest test-delete-session-effect
+  (are
+    [expected effect data]
+    (= expected (bread/effect effect data))
+
+    ;; Anonymous, no params.
+    nil
+    {:effect/name [::account/update :delete-session]
+     :effect/description "Update account state"
+     :effect/key :delete-session
+     :success-key :account/session-deleted
+     :params nil
+     :conn ::FAKEDB}
+    {:user nil}
+
+    ;; Anonymous attempt to delete a session.
+    nil
+    {:effect/name [::account/update :delete-session]
+     :effect/description "Update account state"
+     :effect/key :delete-session
+     :success-key :account/session-deleted
+     :params {:dbid "345"}
+     :conn ::FAKEDB}
+    {:user nil}
+
+    ;; Invalid session id.
+    nil
+    {:effect/name [::account/update :delete-session]
+     :effect/description "Update account state"
+     :effect/key :delete-session
+     :success-key :account/session-deleted
+     :params {:dbid "invalid"}
+     :conn ::FAKEDB}
+    {:user {:user/sessions [{:db/id 234} {:db/id 456} {:db/id 567}]}}
+
+    ;; Invalid session id.
+    nil
+    {:effect/name [::account/update :delete-session]
+     :effect/description "Update account state"
+     :effect/key :delete-session
+     :success-key :account/session-deleted
+     :params {:dbid ""}
+     :conn ::FAKEDB}
+    {:user {:user/sessions [{:db/id 234} {:db/id 456} {:db/id 567}]}}
+
+    ;; Invalid session id.
+    nil
+    {:effect/name [::account/update :delete-session]
+     :effect/description "Update account state"
+     :effect/key :delete-session
+     :success-key :account/session-deleted
+     :params {:dbid nil}
+     :conn ::FAKEDB}
+    {:user {:user/sessions [{:db/id 234} {:db/id 456} {:db/id 567}]}}
+
+    ;; Attempt to delete a different user's session.
+    nil
+    {:effect/name [::account/update :delete-session]
+     :effect/description "Update account state"
+     :effect/key :delete-session
+     :success-key :account/session-deleted
+     :params {:dbid "345"}
+     :conn ::FAKEDB}
+    {:user {:user/sessions [{:db/id 234} {:db/id 456} {:db/id 567}]}}
+
+    ;; Happy path.
+    {:effects
+     [{:effect/name ::db/transact
+       :effect/description "Delete a user session."
+       :effect/key :delete-session
+       :success-key :account/session-deleted
+       :conn ::FAKEDB
+       :txs [[:db/retractEntity 123]]}]}
+    {:effect/name [::account/update :delete-session]
+     :effect/description "Update account state"
+     :effect/key :delete-session
+     :success-key :account/session-deleted
+     :params {:dbid "123"}
+     :conn ::FAKEDB}
+    {:user {:user/sessions [{:db/id 123}]}}
+
+    ;; Happy path; more than one session.
+    {:effects
+     [{:effect/name ::db/transact
+       :effect/description "Delete a user session."
+       :effect/key :delete-session
+       :success-key :account/session-deleted
+       :conn ::FAKEDB
+       :txs [[:db/retractEntity 456]]}]}
+    {:effect/name [::account/update :delete-session]
+     :effect/description "Update account state"
+     :effect/key :delete-session
+     :success-key :account/session-deleted
+     :params {:dbid "456"}
+     :conn ::FAKEDB}
+    {:user {:user/sessions [{:db/id 123} {:db/id 456}]}}
+
+    ,))
+
+(comment
+  (require '[kaocha.repl :as k])
+  (k/run {:color? false}))