🐛 Fix assertion when restoring a deleted component

The changes builder getters now assert that their context was given,
but prepare-restore-component and generate-delete-shapes relied on them
returning nil to fall back to other data. The workspace restores
components with changes that carry no library data, so restoring a
main component or a variant from one of its copies failed.

Add has-library-data?, has-objects? and has-page? to the changes builder,
and check them in those fallbacks before calling the getters.

Add tests that restore a component, and a variant whose container was
deleted, with changes that carry no library data, as the workspace does.

AI-assisted-by: claude-opus-5-5

common/src/app/common/files/changes_builder.cljc

@@ -1264,6 +1264,21 @@
   (assert-page-id! changes)
   (::page-id (meta changes)))
 
+;; The getters above assert that their context has been given. Use these
+;; predicates when a caller has a fallback for a missing context.
+
+(defn has-library-data?
+  [changes]
+  (contains? (meta changes) ::library-data))
+
+(defn has-objects?
+  [changes]
+  (contains? (meta changes) ::file-data))
+
+(defn has-page?
+  [changes]
+  (contains? (meta changes) ::page))
+
 (defn set-text-content
   [changes id content prev-content]
   (assert-page-id! changes)

common/src/app/common/logic/libraries.cljc

@@ -442,9 +442,13 @@
      (prepare-restore-component changes library-data component-id page nil nil nil nil)))
 
   ([changes library-data component-id page position old-id parent-id frame-id]
-   (let [library-data      (or (pcb/get-library-data changes) library-data)
+   (let [library-data      (or (when (pcb/has-library-data? changes)
+                                 (pcb/get-library-data changes))
+                               library-data)
          component         (ctkl/get-deleted-component library-data component-id)
-         objects           (or (pcb/get-objects changes) (:objects page))
+         objects           (or (when (pcb/has-objects? changes)
+                                 (pcb/get-objects changes))
+                               (:objects page))
          parent            (get objects parent-id)
          main-inst         (get-in component [:objects (:main-instance-id component)])
          inside-component? (some? (ctn/get-instance-root (:objects page) parent))

common/src/app/common/logic/shapes.cljc

@@ -267,7 +267,8 @@
    (let [objects (pcb/get-objects changes)
          data    (pcb/get-library-data changes)
          page-id (pcb/get-page-id changes)
-         page    (or (pcb/get-page changes)
+         page    (or (when (pcb/has-page? changes)
+                       (pcb/get-page changes))
                      (ctpl/get-page data page-id))
          ids     (cfh/clean-loops objects ids)
 

common/test/common_tests/logic/comp_creation_test.cljc

@@ -17,6 +17,7 @@
    [app.common.test-helpers.files :as thf]
    [app.common.test-helpers.ids-map :as thi]
    [app.common.test-helpers.shapes :as ths]
+   [app.common.test-helpers.variants :as thv]
    [app.common.types.component :as ctk]
    [app.common.types.components-list :as ctkl]
    [app.common.types.file :as ctf]
@@ -664,3 +665,70 @@
     (t/is (some? copy1-root'))
     (t/is (not (ctk/instance-head? copy1-root')))
     (t/is (not (ctk/in-component-copy? copy1-root')))))
+
+(defn- delete-shapes
+  [file labels]
+  (let [page    (thf/current-page file)
+        [_ changes]
+        (cls/generate-delete-shapes (pcb/empty-changes)
+                                    file
+                                    page
+                                    (:objects page)
+                                    (into #{} (map thi/id) labels)
+                                    {:components-v2 true})]
+    (thf/apply-changes file changes)))
+
+(defn- restore-changes
+  "Build the changes of restoring a deleted component as the workspace does,
+  without any library data or objects in the changes builder."
+  [file component-label]
+  (let [page (thf/current-page file)]
+    (cll/generate-restore-component (pcb/empty-changes)
+                                    (:data file)
+                                    (thi/id component-label)
+                                    (:id file)
+                                    page
+                                    (:objects page))))
+
+(t/deftest test-restore-component-without-library-data
+  (let [;; ==== Setup
+        file    (-> (thf/sample-file :file1)
+                    (tho/add-simple-component-with-copy :component1
+                                                        :main1-root
+                                                        :main1-child
+                                                        :copy1-root)
+                    (delete-shapes [:main1-root]))
+
+        ;; ==== Action
+        changes (restore-changes file :component1)
+        file'   (thf/apply-changes file changes)
+
+        ;; ==== Get
+        component1' (thc/get-component file' :component1)
+        main1-root' (ths/get-shape file' :main1-root)]
+
+    ;; ==== Check
+    (t/is (some? component1'))
+    (t/is (some? main1-root'))))
+
+(t/deftest test-restore-variant-after-deleting-its-container
+  (let [;; ==== Setup
+        file    (-> (thf/sample-file :file1)
+                    (thv/add-variant :v01 :c01 :m01 :c02 :m02)
+                    (delete-shapes [:v01]))
+
+        ;; ==== Action
+        changes (restore-changes file :c01)
+        file'   (thf/apply-changes file changes)
+
+        ;; ==== Get
+        c01'    (thc/get-component file' :c01)
+        m01'    (ths/get-shape file' :m01)]
+
+    ;; ==== Check
+    ;; The container no longer exists, so the main is restored as a
+    ;; component that is not a variant
+    (t/is (some? c01'))
+    (t/is (some? m01'))
+    (t/is (nil? (:variant-id c01')))
+    (t/is (nil? (:variant-id m01')))))