fix: remove unnecessary isObjectNotArray guard in compareDeepIfVisited

Author: fgenois-coveo

lib/mergeDeep.js

@@ -248,16 +248,13 @@ class MergeDeep {
       modifications.push({})
       additions.push({})
       deletions.push({})
-      // visited[id] may be a primitive string (from the non-object branch in processArrays)
-      // — only deep-compare when both sides are real objects
-      if (this.isObjectNotArray(visited[id])) {
-        // Strip the identity field before comparing — it was already used for matching
-        const idPropA = NAME_USERNAME_PROPERTY(a)
-        const idPropV = NAME_USERNAME_PROPERTY(visited[id])
-        const targetObj = idPropA ? Object.fromEntries(Object.entries(a).filter(([k]) => k !== idPropA)) : a
-        const sourceObj = idPropV ? Object.fromEntries(Object.entries(visited[id]).filter(([k]) => k !== idPropV)) : visited[id]
-        this.compareDeep(targetObj, sourceObj, additions[additions.length - 1], modifications[modifications.length - 1], deletions[deletions.length - 1])
-      }
+      // Strip the identity field before comparing — it was already used for matching
+      // and would otherwise appear as a spurious diff (e.g. slug vs name)
+      const idPropA = NAME_USERNAME_PROPERTY(a)
+      const idPropV = NAME_USERNAME_PROPERTY(visited[id])
+      const targetObj = idPropA ? Object.fromEntries(Object.entries(a).filter(([k]) => k !== idPropA)) : a
+      const sourceObj = idPropV ? Object.fromEntries(Object.entries(visited[id]).filter(([k]) => k !== idPropV)) : visited[id]
+      this.compareDeep(targetObj, sourceObj, additions[additions.length - 1], modifications[modifications.length - 1], deletions[deletions.length - 1])
       // Any addtions for the matching key must be moved to modifications
       const lastAddition = additions[additions.length - 1]
       const lastModification = modifications[modifications.length - 1]
@@ -277,7 +274,7 @@ class MergeDeep {
       }
       // Add name attribute to the modifications to make it look better ; it won't be added otherwise as it would be the same
       if (!this.isEmpty(modifications[modifications.length - 1])) {
-        if (this.isObjectNotArray(visited[id])) {
+        if (visited[id]) {
           modifications[modifications.length - 1][NAME_USERNAME_PROPERTY(a)] = id
         }
       }