Refactoring

src/system/footer/shared_2.js

@@ -4,6 +4,8 @@ import mapObj from 'map-obj'
 import omit from 'omit.js'
 import sortOn from 'sort-on'
 
+import { uniqueDeep } from '../../utils/unique.js'
+
 /* eslint-disable max-nested-callbacks, max-lines-per-function, complexity, max-lines, fp/no-loops, max-statements, max-depth, no-unreachable-loop */
 const mainLogic = function (systems) {
   const propEntries = listPropEntries(systems)
@@ -201,13 +203,7 @@ const isReducibleDimension = function ({
 }
 
 const removeDuplicateDimensions = function (dimensionsArray) {
-  return dimensionsArray.filter(isUniqueDimensions)
-}
-
-const isUniqueDimensions = function (dimensions, index, dimensionsArray) {
-  return dimensionsArray
-    .slice(index + 1)
-    .every((dimensionsB) => !isDeepStrictEqual(dimensions, dimensionsB))
+  return uniqueDeep(dimensionsArray)
 }
 
 const normalizeTopSystem = function (dimensionsArray) {

src/utils/unique.js

@@ -0,0 +1,22 @@
+import { isDeepStrictEqual } from 'util'
+
+// Remove duplicate elements using a deep comparison.
+// Uses imperative code for performance.
+// Avoids creating intermediary arrays for memory.
+export const uniqueDeep = function (array) {
+  return array.filter(isUniqueDeep)
+}
+
+const isUniqueDeep = function (value, valueIndex, array) {
+  // eslint-disable-next-line fp/no-loops, fp/no-mutation, fp/no-let
+  for (let index = valueIndex + 1; index < array.length; index += 1) {
+    const valueB = array[index]
+
+    // eslint-disable-next-line max-depth
+    if (isDeepStrictEqual(value, valueB)) {
+      return false
+    }
+  }
+
+  return true
+}