routie dev init since i didn't adhere to any proper guidance up until now

frontend/node_modules/eslint-plugin-perfectionist/dist/utils/compute-group.js

@@ -0,0 +1,64 @@
+import { computeGroupsNames } from './compute-groups-names.js'
+/**
+ * Determines which group an element belongs to based on custom and predefined
+ * groups.
+ *
+ * The function checks groups in the following priority order:
+ *
+ * 1. Custom groups (if defined) - checked first, highest priority
+ * 2. Predefined groups - checked as fallback
+ * 3. Returns 'unknown' if no matching group is found.
+ *
+ * Only groups that exist in options.groups are considered valid.
+ *
+ * @example
+ *
+ * ```ts
+ * const group = computeGroup({
+ *   options: {
+ *     groups: ['react', 'external', 'internal'],
+ *     customGroups: [{ groupName: 'react', anyOf: ['react', 'react-*'] }],
+ *   },
+ *   customGroupMatcher: customGroup => customGroup.anyOf.includes('react'),
+ *   predefinedGroups: ['external'],
+ *   name: 'react-dom',
+ * })
+ * // Returns: 'react'
+ * ```
+ *
+ * @template CustomGroupMatchOptions - Type of custom group match options.
+ * @param params - Parameters for group computation.
+ * @param params.options - Configuration with available groups and custom
+ *   groups.
+ * @param params.customGroupMatcher - Matcher function for custom groups.
+ * @param params.predefinedGroups - Fallback predefined groups to check.
+ * @returns The matched group name or 'unknown' if no group matches.
+ */
+function computeGroup({ customGroupMatcher, predefinedGroups, options }) {
+  let groupsSet = new Set(computeGroupsNames(options.groups))
+  return (
+    computeFirstMatchingCustomGroupName(
+      groupsSet,
+      options.customGroups,
+      customGroupMatcher,
+    ) ??
+    predefinedGroups.find(group => groupsSet.has(group)) ??
+    'unknown'
+  )
+}
+function computeFirstMatchingCustomGroupName(
+  groupsSet,
+  customGroups,
+  customGroupMatcher,
+) {
+  for (let customGroup of customGroups) {
+    if (
+      customGroupMatcher(customGroup) &&
+      groupsSet.has(customGroup.groupName)
+    ) {
+      return customGroup.groupName
+    }
+  }
+  return null
+}
+export { computeGroup }