Fix types for groupBy shim

Author: stormwarning

src/global.d.ts

@@ -0,0 +1,14 @@
+/**
+ * @todo [-object.groupby] When the `groupBy` method is available natively,
+ *       this declaration can be removed.
+ */
+declare module 'object.groupby' {
+	import groupBy from 'object.groupby'
+
+	function groupBy<T>(
+		array: T[],
+		predicate: (item: T) => string | number,
+	): Record<string | number, T[]>
+
+	export = groupBy
+}

src/utils/alphabetize-ranks.ts

@@ -64,7 +64,7 @@ function getSorter(order: OrderDirection) {
 
 		result *= multiplier
 
-		// In case the paths are equal (result === 0), sort them by importKind
+		// In case the paths are equal (result === 0), sort them by importKind.
 		if (!result && multiplierImportKind) {
 			result =
 				multiplierImportKind *
@@ -82,24 +82,20 @@ export function mutateRanksToAlphabetize(
 	imported: ImportNodeObject[],
 	alphabetizeOptions: OrderDirection,
 ) {
-	let groupedByRanks: Record<number, ImportNodeObject[]> = groupBy(
-		imported,
-		(item: ImportNodeObject) => item.rank,
-	)
-
+	let groupedByRanks = groupBy(imported, (item) => item.rank)
 	let sorterFunction = getSorter(alphabetizeOptions)
 
-	// Sort group keys so that they can be iterated on in order
+	// Sort group keys so that they can be iterated on in order.
 	let groupRanks = Object.keys(groupedByRanks).sort((a, b) => Number(a) - Number(b))
 
-	// Sort imports locally within their group
+	// Sort imports locally within their group.
 	for (let groupRank of groupRanks) {
 		groupedByRanks[groupRank].sort(sorterFunction)
 	}
 
-	// Assign globally unique rank to each import
+	// Assign a globally unique rank to each import.
 	let newRank = 0
-	let alphabetizedRanks = groupRanks.reduce((accumulator, groupRank) => {
+	let alphabetizedRanks = groupRanks.reduce<Record<string, number>>((accumulator, groupRank) => {
 		for (let importedItem of groupedByRanks[groupRank]) {
 			accumulator[`${importedItem.value}|${importedItem.node.importKind}`] =
 				Number.parseInt(groupRank, 10) + newRank
@@ -109,10 +105,9 @@ export function mutateRanksToAlphabetize(
 		return accumulator
 	}, {})
 
-	// Mutate the original group-rank with alphabetized-rank
-	// eslint-disable-next-line unicorn/no-array-for-each
-	imported.forEach((importedItem) => {
+	// Mutate the original group-rank with alphabetized-rank.
+	for (let importedItem of imported) {
 		importedItem.rank =
 			alphabetizedRanks[`${importedItem.value}|${importedItem.node.importKind}`]
-	})
+	}
 }