fix(transforms): handle array of strings as input to toProperList

src/transforms/toProperList.test.ts

@@ -4,24 +4,17 @@ import toProperList from './toProperList'
 
 const batch = partial(batchTest, toProperList)
 
-describe('ProperList String (toProperList)', () => {
+describe('Properly Formatted List (toProperList)', () => {
   test(`When the list is empty`, () => {
-    batch([
-      [[], '']
-    ])
+    batch([[[], '']])
   })
 
-
-  test(`No commas and o 'and'`, () => {
-    batch([
-      [['apples'], 'apples']
-    ])
+  test(`No commas and no 'and'`, () => {
+    batch([[['apples'], 'apples']])
   })
 
   test(`With only two items`, () => {
-    batch([
-      [['apples','bananas'], 'apples and bananas']
-    ])
+    batch([[['apples', 'bananas'], 'apples and bananas']])
   })
 
   test(`With three or more items`, () => {
@@ -31,4 +24,15 @@ describe('ProperList String (toProperList)', () => {
       [['apples', 'pears', 'bananas', 'grape', 'lemon'], 'apples, pears, bananas, grape and lemon']
     ])
   })
+
+  test('With an array of inputs', () => {
+    batch([
+      [[['apples', 'pears', 'bananas']], 'apples, pears and bananas'],
+      [[['apples', 'pears', 'bananas', 'grape']], 'apples, pears, bananas and grape'],
+      [
+        [['apples', 'pears', 'bananas', 'grape', 'lemon']],
+        'apples, pears, bananas, grape and lemon'
+      ]
+    ])
+  })
 })

src/transforms/toProperList.ts

@@ -10,35 +10,41 @@
  * @example const itemsString = toProperList(['apples', 'pears', 'bananas']) // => 'apples, pears and bananas'
  *
  */
-export default function toProperList(...items: string[]): string {
-  let itemsString = ''
-  let length = items.length
+export function toProperList(items: string[]): string
+export function toProperList(...items: string[]): string
+export function toProperList(...items: any[]): string {
+  const parts: string[] = Array.isArray(items[0]) ? items[0] : items
+
+  let output = ''
+  const length = parts.length
   // If you have only one item in the array
   if (length === 1) {
-    itemsString = items[0]
+    output = parts[0]
   }
   // If you have only two items in the array
   else if (length === 2) {
-    itemsString = `${items[0]} and ${items[1]}`
+    output = `${parts[0]} and ${parts[1]}`
   }
   // If you have 3 or more items in the array,
   else if (length >= 3) {
     // It traverses all elements of the array adds the fixed dots according to the English language
-    items.forEach((item, index) => {
+    parts.forEach((item, index) => {
       // If it is the penultimate array item
       if (index === length - 2) {
-        itemsString += `${item} and `
+        output += `${item} and `
       }
       // If it is the last item in the array
       else if (index === length - 1) {
-        itemsString += `${item}`
+        output += `${item}`
       }
       // If it is the first or some element before the penultimate one
       else {
-        itemsString += `${item}, `
+        output += `${item}, `
       }
     })
   }
 
-  return itemsString
+  return output
 }
+
+export default toProperList