Changes after code review

@xen-orchestra/defined/.USAGE.md

@@ -2,6 +2,11 @@
 
 Returns the first non-`undefined` value from a list of arguments, evaluating functions if needed.
 
+There is two ways to use this function:
+
+- either with a single array argument: it should return the first non-undefined item
+- or with multiple arguments: it should return the first non-undefined argument
+
 If only `undefined` values, return `undefined`.
 
 ```js
@@ -14,7 +19,7 @@ defined([undefined, null, 10])
 // Returns null
 
 defined([undefined, undefined], [undefined, undefined, 10])
-// Returns 10
+// Returns [undefined, undefined]
 
 defined(() => 'bar', 42)
 // Returns 'bar'

@xen-orchestra/defined/README.md

@@ -16,8 +16,15 @@ npm install --save @xen-orchestra/defined
 
 ## Usage
 
-The defined() function returns the first non-undefined value from a list of arguments, evaluating functions if needed.
-If only undefined values, return undefined.
+### `defined()`
+
+Returns the first non-`undefined` value from a list of arguments, evaluating functions if needed.
+
+There is two ways to use this function:
+- either with a single array argument: it should return the first non-undefined item
+- or with multiple arguments: it should return the first non-undefined argument
+
+If only `undefined` values, return `undefined`.
 
 ```js
 import defined from '@xen-orchestra/defined/index.js'
@@ -29,7 +36,7 @@ defined([undefined, null, 10])
 // Returns null
 
 defined([undefined, undefined], [undefined, undefined, 10])
-// Returns 10
+// Returns [undefined, undefined]
 
 defined(() => 'bar', 42)
 // Returns 'bar'

@xen-orchestra/defined/defined.test.mjs

@@ -12,7 +12,7 @@ describe('defined()', () => {
     assert.deepStrictEqual(defined([undefined, null, 10]), expected)
   })
   it('should return first non undefined value in arrays', () => {
-    const expected = 10
+    const expected = [undefined, undefined, undefined]
     assert.deepStrictEqual(defined([undefined, undefined, undefined], [undefined, undefined, 10]), expected)
   })
   it('should return first non undefined value in function', () => {

@xen-orchestra/defined/index.js

@@ -14,8 +14,12 @@
 // ])
 // ```
 function defined() {
-  const args = [].concat.apply([], arguments)
-  const n = args.length
+  let args = arguments
+  let n = args.length
+  if (n === 1) {
+    args = arguments[0]
+    n = args.length
+  }
 
   for (let i = 0; i < n; ++i) {
     let arg = args[i]