Change to yield undefined instead of null

Author: wooorm

index.js

@@ -44,7 +44,7 @@ export function matches(selector, node) {
  *   CSS selector, such as (`heading`, `link, linkReference`).
  * @param {Node | NodeLike | null | undefined} [tree]
  *   Tree to search.
- * @returns {Node | null}
+ * @returns {Node | undefined}
  *   First node in `tree` that matches `selector` or `null` if nothing is
  *   found.
  *
@@ -54,8 +54,7 @@ export function select(selector, tree) {
   const state = createState(selector, tree)
   state.one = true
   walk(state, tree || undefined)
-  // To do next major: return `undefined`.
-  return state.results[0] || null
+  return state.results[0]
 }
 
 /**

readme.md

@@ -150,7 +150,7 @@ Searches the tree in *[preorder][]*.
 
 ###### Returns
 
-First node in `tree` that matches `selector` or `null` if nothing is found.
+First node in `tree` that matches `selector` or `undefined` if nothing is found.
 
 This could be `tree` itself.
 

test/select.js

@@ -76,7 +76,7 @@ test('select.select()', async function (t) {
     )
 
     await t.test('should yield nothing if not given a node', async function () {
-      assert.equal(select('*'), null)
+      assert.equal(select('*'), undefined)
     })
 
     await t.test('should yield the node if given a node', async function () {
@@ -184,7 +184,7 @@ test('select.select()', async function (t) {
             u('b', 'Delta')
           ])
         ),
-        null
+        undefined
       )
     })
   })
@@ -227,7 +227,7 @@ test('select.select()', async function (t) {
           'c ~ b',
           u('a', [u('b', 'Alpha'), u('c', 'Bravo'), u('d', 'Charlie')])
         ),
-        null
+        undefined
       )
     })
   })
@@ -258,7 +258,7 @@ test('select.select()', async function (t) {
               'c:first-child',
               u('a', [u('b', 'Alpha'), u('c', 'Bravo'), u('d', 'Charlie')])
             ),
-            null
+            undefined
           )
         }
       )
@@ -289,7 +289,7 @@ test('select.select()', async function (t) {
               'c:last-child',
               u('a', [u('b', 'Alpha'), u('c', 'Bravo'), u('d', 'Charlie')])
             ),
-            null
+            undefined
           )
         }
       )
@@ -320,7 +320,7 @@ test('select.select()', async function (t) {
               'c:only-child',
               u('a', [u('b', 'Alpha'), u('c', 'Bravo'), u('d', 'Charlie')])
             ),
-            null
+            undefined
           )
         }
       )
@@ -676,7 +676,7 @@ test('select.select()', async function (t) {
       )
 
       await t.test('should return nothing without matches', async function () {
-        assert.equal(select('b:first-of-type', u('a', [])), null)
+        assert.equal(select('b:first-of-type', u('a', [])), undefined)
       })
     })
 
@@ -702,7 +702,7 @@ test('select.select()', async function (t) {
       )
 
       await t.test('should return nothing without matches', async function () {
-        assert.equal(select('b:last-of-type', u('a', [])), null)
+        assert.equal(select('b:last-of-type', u('a', [])), undefined)
       })
     })
 
@@ -737,13 +737,13 @@ test('select.select()', async function (t) {
                 u('c', 'Foxtrot')
               ])
             ),
-            null
+            undefined
           )
         }
       )
 
       await t.test('should return nothing without matches', async function () {
-        assert.equal(select('b:only-of-type', u('a', [])), null)
+        assert.equal(select('b:only-of-type', u('a', [])), undefined)
       })
     })