Docs: Recognise legacy idiom for QUnit.test.if()

docs/api/QUnit/test.if.md

@@ -16,14 +16,14 @@ Add a test that only runs if a condition is true.
 | parameter | description |
 |-----------|-------------|
 | `name` (string) | Title of unit being tested |
-| `condition` (string) | Expression to decide if the test should be run |
+| `condition` (string) | Expression to decide if the test should run |
 | `callback` (function) | Function that performs the test |
 
 If the condition is true, this is equivalent to calling [`QUnit.test()`](./test.md).
 
 If the conditional is false, this is equivalent to calling [`QUnit.test.skip()`](./test.skip.md), and test will not run. Instead, it will be listed in the results as a "skipped" test.
 
-As a codebase becomes bigger, you may need to conditionally skip an entire group of tests. You can use [`QUnit.module.if()`](./module.md) to recursively skip all tests in a module based on a given condition.
+As a codebase becomes bigger, you may need to conditionally skip an entire group of tests. You can use [`QUnit.module.if()`](./module.md) to recursively skip all tests in a module based on a given requirement.
 
 ## Examples
 
@@ -41,7 +41,6 @@ QUnit.test.if('render', typeof document !== 'undefined', function (assert) {
 This is equivalent to:
 
 ```js
-// Skip if executed without a DOM
 if (typeof document !== 'undefined') {
   QUnit.test('render', function (assert) {
     assert.strictEqual(MyApp.render(), '<p>Hello world!</p>');
@@ -60,3 +59,17 @@ QUnit.test('render', function (assert) {
   assert.strictEqual(MyApp.render(), '<p>Hello world!</p>');
 });
 ```
+
+### Legacy idom
+
+Prior to QUnit 3.0, the following shortcuts were sometimes used. This may be replaced by `QUnit.test.if()`.
+
+```js
+(typeof document !== 'undefined' ? QUnit.test : QUnit.skip)('example', function (assert) {
+  assert.true(true);
+});
+
+QUnit[typeof document !== 'undefined' ? 'test' : 'skip']('example', function (assert) {
+  assert.strue(true);
+});
+```