Partially restore b6e26b5

Restore tests for an invalid arbitrary substitution nested in a function or
simple block, to ensure they are looked for recursively.

Restore tests for a comma or a positioned {} as a non-strict comma-containing
<declaration-value> in var(). But move it as a test of <var()>, since it is
presumably a strict comma-containing <declaration-value> in <var-args>.

Author: cdoublev

__tests__/style.js

@@ -375,6 +375,7 @@ describe('arbitrary substitution', () => {
     test('invalid', () => {
         const style = createStyleBlock()
         const invalid = [
+            // Invalid component value
             ['env(name) "\n'],
             ['env(name) url(bad .url)'],
             ['env(name) ]'],
@@ -386,6 +387,9 @@ describe('arbitrary substitution', () => {
             ['{} env(name)', 'color'],
             ['env(name) !important'],
             ['!important env(name)'],
+            // Nested
+            ['fn(env())'],
+            ['{env()}'],
         ]
         invalid.forEach(([input, property = '--custom']) => {
             style.setProperty(property, input)

__tests__/value.js

@@ -4289,6 +4289,20 @@ describe('<url-set>', () => {
         })
     })
 })
+describe('<var()>', () => {
+    test('representation', () => {
+        const property = dashedIdent('--custom', ['<custom-property-name>'])
+        expect(parse('<var()>', 'var(--custom)', false)).toMatchObject({
+            name: 'var',
+            value: list([property, omitted, omitted]),
+            types: ['<function>', '<var()>'],
+        })
+    })
+    test('valid', () => {
+        expect(parse('<var()>', 'var(--custom,,)')).toBe('var(--custom,,)')
+        expect(parse('<var()>', 'var(--custom, 1 {})')).toBe('var(--custom, 1 {})')
+    })
+})
 describe('<view()>', () => {
     test('representation', () => {
         expect(parse('<view()>', 'view()', false)).toMatchObject({