Merge pull request #1922 from tim-we/improve-at-rule-types

Improve AtRule#nodes type

lib/at-rule.d.ts

@@ -86,6 +86,25 @@ declare class AtRule_ extends Container {
    * ```
    */
   name: string
+  /**
+   * An array containing the layer’s children.
+   *
+   * ```js
+   * const root = postcss.parse('@layer example { a { color: black } }')
+   * const layer = root.first
+   * layer.nodes.length           //=> 1
+   * layer.nodes[0].selector      //=> 'a'
+   * ```
+   *
+   * Can be `undefinded` if the at-rule has no body.
+   *
+   * ```js
+   * const root = postcss.parse('@layer a, b, c;')
+   * const layer = root.first
+   * layer.nodes //=> undefined
+   * ```
+   */
+  nodes: Container['nodes']
   /**
    * The at-rule’s parameters, the values that follow the at-rule’s name
    * but precede any `{}` block.

lib/container.d.ts

@@ -43,7 +43,7 @@ declare abstract class Container_<Child extends Node = ChildNode> extends Node {
    * root.nodes[0].nodes[0].prop //=> 'color'
    * ```
    */
-  nodes: Child[]
+  nodes: Child[] | undefined
 
   /**
    * Inserts new nodes to the end of the container.

lib/document.d.ts

@@ -35,6 +35,7 @@ declare namespace Document {
  * ```
  */
 declare class Document_ extends Container<Root> {
+  nodes: Root[]
   parent: undefined
   type: 'document'
 

lib/root.d.ts

@@ -54,6 +54,7 @@ declare namespace Root {
  * ```
  */
 declare class Root_ extends Container {
+  nodes: NonNullable<Container['nodes']>
   parent: Document | undefined
   raws: Root.RootRaws
   type: 'root'

lib/rule.d.ts

@@ -69,6 +69,7 @@ declare namespace Rule {
  * ```
  */
 declare class Rule_ extends Container {
+  nodes: NonNullable<Container['nodes']>
   parent: Container | undefined
   raws: Rule.RuleRaws
   /**

test/at-rule.test.ts

@@ -24,15 +24,15 @@ test('creates nodes property on prepend()', () => {
   type(rule.nodes, 'undefined')
 
   rule.prepend('color: black')
-  is(rule.nodes.length, 1)
+  is(rule.nodes?.length, 1)
 })
 
 test('creates nodes property on append()', () => {
   let rule = new AtRule()
   type(rule.nodes, 'undefined')
 
   rule.append('color: black')
-  is(rule.nodes.length, 1)
+  is(rule.nodes?.length, 1)
 })
 
 test('inserts default spaces', () => {
@@ -48,4 +48,10 @@ test('clone spaces from another at-rule', () => {
   is(rule.toString(), '@page 1{}')
 })
 
+test('at-rule without body has no nodes property', () => {
+  let root = parse('@layer a, b, c;');
+  let layer = root.first as AtRule
+  type(layer.nodes, 'undefined')
+});
+
 test.run()

test/visitor.test.ts

@@ -18,9 +18,9 @@ import postcss, {
 
 function hasAlready(parent: Container | undefined, selector: string): boolean {
   if (typeof parent === 'undefined') return false
-  return parent.nodes.some(i => {
+  return parent.nodes?.some(i => {
     return i.type === 'rule' && i.selectors.includes(selector)
-  })
+  }) ?? false
 }
 
 function addIndex(array: any[][]): any[][] {
@@ -1559,9 +1559,9 @@ test('append works after reassigning nodes through .parent', async () => {
     OnceExit(root) {
       let firstNode = root.nodes[0] as AtRule
       let secondNode = root.nodes[1] as AtRule
-      let rule2 = secondNode.nodes[0]
+      let rule2 = secondNode.nodes![0]
       rule2.parent!.nodes = rule2.parent!.nodes
-      firstNode.append(...secondNode.nodes)
+      firstNode.append(...secondNode.nodes!)
       secondNode.remove()
     },
 
@@ -1580,7 +1580,7 @@ test('append works after reassigning nodes through .parent', async () => {
 
       let atrule = rule.nodes[0]
 
-      atrule.append(rule.clone({ nodes: [] }).append(...atrule.nodes))
+      atrule.append(rule.clone({ nodes: [] }).append(...atrule.nodes!))
 
       rule.after(atrule)
       rule.remove()