Change to expect, yield undefined

lib/handlers/list-item.js

@@ -17,7 +17,7 @@
  *   Info passed around.
  * @param {ListItem} node
  *   mdast node.
- * @param {Parents | null | undefined} parent
+ * @param {Parents | undefined} parent
  *   Parent of `node`.
  * @returns {Element}
  *   hast node.

lib/handlers/table-row.js

@@ -17,7 +17,7 @@
  *   Info passed around.
  * @param {TableRow} node
  *   mdast node.
- * @param {Parents | null | undefined} parent
+ * @param {Parents | undefined} parent
  *   Parent of `node`.
  * @returns {Element}
  *   hast node.

lib/index.js

@@ -82,7 +82,7 @@ import {createState} from './state.js'
  *   mdast tree.
  * @param {Options | null | undefined} [options]
  *   Configuration (optional).
- * @returns {HastNodes | null | undefined}
+ * @returns {HastNodes | undefined}
  *   hast tree.
  */
 // To do: next major: always return a single `root`.

lib/state.js

@@ -15,11 +15,11 @@
 /**
  * @typedef EmbeddedHastFields
  *   hast fields.
- * @property {string | null | undefined} [hName]
+ * @property {string | undefined} [hName]
  *   Generate a specific element with this tag name instead.
- * @property {HastProperties | null | undefined} [hProperties]
+ * @property {HastProperties | undefined} [hProperties]
  *   Generate an element with these properties instead.
- * @property {Array<HastElementContent> | null | undefined} [hChildren]
+ * @property {Array<HastElementContent> | undefined} [hChildren]
  *   Generate an element with this content instead.
  *
  *   To do: type data!
@@ -29,36 +29,20 @@
  *
  *   To do: type data!
  *
- * @typedef {MdastNodes & {data?: MdastData | null | undefined}} MdastNodeWithData
+ * @typedef {MdastNodes & {data?: MdastData | undefined}} MdastNodeWithData
  *   mdast node with embedded hast data.
  *
  *   To do: type data!
  *
- * @typedef PointLike
- *   Point-like value.
- * @property {number | null | undefined} [line]
- *   Line.
- * @property {number | null | undefined} [column]
- *   Column.
- * @property {number | null | undefined} [offset]
- *   Offset.
- *
- * @typedef PositionLike
- *   Position-like value.
- * @property {PointLike | null | undefined} [start]
- *   Point-like value.
- * @property {PointLike | null | undefined} [end]
- *   Point-like value.
- *
  * @callback Handler
  *   Handle a node.
  * @param {State} state
  *   Info passed around.
  * @param {any} node
  *   mdast node to handle.
- * @param {MdastParents | null | undefined} parent
+ * @param {MdastParents | undefined} parent
  *   Parent of `node`.
- * @returns {Array<HastElementContent> | HastElementContent | null | undefined}
+ * @returns {Array<HastElementContent> | HastElementContent | undefined}
  *   hast node.
  *
  * @typedef State
@@ -77,13 +61,13 @@
  *   Identifiers of order when footnote calls first appear in tree order.
  * @property {Handlers} handlers
  *   Applied handlers.
- * @property {(node: MdastNodes, parent: MdastParents | null | undefined) => Array<HastElementContent> | HastElementContent | null | undefined} one
+ * @property {(node: MdastNodes, parent: MdastParents | undefined) => Array<HastElementContent> | HastElementContent | undefined} one
  *   Transform an mdast node to hast.
  * @property {Options} options
  *   Configuration.
  * @property {(from: MdastNodes, node: HastNodes) => void} patch
  *   Copy a node’s positional info.
- * @property {<Type extends HastRootContent>(nodes: Array<Type>, loose?: boolean | null | undefined) => Array<HastText | Type>} wrap
+ * @property {<Type extends HastRootContent>(nodes: Array<Type>, loose?: boolean | undefined) => Array<HastText | Type>} wrap
  *   Wrap `nodes` with line endings between each node, adds initial/final line endings when `loose`.
  *
  * @typedef Options
@@ -121,7 +105,7 @@
 
 import {visit} from 'unist-util-visit'
 import {position} from 'unist-util-position'
-import {handlers} from './handlers/index.js'
+import {handlers as defaultHandlers} from './handlers/index.js'
 
 const own = {}.hasOwnProperty
 
@@ -143,6 +127,10 @@ export function createState(tree, options) {
   const footnoteById = new Map()
   /** @type {Map<string, number>} */
   const footnoteCounts = new Map()
+  /** @type {Handlers} */
+  // @ts-expect-error: the root handler returns a root.
+  // Hard to type.
+  const handlers = {...defaultHandlers, ...settings.handlers}
 
   /** @type {State} */
   const state = {
@@ -152,13 +140,10 @@ export function createState(tree, options) {
     footnoteById,
     footnoteCounts,
     footnoteOrder: [],
-    // @ts-expect-error: fix `null` handling?
-    handlers: {...handlers, ...settings.handlers},
-    // @ts-expect-error: fix `null` handling.
+    handlers,
     one: oneBound,
     options: settings,
     patch,
-    // @ts-expect-error: fix `null` handling.
     wrap
   }
 
@@ -185,7 +170,7 @@ export function createState(tree, options) {
    *   mdast node.
    * @param {MdastParents | undefined} [parent]
    *   Parent of `node`.
-   * @returns {Array<HastElementContent> | HastElementContent | null | undefined}
+   * @returns {Array<HastElementContent> | HastElementContent | undefined}
    *   Resulting hast node.
    */
   function oneBound(node, parent) {
@@ -298,7 +283,7 @@ function applyData(from, to) {
  *   mdast node.
  * @param {MdastParents | undefined} [parent]
  *   Parent of `node`.
- * @returns {Array<HastElementContent> | HastElementContent | null | undefined}
+ * @returns {Array<HastElementContent> | HastElementContent | undefined}
  *   Resulting hast node.
  */
 // To do: next major: do not expose, keep bound.

readme.md

@@ -135,7 +135,7 @@ Transform mdast to hast.
 
 ###### Returns
 
-hast tree ([`HastNode | null | undefined`][hast-node]).
+hast tree ([`HastNode | undefined`][hast-node]).
 
 ##### Notes
 
@@ -214,12 +214,12 @@ Handle a node (TypeScript).
     — info passed around
 *   `node` ([`MdastNode`][mdast-node])
     — node to handle
-*   `parent` ([`MdastNode | null | undefined`][mdast-node])
+*   `parent` ([`MdastNode | undefined`][mdast-node])
     — parent of `node`
 
 ###### Returns
 
-Result ([`HastNode | Array<HastNode> | null | undefined`][mdast-node]).
+Result ([`Array<HastNode> | HastNode | undefined`][hast-node]).
 
 ### `Handlers`