Add support for null as input in types

lib/types.js

@@ -137,17 +137,17 @@
  *   An entry on some character which is unsafe in certain contexts.
  * @property {string} character
  *   The single character.
- * @property {string | Array<string> | undefined} [inConstruct]
+ * @property {string | Array<string> | null | undefined} [inConstruct]
  *   Constructs where this is bad.
- * @property {string | Array<string> | undefined} [notInConstruct]
+ * @property {string | Array<string> | null | undefined} [notInConstruct]
  *   Constructs where this is fine.
- * @property {string | undefined} [after]
+ * @property {string | null | undefined} [after]
  *   Conditional character before.
- * @property {string | undefined} [before]
+ * @property {string | null | undefined} [before]
  *   Conditional character after (can’t be used together with `atBreak`).
- * @property {boolean | undefined} [atBreak]
+ * @property {boolean | null | undefined} [atBreak]
  *   Conditionally, at a break (can’t be used together with `before`).
- * @property {RegExp | undefined} [_compiled]
+ * @property {RegExp | null | undefined} [_compiled]
  *   The unsafe pattern (this whole object) compiled as a regex.
  *
  *   This is internal and must not be defined.
@@ -156,9 +156,9 @@
 /**
  * @typedef Options
  *   Configuration (optional).
- * @property {'-' | '*' | '+' | undefined} [bullet='*']
+ * @property {'-' | '*' | '+' | null | undefined} [bullet='*']
  *   Marker to use for bullets of items in unordered lists.
- * @property {'-' | '*' | '+' | undefined} [bulletOther]
+ * @property {'-' | '*' | '+' | null | undefined} [bulletOther]
  *   Marker to use in certain cases where the primary bullet doesn’t work.
  *
  *   There are three cases where the primary bullet can’t be used:
@@ -181,9 +181,9 @@
  *       To solve for both, we instead inject an empty comment between the two
  *       lists: `* a\n<!---->\n* b`, but if `bulletOther` is given explicitly,
  *       it will be used instead
- * @property {'.' | ')' | undefined} [bulletOrdered='.']
+ * @property {'.' | ')' | null | undefined} [bulletOrdered='.']
  *   Marker to use for bullets of items in ordered lists.
- * @property {'.' | ')' | undefined} [bulletOrderedOther]
+ * @property {'.' | ')' | null | undefined} [bulletOrderedOther]
  *   Marker to use in certain cases where the primary bullet for ordered items
  *   doesn’t work.
  *
@@ -195,49 +195,49 @@
  *       To solve for both, we instead inject an empty comment between the two
  *       lists: `1. a\n<!---->\n1. b`, but if `bulletOrderedOther` is given
  *       explicitly, it will be used instead
- * @property {boolean | undefined} [closeAtx=false]
+ * @property {boolean | null | undefined} [closeAtx=false]
  *   Whether to add the same number of number signs (`#`) at the end of an ATX
  *   heading as the opening sequence.
- * @property {'_' | '*' | undefined} [emphasis='*']
+ * @property {'_' | '*' | null | undefined} [emphasis='*']
  *   Marker to use for emphasis.
- * @property {'~' | '`' | undefined} [fence='`']
+ * @property {'~' | '`' | null | undefined} [fence='`']
  *   Marker to use for fenced code.
- * @property {boolean | undefined} [fences=false]
+ * @property {boolean | null | undefined} [fences=false]
  *   Whether to use fenced code always.
  *
  *   The default is to use fenced code if there is a language defined, if the
  *   code is empty, or if it starts or ends in blank lines.
- * @property {boolean | undefined} [incrementListMarker=true]
+ * @property {boolean | null | undefined} [incrementListMarker=true]
  *   Whether to increment the counter of ordered lists items.
- * @property {'tab' | 'one' | 'mixed' | undefined} [listItemIndent='tab']
+ * @property {'tab' | 'one' | 'mixed' | null | undefined} [listItemIndent='tab']
  *   How to indent the content of list items.
  *
  *   Either with the size of the bullet plus one space (when `'one'`), a tab
  *   stop (`'tab'`), or depending on the item and its parent list (`'mixed'`,
  *   uses `'one'` if the item and list are tight and `'tab'` otherwise).
- * @property {'"' | "'" | undefined} [quote='"']
+ * @property {'"' | "'" | null | undefined} [quote='"']
  *   Marker to use for titles.
- * @property {boolean | undefined} [resourceLink=false]
+ * @property {boolean | null | undefined} [resourceLink=false]
  *   Whether to always use resource links.
  *
  *   The default is to use autolinks (`<https://example.com>`) when possible
  *   and resource links (`[text](url)`) otherwise.
- * @property {'-' | '_' | '*' | undefined} [rule='*']
+ * @property {'-' | '_' | '*' | null | undefined} [rule='*']
  *   Marker to use for thematic breaks.
- * @property {number | undefined} [ruleRepetition=3]
+ * @property {number | null | undefined} [ruleRepetition=3]
  *   Number of markers to use for thematic breaks.
- * @property {boolean | undefined} [ruleSpaces=false]
+ * @property {boolean | null | undefined} [ruleSpaces=false]
  *   Whether to add spaces between markers in thematic breaks.
- * @property {boolean | undefined} [setext=false]
+ * @property {boolean | null | undefined} [setext=false]
  *   Whether to use setext headings when possible.
  *
  *   The default is to always use ATX headings (`# heading`) instead of setext
  *   headings (`heading\n=======`).
  *   Setext headings can’t be used for empty headings or headings with a rank
  *   of three or more.
- * @property {'_' | '*' | undefined} [strong='*']
+ * @property {'_' | '*' | null | undefined} [strong='*']
  *   Marker to use for strong.
- * @property {boolean | undefined} [tightDefinitions=false]
+ * @property {boolean | null | undefined} [tightDefinitions=false]
  *   Whether to join definitions without a blank line.
  *
  *   The default is to add blank lines between any flow (“block”) construct.
@@ -250,23 +250,23 @@
  *     }
  *   }
  *   ```
- * @property {Handlers | undefined} [handlers={}]
+ * @property {Handlers | null | undefined} [handlers={}]
  *   Object mapping node types to custom handlers.
  *
  *   Useful for syntax extensions.
  *   This option is a bit advanced.
  *   It’s recommended to look at the code in `lib/handle/` in
  *   `mdast-util-to-markdown` for examples.
- * @property {Array<Join> | undefined} [join=[]]
+ * @property {Array<Join> | null | undefined} [join=[]]
  *   List of functions used to determine what to place between two flow nodes.
- * @property {Array<Unsafe> | undefined} [unsafe=[]]
+ * @property {Array<Unsafe> | null | undefined} [unsafe=[]]
  *   List of extra patterns to escape.
  *
  *   Useful for syntax extensions.
  *   This option is quite advanced.
  *   It’s recommended to look at the code in `lib/unsafe.js` in
  *   `mdast-util-to-markdown` for examples.
- * @property {Array<Options> | undefined} [extensions=[]]
+ * @property {Array<Options> | null | undefined} [extensions=[]]
  *   List of extensions to include.
  *
  *   Each `ToMarkdownExtension` is an object with the same interface as

lib/util/check-bullet-ordered-other.js

@@ -7,7 +7,7 @@ import {checkBulletOrdered} from './check-bullet-ordered.js'
 
 /**
  * @param {Context} context
- * @returns {Exclude<Options['bulletOrdered'], undefined>}
+ * @returns {Exclude<Options['bulletOrdered'], null | undefined>}
  */
 export function checkBulletOrderedOther(context) {
   const bulletOrdered = checkBulletOrdered(context)

lib/util/check-bullet-ordered.js

@@ -5,7 +5,7 @@
 
 /**
  * @param {Context} context
- * @returns {Exclude<Options['bulletOrdered'], undefined>}
+ * @returns {Exclude<Options['bulletOrdered'], null | undefined>}
  */
 export function checkBulletOrdered(context) {
   const marker = context.options.bulletOrdered || '.'

lib/util/check-bullet-other.js

@@ -7,7 +7,7 @@ import {checkBullet} from './check-bullet.js'
 
 /**
  * @param {Context} context
- * @returns {Exclude<Options['bullet'], undefined>}
+ * @returns {Exclude<Options['bullet'], null | undefined>}
  */
 export function checkBulletOther(context) {
   const bullet = checkBullet(context)

lib/util/check-bullet.js

@@ -5,7 +5,7 @@
 
 /**
  * @param {Context} context
- * @returns {Exclude<Options['bullet'], undefined>}
+ * @returns {Exclude<Options['bullet'], null | undefined>}
  */
 export function checkBullet(context) {
   const marker = context.options.bullet || '*'

lib/util/check-emphasis.js

@@ -5,7 +5,7 @@
 
 /**
  * @param {Context} context
- * @returns {Exclude<Options['emphasis'], undefined>}
+ * @returns {Exclude<Options['emphasis'], null | undefined>}
  */
 export function checkEmphasis(context) {
   const marker = context.options.emphasis || '*'

lib/util/check-fence.js

@@ -5,7 +5,7 @@
 
 /**
  * @param {Context} context
- * @returns {Exclude<Options['fence'], undefined>}
+ * @returns {Exclude<Options['fence'], null | undefined>}
  */
 export function checkFence(context) {
   const marker = context.options.fence || '`'

lib/util/check-list-item-indent.js

@@ -5,7 +5,7 @@
 
 /**
  * @param {Context} context
- * @returns {Exclude<Options['listItemIndent'], undefined>}
+ * @returns {Exclude<Options['listItemIndent'], null | undefined>}
  */
 export function checkListItemIndent(context) {
   const style = context.options.listItemIndent || 'tab'

lib/util/check-quote.js

@@ -5,7 +5,7 @@
 
 /**
  * @param {Context} context
- * @returns {Exclude<Options['quote'], undefined>}
+ * @returns {Exclude<Options['quote'], null | undefined>}
  */
 export function checkQuote(context) {
   const marker = context.options.quote || '"'

lib/util/check-rule-repetition.js

@@ -5,7 +5,7 @@
 
 /**
  * @param {Context} context
- * @returns {Exclude<Options['ruleRepetition'], undefined>}
+ * @returns {Exclude<Options['ruleRepetition'], null | undefined>}
  */
 export function checkRuleRepetition(context) {
   const repetition = context.options.ruleRepetition || 3

lib/util/check-rule.js

@@ -5,7 +5,7 @@
 
 /**
  * @param {Context} context
- * @returns {Exclude<Options['rule'], undefined>}
+ * @returns {Exclude<Options['rule'], null | undefined>}
  */
 export function checkRule(context) {
   const marker = context.options.rule || '*'

lib/util/check-strong.js

@@ -5,7 +5,7 @@
 
 /**
  * @param {Context} context
- * @returns {Exclude<Options['strong'], undefined>}
+ * @returns {Exclude<Options['strong'], null | undefined>}
  */
 export function checkStrong(context) {
   const marker = context.options.strong || '*'