Add support for passing components

.gitignore

@@ -4,3 +4,4 @@
 coverage/
 node_modules/
 yarn.lock
+!lib/components.d.ts

index.js

@@ -1,4 +1,5 @@
 /**
+ * @typedef {import('./lib/components.js').Components} Components
  * @typedef {import('./lib/index.js').Fragment} Fragment
  * @typedef {import('./lib/index.js').Jsx} Jsx
  * @typedef {import('./lib/index.js').JsxDev} JsxDev

lib/components.d.ts

@@ -0,0 +1,57 @@
+/**
+ * Basic functional component: given props, returns an element.
+ *
+ * @typeParam ComponentProps
+ *   Props type.
+ * @param props
+ *   Props.
+ * @returns
+ *   Result.
+ */
+export type FunctionComponent<ComponentProps> = (
+  props: ComponentProps
+) => JSX.Element | string | null | undefined
+
+/**
+ * Class component: given props, returns an instance.
+ *
+ * @typeParam ComponentProps
+ *   Props type.
+ * @param props
+ *   Props.
+ * @returns
+ *   Instance.
+ */
+export type ClassComponent<ComponentProps> = new (
+  props: ComponentProps
+) => JSX.ElementClass
+
+/**
+ * Function or class component.
+ *
+ * You can access props at `JSX.IntrinsicElements`.
+ * For example, to find props for `a`, use `JSX.IntrinsicElements['a']`.
+ *
+ * @typeParam ComponentProps
+ *   Props type.
+ */
+export type Component<ComponentProps> =
+  | FunctionComponent<ComponentProps>
+  | ClassComponent<ComponentProps>
+
+/**
+ * Possible components to use.
+ *
+ * Each key is a tag name typed in `JSX.IntrinsicElements`.
+ * Each value is a component accepting the corresponding props or a different
+ * tag name.
+ *
+ * You can access props at `JSX.IntrinsicElements`.
+ * For example, to find props for `a`, use `JSX.IntrinsicElements['a']`.
+
+ */
+export type Components = {
+  [TagName in keyof JSX.IntrinsicElements]:
+    | Component<JSX.IntrinsicElements[TagName]>
+    | keyof JSX.IntrinsicElements
+}

lib/components.js

@@ -0,0 +1,2 @@
+// TypeScript only.
+export {}

lib/index.js

@@ -3,12 +3,15 @@
  * @typedef {import('hast').Content} Content
  * @typedef {import('hast').Element} Element
  * @typedef {import('hast').Root} Root
+ * @typedef {import('./components.js').Components} Components
  */
 
 /**
  * @typedef {Content | Root} Node
  * @typedef {Extract<Node, import('unist').Parent>} Parent
- *
+ */
+
+/**
  * @typedef {unknown} Fragment
  *   Represent the children, typically a symbol.
  *
@@ -61,7 +64,7 @@
  * @typedef {[string, Value]} Field
  *   Property field.
  *
- * @typedef {JSX.Element | string} Child
+ * @typedef {JSX.Element | string | null | undefined} Child
  *   Child.
  *
  * @typedef {{children: Array<Child>, [prop: string]: Value | Array<Child>}} Props
@@ -84,6 +87,8 @@
  *   Info passed around.
  * @property {string | undefined} filePath
  *   File path.
+ * @property {Partial<Components>} components
+ *   Components to swap.
  * @property {Schema} schema
  *   Current schema.
  * @property {unknown} Fragment
@@ -93,6 +98,11 @@
  *
  * @typedef RegularFields
  *   Configuration.
+ * @property {Partial<Components> | null | undefined} [components]
+ *   Components to use.
+ *
+ *   Each key is the name of an HTML (or SVG) element to override.
+ *   The value is the component to render instead.
  * @property {string | null | undefined} [filePath]
  *   File path to the original source file.
  *
@@ -215,6 +225,7 @@ export function toJsxRuntime(tree, options) {
   const state = {
     Fragment: options.Fragment,
     schema: options.space === 'svg' ? svg : html,
+    components: options.components || {},
     filePath,
     create
   }
@@ -262,9 +273,15 @@ function one(state, node, key) {
     }
 
     const children = createChildren(state, node)
-    const type = node.type === 'root' ? state.Fragment : node.tagName
     const props = createProperties(state, node)
 
+    let type = node.type === 'root' ? state.Fragment : node.tagName
+
+    if (typeof type === 'string' && own.call(state.components, type)) {
+      const key = /** @type {keyof JSX.IntrinsicElements} */ (type)
+      type = state.components[key]
+    }
+
     props.children = children
 
     // Restore parent schema.

package.json

@@ -80,6 +80,7 @@
     "prettier": true,
     "#": "`n` is wrong",
     "rules": {
+      "@typescript-eslint/ban-types": "off",
       "n/file-extension-in-import": "off"
     }
   },

readme.md

@@ -20,6 +20,7 @@ with an automatic JSX runtime.
 *   [API](#api)
     *   [`toJsxRuntime(tree, options)`](#tojsxruntimetree-options)
     *   [`Options`](#options)
+    *   [`Components`](#components-1)
     *   [`Fragment`](#fragment-1)
     *   [`Jsx`](#jsx-1)
     *   [`JsxDev`](#jsxdev-1)
@@ -143,6 +144,13 @@ Static JSX ([`Jsx`][jsx], required in production).
 
 Development JSX ([`JsxDev`][jsxdev], required in development).
 
+###### `components`
+
+Components to use ([`Partial<Components>`][components], optional).
+
+Each key is the name of an HTML (or SVG) element to override.
+The value is the component to render instead.
+
 ###### `development`
 
 Whether to use `jsxDEV` when on or `jsx` and `jsxs` when off (`boolean`,
@@ -170,6 +178,33 @@ it.
 > Passing SVG might break but fragments of modern SVG should be fine.
 > Use `xast` if you need to support SVG as XML.
 
+### `Components`
+
+Possible components to use (TypeScript type).
+
+Each key is a tag name typed in `JSX.IntrinsicElements`.
+Each value is a component accepting the corresponding props or a different tag
+name.
+
+You can access props at `JSX.IntrinsicElements`.
+For example, to find props for `a`, use `JSX.IntrinsicElements['a']`.
+
+###### Type
+
+```ts
+type Components = {
+  [TagName in keyof JSX.IntrinsicElements]:
+    | Component<JSX.IntrinsicElements[TagName]>
+    | keyof JSX.IntrinsicElements
+}
+
+type Component<ComponentProps> =
+  // Function component:
+  | ((props: ComponentProps) => JSX.Element | string | null | undefined)
+  // Class component:
+  | (new (props: ComponentProps) => JSX.ElementClass)
+```
+
 ### `Fragment`
 
 Represent the children, typically a symbol (TypeScript type).
@@ -348,9 +383,9 @@ followed by browsers such as Chrome, Firefox, and Safari.
 ## Types
 
 This package is fully typed with [TypeScript][].
-It exports the additional types [`Fragment`][fragment], [`Jsx`][jsx],
-[`JsxDev`][jsxdev], [`Options`][options], [`Props`][props], [`Source`][source],
-and [`Space`][Space].
+It exports the additional types [`Components`][components],
+[`Fragment`][fragment], [`Jsx`][jsx], [`JsxDev`][jsxdev], [`Options`][options],
+[`Props`][props], [`Source`][source], and [`Space`][Space].
 
 The function `toJsxRuntime` returns a `JSX.Element`, which means that the JSX
 namespace has to by typed.
@@ -463,3 +498,5 @@ abide by its terms.
 [source]: #source
 
 [space]: #space-1
+
+[components]: #components-1

test/index.js

@@ -7,6 +7,7 @@
 
 import assert from 'node:assert/strict'
 import test from 'node:test'
+import React from 'react'
 import * as prod from 'react/jsx-runtime'
 import * as dev from 'react/jsx-dev-runtime'
 import {renderToStaticMarkup} from 'react-dom/server'
@@ -255,6 +256,7 @@ test('properties', () => {
     'should support properties in the SVG space'
   )
 })
+
 test('children', () => {
   assert.equal(
     renderToStaticMarkup(toJsxRuntime(h('a'), production)),
@@ -354,3 +356,48 @@ test('source', () => {
     return source
   }
 })
+
+test('components', () => {
+  assert.equal(
+    renderToStaticMarkup(
+      toJsxRuntime(h('b#x'), {
+        ...production,
+        components: {
+          b(props) {
+            // Note: types for this are working.
+            assert(props.id === 'x')
+            return 'a'
+          }
+        }
+      })
+    ),
+    'a',
+    'should support function components'
+  )
+
+  assert.equal(
+    renderToStaticMarkup(
+      toJsxRuntime(h('b#x'), {
+        ...production,
+        components: {
+          b: class extends React.Component {
+            /**
+             * @param {JSX.IntrinsicElements['b']} props
+             */
+            constructor(props) {
+              super(props)
+              // Note: types for this are working.
+              assert(props.id === 'x')
+            }
+
+            render() {
+              return 'a'
+            }
+          }
+        }
+      })
+    ),
+    'a',
+    'should support class components'
+  )
+})

tsconfig.json

@@ -1,5 +1,5 @@
 {
-  "include": ["**/**.js"],
+  "include": ["**/**.js", "lib/components.d.ts"],
   "exclude": ["coverage/", "node_modules/"],
   "compilerOptions": {
     "checkJs": true,