.github/workflows/main.yml

@@ -1,21 +1,21 @@
-name: main
-on:
-  - pull_request
-  - push
 jobs:
   main:
     name: ${{matrix.node}}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-node@v3
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
         with:
           node-version: ${{matrix.node}}
       - run: npm install
       - run: npm test
-      - uses: codecov/codecov-action@v3
+      - uses: codecov/codecov-action@v4
     strategy:
       matrix:
         node:
-          - lts/gallium
+          - lts/hydrogen
           - node
+name: main
+on:
+  - pull_request
+  - push

.gitignore

@@ -1,7 +1,9 @@
 coverage/
 node_modules/
+*.d.ts.map
 *.d.ts
 *.log
+*.tsbuildinfo
 .DS_Store
 yarn.lock
 !/complex-types.d.ts

lib/index.js

@@ -1,13 +1,8 @@
 /**
- * @typedef {import('mdast-util-from-markdown').CompileContext} CompileContext
- * @typedef {import('mdast-util-from-markdown').Extension} FromMarkdownExtension
- * @typedef {import('mdast-util-from-markdown').Handle} FromMarkdownHandle
- *
- * @typedef {import('mdast-util-to-markdown').Handle} ToMarkdownHandle
- * @typedef {import('mdast-util-to-markdown').Options} ToMarkdownExtension
- *
- * @typedef {import('../index.js').MdxFlowExpression} MdxFlowExpression
- * @typedef {import('../index.js').MdxTextExpression} MdxTextExpression
+ * @import {CompileContext, Extension as FromMarkdownExtension, Handle as FromMarkdownHandle} from 'mdast-util-from-markdown'
+ * @import {MdxFlowExpression, MdxTextExpression} from 'mdast-util-mdx-expression'
+ * @import {Handle as ToMarkdownHandle, Options as ToMarkdownExtension, State} from 'mdast-util-to-markdown'
+ * @import {Parents} from 'mdast'
  */
 
 import {ok as assert} from 'devlop'
@@ -104,8 +99,22 @@ function exitMdxExpressionData(token) {
 /**
  * @type {ToMarkdownHandle}
  * @param {MdxFlowExpression | MdxTextExpression} node
+ *   Node.
+ * @param {Parents | undefined} parent
+ *   Parent, if any.
+ * @param {State} state
+ *   Info passed around about the current state.
+ * @returns {string}
+ *   Serialized markdown.
  */
-function handleMdxExpression(node) {
+function handleMdxExpression(node, parent, state) {
   const value = node.value || ''
-  return '{' + value + '}'
+  const result = state.indentLines(value, function (line, index, blank) {
+    // Tab-size to eat has to be the same as what we serialize as.
+    // While in some places in markdown that’s 4, in JS it’s more common as 2.
+    // Which is what’s also in `mdast-util-mdx-jsx`:
+    // <https://github.com/syntax-tree/mdast-util-mdx-jsx/blob/40b951b/lib/index.js#L52>
+    return (index === 0 || blank ? '' : '  ') + line
+  })
+  return '{' + result + '}'
 }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "mdast-util-mdx-expression",
-  "version": "2.0.0",
+  "version": "2.0.1",
   "description": "mdast extension to parse and serialize MDX (or MDX.js) expressions",
   "license": "MIT",
   "keywords": [
@@ -45,22 +45,22 @@
   },
   "devDependencies": {
     "@types/acorn": "^4.0.0",
-    "@types/node": "^20.0.0",
+    "@types/node": "^22.0.0",
     "acorn": "^8.0.0",
-    "c8": "^8.0.0",
-    "micromark-extension-mdx-expression": "^2.0.0",
-    "prettier": "^2.0.0",
-    "remark-cli": "^11.0.0",
-    "remark-preset-wooorm": "^9.0.0",
+    "c8": "^10.0.0",
+    "micromark-extension-mdx-expression": "^3.0.0",
+    "prettier": "^3.0.0",
+    "remark-cli": "^12.0.0",
+    "remark-preset-wooorm": "^10.0.0",
     "type-coverage": "^2.0.0",
     "typescript": "^5.0.0",
     "unist-util-remove-position": "^5.0.0",
-    "xo": "^0.54.0"
+    "xo": "^0.59.0"
   },
   "scripts": {
     "prepack": "npm run build && npm run format",
     "build": "tsc --build --clean && tsc --build && type-coverage",
-    "format": "remark . -qfo && prettier . -w --loglevel warn && xo --fix",
+    "format": "remark . -qfo && prettier . -w --log-level warn && xo --fix",
     "test-api-prod": "node --conditions production test.js",
     "test-api-dev": "node --conditions development test.js",
     "test-api": "npm run test-api-dev && npm run test-api-prod",
@@ -98,6 +98,9 @@
         }
       }
     ],
-    "prettier": true
+    "prettier": true,
+    "rules": {
+      "unicorn/prefer-at": "off"
+    }
   }
 }

readme.md

@@ -12,27 +12,27 @@
 
 ## Contents
 
-*   [What is this?](#what-is-this)
-*   [When to use this](#when-to-use-this)
-*   [Install](#install)
-*   [Use](#use)
-*   [API](#api)
-    *   [`mdxExpressionFromMarkdown()`](#mdxexpressionfrommarkdown)
-    *   [`mdxExpressionToMarkdown()`](#mdxexpressiontomarkdown)
-    *   [`MdxFlowExpression`](#mdxflowexpression)
-    *   [`MdxTextExpression`](#mdxtextexpression)
-    *   [`MdxFlowExpressionHast`](#mdxflowexpressionhast)
-    *   [`MdxTextExpressionHast`](#mdxtextexpressionhast)
-*   [HTML](#html)
-*   [Syntax](#syntax)
-*   [Syntax tree](#syntax-tree)
-    *   [Nodes](#nodes)
-    *   [Content model](#content-model)
-*   [Types](#types)
-*   [Compatibility](#compatibility)
-*   [Related](#related)
-*   [Contribute](#contribute)
-*   [License](#license)
+* [What is this?](#what-is-this)
+* [When to use this](#when-to-use-this)
+* [Install](#install)
+* [Use](#use)
+* [API](#api)
+  * [`mdxExpressionFromMarkdown()`](#mdxexpressionfrommarkdown)
+  * [`mdxExpressionToMarkdown()`](#mdxexpressiontomarkdown)
+  * [`MdxFlowExpression`](#mdxflowexpression)
+  * [`MdxTextExpression`](#mdxtextexpression)
+  * [`MdxFlowExpressionHast`](#mdxflowexpressionhast)
+  * [`MdxTextExpressionHast`](#mdxtextexpressionhast)
+* [HTML](#html)
+* [Syntax](#syntax)
+* [Syntax tree](#syntax-tree)
+  * [Nodes](#nodes)
+  * [Content model](#content-model)
+* [Types](#types)
+* [Compatibility](#compatibility)
+* [Related](#related)
+* [Contribute](#contribute)
+* [License](#license)
 
 ## What is this?
 
@@ -390,12 +390,13 @@ somewhere in your types, as that registers the new node types in the tree.
 
 ```js
 /**
- * @typedef {import('mdast-util-mdx-expression')}
+ * @import {} from 'mdast-util-mdx-expression'
+ * @import {Root} from 'mdast'
  */
 
 import {visit} from 'unist-util-visit'
 
-/** @type {import('mdast').Root} */
+/** @type {Root} */
 const tree = getMdastNodeSomeHow()
 
 visit(tree, function (node) {
@@ -418,12 +419,12 @@ This utility works with `mdast-util-from-markdown` version 2+ and
 
 ## Related
 
-*   [`remarkjs/remark-mdx`][remark-mdx]
-    — remark plugin to support MDX
-*   [`syntax-tree/mdast-util-mdx`][mdast-util-mdx]
-    — mdast utility to support MDX
-*   [`micromark/micromark-extension-mdx-expression`][extension]
-    — micromark extension to parse MDX expressions
+* [`remarkjs/remark-mdx`][remark-mdx]
+  — remark plugin to support MDX
+* [`syntax-tree/mdast-util-mdx`][mdast-util-mdx]
+  — mdast utility to support MDX
+* [`micromark/micromark-extension-mdx-expression`][extension]
+  — micromark extension to parse MDX expressions
 
 ## Contribute
 

test.js

@@ -50,7 +50,7 @@ test('mdxExpressionFromMarkdown()', async function (t) {
   )
 
   await t.test(
-    'should support a flow expression (agnostic)',
+    'should support an indented flow expression (agnostic)',
     async function () {
       assert.deepEqual(
         fromMarkdown('{\n  1 + 1\n}', {
@@ -62,7 +62,7 @@ test('mdxExpressionFromMarkdown()', async function (t) {
           children: [
             {
               type: 'mdxFlowExpression',
-              value: '\n  1 + 1\n',
+              value: '\n1 + 1\n',
               position: {
                 start: {line: 1, column: 1, offset: 0},
                 end: {line: 3, column: 2, offset: 11}
@@ -270,6 +270,7 @@ test('mdxExpressionFromMarkdown()', async function (t) {
       removePosition(tree, {force: true})
 
       // Cheap clone to remove non-JSON values.
+      // eslint-disable-next-line unicorn/prefer-structured-clone -- `JSON` to drop instances.
       tree = JSON.parse(JSON.stringify(tree))
 
       assert.deepEqual(tree, {
@@ -336,6 +337,7 @@ test('mdxExpressionFromMarkdown()', async function (t) {
     removePosition(tree, {force: true})
 
     // Cheap clone to remove non-JSON values.
+    // eslint-disable-next-line unicorn/prefer-structured-clone -- `JSON` to drop instances.
     tree = JSON.parse(JSON.stringify(tree))
 
     assert.deepEqual(tree, {
@@ -465,7 +467,7 @@ test('mdxExpressionToMarkdown()', async function (t) {
         },
         {extensions: [mdxExpressionToMarkdown()]}
       ),
-      '{a + b}\n\n{\nc +\n1\n}\n\n{}\n\nd\n'
+      '{a + b}\n\n{\n  c +\n  1\n}\n\n{}\n\nd\n'
     )
   })
 
@@ -514,7 +516,7 @@ test('mdxExpressionToMarkdown()', async function (t) {
 
 test('roundtrip', async function (t) {
   await t.test(
-    'should *not* strip superfluous whitespace depending on the opening prefix, when roundtripping expressions (flow)',
+    'should strip superfluous whitespace depending on the opening prefix, when roundtripping expressions (flow)',
     async function () {
       assert.deepEqual(
         toMarkdown(
@@ -524,7 +526,7 @@ test('roundtrip', async function (t) {
           }),
           {extensions: [mdxExpressionToMarkdown()]}
         ),
-        '{`\n a\n `}\n'
+        '{`\n  a\n  `}\n'
       )
     }
   )

tsconfig.json

@@ -2,6 +2,7 @@
   "compilerOptions": {
     "checkJs": true,
     "customConditions": ["development"],
+    "declarationMap": true,
     "declaration": true,
     "emitDeclarationOnly": true,
     "exactOptionalPropertyTypes": true,