perf: extract parseMdx, exports everything in package

Author: JounQin

README.md

@@ -2,7 +2,7 @@
   <a href="https://eslint.org">
     <img src="https://eslint.org/assets/img/logo.svg" height="50">
   </a>
-  <a href="https://github.com/rx-ts/eslint-plugin-mdx">
+  <a href="#readme">
     <img src="assets/heart.svg" height="50">
   </a>
   <a href="https://github.com/mdx-js/mdx">
@@ -86,6 +86,13 @@ npm i -D @rxts/eslint-plugin-mdx
    }
    ```
 
+## Limitations
+
+1. This parser/plugin can only handle ES syntaxes for you, markdown related syntaxes will just be ignored, you can use [markdownlint](https://github.com/markdownlint/markdownlint) to lint that part.
+
+2. `MDX` can render `jsx` block automatically without exporting them, but `eslint` will report `no-unused-expressions` issue which could be unexpected, so you may need to disable this rule for `*.mdx`.
+   I'm not going to disable this rule in the recommended config, because I'm going to add a custom `mdx/no-unused-expressions` rule to replace the incompatible one, which should not affect the `jsx` codes.
+
 ## Changelog
 
 Detailed changes for each release are documented in [CHANGELOG.md](./CHANGELOG.md).

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@rxts/eslint-plugin-mdx",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "description": "ESLint Parser/Plugin for MDX",
   "repository": "[email protected]:rx-ts/eslint-plugin-mdx.git",
   "author": "JounQin <[email protected]>",

src/helper.ts

@@ -0,0 +1,75 @@
+import { Position } from 'unist'
+import { AST } from 'eslint'
+// SourceLocation` is not exported from estree, but it is actually working
+// eslint-disable-next-line import/named
+import { SourceLocation } from 'estree'
+
+export const normalizePosition = (position: Position) => {
+  const start = position.start.offset
+  const end = position.end.offset
+  return {
+    range: [start, end] as AST.Range,
+    loc: {
+      ...position,
+    },
+    start,
+    end,
+  }
+}
+
+export interface BaseNode {
+  type: string
+  loc?: SourceLocation
+  range?: [number, number]
+}
+
+export function restoreNodeLocation<T extends BaseNode>(
+  node: T,
+  startLine: number,
+  offset = 0,
+): T {
+  if (!node || !node.loc || !node.range) {
+    return node
+  }
+
+  Object.entries(node).forEach(([key, value]) => {
+    if (!value) {
+      return
+    }
+
+    if (Array.isArray(value)) {
+      node[key as keyof T] = value.map(child =>
+        restoreNodeLocation(child, startLine, offset),
+      ) as any
+    } else {
+      node[key as keyof T] = restoreNodeLocation(
+        value,
+        startLine,
+        offset,
+      ) as T[keyof T]
+    }
+  })
+
+  const {
+    loc: { start: startLoc, end: endLoc },
+    range,
+  } = node
+  const start = range[0] + offset
+  const end = range[1] + offset
+  return {
+    ...node,
+    start,
+    end,
+    range: [start, end],
+    loc: {
+      start: {
+        line: startLine + startLoc.line,
+        column: startLoc.column,
+      },
+      end: {
+        line: startLine + endLoc.line,
+        column: endLoc.column,
+      },
+    },
+  }
+}

src/index.ts

@@ -1,6 +1,9 @@
 import path from 'path'
 
-export { parseForESLint } from './parser'
+export * from './helper'
+export * from './parser'
+export * from './regexp'
+export * from './traverse'
 
 export const configs = {
   recommended: {

src/parser.ts

@@ -7,86 +7,23 @@ import remarkParse from 'remark-parse'
 import remarkStringify from 'remark-stringify'
 import unified from 'unified'
 
+import { normalizePosition, restoreNodeLocation } from './helper'
+import { isComment } from './regexp'
 import { traverse } from './traverse'
-import { isComment } from './utils'
 
-import { Position, Parent } from 'unist'
 import { AST, Linter } from 'eslint'
-// SourceLocation` is not exported from estree, but it is actually working
-// eslint-disable-next-line import/named
-import { SourceLocation } from 'estree'
+import { Parent } from 'unist'
 
-const normalizePosition = (position: Position) => {
-  const start = position.start.offset
-  const end = position.end.offset
-  return {
-    range: [start, end] as AST.Range,
-    loc: {
-      ...position,
-    },
-    start,
-    end,
-  }
-}
-
-interface BaseNode {
-  type: string
-  loc?: SourceLocation
-  range?: [number, number]
-}
-
-function normalizeLoc<T extends BaseNode>(
-  node: T,
-  startLine: number,
-  offset = 0,
-): T {
-  if (!node || !node.loc || !node.range) {
-    return node
-  }
-
-  Object.entries(node).forEach(([key, value]) => {
-    if (!value) {
-      return
-    }
-
-    if (Array.isArray(value)) {
-      node[key as keyof T] = value.map(child =>
-        normalizeLoc(child, startLine, offset),
-      ) as any
-    } else {
-      node[key as keyof T] = normalizeLoc(
-        value,
-        startLine,
-        offset,
-      ) as T[keyof T]
-    }
-  })
+export const AST_PROPS = ['body', 'comments', 'tokens'] as const
+export const ES_NODE_TYPES = ['export', 'import', 'jsx'] as const
 
-  const {
-    loc: { start: startLoc, end: endLoc },
-    range,
-  } = node
-  const start = range[0] + offset
-  const end = range[1] + offset
-  return {
-    ...node,
-    start,
-    end,
-    range: [start, end],
-    loc: {
-      start: {
-        line: startLine + startLoc.line,
-        column: startLoc.column,
-      },
-      end: {
-        line: startLine + endLoc.line,
-        column: endLoc.column,
-      },
-    },
-  }
-}
+export type EsNodeType = (typeof ES_NODE_TYPES)[number]
 
-export const AST_PROPS = ['body', 'comments', 'tokens'] as const
+export const parseMdx = unified()
+  .use<any>(remarkParse)
+  .use<any>(remarkStringify)
+  .use(remarkMdx)
+  .freeze().parse
 
 export const parseForESLint = (
   code: string,
@@ -102,7 +39,7 @@ export const parseForESLint = (
         parser = parser.parseForESLint || parser.parse
       }
       if (typeof parser !== 'function') {
-        throw new Error(
+        throw new TypeError(
           `Invalid custom parser for \`eslint-plugin-mdx\`: ${parser}`,
         )
       }
@@ -111,11 +48,7 @@ export const parseForESLint = (
     parser = esParse
   }
 
-  const root = unified()
-    .use<any>(remarkParse)
-    .use<any>(remarkStringify)
-    .use(remarkMdx)
-    .parse(code) as Parent
+  const root = parseMdx(code) as Parent
 
   const ast: AST.Program = {
     ...normalizePosition(root.position),
@@ -128,7 +61,7 @@ export const parseForESLint = (
 
   traverse(root, {
     enter({ position, type }) {
-      if (!['export', 'import', 'jsx'].includes(type)) {
+      if (!ES_NODE_TYPES.includes(type as EsNodeType)) {
         return
       }
 
@@ -162,7 +95,9 @@ export const parseForESLint = (
         ast[prop].push(
           // unfortunately, TS complains about incompatible signature
           // @ts-ignore
-          ...program[prop].map(item => normalizeLoc(item, startLine, offset)),
+          ...program[prop].map(item =>
+            restoreNodeLocation(item, startLine, offset),
+          ),
         ),
       )
     },

src/utils.ts renamed to src/regexp.ts

@@ -4,7 +4,7 @@ import {
   isVoidTag,
   isComment,
   isOpenCloseTag,
-} from './utils'
+} from './regexp'
 
 import { Node, Parent } from 'unist'
 

src/traverse.ts

@@ -1,7 +1,3 @@
 {
-  "extends": "../tsconfig.json",
-  "compilerOptions": {
-    "declaration": true,
-    "outDir": "../dist"
-  }
+  "extends": "../tsconfig.json"
 }

src/tsconfig.json

@@ -2,11 +2,13 @@
   "compilerOptions": {
     "allowSyntheticDefaultImports": true,
     "baseUrl": ".",
+    "declaration": true,
     "esModuleInterop": true,
     "jsx": "preserve",
     "lib": ["esnext"],
     "module": "commonjs",
     "moduleResolution": "node",
+    "outDir": "dist",
     "sourceMap": true,
     "strict": true,
     "strictNullChecks": false,