Support async processing

[wooorm]

Subject of the issue

eslint-mdx uses .processSync instead of .process, causing async plugins to fail.

Error: `processSync` finished async. Use `process` instead
Occurred while linting /Users/tilde/Code/oss/mdx/packages/remark-mdx/readme.md:1
    at assertDone (/Users/tilde/Code/oss/mdx/node_modules/unified/index.js:469:11)
    at Function.processSync (/Users/tilde/Code/oss/mdx/node_modules/unified/index.js:401:5)
    at Program (/Users/tilde/Code/oss/mdx/node_modules/eslint-plugin-mdx/lib/cjs.js:361:44)
    at /Users/tilde/Code/oss/mdx/node_modules/eslint/lib/linter/safe-emitter.js:45:58
    at Array.forEach (<anonymous>)
    at Object.emit (/Users/tilde/Code/oss/mdx/node_modules/eslint/lib/linter/safe-emitter.js:45:38)
    at NodeEventGenerator.applySelector (/Users/tilde/Code/oss/mdx/node_modules/eslint/lib/linter/node-event-generator.js:254:26)
    at NodeEventGenerator.applySelectors (/Users/tilde/Code/oss/mdx/node_modules/eslint/lib/linter/node-event-generator.js:283:22)
    at NodeEventGenerator.enterNode (/Users/tilde/Code/oss/mdx/node_modules/eslint/lib/linter/node-event-generator.js:297:14)
    at CodePathAnalyzer.enterNode (/Users/tilde/Code/oss/mdx/node_modules/eslint/lib/linter/code-path-analysis/code-path-analyzer.js:634:23)

Your environment

• OS: osx latest
• Packages:
• Env: node 13.10, 6.14, yarn 1.22

Steps to reproduce

yarn format in mdx-js/mdx (with changes on a branch)

Expected behaviour

Support async plugins:

eslint-mdx/packages/eslint-plugin-mdx/src/rules/remark.ts

Line 40 in 96fc83a

const file = remarkProcessor.processSync(

Actual behaviour

Crash.

---

P.S. aside: you may be interested in vfile-to-eslint

[JounQin]

Yes, it is a known issue, and that's why validate-links rule is disabled in mdx-js/mdx.

As I know asynchronous rule is not supported by ESLint itself right now, or is there any workaround to support?

Related: #73 and eslint/rfcs#4

[wooorm]

Ahh okay, didn’t know ESLint didn’t support that 🤔

[karlhorky]

Looks like ESLint is getting parallel processing support: eslint/rfcs#42

(eslint/rfcs#4 is closed now)

[JounQin]

Cannot do much before ESLint changes.

[karlhorky]

Wow, this is great! Does this mean that the validate-links rule will be enabled again for Markdown / MDX?

Is there anywhere where we can follow along with this?

[JounQin]

@karlhorky

Yes! You can try it with latest codesandbox build right now.

https://ci.codesandbox.io/status/mdx-js/eslint-mdx/pr/309/builds/125085

[JounQin]

v1.13.0 has been released!