[feat] Can you please provide sync API with async together?

[JounQin]

All APIs changed to be async in #75, but it would be great to still support legacy sync APIs.

I'm trying to integrate this tool to ESLint which does not support async rule for now.

So my proposal is to add lintTextSync, fixTextSync APIs, etc.

Some async rules like textlint-rule-no-dead-link won't work for sync API, that's OK, the user should just disable async rules if they want to use sync API.

If you agree, I'm glad to raise a PR for it.

[azu]

I will not plan that implement sync API.
It will make some inconsistency(Parallel linting, async rule which you suggested) and It will grow maintenance cost.

ESLint will support async API in the future.
eslint/rfcs#42
In another way, sync-rpc may helps you.(I've not tested)

Also, textlint-rule-eslint integrate with ESLint.

[JounQin]

ESLint will support async API in the future.

Yes, but it requires a long time to go.

In another way, sync-rpc may helps you.(I've not tested)

Thanks for this suggestion, I'll give it a try.

Also, textlint-rule-eslint integrate with ESLint.

It aims different things as my purpose, it runs ESLint for JavaScript codes just like eslint-plugin-markdown.

But what I'm doing is run textlint for all files as an ESLint plugin.

[JounQin]

It will make some inconsistency(Parallel linting, async rule which you suggested) and It will grow maintenance cost.

Many tools support async/sync at the same time, and most of the logic codes could be shared.

unified#process
unified#processSync

cosmiconfig#async
cosmiconfig#sync

[JounQin]

@azu I'm doing similar things for markuplint at the same time: markuplint/markuplint#155

We can test async and sync rules at the same time easily like above PR.

[azu]

Comparing cosmiconfig is not fair.
That is the library. textlint is not a library.

unified support async plugin, but it just throws an Error on runSync.

var vfile = require("vfile");
var unified = require("unified");
var f = vfile("alpha");
var n = { type: "bravo" };
var e = { type: "charlie" };
const file = unified().use(plugin).runSync(n, f);
console.log(file);

function plugin() {
    return transformer;
}

async function transformer(tree, file) {
    console.log(tree, file);
    return e;
}

Error: runSync finished async. Use run instead

https://runkit.com/azu/6083a90f2912a2001a3a1fe8

In my experience, 20 - 30% of rules use async API.
Especially, almost 40 - 50% use async API in Japanese rules.
(These rules load a large dictionary like kuromojin)

Sync to async is easy, but the reverse is difficult.
I concern that sync API will be debt and I not want to implement/maintenance Sync API.

Thanks for suggestion.

[JounQin]

Error: runSync finished async. Use run instead

Yes, I've mentioned:

Some async rules like textlint-rule-no-dead-link won't work for sync API, that's OK, the user should just disable async rules if they want to use sync API.

---

I concern that sync API will be debt and I not want to implement/maintenance Sync API.

That's unfortunately if you've decided that.

Or may I raise a PR first to see how difficult would it cost? That's OK if you decide not to merge that even.

[azu]

Or may I raise a PR first to see how difficult would it cost? That's OK if you decide not to merge that even.

Yes!
It is good that discusses on implementation.

[azu]

Closed by #757 (comment)