GrammarRegistry.loadGrammar does not catch errors from addGrammar

[50Wliu]

Prerequisites

• Put an X between the brackets on this line if you have done all of the following:
  • Reproduced the problem in Safe Mode: https://flight-manual.atom.io/hacking-atom/sections/debugging/#using-safe-mode
  • Followed all applicable steps in the debugging guide: https://flight-manual.atom.io/hacking-atom/sections/debugging/
  • Checked the FAQs on the message board for common solutions: https://discuss.atom.io/c/faq
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Description

While investigating 50Wliu/language-hclrs#4, I root-caused the issue to using a newer tree-sitter version than Atom supported. However, this was non-obvious, and the only place it was reported was in the console.

When loading grammars, loadGrammar checks to make sure that readGrammar succeeds:

atom/src/grammar-registry.js

Lines 552 to 553 in 3f4b251

	this.readGrammar(grammarPath, (error, grammar) => {
	if (error) return callback(error);

However, there are no checks for the subsequent addGrammar call:

atom/src/grammar-registry.js

Lines 554 to 555 in 3f4b251

	this.addGrammar(grammar);
	callback(null, grammar);

Even though addGrammar can fail when (eventually) calling TreeSitterLanguageMode.parse, which itself calls parser.setLanguage which can throw.

atom/src/tree-sitter-language-mode.js

Line 117 in 3f4b251

parser.setLanguage(language);

Resulting in e.g.

Steps to Reproduce

1. Install language-hclrs@0.0.2
2. Set language to HCLRS

Expected behavior:

A helpful error notificaton.

Actual behavior:

Nothing! Why isn't my syntax highlighting working?

Reproduces how often:

100%

Versions

1.58.0, Windows 11 Insider.

Additional Information

N/A

[icecream17]

Wow, this information here is more helpful than the information I gave at #22129... going to update that

[50Wliu]

Whoops, didn't search for the right keywords 😊. Figures that this has already been reported.

I'll keep this one open to track the fact that loadGrammar is unreliable at reporting errors, and #22129 seems better suited to tracking how Atom can support languages that use tree-sitter 0.19.0+ :).

[claytonrcarter]

This also seems to be happening outside of GrammarRegistry.loadGrammar. In particular, if a "working" tree-sitter grammar is loaded but a "not working" grammar is injected into some part of it. Also, because injections can happen in multiple places, this could trigger multiple errors.