feat(ast/estree)!: replace serde with custom ESTree serializer

[overlookmotel]

Replace serde with a custom serializer specialized for writing JSON.

impl Serialize -> impl ESTree. I've called it ESTree in case we want to add e.g. impl Babel later on.

The main motivation is that with control of the serializer, we can make it stateful, so we can extend it to, for example, omit TS fields based on a flag. This is pretty much impossible with serde's interface.

But a side-effect of the simpler implementation is that it's also more performant.

The usage of ESTree trait is very similar to serde::Serialize. Main differences:

• serialize method is infallible. Does not return a Result.
• state = serializer.serialize_struct(); instead of map = serializer.serialize_map();.
• state.serialize_field(...) instead of map.serialize_entry(...).
• Struct keys must be strings, and JSON-safe (not including " or other characters that require escaping in JSON).

This is a breaking change, as it's possible downstream consumers are using serde to serialize our AST to other formats. I'd guess unlikely, but possible. We can always implement serde::Serialize as well as ESTree further down the line if there's a demand.

[overlookmotel]

• feat(ast/estree)!: replace serde with custom ESTree serializer #9256 👈 (View in Graphite)
• refactor(ast/estree): simplify serializer for BindingProperty #9255
• refactor(allocator, linter): shorten serde impls #9254
• main

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[codspeed-hq]

CodSpeed Performance Report

Merging #9256 will improve performances by 24.22%

_{Comparing 02-20-feat_ast_estree_replace_serde_with_custom_estree_serializer (53d9342) with main (464762e)}

Summary

⚡ 1 improvements
✅ 32 untouched benchmarks

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
⚡	estree[checker.ts]	189.9 ms	152.9 ms	+24.22%

[overlookmotel]

#9259 adapted @oxc-parser/wasm NPM package to transfer AST to JS as a JSON string. So this PR now plays nicely with that NPM package.

oxc-wasm is still transferring AST as a wasm_bindgen::JsValue, and the code to do that in this PR is very unperformant. But that'd be easier to fix after this PR, rather than trying to change it first. As oxc-wasm package isn't designed for public consumption anyway, I think it should be OK to leave it in a dodgy state temporarily.

So I think we can merge this now.

[Boshen]

Merge activity

• Feb 20, 10:24 PM EST: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.