# fervid

**Repository Path**: mlzzen/fervid

## Basic Information

- **Project Name**: fervid
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Apache-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2024-12-31
- **Last Updated**: 2024-12-31

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

<div style="text-align: center">
<img src="logo.png" width="280" height="120">
</div>

# fervid
All-In-One Vue compiler written in Rust.
Currently in alpha stage, the closest goal is to reach feature-parity with the current [Vue SFC compiler](https://sfc.vuejs.org).


## Getting started
Instructions on how to use `fervid` in Vue CLI and Vite are coming very soon!


## Progress till MVP ![84%](https://geps.dev/progress/84)
A minimal target of this project includes (see [Roadmap](#roadmap)):
- Vue 3 code generation;
- [unplugin](https://github.com/unjs/unplugin) integration;
- [Farm](https://github.com/farm-fe/farm) native plugin;
- Dev/prod mode support;
- `<script setup>` support;
- Example Vue project with configuration;
- Performance comparison.

## Is it correct?
This project uses [Vue SFC playground](https://sfc.vuejs.org) as its reference to compare the output.
As of November 2023, fervid is capable of producing the DEV and PROD code almost identical to the official compiler, with some differences in:
- Context variables. This includes usages like `{{ foo + bar.buzz }}` or `<div v-if="isShown">`.
  Support for them in fervid is almost complete.
- [WIP] Patch flags. These are used to help Vue runtime when diffing the VNodes. If a VNode only has one prop which is dynamic, and all the other props and text are static, this needs to be conveyed to Vue for fast updates.
  Support for them is ongoing.

To check correctness of fervid, you can compare the [playground output](https://phoenix-ru.github.io/fervid/) to the output of [official compiler](https://play.vuejs.org).

Please note that "correctness" of output will depend on the version of Vue, as Vue team may change the output and/or behaviour of the compiler. This is a challenge for fervid.

## Is it fast?
Yes, it is incredibly fast. In fact, below is a benchmark run for a [test component](crates/fervid/benches/fixtures/input.vue).

```
  @vue/compiler-sfc:
    954 ops/s, ±1.15%     | slowest, 98.42% slower

  @fervid/napi sync:
    6 464 ops/s, ±0.08%   | 89.29% slower

  @fervid/napi async (4 threads):
    11 624 ops/s, ±2.12%  | 80.73% slower

  @fervid/napi async CPUS (23 threads):
    60 329 ops/s, ±0.67%  | fastest
```

<!-- 
| Action                     | Mean time    |
|----------------------------|--------------|
| Parsing                    | 5.58µs       |
| Code generation: CSR + DEV | 16.26µs      | -->

> Note: results are for AMD Ryzen 9 7900X running on Fedora 38 with kernel version 6.5.9

<!-- Micro-benchmarking has been done using Criterion, code for benchmarks can be found in `benches` directory. -->
Benchmarking in Node.js has been done using [`benny`](https://github.com/caderek/benny), slightly modified to take `libuv` threads into consideration.
[Source code for a benchmark](crates/fervid_napi/benchmark/bench.ts).

Better benchmarking is a TODO and has a lower priority compared to feature-completeness and usability in real-world scenarios, so **Pull Requests are welcome**.

## Crates

### `fervid` ![wip](https://badgen.net/badge/Status/In%20progress/blue)
The main crate. It exports a `compile` method which glues all the stages together, from taking a source string to outputting compiled code and assets.
For finer-grained compilation you can use other crates directly.

### `fervid_core` ![alpha](https://badgen.net/badge/Status/Alpha%20-%20almost%20stable/cyan)
The core structures and functionality shared across crates.

### `fervid_parser` ![alpha](https://badgen.net/badge/Status/Alpha%20-%20almost%20stable/cyan)
Parser for Vue SFC based on [swc_html_parser](https://rustdoc.swc.rs/swc_html_parser/).

### `fervid_transform` ![alpha](https://badgen.net/badge/Status/Alpha%20-%20feedback%20welcome/cyan)
This crate is responsible for AST transformation.
Handles `<script>` and `<script setup>` analysis and transformations, along with Typescript.
Based on [SWC](https://github.com/swc-project/swc) and provides fast and correct transforms without using regular expressions.

### `fervid_css` ![alpha](https://badgen.net/badge/Status/Alpha%20-%20feedback%20welcome/cyan)
Works on the `<style>` block and enables `scoped` styles, CSS Modules and Vue-specific transformations. The backbone of this crate is [swc_css_parser](https://crates.io/crates/swc_css_parser).

### `fervid_napi` ![alpha](https://badgen.net/badge/Status/Alpha%20-%20feedback%20welcome/cyan)
NAPI-rs bindings for usage in Node.js.

### `fervid_deno` ![future](https://badgen.net/badge/Status/Planned/orange)
Deno bindings for usage in Deno.

### `fervid_plugin` and `fervid_plugin_api` ![future](https://badgen.net/badge/Status/Planned/orange)
These crates allow authoring plugins for `fervid` in Rust using dynamically loaded libraries (`.so`, `.dll` and `.dylib`).
These plugins allow anyone to customize how a Vue SFC is parsed, optimized and code-generated.

## Roadmap
Parser
- [x] Template parsing
- [x] W3 Spec compliance

Transformer
- [x] Template scope construction
- [ ] Error reporting
- [x] JS/TS imports analysis (powered by swc_ecma_parser)
- [x] `setup`/`data`/`props` analysis
- [x] Processing `<style scoped>`
- [ ] `<script setup>` support
  - [x] Bindings collection;
  - [x] Return statement: inline vs render function;
  - [x] defineProps
  - [x] defineEmits
  - [x] defineExpose
  - [x] defineOptions
  - [x] defineSlots
  - [x] defineModel
  - [ ] Tests

Code generator
- [ ] Basic Vue3 code generation
  - [x] Elements
    - [x] `createElementVNode`
    - [x] Attributes
      - [x] Static + Dynamic
      - [x] `style` merging
      - [x] `class` merging
    - [x] Children
  - [x] Components
    - [x] `createVNode`
    - [x] Slots
  - [x] Context-awareness (`_ctx`, `$data`, `$setup`)
  - [x] Directives
    - [x] v-on
    - [x] v-bind
    - [x] v-if / v-else-if / v-else
    - [x] v-for
    - [x] v-show
    - [x] v-slot
    - [x] v-model
    - [x] v-cloak
    - [x] v-html
    - [x] v-memo
    - [x] v-once
    - [x] v-pre
    - [x] v-text
    - [x] Custom directives
  - [x] Built-in components
    - [x] keep-alive
    - [x] component
    - [x] transition
    - [x] transition-group
    - [x] teleport
    - [x] slot
    - [x] suspense
  - [ ] Patch flags
  - [ ] Hoisting

- [x] DEV/PROD mode
- [x] Hot Module Replacement (HMR)
- [ ] Vue 2.7 support
- [ ] SSR with inline critical CSS support
- [ ] Eager pre-compilation of Vue imports (avoid unneccessary bundler->compiler calls)

Integrations
- [x] WASM binary (unpublished)
- [x] NAPI binary [@fervid/napi](https://www.npmjs.com/package/@fervid/napi)
- [x] [unplugin](https://github.com/unjs/unplugin) (in progress)
- [ ] [Farm](https://github.com/farm-fe/farm) native plugin
- [ ] [Turbopack](https://github.com/vercel/turbo) plugin (when plugin system is defined)