# @componentor/quickjs-singlefile-mjs-debug-asyncify

Variant with the WASM data embedded into a NodeJS ESModule.

This generated package is part of [quickjs-emscripten](https://github.com/componentor/quickjs-emscripten).
It contains a variant of the quickjs WASM library, and can be used with @componentor/quickjs-emscripten-core.

```typescript
import variant from "@componentor/quickjs-singlefile-mjs-debug-asyncify"
import { newQuickJSAsyncWASMModuleFromVariant } from "@componentor/quickjs-emscripten-core"
const QuickJS = await newQuickJSAsyncWASMModuleFromVariant(variant)
```

This variant was built with the following settings:

## Library: quickjs

The original [bellard/quickjs](https://github.com/bellard/quickjs) library.

Version [2024-02-14+36911f0d](https://github.com/bellard/quickjs/commit/36911f0d3ab1a4c190a4d5cbe7c2db225a455389) vendored to quickjs-emscripten on 2024-06-15.

## Release mode: debug

Enables assertions and memory sanitizers. Try to run your tests against debug variants, in addition to your preferred production variant, to catch more bugs.

## Exports: import

Exports the following in package.json for the package entrypoint:

- Exports a NodeJS-compatible ESModule. Cannot be imported synchronously from a NodeJS CommonJS module.

## Extra async magic? Yes

Build run through the ASYNCIFY WebAssembly transform. This imposes substantial size (2x the size of sync) and speed penalties (40% the speed of sync). In return, allows synchronous calls from the QuickJS WASM runtime to async functions on the host. The extra magic makes this variant slower than sync variants. Note that both variants support regular async functions. Only adopt ASYNCIFY if you need to! The [QuickJSAsyncRuntime](https://github.com/componentor/quickjs-emscripten/blob/main/doc/quickjs-emscripten/classes/QuickJSAsyncRuntime.md) and [QuickJSAsyncContext](https://github.com/componentor/quickjs-emscripten/blob/main/doc/quickjs-emscripten/classes/QuickJSAsyncContext.md) classes expose the ASYNCIFY-specific APIs.

## Single-file, or separate .wasm file? singlefile

The WASM runtime is included directly in the JS file. Use if you run into issues with missing .wasm files when building or deploying your app.

## More details

Full variant JSON description:

```json
{
  "library": "quickjs",
  "releaseMode": "debug",
  "syncMode": "asyncify",
  "description": "Variant with the WASM data embedded into a NodeJS ESModule.",
  "emscriptenInclusion": "singlefile",
  "exports": {
    "import": {
      "emscriptenEnvironment": ["node"]
    }
  }
}
```

Variant-specific Emscripten build flags:

```json
[
  "-s ASYNCIFY=1",
  "-DQTS_ASYNCIFY=1",
  "-DQTS_ASYNCIFY_DEFAULT_STACK_SIZE=81920",
  "-s ASYNCIFY_STACK_SIZE=81920",
  "-s ASYNCIFY_REMOVE=@$(BUILD_WRAPPER)/asyncify-remove.json",
  "-s ASYNCIFY_IMPORTS=@$(BUILD_WRAPPER)/asyncify-imports.json",
  "-lasync.js",
  "-O0",
  "-DQTS_DEBUG_MODE",
  "-DDUMP_LEAKS=1",
  "-gsource-map",
  "-s ASSERTIONS=1",
  "--pre-js $(TEMPLATES)/pre-extension.js",
  "--pre-js $(TEMPLATES)/pre-sourceMapJson.js",
  "--pre-js $(TEMPLATES)/pre-wasmOffsetConverter.js",
  "--pre-js $(TEMPLATES)/pre-wasmMemory.js",
  "-s SINGLE_FILE=1",
  "-O3"
]
```
