/**
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* The WASI API provides an implementation of the [WebAssembly System Interface](https://wasi.dev/) specification. WASI gives sandboxed WebAssembly applications access to the
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* underlying operating system via a collection of POSIX-like functions.
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*
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* ```js
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* import { readFile } from 'fs/promises';
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* import { WASI } from 'wasi';
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* import { argv, env } from 'process';
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*
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* const wasi = new WASI({
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* args: argv,
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* env,
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* preopens: {
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* '/sandbox': '/some/real/path/that/wasm/can/access'
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* }
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* });
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*
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* // Some WASI binaries require:
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* // const importObject = { wasi_unstable: wasi.wasiImport };
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* const importObject = { wasi_snapshot_preview1: wasi.wasiImport };
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*
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* const wasm = await WebAssembly.compile(
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* await readFile(new URL('./demo.wasm', import.meta.url))
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* );
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* const instance = await WebAssembly.instantiate(wasm, importObject);
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*
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* wasi.start(instance);
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* ```
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*
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* To run the above example, create a new WebAssembly text format file named`demo.wat`:
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*
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* ```text
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* (module
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* ;; Import the required fd_write WASI function which will write the given io vectors to stdout
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* ;; The function signature for fd_write is:
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* ;; (File Descriptor, *iovs, iovs_len, nwritten) -> Returns number of bytes written
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* (import "wasi_snapshot_preview1" "fd_write" (func $fd_write (param i32 i32 i32 i32) (result i32)))
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*
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* (memory 1)
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* (export "memory" (memory 0))
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*
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* ;; Write 'hello world\n' to memory at an offset of 8 bytes
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* ;; Note the trailing newline which is required for the text to appear
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* (data (i32.const 8) "hello world\n")
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*
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* (func $main (export "_start")
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* ;; Creating a new io vector within linear memory
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* (i32.store (i32.const 0) (i32.const 8)) ;; iov.iov_base - This is a pointer to the start of the 'hello world\n' string
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* (i32.store (i32.const 4) (i32.const 12)) ;; iov.iov_len - The length of the 'hello world\n' string
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*
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* (call $fd_write
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* (i32.const 1) ;; file_descriptor - 1 for stdout
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* (i32.const 0) ;; *iovs - The pointer to the iov array, which is stored at memory location 0
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* (i32.const 1) ;; iovs_len - We're printing 1 string stored in an iov - so one.
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* (i32.const 20) ;; nwritten - A place in memory to store the number of bytes written
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* )
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* drop ;; Discard the number of bytes written from the top of the stack
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* )
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* )
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* ```
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*
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* Use [wabt](https://github.com/WebAssembly/wabt) to compile `.wat` to `.wasm`
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*
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* ```console
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* $ wat2wasm demo.wat
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* ```
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*
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* The `--experimental-wasi-unstable-preview1` CLI argument is needed for this
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* example to run.
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* @experimental
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* @see [source](https://github.com/nodejs/node/blob/v17.0.0/lib/wasi.js)
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*/
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declare module 'wasi' {
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interface WASIOptions {
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/**
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* An array of strings that the WebAssembly application will
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* see as command line arguments. The first argument is the virtual path to the
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* WASI command itself.
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*/
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args?: string[] | undefined;
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/**
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* An object similar to `process.env` that the WebAssembly
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* application will see as its environment.
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*/
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env?: object | undefined;
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/**
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* This object represents the WebAssembly application's
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* sandbox directory structure. The string keys of `preopens` are treated as
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* directories within the sandbox. The corresponding values in `preopens` are
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* the real paths to those directories on the host machine.
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*/
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preopens?: NodeJS.Dict<string> | undefined;
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/**
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* By default, WASI applications terminate the Node.js
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* process via the `__wasi_proc_exit()` function. Setting this option to `true`
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* causes `wasi.start()` to return the exit code rather than terminate the
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* process.
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* @default false
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*/
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returnOnExit?: boolean | undefined;
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/**
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* The file descriptor used as standard input in the WebAssembly application.
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* @default 0
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*/
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stdin?: number | undefined;
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/**
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* The file descriptor used as standard output in the WebAssembly application.
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* @default 1
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*/
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stdout?: number | undefined;
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/**
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* The file descriptor used as standard error in the WebAssembly application.
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* @default 2
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*/
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stderr?: number | undefined;
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}
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/**
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* The `WASI` class provides the WASI system call API and additional convenience
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* methods for working with WASI-based applications. Each `WASI` instance
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* represents a distinct sandbox environment. For security purposes, each `WASI`instance must have its command-line arguments, environment variables, and
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* sandbox directory structure configured explicitly.
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* @since v13.3.0, v12.16.0
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*/
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class WASI {
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constructor(options?: WASIOptions);
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/**
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* Attempt to begin execution of `instance` as a WASI command by invoking its`_start()` export. If `instance` does not contain a `_start()` export, or if`instance` contains an `_initialize()`
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* export, then an exception is thrown.
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*
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* `start()` requires that `instance` exports a [`WebAssembly.Memory`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WebAssembly/Memory) named`memory`. If
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* `instance` does not have a `memory` export an exception is thrown.
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*
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* If `start()` is called more than once, an exception is thrown.
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* @since v13.3.0, v12.16.0
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*/
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start(instance: object): void; // TODO: avoid DOM dependency until WASM moved to own lib.
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/**
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* Attempt to initialize `instance` as a WASI reactor by invoking its`_initialize()` export, if it is present. If `instance` contains a `_start()`export, then an exception is thrown.
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*
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* `initialize()` requires that `instance` exports a [`WebAssembly.Memory`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WebAssembly/Memory) named`memory`.
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* If `instance` does not have a `memory` export an exception is thrown.
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*
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* If `initialize()` is called more than once, an exception is thrown.
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* @since v14.6.0, v12.19.0
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*/
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initialize(instance: object): void; // TODO: avoid DOM dependency until WASM moved to own lib.
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/**
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* `wasiImport` is an object that implements the WASI system call API. This object
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* should be passed as the `wasi_snapshot_preview1` import during the instantiation
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* of a [`WebAssembly.Instance`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WebAssembly/Instance).
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* @since v13.3.0, v12.16.0
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*/
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readonly wasiImport: NodeJS.Dict<any>; // TODO: Narrow to DOM types
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}
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}
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declare module 'node:wasi' {
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export * from 'wasi';
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}
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