add wasi runner

src/handlers/index.ts

@@ -72,6 +72,7 @@ import xcursorHandler from "./xcursor.ts";
 import shToElfHandler from "./shToElf.ts";
 import cssHandler from "./css.ts";
 import TypstHandler from "./typst.ts";
+import wasiRunnerHandler from "./wasiRunner.ts";
 
 const handlers: FormatHandler[] = [];
 try { handlers.push(new svgTraceHandler()) } catch (_) { };
@@ -150,5 +151,6 @@ try { handlers.push(new xcursorHandler()) } catch (_) { };
 try { handlers.push(new shToElfHandler()) } catch (_) { };
 try { handlers.push(new cssHandler()) } catch (_) { };
 try { handlers.push(new TypstHandler()) } catch (_) { };
+try { handlers.push(new wasiRunnerHandler()) } catch (_) { };
 
 export default handlers;

src/handlers/wasiRunner.ts

@@ -0,0 +1,61 @@
+// file: wasiRunner.ts
+
+import type { FileData, FileFormat, FormatHandler } from "../FormatHandler.ts";
+import CommonFormats, { Category } from "src/CommonFormats.ts";
+import { WASI, File, OpenFile, ConsoleStdout, PreopenDirectory } from "@bjorn3/browser_wasi_shim";
+
+class wasiRunnerHandler implements FormatHandler {
+
+  public name: string = "wasiRunner";
+  public supportedFormats: FileFormat[] = [
+    {
+      name: "WebAssembly Binary (Wasm)",
+      format: "wasm",
+      extension: "wasm",
+      mime: "application/wasm",
+      from: true,
+      to: false,
+      internal: "wasm",
+      category: Category.CODE,
+      lossless: true,
+    },
+    CommonFormats.TEXT.builder("txt").allowTo()
+  ];
+  public ready: boolean = false;
+
+  async init () {
+    this.ready = true;
+  }
+
+  async doConvert (
+    inputFiles: FileData[],
+    inputFormat: FileFormat,
+    outputFormat: FileFormat
+  ): Promise<FileData[]> {
+    const outputFiles: FileData[] = [];
+    for (const inputFile of inputFiles) {
+      let output: number[] = [];
+      let fds = [
+        new OpenFile(new File([])), // stdin
+        new ConsoleStdout((buffer) => output.push(...buffer)),
+        new ConsoleStdout((buffer) => output.push(...buffer)),
+      ];
+      let wasi = new WASI([inputFile.name], [], fds);
+
+      let wasm = await WebAssembly.compile(new Uint8Array(inputFile.bytes));
+      let inst = await WebAssembly.instantiate(wasm, {
+        "wasi_snapshot_preview1": wasi.wasiImport,
+      }) as any;
+      wasi.start(inst);
+
+      outputFiles.push({
+        name: inputFile.name.replace(/\.[^.]+$/, "") + `.txt`,
+        bytes: new Uint8Array(output)
+      })
+    }
+    return outputFiles;
+  }
+
+}
+
+export default wasiRunnerHandler;