improve shebang script writing

src/install/install.zig

@@ -2592,22 +2592,30 @@ pub const PackageManager = struct {
         };
         defer node_gyp_file.close();
 
-        var bytes: string = switch (Environment.os) {
-            else => "#!/usr/bin/env node\nrequire(\"child_process\").spawnSync(\"bun\",[\"x\",\"node-gyp\",...process.argv.slice(2)],{stdio:\"inherit\"})",
-            .windows => "@node -e \"require('child_process').spawnSync('bun',['x','node-gyp',...process.argv.slice(2)],{stdio:'inherit'})\"",
+        const shebang = switch (Environment.os) {
+            .windows =>
+            \\0</* :{
+            \\  @echo off
+            \\  node %~f0 %*
+            \\  exit /b %errorlevel%
+            \\:} */0;
+            \\
+            ,
+            else =>
+            \\#!/usr/bin/env node
+            \\
+            ,
+        };
+        const content =
+            \\const child_process = require("child_process");
+            \\child_process.spawnSync("bun", ["x", "node-gyp", ...process.argv.slice(2)], { stdio: "inherit" });
+            \\
+        ;
+
+        node_gyp_file.writeAll(shebang ++ content) catch |err| {
+            Output.prettyErrorln("<r><red>error<r>: <b><red>{s}<r> writing to " ++ file_name ++ " file", .{@errorName(err)});
+            Global.crash();
         };
-        var index: usize = 0;
-        while (index < bytes.len) {
-            switch (bun.sys.write(bun.toFD(node_gyp_file.handle), bytes[index..])) {
-                .result => |written| {
-                    index += written;
-                },
-                .err => |err| {
-                    Output.prettyErrorln("<r><red>error<r>: <b><red>{s}<r> writing to " ++ file_name ++ " file", .{@tagName(err.getErrno())});
-                    Global.crash();
-                },
-            }
-        }
 
         // Add our node-gyp tempdir to the path
         const existing_path = this.env.get("PATH") orelse "";

test/cli/install/registry/bun-install-registry.test.ts

@@ -4447,12 +4447,10 @@ test("it should be able to find binary in node_modules/.bin from parent director
 
   await cp(join(packageDir, "bunfig.toml"), join(packageDir, "morePackageDir", "bunfig.toml"));
 
-  await await writeFile(
+  await writeShebangScript(
     join(packageDir, "node_modules", ".bin", "missing-bin"),
-    `#!/usr/bin/env node
-require("fs").writeFileSync("missing-bin.txt", "missing-bin@WHAT");
-`,
-    { mode: 0o777 },
+    "node",
+    `require("fs").writeFileSync("missing-bin.txt", "missing-bin@WHAT");`,
   );
 
   const { stdout, stderr, exited } = spawn({

test/harness.ts

@@ -1,7 +1,7 @@
 import { gc as bunGC, unsafe, which } from "bun";
 import { describe, test, expect, afterAll, beforeAll } from "bun:test";
-import { readlink, readFile } from "fs/promises";
-import { isAbsolute } from "path";
+import { readlink, readFile, writeFile } from "fs/promises";
+import { isAbsolute, sep } from "path";
 import { openSync, closeSync } from "node:fs";
 
 export const isMacOS = process.platform === "darwin";
@@ -557,3 +557,21 @@ export function toTOMLString(opts: object) {
   }
   return ret;
 }
+
+const shebang_posix = (program: string) => `#!/usr/bin/env ${program}
+`;
+
+const shebang_windows = (program: string) => `0</* :{
+  @echo off
+  ${program} %~f0 %*
+  exit /b %errorlevel%
+:} */0;
+`;
+
+export function writeShebangScript(path: string, program: string, data: string) {
+  if (!isWindows) {
+    return writeFile(path, shebang_posix(program) + "\n" + data, { mode: 0o777 });
+  } else {
+    return writeFile(path + ".cmd", shebang_windows(program) + "\n" + data);
+  }
+}