Fix(bundler): allow generating exe file in nested path. (#4226)

* Fix(bundler): allow generating binary file in nested path.
Close: #4195

* Add read flag for fd.

* refactor

src/c.zig

@@ -116,7 +116,8 @@ pub fn moveFileZWithHandle(from_handle: std.os.fd_t, from_dir: std.os.fd_t, file
     std.os.renameatZ(from_dir, filename, to_dir, destination) catch |err| {
         switch (err) {
             error.RenameAcrossMountPoints => {
-                try moveFileZSlowWithHandle(from_handle, to_dir, destination);
+                try copyFileZSlowWithHandle(from_handle, to_dir, destination);
+                std.os.unlinkatZ(from_dir, filename, 0) catch {};
             },
             else => {
                 return err;
@@ -129,10 +130,12 @@ pub fn moveFileZWithHandle(from_handle: std.os.fd_t, from_dir: std.os.fd_t, file
 // macOS & BSDs will be slow because
 pub fn moveFileZSlow(from_dir: std.os.fd_t, filename: [*:0]const u8, to_dir: std.os.fd_t, destination: [*:0]const u8) !void {
     const in_handle = try std.os.openatZ(from_dir, filename, std.os.O.RDONLY | std.os.O.CLOEXEC, 0o600);
-    try moveFileZSlowWithHandle(in_handle, to_dir, destination);
+    defer std.os.close(in_handle);
+    try copyFileZSlowWithHandle(in_handle, to_dir, destination);
+    std.os.unlinkatZ(from_dir, filename, 0) catch {};
 }
 
-pub fn moveFileZSlowWithHandle(in_handle: std.os.fd_t, to_dir: std.os.fd_t, destination: [*:0]const u8) !void {
+pub fn copyFileZSlowWithHandle(in_handle: std.os.fd_t, to_dir: std.os.fd_t, destination: [*:0]const u8) !void {
     const stat_ = try std.os.fstat(in_handle);
     // delete if exists, don't care if it fails. it may fail due to the file not existing
     // delete here because we run into weird truncation issues if we do not

src/standalone_bun.zig

@@ -257,7 +257,7 @@ pub const StandaloneModuleGraph = struct {
                 // if we're on a mac, use clonefile() if we can
                 // failure is okay, clonefile is just a fast path.
                 if (Syscall.clonefile(self_exeZ, zname) == .result) {
-                    switch (Syscall.open(zname, std.os.O.WRONLY | std.os.O.CLOEXEC, 0)) {
+                    switch (Syscall.open(zname, std.os.O.RDWR | std.os.O.CLOEXEC, 0)) {
                         .result => |res| break :brk res,
                         .err => {},
                     }
@@ -269,7 +269,7 @@ pub const StandaloneModuleGraph = struct {
             const fd = brk2: {
                 var tried_changing_abs_dir = false;
                 for (0..3) |retry| {
-                    switch (Syscall.open(zname, std.os.O.CLOEXEC | std.os.O.WRONLY | std.os.O.CREAT, 0)) {
+                    switch (Syscall.open(zname, std.os.O.CLOEXEC | std.os.O.RDWR | std.os.O.CREAT, 0)) {
                         .result => |res| break :brk2 res,
                         .err => |err| {
                             if (retry < 2) {
@@ -439,7 +439,7 @@ pub const StandaloneModuleGraph = struct {
             std.fs.cwd().fd,
             &(try std.os.toPosixPath(temp_location)),
             root_dir.dir.fd,
-            &(try std.os.toPosixPath(outfile)),
+            &(try std.os.toPosixPath(std.fs.path.basename(outfile))),
         ) catch |err| {
             if (err == error.IsDir) {
                 Output.prettyErrorln("<r><red>error<r><d>:<r> {} is a directory. Please choose a different --outfile or delete the directory", .{bun.fmt.quote(outfile)});

test/bundler/cli.test.ts

@@ -1,6 +1,8 @@
 import { bunEnv, bunExe } from "harness";
-import path from "path";
 import { describe, expect, test } from "bun:test";
+import fs from "node:fs";
+import { tmpdir } from "node:os";
+import path from "node:path";
 
 describe("bun build", () => {
   test("warnings dont return exit code 1", () => {
@@ -13,4 +15,41 @@ describe("bun build", () => {
       'warn: "key" prop before a {...spread} is deprecated in JSX. Falling back to classic runtime.',
     );
   });
+
+  test("generating a standalone binary in nested path, issue #4195", () => {
+    function testCompile(outfile: string) {
+      const { exitCode } = Bun.spawnSync({
+        cmd: [
+          bunExe(),
+          "build",
+          path.join(import.meta.dir, "./fixtures/trivial/index.js"),
+          "--compile",
+          "--outfile",
+          outfile,
+        ],
+        env: bunEnv,
+      });
+      expect(exitCode).toBe(0);
+    }
+    function testExec(outfile: string) {
+      const { exitCode } = Bun.spawnSync({
+        cmd: [outfile],
+      });
+      expect(exitCode).toBe(0);
+    }
+    {
+      const baseDir = `${tmpdir()}/bun-build-outfile-${Date.now()}`;
+      const outfile = path.join(baseDir, "index.exe");
+      testCompile(outfile);
+      testExec(outfile);
+      fs.rmSync(baseDir, { recursive: true, force: true });
+    }
+    {
+      const baseDir = `${tmpdir()}/bun-build-outfile2-${Date.now()}`;
+      const outfile = path.join(baseDir, "b/u/n", "index.exe");
+      testCompile(outfile);
+      testExec(outfile);
+      fs.rmSync(baseDir, { recursive: true, force: true });
+    }
+  });
 });