diff --git a/lib/std/fs/test.zig b/lib/std/fs/test.zig
index 98fef1b2ce..546435f4ab 100644
--- a/lib/std/fs/test.zig
+++ b/lib/std/fs/test.zig
@@ -320,14 +320,8 @@ test "accessAbsolute" {
     var tmp = tmpDir(.{});
     defer tmp.cleanup();
 
-    var arena = ArenaAllocator.init(testing.allocator);
-    defer arena.deinit();
-    const allocator = arena.allocator();
-
-    const base_path = blk: {
-        const relative_path = try fs.path.join(allocator, &.{ ".zig-cache", "tmp", tmp.sub_path[0..] });
-        break :blk try fs.realpathAlloc(allocator, relative_path);
-    };
+    const base_path = try tmp.dir.realpathAlloc(testing.allocator, ".");
+    defer testing.allocator.free(base_path);
 
     try fs.accessAbsolute(base_path, .{});
 }
@@ -338,25 +332,52 @@ test "openDirAbsolute" {
     var tmp = tmpDir(.{});
     defer tmp.cleanup();
 
-    try tmp.dir.makeDir("subdir");
-    var arena = ArenaAllocator.init(testing.allocator);
-    defer arena.deinit();
-    const allocator = arena.allocator();
+    const tmp_ino = (try tmp.dir.stat()).inode;
 
-    const base_path = blk: {
-        const relative_path = try fs.path.join(allocator, &.{ ".zig-cache", "tmp", tmp.sub_path[0..], "subdir" });
-        break :blk try fs.realpathAlloc(allocator, relative_path);
-    };
+    try tmp.dir.makeDir("subdir");
+    const sub_path = try tmp.dir.realpathAlloc(testing.allocator, "subdir");
+    defer testing.allocator.free(sub_path);
+
+    // Can open sub_path
+    var tmp_sub = try fs.openDirAbsolute(sub_path, .{});
+    defer tmp_sub.close();
+
+    const sub_ino = (try tmp_sub.stat()).inode;
 
     {
-        var dir = try fs.openDirAbsolute(base_path, .{});
-        defer dir.close();
-    }
+        // Can open sub_path + ".."
+        const dir_path = try fs.path.join(testing.allocator, &.{ sub_path, ".." });
+        defer testing.allocator.free(dir_path);
 
-    for ([_][]const u8{ ".", ".." }) |sub_path| {
-        const dir_path = try fs.path.join(allocator, &.{ base_path, sub_path });
         var dir = try fs.openDirAbsolute(dir_path, .{});
         defer dir.close();
+
+        const ino = (try dir.stat()).inode;
+        try testing.expectEqual(tmp_ino, ino);
+    }
+
+    {
+        // Can open sub_path + "."
+        const dir_path = try fs.path.join(testing.allocator, &.{ sub_path, "." });
+        defer testing.allocator.free(dir_path);
+
+        var dir = try fs.openDirAbsolute(dir_path, .{});
+        defer dir.close();
+
+        const ino = (try dir.stat()).inode;
+        try testing.expectEqual(sub_ino, ino);
+    }
+
+    {
+        // Can open subdir + "..", with some extra "."
+        const dir_path = try fs.path.join(testing.allocator, &.{ sub_path, ".", "..", "." });
+        defer testing.allocator.free(dir_path);
+
+        var dir = try fs.openDirAbsolute(dir_path, .{});
+        defer dir.close();
+
+        const ino = (try dir.stat()).inode;
+        try testing.expectEqual(tmp_ino, ino);
     }
 }
 
@@ -409,10 +430,7 @@ test "readLinkAbsolute" {
     defer arena.deinit();
     const allocator = arena.allocator();
 
-    const base_path = blk: {
-        const relative_path = try fs.path.join(allocator, &.{ ".zig-cache", "tmp", tmp.sub_path[0..] });
-        break :blk try fs.realpathAlloc(allocator, relative_path);
-    };
+    const base_path = try tmp.dir.realpathAlloc(allocator, ".");
 
     {
         const target_path = try fs.path.join(allocator, &.{ base_path, "file.txt" });
@@ -748,7 +766,6 @@ test "directory operations on files" {
 test "file operations on directories" {
     // TODO: fix this test on FreeBSD. https://github.com/ziglang/zig/issues/1759
     if (native_os == .freebsd) return error.SkipZigTest;
-    if (native_os == .wasi and builtin.link_libc) return error.SkipZigTest; // https://github.com/ziglang/zig/issues/20747
 
     try testWithAllSupportedPathTypes(struct {
         fn impl(ctx: *TestContext) !void {
@@ -759,18 +776,30 @@ test "file operations on directories" {
             try testing.expectError(error.IsDir, ctx.dir.createFile(test_dir_name, .{}));
             try testing.expectError(error.IsDir, ctx.dir.deleteFile(test_dir_name));
             switch (native_os) {
-                // no error when reading a directory.
-                .dragonfly, .netbsd => {},
-                // Currently, WASI will return error.Unexpected (via ENOTCAPABLE) when attempting fd_read on a directory handle.
-                // TODO: Re-enable on WASI once https://github.com/bytecodealliance/wasmtime/issues/1935 is resolved.
-                .wasi => {},
+                .dragonfly, .netbsd => {
+                    // no error when reading a directory. See https://github.com/ziglang/zig/issues/5732
+                    const buf = try ctx.dir.readFileAlloc(testing.allocator, test_dir_name, std.math.maxInt(usize));
+                    testing.allocator.free(buf);
+                },
+                .wasi => {
+                    // WASI return EBADF, which gets mapped to NotOpenForReading.
+                    // See https://github.com/bytecodealliance/wasmtime/issues/1935
+                    try testing.expectError(error.NotOpenForReading, ctx.dir.readFileAlloc(testing.allocator, test_dir_name, std.math.maxInt(usize)));
+                },
                 else => {
                     try testing.expectError(error.IsDir, ctx.dir.readFileAlloc(testing.allocator, test_dir_name, std.math.maxInt(usize)));
                 },
             }
-            // Note: The `.mode = .read_write` is necessary to ensure the error occurs on all platforms.
-            // TODO: Add a read-only test as well, see https://github.com/ziglang/zig/issues/5732
-            try testing.expectError(error.IsDir, ctx.dir.openFile(test_dir_name, .{ .mode = .read_write }));
+
+            if (native_os == .wasi and builtin.link_libc) {
+                // wasmtime unexpectedly succeeds here, see https://github.com/ziglang/zig/issues/20747
+                const handle = try ctx.dir.openFile(test_dir_name, .{ .mode = .read_write });
+                handle.close();
+            } else {
+                // Note: The `.mode = .read_write` is necessary to ensure the error occurs on all platforms.
+                // TODO: Add a read-only test as well, see https://github.com/ziglang/zig/issues/5732
+                try testing.expectError(error.IsDir, ctx.dir.openFile(test_dir_name, .{ .mode = .read_write }));
+            }
 
             if (ctx.path_type == .absolute and comptime PathType.absolute.isSupported(builtin.os)) {
                 try testing.expectError(error.IsDir, fs.createFileAbsolute(test_dir_name, .{}));
@@ -993,10 +1022,7 @@ test "renameAbsolute" {
     defer arena.deinit();
     const allocator = arena.allocator();
 
-    const base_path = blk: {
-        const relative_path = try fs.path.join(allocator, &.{ ".zig-cache", "tmp", tmp_dir.sub_path[0..] });
-        break :blk try fs.realpathAlloc(allocator, relative_path);
-    };
+    const base_path = try tmp_dir.dir.realpathAlloc(allocator, ".");
 
     try testing.expectError(error.FileNotFound, fs.renameAbsolute(
         try fs.path.join(allocator, &.{ base_path, "missing_file_name" }),
@@ -1386,7 +1412,6 @@ test "sendfile" {
     defer tmp.cleanup();
 
     try tmp.dir.makePath("os_test_tmp");
-    defer tmp.dir.deleteTree("os_test_tmp") catch {};
 
     var dir = try tmp.dir.openDir("os_test_tmp", .{});
     defer dir.close();
@@ -1451,7 +1476,6 @@ test "copyRangeAll" {
     defer tmp.cleanup();
 
     try tmp.dir.makePath("os_test_tmp");
-    defer tmp.dir.deleteTree("os_test_tmp") catch {};
 
     var dir = try tmp.dir.openDir("os_test_tmp", .{});
     defer dir.close();
@@ -1800,10 +1824,7 @@ test "'.' and '..' in absolute functions" {
     defer arena.deinit();
     const allocator = arena.allocator();
 
-    const base_path = blk: {
-        const relative_path = try fs.path.join(allocator, &.{ ".zig-cache", "tmp", tmp.sub_path[0..] });
-        break :blk try fs.realpathAlloc(allocator, relative_path);
-    };
+    const base_path = try tmp.dir.realpathAlloc(allocator, ".");
 
     const subdir_path = try fs.path.join(allocator, &.{ base_path, "./subdir" });
     try fs.makeDirAbsolute(subdir_path);
diff --git a/lib/std/io/test.zig b/lib/std/io/test.zig
index 6505fcd4fa..523b25c9c8 100644
--- a/lib/std/io/test.zig
+++ b/lib/std/io/test.zig
@@ -108,10 +108,7 @@ test "File seek ops" {
 
     const tmp_file_name = "temp_test_file.txt";
     var file = try tmp.dir.createFile(tmp_file_name, .{});
-    defer {
-        file.close();
-        tmp.dir.deleteFile(tmp_file_name) catch {};
-    }
+    defer file.close();
 
     try file.writeAll(&([_]u8{0x55} ** 8192));
 
@@ -135,10 +132,7 @@ test "setEndPos" {
 
     const tmp_file_name = "temp_test_file.txt";
     var file = try tmp.dir.createFile(tmp_file_name, .{});
-    defer {
-        file.close();
-        tmp.dir.deleteFile(tmp_file_name) catch {};
-    }
+    defer file.close();
 
     // Verify that the file size changes and the file offset is not moved
     try std.testing.expect((try file.getEndPos()) == 0);
@@ -161,10 +155,8 @@ test "updateTimes" {
 
     const tmp_file_name = "just_a_temporary_file.txt";
     var file = try tmp.dir.createFile(tmp_file_name, .{ .read = true });
-    defer {
-        file.close();
-        tmp.dir.deleteFile(tmp_file_name) catch {};
-    }
+    defer file.close();
+
     const stat_old = try file.stat();
     // Set atime and mtime to 5s before
     try file.updateTimes(
diff --git a/lib/std/posix/test.zig b/lib/std/posix/test.zig
index 29756cae69..9678bfb261 100644
--- a/lib/std/posix/test.zig
+++ b/lib/std/posix/test.zig
@@ -8,7 +8,6 @@ const io = std.io;
 const fs = std.fs;
 const mem = std.mem;
 const elf = std.elf;
-const File = std.fs.File;
 const Thread = std.Thread;
 const linux = std.os.linux;
 
@@ -19,8 +18,6 @@ const AtomicRmwOp = std.builtin.AtomicRmwOp;
 const AtomicOrder = std.builtin.AtomicOrder;
 const native_os = builtin.target.os.tag;
 const tmpDir = std.testing.tmpDir;
-const Dir = std.fs.Dir;
-const ArenaAllocator = std.heap.ArenaAllocator;
 
 // https://github.com/ziglang/zig/issues/20288
 test "WTF-8 to WTF-16 conversion buffer overflows" {
@@ -115,50 +112,62 @@ test "open smoke test" {
     var tmp = tmpDir(.{});
     defer tmp.cleanup();
 
-    // Get base abs path
-    var arena = ArenaAllocator.init(testing.allocator);
-    defer arena.deinit();
-    const allocator = arena.allocator();
+    const base_path = try tmp.dir.realpathAlloc(a, ".");
+    defer a.free(base_path);
 
-    const base_path = blk: {
-        const relative_path = try fs.path.join(allocator, &[_][]const u8{ ".zig-cache", "tmp", tmp.sub_path[0..] });
-        break :blk try fs.realpathAlloc(allocator, relative_path);
-    };
-
-    var file_path: []u8 = undefined;
-    var fd: posix.fd_t = undefined;
     const mode: posix.mode_t = if (native_os == .windows) 0 else 0o666;
 
-    // Create some file using `open`.
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_file" });
-    fd = try posix.open(file_path, .{ .ACCMODE = .RDWR, .CREAT = true, .EXCL = true }, mode);
-    posix.close(fd);
+    {
+        // Create some file using `open`.
+        const file_path = try fs.path.join(a, &.{ base_path, "some_file" });
+        defer a.free(file_path);
+        const fd = try posix.open(file_path, .{ .ACCMODE = .RDWR, .CREAT = true, .EXCL = true }, mode);
+        posix.close(fd);
+    }
 
-    // Try this again with the same flags. This op should fail with error.PathAlreadyExists.
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_file" });
-    try expectError(error.PathAlreadyExists, posix.open(file_path, .{ .ACCMODE = .RDWR, .CREAT = true, .EXCL = true }, mode));
+    {
+        // Try this again with the same flags. This op should fail with error.PathAlreadyExists.
+        const file_path = try fs.path.join(a, &.{ base_path, "some_file" });
+        defer a.free(file_path);
+        try expectError(error.PathAlreadyExists, posix.open(file_path, .{ .ACCMODE = .RDWR, .CREAT = true, .EXCL = true }, mode));
+    }
 
-    // Try opening without `EXCL` flag.
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_file" });
-    fd = try posix.open(file_path, .{ .ACCMODE = .RDWR, .CREAT = true }, mode);
-    posix.close(fd);
+    {
+        // Try opening without `EXCL` flag.
+        const file_path = try fs.path.join(a, &.{ base_path, "some_file" });
+        defer a.free(file_path);
+        const fd = try posix.open(file_path, .{ .ACCMODE = .RDWR, .CREAT = true }, mode);
+        posix.close(fd);
+    }
 
-    // Try opening as a directory which should fail.
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_file" });
-    try expectError(error.NotDir, posix.open(file_path, .{ .ACCMODE = .RDWR, .DIRECTORY = true }, mode));
+    {
+        // Try opening as a directory which should fail.
+        const file_path = try fs.path.join(a, &.{ base_path, "some_file" });
+        defer a.free(file_path);
+        try expectError(error.NotDir, posix.open(file_path, .{ .ACCMODE = .RDWR, .DIRECTORY = true }, mode));
+    }
 
-    // Create some directory
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_dir" });
-    try posix.mkdir(file_path, mode);
+    {
+        // Create some directory
+        const file_path = try fs.path.join(a, &.{ base_path, "some_dir" });
+        defer a.free(file_path);
+        try posix.mkdir(file_path, mode);
+    }
 
-    // Open dir using `open`
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_dir" });
-    fd = try posix.open(file_path, .{ .ACCMODE = .RDONLY, .DIRECTORY = true }, mode);
-    posix.close(fd);
+    {
+        // Open dir using `open`
+        const file_path = try fs.path.join(a, &.{ base_path, "some_dir" });
+        defer a.free(file_path);
+        const fd = try posix.open(file_path, .{ .ACCMODE = .RDONLY, .DIRECTORY = true }, mode);
+        posix.close(fd);
+    }
 
-    // Try opening as file which should fail.
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_dir" });
-    try expectError(error.IsDir, posix.open(file_path, .{ .ACCMODE = .RDWR }, mode));
+    {
+        // Try opening as file which should fail.
+        const file_path = try fs.path.join(a, &.{ base_path, "some_dir" });
+        defer a.free(file_path);
+        try expectError(error.IsDir, posix.open(file_path, .{ .ACCMODE = .RDWR }, mode));
+    }
 }
 
 test "openat smoke test" {
@@ -705,8 +714,6 @@ test "mmap" {
             try testing.expectEqual(i, try stream.readInt(u32, .little));
         }
     }
-
-    try tmp.dir.deleteFile(test_out_file);
 }
 
 test "getenv" {
@@ -732,10 +739,7 @@ test "fcntl" {
     const test_out_file = "os_tmp_test";
 
     const file = try tmp.dir.createFile(test_out_file, .{});
-    defer {
-        file.close();
-        tmp.dir.deleteFile(test_out_file) catch {};
-    }
+    defer file.close();
 
     // Note: The test assumes createFile opens the file with CLOEXEC
     {
@@ -771,10 +775,7 @@ test "sync" {
 
     const test_out_file = "os_tmp_test";
     const file = try tmp.dir.createFile(test_out_file, .{});
-    defer {
-        file.close();
-        tmp.dir.deleteFile(test_out_file) catch {};
-    }
+    defer file.close();
 
     posix.sync();
     try posix.syncfs(file.handle);
@@ -791,10 +792,7 @@ test "fsync" {
 
     const test_out_file = "os_tmp_test";
     const file = try tmp.dir.createFile(test_out_file, .{});
-    defer {
-        file.close();
-        tmp.dir.deleteFile(test_out_file) catch {};
-    }
+    defer file.close();
 
     try posix.fsync(file.handle);
     try posix.fdatasync(file.handle);
@@ -1041,54 +1039,65 @@ test "rename smoke test" {
     var tmp = tmpDir(.{});
     defer tmp.cleanup();
 
-    // Get base abs path
-    var arena = ArenaAllocator.init(testing.allocator);
-    defer arena.deinit();
-    const allocator = arena.allocator();
+    const base_path = try tmp.dir.realpathAlloc(a, ".");
+    defer a.free(base_path);
 
-    const base_path = blk: {
-        const relative_path = try fs.path.join(allocator, &[_][]const u8{ ".zig-cache", "tmp", tmp.sub_path[0..] });
-        break :blk try fs.realpathAlloc(allocator, relative_path);
-    };
-
-    var file_path: []u8 = undefined;
-    var fd: posix.fd_t = undefined;
     const mode: posix.mode_t = if (native_os == .windows) 0 else 0o666;
 
-    // Create some file using `open`.
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_file" });
-    fd = try posix.open(file_path, .{ .ACCMODE = .RDWR, .CREAT = true, .EXCL = true }, mode);
-    posix.close(fd);
+    {
+        // Create some file using `open`.
+        const file_path = try fs.path.join(a, &.{ base_path, "some_file" });
+        defer a.free(file_path);
+        const fd = try posix.open(file_path, .{ .ACCMODE = .RDWR, .CREAT = true, .EXCL = true }, mode);
+        posix.close(fd);
 
-    // Rename the file
-    var new_file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_other_file" });
-    try posix.rename(file_path, new_file_path);
+        // Rename the file
+        const new_file_path = try fs.path.join(a, &.{ base_path, "some_other_file" });
+        defer a.free(new_file_path);
+        try posix.rename(file_path, new_file_path);
+    }
 
-    // Try opening renamed file
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_other_file" });
-    fd = try posix.open(file_path, .{ .ACCMODE = .RDWR }, mode);
-    posix.close(fd);
+    {
+        // Try opening renamed file
+        const file_path = try fs.path.join(a, &.{ base_path, "some_other_file" });
+        defer a.free(file_path);
+        const fd = try posix.open(file_path, .{ .ACCMODE = .RDWR }, mode);
+        posix.close(fd);
+    }
 
-    // Try opening original file - should fail with error.FileNotFound
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_file" });
-    try expectError(error.FileNotFound, posix.open(file_path, .{ .ACCMODE = .RDWR }, mode));
+    {
+        // Try opening original file - should fail with error.FileNotFound
+        const file_path = try fs.path.join(a, &.{ base_path, "some_file" });
+        defer a.free(file_path);
+        try expectError(error.FileNotFound, posix.open(file_path, .{ .ACCMODE = .RDWR }, mode));
+    }
 
-    // Create some directory
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_dir" });
-    try posix.mkdir(file_path, mode);
+    {
+        // Create some directory
+        const file_path = try fs.path.join(a, &.{ base_path, "some_dir" });
+        defer a.free(file_path);
+        try posix.mkdir(file_path, mode);
 
-    // Rename the directory
-    new_file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_other_dir" });
-    try posix.rename(file_path, new_file_path);
+        // Rename the directory
+        const new_file_path = try fs.path.join(a, &.{ base_path, "some_other_dir" });
+        defer a.free(new_file_path);
+        try posix.rename(file_path, new_file_path);
+    }
 
-    // Try opening renamed directory
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_other_dir" });
-    fd = try posix.open(file_path, .{ .ACCMODE = .RDONLY, .DIRECTORY = true }, mode);
-    posix.close(fd);
+    {
+        // Try opening renamed directory
+        const file_path = try fs.path.join(a, &.{ base_path, "some_other_dir" });
+        defer a.free(file_path);
+        const fd = try posix.open(file_path, .{ .ACCMODE = .RDONLY, .DIRECTORY = true }, mode);
+        posix.close(fd);
+    }
 
-    // Try opening original directory - should fail with error.FileNotFound
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_dir" });
-    try expectError(error.FileNotFound, posix.open(file_path, .{ .ACCMODE = .RDONLY, .DIRECTORY = true }, mode));
+    {
+        // Try opening original directory - should fail with error.FileNotFound
+        const file_path = try fs.path.join(a, &.{ base_path, "some_dir" });
+        defer a.free(file_path);
+        try expectError(error.FileNotFound, posix.open(file_path, .{ .ACCMODE = .RDONLY, .DIRECTORY = true }, mode));
+    }
 }
 
 test "access smoke test" {
@@ -1098,44 +1107,50 @@ test "access smoke test" {
     var tmp = tmpDir(.{});
     defer tmp.cleanup();
 
-    // Get base abs path
-    var arena = ArenaAllocator.init(testing.allocator);
-    defer arena.deinit();
-    const allocator = arena.allocator();
+    const base_path = try tmp.dir.realpathAlloc(a, ".");
+    defer a.free(base_path);
 
-    const base_path = blk: {
-        const relative_path = try fs.path.join(allocator, &[_][]const u8{ ".zig-cache", "tmp", tmp.sub_path[0..] });
-        break :blk try fs.realpathAlloc(allocator, relative_path);
-    };
-
-    var file_path: []u8 = undefined;
-    var fd: posix.fd_t = undefined;
     const mode: posix.mode_t = if (native_os == .windows) 0 else 0o666;
-
-    // Create some file using `open`.
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_file" });
-    fd = try posix.open(file_path, .{ .ACCMODE = .RDWR, .CREAT = true, .EXCL = true }, mode);
-    posix.close(fd);
-
-    // Try to access() the file
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_file" });
-    if (native_os == .windows) {
-        try posix.access(file_path, posix.F_OK);
-    } else {
-        try posix.access(file_path, posix.F_OK | posix.W_OK | posix.R_OK);
+    {
+        // Create some file using `open`.
+        const file_path = try fs.path.join(a, &.{ base_path, "some_file" });
+        defer a.free(file_path);
+        const fd = try posix.open(file_path, .{ .ACCMODE = .RDWR, .CREAT = true, .EXCL = true }, mode);
+        posix.close(fd);
     }
 
-    // Try to access() a non-existent file - should fail with error.FileNotFound
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_other_file" });
-    try expectError(error.FileNotFound, posix.access(file_path, posix.F_OK));
+    {
+        // Try to access() the file
+        const file_path = try fs.path.join(a, &.{ base_path, "some_file" });
+        defer a.free(file_path);
+        if (native_os == .windows) {
+            try posix.access(file_path, posix.F_OK);
+        } else {
+            try posix.access(file_path, posix.F_OK | posix.W_OK | posix.R_OK);
+        }
+    }
 
-    // Create some directory
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_dir" });
-    try posix.mkdir(file_path, mode);
+    {
+        // Try to access() a non-existent file - should fail with error.FileNotFound
+        const file_path = try fs.path.join(a, &.{ base_path, "some_other_file" });
+        defer a.free(file_path);
+        try expectError(error.FileNotFound, posix.access(file_path, posix.F_OK));
+    }
 
-    // Try to access() the directory
-    file_path = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_dir" });
-    try posix.access(file_path, posix.F_OK);
+    {
+        // Create some directory
+        const file_path = try fs.path.join(a, &.{ base_path, "some_dir" });
+        defer a.free(file_path);
+        try posix.mkdir(file_path, mode);
+    }
+
+    {
+        // Try to access() the directory
+        const file_path = try fs.path.join(a, &.{ base_path, "some_dir" });
+        defer a.free(file_path);
+
+        try posix.access(file_path, posix.F_OK);
+    }
 }
 
 test "timerfd" {
@@ -1167,103 +1182,59 @@ test "isatty" {
 }
 
 test "read with empty buffer" {
-    if (native_os == .wasi) return error.SkipZigTest;
-
     var tmp = tmpDir(.{});
     defer tmp.cleanup();
 
-    var arena = ArenaAllocator.init(testing.allocator);
-    defer arena.deinit();
-    const allocator = arena.allocator();
-
-    // Get base abs path
-    const base_path = blk: {
-        const relative_path = try fs.path.join(allocator, &[_][]const u8{ ".zig-cache", "tmp", tmp.sub_path[0..] });
-        break :blk try fs.realpathAlloc(allocator, relative_path);
-    };
-
-    const file_path: []u8 = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_file" });
-    var file = try fs.cwd().createFile(file_path, .{ .read = true });
+    var file = try tmp.dir.createFile("read_empty", .{ .read = true });
     defer file.close();
 
-    const bytes = try allocator.alloc(u8, 0);
+    const bytes = try a.alloc(u8, 0);
+    defer a.free(bytes);
 
-    _ = try posix.read(file.handle, bytes);
+    const rc = try posix.read(file.handle, bytes);
+    try expectEqual(rc, 0);
 }
 
 test "pread with empty buffer" {
-    if (native_os == .wasi) return error.SkipZigTest;
-
     var tmp = tmpDir(.{});
     defer tmp.cleanup();
 
-    var arena = ArenaAllocator.init(testing.allocator);
-    defer arena.deinit();
-    const allocator = arena.allocator();
-
-    // Get base abs path
-    const base_path = blk: {
-        const relative_path = try fs.path.join(allocator, &[_][]const u8{ ".zig-cache", "tmp", tmp.sub_path[0..] });
-        break :blk try fs.realpathAlloc(allocator, relative_path);
-    };
-
-    const file_path: []u8 = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_file" });
-    var file = try fs.cwd().createFile(file_path, .{ .read = true });
+    var file = try tmp.dir.createFile("pread_empty", .{ .read = true });
     defer file.close();
 
-    const bytes = try allocator.alloc(u8, 0);
+    const bytes = try a.alloc(u8, 0);
+    defer a.free(bytes);
 
-    _ = try posix.pread(file.handle, bytes, 0);
+    const rc = try posix.pread(file.handle, bytes, 0);
+    try expectEqual(rc, 0);
 }
 
 test "write with empty buffer" {
-    if (native_os == .wasi) return error.SkipZigTest;
-
     var tmp = tmpDir(.{});
     defer tmp.cleanup();
 
-    var arena = ArenaAllocator.init(testing.allocator);
-    defer arena.deinit();
-    const allocator = arena.allocator();
-
-    // Get base abs path
-    const base_path = blk: {
-        const relative_path = try fs.path.join(allocator, &[_][]const u8{ ".zig-cache", "tmp", tmp.sub_path[0..] });
-        break :blk try fs.realpathAlloc(allocator, relative_path);
-    };
-
-    const file_path: []u8 = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_file" });
-    var file = try fs.cwd().createFile(file_path, .{});
+    var file = try tmp.dir.createFile("write_empty", .{});
     defer file.close();
 
-    const bytes = try allocator.alloc(u8, 0);
+    const bytes = try a.alloc(u8, 0);
+    defer a.free(bytes);
 
-    _ = try posix.write(file.handle, bytes);
+    const rc = try posix.write(file.handle, bytes);
+    try expectEqual(rc, 0);
 }
 
 test "pwrite with empty buffer" {
-    if (native_os == .wasi) return error.SkipZigTest;
-
     var tmp = tmpDir(.{});
     defer tmp.cleanup();
 
-    var arena = ArenaAllocator.init(testing.allocator);
-    defer arena.deinit();
-    const allocator = arena.allocator();
-
-    // Get base abs path
-    const base_path = blk: {
-        const relative_path = try fs.path.join(allocator, &[_][]const u8{ ".zig-cache", "tmp", tmp.sub_path[0..] });
-        break :blk try fs.realpathAlloc(allocator, relative_path);
-    };
-
-    const file_path: []u8 = try fs.path.join(allocator, &[_][]const u8{ base_path, "some_file" });
-    var file = try fs.cwd().createFile(file_path, .{});
+    var file = try tmp.dir.createFile("pwrite_empty", .{});
     defer file.close();
 
-    const bytes = try allocator.alloc(u8, 0);
+    const bytes = try a.alloc(u8, 0);
+    defer a.free(bytes);
 
-    _ = try posix.pwrite(file.handle, bytes, 0);
+    const rc = try posix.pwrite(file.handle, bytes, 0);
+    try expectEqual(rc, 0);
 }
 
 fn expectMode(dir: posix.fd_t, file: []const u8, mode: posix.mode_t) !void {