test: std.fs.File -> std.Io.File

43 files changed, 106 insertions, 102 deletions

diff --git a/test/cases/disable_stack_tracing.zig b/test/cases/disable_stack_tracing.zig
index 044eaf7012..5b394beeeb 100644
--- a/test/cases/disable_stack_tracing.zig
+++ b/test/cases/disable_stack_tracing.zig
@@ -5,7 +5,7 @@ pub const std_options: std.Options = .{
 pub fn main() !void {
     var st_buf: [8]usize = undefined;
     var buf: [1024]u8 = undefined;
-    var stdout = std.fs.File.stdout().writer(&buf);
+    var stdout = std.Io.File.stdout().writer(&buf);
 
     const captured_st = try foo(&stdout.interface, &st_buf);
     try std.debug.writeStackTrace(&captured_st, &stdout.interface, .no_color);
diff --git a/test/incremental/add_decl b/test/incremental/add_decl
index 9efd274b9e..031085ca58 100644
--- a/test/incremental/add_decl
+++ b/test/incremental/add_decl
@@ -7,7 +7,7 @@
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(foo);
+    try std.Io.File.stdout().writeAll(foo);
 }
 const foo = "good morning\n";
 #expect_stdout="good morning\n"
@@ -16,7 +16,7 @@ const foo = "good morning\n";
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(foo);
+    try std.Io.File.stdout().writeAll(foo);
 }
 const foo = "good morning\n";
 const bar = "good evening\n";
@@ -26,7 +26,7 @@ const bar = "good evening\n";
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(bar);
+    try std.Io.File.stdout().writeAll(bar);
 }
 const foo = "good morning\n";
 const bar = "good evening\n";
@@ -36,7 +36,7 @@ const bar = "good evening\n";
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(qux);
+    try std.Io.File.stdout().writeAll(qux);
 }
 const foo = "good morning\n";
 const bar = "good evening\n";
@@ -46,7 +46,7 @@ const bar = "good evening\n";
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(qux);
+    try std.Io.File.stdout().writeAll(qux);
 }
 const foo = "good morning\n";
 const bar = "good evening\n";
@@ -57,7 +57,7 @@ const qux = "good night\n";
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(qux);
+    try std.Io.File.stdout().writeAll(qux);
 }
 const qux = "good night\n";
 #expect_stdout="good night\n"
diff --git a/test/incremental/add_decl_namespaced b/test/incremental/add_decl_namespaced
index 1025ae24e1..cbeaf4865e 100644
--- a/test/incremental/add_decl_namespaced
+++ b/test/incremental/add_decl_namespaced
@@ -7,7 +7,7 @@
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(@This().foo);
+    try std.Io.File.stdout().writeAll(@This().foo);
 }
 const foo = "good morning\n";
 #expect_stdout="good morning\n"
@@ -16,7 +16,7 @@ const foo = "good morning\n";
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(@This().foo);
+    try std.Io.File.stdout().writeAll(@This().foo);
 }
 const foo = "good morning\n";
 const bar = "good evening\n";
@@ -26,7 +26,7 @@ const bar = "good evening\n";
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(@This().bar);
+    try std.Io.File.stdout().writeAll(@This().bar);
 }
 const foo = "good morning\n";
 const bar = "good evening\n";
@@ -36,7 +36,7 @@ const bar = "good evening\n";
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(@This().qux);
+    try std.Io.File.stdout().writeAll(@This().qux);
 }
 const foo = "good morning\n";
 const bar = "good evening\n";
@@ -47,7 +47,7 @@ const bar = "good evening\n";
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(@This().qux);
+    try std.Io.File.stdout().writeAll(@This().qux);
 }
 const foo = "good morning\n";
 const bar = "good evening\n";
@@ -58,7 +58,7 @@ const qux = "good night\n";
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(@This().qux);
+    try std.Io.File.stdout().writeAll(@This().qux);
 }
 const qux = "good night\n";
 #expect_stdout="good night\n"
diff --git a/test/incremental/bad_import b/test/incremental/bad_import
index 9b6be8b176..ad66c17b5b 100644
--- a/test/incremental/bad_import
+++ b/test/incremental/bad_import
@@ -8,7 +8,7 @@
 #file=main.zig
 pub fn main() !void {
     _ = @import("foo.zig");
-    try std.fs.File.stdout().writeAll("success\n");
+    try std.Io.File.stdout().writeAll("success\n");
 }
 const std = @import("std");
 #file=foo.zig
@@ -30,7 +30,7 @@ comptime {
 #file=main.zig
 pub fn main() !void {
     //_ = @import("foo.zig");
-    try std.fs.File.stdout().writeAll("success\n");
+    try std.Io.File.stdout().writeAll("success\n");
 }
 const std = @import("std");
 #expect_stdout="success\n"
diff --git a/test/incremental/change_embed_file b/test/incremental/change_embed_file
index 85d861ab93..1eed90dc32 100644
--- a/test/incremental/change_embed_file
+++ b/test/incremental/change_embed_file
@@ -8,7 +8,7 @@
 const std = @import("std");
 const string = @embedFile("string.txt");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(string);
+    try std.Io.File.stdout().writeAll(string);
 }
 #file=string.txt
 Hello, World!
@@ -28,7 +28,7 @@ Hello again, World!
 const std = @import("std");
 const string = @embedFile("string.txt");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll("a hardcoded string\n");
+    try std.Io.File.stdout().writeAll("a hardcoded string\n");
 }
 #expect_stdout="a hardcoded string\n"
 
@@ -37,7 +37,7 @@ pub fn main() !void {
 const std = @import("std");
 const string = @embedFile("string.txt");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(string);
+    try std.Io.File.stdout().writeAll(string);
 }
 #expect_error=main.zig:2:27: error: unable to open 'string.txt': FileNotFound
 
diff --git a/test/incremental/change_enum_tag_type b/test/incremental/change_enum_tag_type
index 906f910271..6e72b3e573 100644
--- a/test/incremental/change_enum_tag_type
+++ b/test/incremental/change_enum_tag_type
@@ -15,7 +15,7 @@ const Foo = enum(Tag) {
 pub fn main() !void {
     var val: Foo = undefined;
     val = .a;
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("{s}\n", .{@tagName(val)});
 }
 const std = @import("std");
@@ -33,7 +33,7 @@ const Foo = enum(Tag) {
 pub fn main() !void {
     var val: Foo = undefined;
     val = .a;
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("{s}\n", .{@tagName(val)});
 }
 comptime {
@@ -56,7 +56,7 @@ const Foo = enum(Tag) {
 pub fn main() !void {
     var val: Foo = undefined;
     val = .a;
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("{s}\n", .{@tagName(val)});
 }
 const std = @import("std");
diff --git a/test/incremental/change_exports b/test/incremental/change_exports
index b0850626d6..0090d45d8e 100644
--- a/test/incremental/change_exports
+++ b/test/incremental/change_exports
@@ -17,7 +17,7 @@ pub fn main() !void {
         extern const bar: u32;
     };
     S.foo();
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("{}\n", .{S.bar});
 }
 const std = @import("std");
@@ -39,7 +39,7 @@ pub fn main() !void {
         extern const other: u32;
     };
     S.foo();
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("{} {}\n", .{ S.bar, S.other });
 }
 const std = @import("std");
@@ -62,7 +62,7 @@ pub fn main() !void {
         extern const other: u32;
     };
     S.foo();
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("{} {}\n", .{ S.bar, S.other });
 }
 const std = @import("std");
@@ -87,7 +87,7 @@ pub fn main() !void {
         extern const other: u32;
     };
     S.foo();
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("{} {}\n", .{ S.bar, S.other });
 }
 const std = @import("std");
@@ -133,7 +133,7 @@ pub fn main() !void {
         extern const other: u32;
     };
     S.foo();
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("{} {}\n", .{ S.bar, S.other });
 }
 const std = @import("std");
@@ -158,7 +158,7 @@ pub fn main() !void {
         extern const other: u32;
     };
     S.foo();
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("{} {}\n", .{ S.bar, S.other });
 }
 const std = @import("std");
diff --git a/test/incremental/change_fn_type b/test/incremental/change_fn_type
index df788684cd..bcf006861a 100644
--- a/test/incremental/change_fn_type
+++ b/test/incremental/change_fn_type
@@ -8,7 +8,7 @@ pub fn main() !void {
     try foo(123);
 }
 fn foo(x: u8) !void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     return stdout_writer.interface.print("{d}\n", .{x});
 }
 const std = @import("std");
@@ -20,7 +20,7 @@ pub fn main() !void {
     try foo(123);
 }
 fn foo(x: i64) !void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     return stdout_writer.interface.print("{d}\n", .{x});
 }
 const std = @import("std");
@@ -32,7 +32,7 @@ pub fn main() !void {
     try foo(-42);
 }
 fn foo(x: i64) !void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     return stdout_writer.interface.print("{d}\n", .{x});
 }
 const std = @import("std");
diff --git a/test/incremental/change_generic_line_number b/test/incremental/change_generic_line_number
index f1920c67e6..252261af66 100644
--- a/test/incremental/change_generic_line_number
+++ b/test/incremental/change_generic_line_number
@@ -7,7 +7,7 @@ const std = @import("std");
 fn Printer(message: []const u8) type {
     return struct {
         fn print() !void {
-            try std.fs.File.stdout().writeAll(message);
+            try std.Io.File.stdout().writeAll(message);
         }
     };
 }
@@ -23,7 +23,7 @@ const std = @import("std");
 fn Printer(message: []const u8) type {
     return struct {
         fn print() !void {
-            try std.fs.File.stdout().writeAll(message);
+            try std.Io.File.stdout().writeAll(message);
         }
     };
 }
diff --git a/test/incremental/change_line_number b/test/incremental/change_line_number
index 5c809b8fa9..a905745e6a 100644
--- a/test/incremental/change_line_number
+++ b/test/incremental/change_line_number
@@ -5,7 +5,7 @@
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll("foo\n");
+    try std.Io.File.stdout().writeAll("foo\n");
 }
 #expect_stdout="foo\n"
 #update=change line number
@@ -13,6 +13,6 @@ pub fn main() !void {
 const std = @import("std");
 
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll("foo\n");
+    try std.Io.File.stdout().writeAll("foo\n");
 }
 #expect_stdout="foo\n"
diff --git a/test/incremental/change_panic_handler b/test/incremental/change_panic_handler
index 070384887a..2fe9240b9b 100644
--- a/test/incremental/change_panic_handler
+++ b/test/incremental/change_panic_handler
@@ -12,7 +12,7 @@ pub fn main() !u8 {
 }
 pub const panic = std.debug.FullPanic(myPanic);
 fn myPanic(msg: []const u8, _: ?usize) noreturn {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     stdout_writer.interface.print("panic message: {s}\n", .{msg}) catch {};
     std.process.exit(0);
 }
@@ -29,7 +29,7 @@ pub fn main() !u8 {
 }
 pub const panic = std.debug.FullPanic(myPanic);
 fn myPanic(msg: []const u8, _: ?usize) noreturn {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     stdout_writer.interface.print("new panic message: {s}\n", .{msg}) catch {};
     std.process.exit(0);
 }
@@ -46,7 +46,7 @@ pub fn main() !u8 {
 }
 pub const panic = std.debug.FullPanic(myPanicNew);
 fn myPanicNew(msg: []const u8, _: ?usize) noreturn {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     stdout_writer.interface.print("third panic message: {s}\n", .{msg}) catch {};
     std.process.exit(0);
 }
diff --git a/test/incremental/change_panic_handler_explicit b/test/incremental/change_panic_handler_explicit
index 774b18bbfd..7daa851c8f 100644
--- a/test/incremental/change_panic_handler_explicit
+++ b/test/incremental/change_panic_handler_explicit
@@ -42,7 +42,7 @@ pub const panic = struct {
     pub const noreturnReturned = no_panic.noreturnReturned;
 };
 fn myPanic(msg: []const u8, _: ?usize) noreturn {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     stdout_writer.interface.print("panic message: {s}\n", .{msg}) catch {};
     std.process.exit(0);
 }
@@ -89,7 +89,7 @@ pub const panic = struct {
     pub const noreturnReturned = no_panic.noreturnReturned;
 };
 fn myPanic(msg: []const u8, _: ?usize) noreturn {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     stdout_writer.interface.print("new panic message: {s}\n", .{msg}) catch {};
     std.process.exit(0);
 }
@@ -136,7 +136,7 @@ pub const panic = struct {
     pub const noreturnReturned = no_panic.noreturnReturned;
 };
 fn myPanicNew(msg: []const u8, _: ?usize) noreturn {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     stdout_writer.interface.print("third panic message: {s}\n", .{msg}) catch {};
     std.process.exit(0);
 }
diff --git a/test/incremental/change_shift_op b/test/incremental/change_shift_op
index 41b5d19266..557c17c0b1 100644
--- a/test/incremental/change_shift_op
+++ b/test/incremental/change_shift_op
@@ -9,7 +9,7 @@ pub fn main() !void {
     try foo(0x1300);
 }
 fn foo(x: u16) !void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("0x{x}\n", .{x << 4});
 }
 const std = @import("std");
@@ -20,7 +20,7 @@ pub fn main() !void {
     try foo(0x1300);
 }
 fn foo(x: u16) !void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("0x{x}\n", .{x >> 4});
 }
 const std = @import("std");
diff --git a/test/incremental/change_struct_same_fields b/test/incremental/change_struct_same_fields
index 7af1161326..ef8ffab52d 100644
--- a/test/incremental/change_struct_same_fields
+++ b/test/incremental/change_struct_same_fields
@@ -11,7 +11,7 @@ pub fn main() !void {
     try foo(&val);
 }
 fn foo(val: *const S) !void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print(
         "{d} {d}\n",
         .{ val.x, val.y },
@@ -28,7 +28,7 @@ pub fn main() !void {
     try foo(&val);
 }
 fn foo(val: *const S) !void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print(
         "{d} {d}\n",
         .{ val.x, val.y },
@@ -45,7 +45,7 @@ pub fn main() !void {
     try foo(&val);
 }
 fn foo(val: *const S) !void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print(
         "{d} {d}\n",
         .{ val.x, val.y },
diff --git a/test/incremental/change_zon_file b/test/incremental/change_zon_file
index 62f73dd3bf..8a4c69cf21 100644
--- a/test/incremental/change_zon_file
+++ b/test/incremental/change_zon_file
@@ -8,7 +8,7 @@
 const std = @import("std");
 const message: []const u8 = @import("message.zon");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(message);
+    try std.Io.File.stdout().writeAll(message);
 }
 #file=message.zon
 "Hello, World!\n"
@@ -29,7 +29,7 @@ pub fn main() !void {
 const std = @import("std");
 const message: []const u8 = @import("message.zon");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll("a hardcoded string\n");
+    try std.Io.File.stdout().writeAll("a hardcoded string\n");
 }
 #expect_error=message.zon:1:1: error: unable to load 'message.zon': FileNotFound
 #expect_error=main.zig:2:37: note: file imported here
@@ -44,6 +44,6 @@ pub fn main() !void {
 const std = @import("std");
 const message: []const u8 = @import("message.zon");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(message);
+    try std.Io.File.stdout().writeAll(message);
 }
 #expect_stdout="We're back, World!\n"
diff --git a/test/incremental/change_zon_file_no_result_type b/test/incremental/change_zon_file_no_result_type
index 498543e4f1..2dd601765f 100644
--- a/test/incremental/change_zon_file_no_result_type
+++ b/test/incremental/change_zon_file_no_result_type
@@ -7,7 +7,7 @@
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(@import("foo.zon").message);
+    try std.Io.File.stdout().writeAll(@import("foo.zon").message);
 }
 #file=foo.zon
 .{
diff --git a/test/incremental/compile_log b/test/incremental/compile_log
index 697bb26569..d52259f122 100644
--- a/test/incremental/compile_log
+++ b/test/incremental/compile_log
@@ -8,7 +8,7 @@
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll("Hello, World!\n");
+    try std.Io.File.stdout().writeAll("Hello, World!\n");
 }
 #expect_stdout="Hello, World!\n"
 
@@ -16,7 +16,7 @@ pub fn main() !void {
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll("Hello, World!\n");
+    try std.Io.File.stdout().writeAll("Hello, World!\n");
     @compileLog("this is a log");
 }
 #expect_error=main.zig:4:5: error: found compile log statement
@@ -26,6 +26,6 @@ pub fn main() !void {
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll("Hello, World!\n");
+    try std.Io.File.stdout().writeAll("Hello, World!\n");
 }
 #expect_stdout="Hello, World!\n"
diff --git a/test/incremental/fix_astgen_failure b/test/incremental/fix_astgen_failure
index 8b1b3adbf7..4dce2492e7 100644
--- a/test/incremental/fix_astgen_failure
+++ b/test/incremental/fix_astgen_failure
@@ -10,21 +10,21 @@ pub fn main() !void {
 }
 #file=foo.zig
 pub fn hello() !void {
-    try std.fs.File.stdout().writeAll("Hello, World!\n");
+    try std.Io.File.stdout().writeAll("Hello, World!\n");
 }
 #expect_error=foo.zig:2:9: error: use of undeclared identifier 'std'
 #update=fix the error
 #file=foo.zig
 const std = @import("std");
 pub fn hello() !void {
-    try std.fs.File.stdout().writeAll("Hello, World!\n");
+    try std.Io.File.stdout().writeAll("Hello, World!\n");
 }
 #expect_stdout="Hello, World!\n"
 #update=add new error
 #file=foo.zig
 const std = @import("std");
 pub fn hello() !void {
-    try std.fs.File.stdout().writeAll(hello_str);
+    try std.Io.File.stdout().writeAll(hello_str);
 }
 #expect_error=foo.zig:3:39: error: use of undeclared identifier 'hello_str'
 #update=fix the new error
@@ -32,6 +32,6 @@ pub fn hello() !void {
 const std = @import("std");
 const hello_str = "Hello, World! Again!\n";
 pub fn hello() !void {
-    try std.fs.File.stdout().writeAll(hello_str);
+    try std.Io.File.stdout().writeAll(hello_str);
 }
 #expect_stdout="Hello, World! Again!\n"
diff --git a/test/incremental/function_becomes_inline b/test/incremental/function_becomes_inline
index 240d7a54af..07cd98ef28 100644
--- a/test/incremental/function_becomes_inline
+++ b/test/incremental/function_becomes_inline
@@ -8,7 +8,7 @@ pub fn main() !void {
     try foo();
 }
 fn foo() !void {
-    try std.fs.File.stdout().writeAll("Hello, World!\n");
+    try std.Io.File.stdout().writeAll("Hello, World!\n");
 }
 const std = @import("std");
 #expect_stdout="Hello, World!\n"
@@ -19,7 +19,7 @@ pub fn main() !void {
     try foo();
 }
 inline fn foo() !void {
-    try std.fs.File.stdout().writeAll("Hello, World!\n");
+    try std.Io.File.stdout().writeAll("Hello, World!\n");
 }
 const std = @import("std");
 #expect_stdout="Hello, World!\n"
@@ -30,7 +30,7 @@ pub fn main() !void {
     try foo();
 }
 inline fn foo() !void {
-    try std.fs.File.stdout().writeAll("Hello, `inline` World!\n");
+    try std.Io.File.stdout().writeAll("Hello, `inline` World!\n");
 }
 const std = @import("std");
 #expect_stdout="Hello, `inline` World!\n"
diff --git a/test/incremental/hello b/test/incremental/hello
index dc6f02177f..8ff8f61bc0 100644
--- a/test/incremental/hello
+++ b/test/incremental/hello
@@ -7,13 +7,13 @@
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll("good morning\n");
+    try std.Io.File.stdout().writeAll("good morning\n");
 }
 #expect_stdout="good morning\n"
 #update=change the string
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll("おはようございます\n");
+    try std.Io.File.stdout().writeAll("おはようございます\n");
 }
 #expect_stdout="おはようございます\n"
diff --git a/test/incremental/make_decl_pub b/test/incremental/make_decl_pub
index b25b117160..9d90ca51eb 100644
--- a/test/incremental/make_decl_pub
+++ b/test/incremental/make_decl_pub
@@ -12,7 +12,7 @@ pub fn main() !void {
 #file=foo.zig
 const std = @import("std");
 fn hello() !void {
-    try std.fs.File.stdout().writeAll("Hello, World!\n");
+    try std.Io.File.stdout().writeAll("Hello, World!\n");
 }
 #expect_error=main.zig:3:12: error: 'hello' is not marked 'pub'
 #expect_error=foo.zig:2:1: note: declared here
@@ -21,6 +21,6 @@ fn hello() !void {
 #file=foo.zig
 const std = @import("std");
 pub fn hello() !void {
-    try std.fs.File.stdout().writeAll("Hello, World!\n");
+    try std.Io.File.stdout().writeAll("Hello, World!\n");
 }
 #expect_stdout="Hello, World!\n"
diff --git a/test/incremental/modify_inline_fn b/test/incremental/modify_inline_fn
index d485d8ffd5..2c1478682e 100644
--- a/test/incremental/modify_inline_fn
+++ b/test/incremental/modify_inline_fn
@@ -8,7 +8,7 @@
 const std = @import("std");
 pub fn main() !void {
     const str = getStr();
-    try std.fs.File.stdout().writeAll(str);
+    try std.Io.File.stdout().writeAll(str);
 }
 inline fn getStr() []const u8 {
     return "foo\n";
@@ -19,7 +19,7 @@ inline fn getStr() []const u8 {
 const std = @import("std");
 pub fn main() !void {
     const str = getStr();
-    try std.fs.File.stdout().writeAll(str);
+    try std.Io.File.stdout().writeAll(str);
 }
 inline fn getStr() []const u8 {
     return "bar\n";
diff --git a/test/incremental/move_src b/test/incremental/move_src
index 4f43e8ea6a..d6a21fc562 100644
--- a/test/incremental/move_src
+++ b/test/incremental/move_src
@@ -7,7 +7,7 @@
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("{d} {d}\n", .{ foo(), bar() });
 }
 fn foo() u32 {
@@ -22,7 +22,7 @@ fn bar() u32 {
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("{d} {d}\n", .{ foo(), bar() });
 }
 
diff --git a/test/incremental/no_change_preserves_tag_names b/test/incremental/no_change_preserves_tag_names
index 623496119d..e399e083e1 100644
--- a/test/incremental/no_change_preserves_tag_names
+++ b/test/incremental/no_change_preserves_tag_names
@@ -8,7 +8,7 @@
 const std = @import("std");
 var some_enum: enum { first, second } = .first;
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(@tagName(some_enum));
+    try std.Io.File.stdout().writeAll(@tagName(some_enum));
 }
 #expect_stdout="first"
 #update=no change
@@ -16,6 +16,6 @@ pub fn main() !void {
 const std = @import("std");
 var some_enum: enum { first, second } = .first;
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(@tagName(some_enum));
+    try std.Io.File.stdout().writeAll(@tagName(some_enum));
 }
 #expect_stdout="first"
diff --git a/test/incremental/recursive_function_becomes_non_recursive b/test/incremental/recursive_function_becomes_non_recursive
index a5a03749b8..20e43b64b7 100644
--- a/test/incremental/recursive_function_becomes_non_recursive
+++ b/test/incremental/recursive_function_becomes_non_recursive
@@ -9,7 +9,7 @@ pub fn main() !void {
     try foo(false);
 }
 fn foo(recurse: bool) !void {
-    const stdout = std.fs.File.stdout();
+    const stdout = std.Io.File.stdout();
     if (recurse) return foo(true);
     try stdout.writeAll("non-recursive path\n");
 }
@@ -22,7 +22,7 @@ pub fn main() !void {
     try foo(true);
 }
 fn foo(recurse: bool) !void {
-    const stdout = std.fs.File.stdout();
+    const stdout = std.Io.File.stdout();
     if (recurse) return stdout.writeAll("x==1\n");
     try stdout.writeAll("non-recursive path\n");
 }
diff --git a/test/incremental/remove_enum_field b/test/incremental/remove_enum_field
index 02daf2a0fb..bbcf7718e9 100644
--- a/test/incremental/remove_enum_field
+++ b/test/incremental/remove_enum_field
@@ -10,7 +10,7 @@ const MyEnum = enum(u8) {
     bar = 2,
 };
 pub fn main() !void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("{}\n", .{@intFromEnum(MyEnum.foo)});
 }
 const std = @import("std");
@@ -22,7 +22,7 @@ const MyEnum = enum(u8) {
     bar = 2,
 };
 pub fn main() !void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     try stdout_writer.interface.print("{}\n", .{@intFromEnum(MyEnum.foo)});
 }
 const std = @import("std");
diff --git a/test/incremental/unreferenced_error b/test/incremental/unreferenced_error
index 505fb3d5f4..1c1f1f7a8f 100644
--- a/test/incremental/unreferenced_error
+++ b/test/incremental/unreferenced_error
@@ -7,7 +7,7 @@
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(a);
+    try std.Io.File.stdout().writeAll(a);
 }
 const a = "Hello, World!\n";
 #expect_stdout="Hello, World!\n"
@@ -16,7 +16,7 @@ const a = "Hello, World!\n";
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(a);
+    try std.Io.File.stdout().writeAll(a);
 }
 const a = @compileError("bad a");
 #expect_error=main.zig:5:11: error: bad a
@@ -25,7 +25,7 @@ const a = @compileError("bad a");
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(b);
+    try std.Io.File.stdout().writeAll(b);
 }
 const a = @compileError("bad a");
 const b = "Hi there!\n";
@@ -35,7 +35,7 @@ const b = "Hi there!\n";
 #file=main.zig
 const std = @import("std");
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll(a);
+    try std.Io.File.stdout().writeAll(a);
 }
 const a = "Back to a\n";
 const b = @compileError("bad b");
diff --git a/test/link/bss/main.zig b/test/link/bss/main.zig
index 2785a8360f..9c104fec04 100644
--- a/test/link/bss/main.zig
+++ b/test/link/bss/main.zig
@@ -4,7 +4,7 @@ const std = @import("std");
 var buffer: [0x1000000]u64 = [1]u64{0} ** 0x1000000;
 
 pub fn main() anyerror!void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
 
     buffer[0x10] = 1;
 
diff --git a/test/link/elf.zig b/test/link/elf.zig
index 824fc76e92..6d9912193b 100644
--- a/test/link/elf.zig
+++ b/test/link/elf.zig
@@ -1323,7 +1323,7 @@ fn testGcSectionsZig(b: *Build, opts: Options) *Step {
             \\extern var live_var2: i32;
             \\extern fn live_fn2() void;
             \\pub fn main() void {
-            \\    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+            \\    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
             \\    stdout_writer.interface.print("{d} {d}\n", .{ live_var1, live_var2 }) catch @panic("fail");
             \\    live_fn2();
             \\}
@@ -1365,7 +1365,7 @@ fn testGcSectionsZig(b: *Build, opts: Options) *Step {
             \\extern var live_var2: i32;
             \\extern fn live_fn2() void;
             \\pub fn main() void {
-            \\    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+            \\    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
             \\    stdout_writer.interface.print("{d} {d}\n", .{ live_var1, live_var2 }) catch @panic("fail");
             \\    live_fn2();
             \\}
diff --git a/test/link/macho.zig b/test/link/macho.zig
index 4fc0cad0ee..0f3df8c2d8 100644
--- a/test/link/macho.zig
+++ b/test/link/macho.zig
@@ -716,7 +716,7 @@ fn testHelloZig(b: *Build, opts: Options) *Step {
     const exe = addExecutable(b, opts, .{ .name = "main", .zig_source_bytes =
         \\const std = @import("std");
         \\pub fn main() void {
-        \\    std.fs.File.stdout().writeAll("Hello world!\n") catch @panic("fail");
+        \\    std.Io.File.stdout().writeAll("Hello world!\n") catch @panic("fail");
         \\}
     });
 
@@ -2371,7 +2371,7 @@ fn testTlsZig(b: *Build, opts: Options) *Step {
         \\threadlocal var x: i32 = 0;
         \\threadlocal var y: i32 = -1;
         \\pub fn main() void {
-        \\    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+        \\    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
         \\    stdout_writer.interface.print("{d} {d}\n", .{x, y}) catch unreachable;
         \\    x -= 1;
         \\    y += 1;
diff --git a/test/link/wasm/extern/main.zig b/test/link/wasm/extern/main.zig
index 9635f64a40..a841cc40a6 100644
--- a/test/link/wasm/extern/main.zig
+++ b/test/link/wasm/extern/main.zig
@@ -3,6 +3,6 @@ const std = @import("std");
 extern const foo: u32;
 
 pub fn main() void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     stdout_writer.interface.print("Result: {d}", .{foo}) catch {};
 }
diff --git a/test/src/Cases.zig b/test/src/Cases.zig
index b1fece44d9..5889449bbe 100644
--- a/test/src/Cases.zig
+++ b/test/src/Cases.zig
@@ -1,6 +1,8 @@
 const Cases = @This();
 const builtin = @import("builtin");
+
 const std = @import("std");
+const Io = std.Io;
 const assert = std.debug.assert;
 const Allocator = std.mem.Allocator;
 const getExternalExecutor = std.zig.system.getExternalExecutor;
@@ -313,7 +315,7 @@ pub fn addCompile(
 /// Each file should include a test manifest as a contiguous block of comments at
 /// the end of the file. The first line should be the test type, followed by a set of
 /// key-value config values, followed by a blank line, then the expected output.
-pub fn addFromDir(ctx: *Cases, dir: std.fs.Dir, b: *std.Build) void {
+pub fn addFromDir(ctx: *Cases, dir: Io.Dir, b: *std.Build) void {
     var current_file: []const u8 = "none";
     ctx.addFromDirInner(dir, &current_file, b) catch |err| {
         std.debug.panicExtra(
@@ -326,7 +328,7 @@ pub fn addFromDir(ctx: *Cases, dir: std.fs.Dir, b: *std.Build) void {
 
 fn addFromDirInner(
     ctx: *Cases,
-    iterable_dir: std.fs.Dir,
+    iterable_dir: Io.Dir,
     /// This is kept up to date with the currently being processed file so
     /// that if any errors occur the caller knows it happened during this file.
     current_file: *[]const u8,
diff --git a/test/src/convert-stack-trace.zig b/test/src/convert-stack-trace.zig
index 91be53a8e5..8d04500fba 100644
--- a/test/src/convert-stack-trace.zig
+++ b/test/src/convert-stack-trace.zig
@@ -44,7 +44,7 @@ pub fn main() !void {
     const in_file = try std.fs.cwd().openFile(args[1], .{});
     defer in_file.close();
 
-    const out_file: std.fs.File = .stdout();
+    const out_file: std.Io.File = .stdout();
 
     var in_fr = in_file.reader(io, &read_buf);
     var out_fw = out_file.writer(&write_buf);
diff --git a/test/standalone/child_process/child.zig b/test/standalone/child_process/child.zig
index 2e74f30882..5dbf95af4c 100644
--- a/test/standalone/child_process/child.zig
+++ b/test/standalone/child_process/child.zig
@@ -33,12 +33,12 @@ fn run(allocator: std.mem.Allocator, io: Io) !void {
     }
 
     // test stdout pipe; parent verifies
-    try std.fs.File.stdout().writeAll("hello from stdout");
+    try std.Io.File.stdout().writeAll("hello from stdout");
 
     // test stdin pipe from parent
     const hello_stdin = "hello from stdin";
     var buf: [hello_stdin.len]u8 = undefined;
-    const stdin: std.fs.File = .stdin();
+    const stdin: std.Io.File = .stdin();
     var reader = stdin.reader(io, &.{});
     const n = try reader.interface.readSliceShort(&buf);
     if (!std.mem.eql(u8, buf[0..n], hello_stdin)) {
@@ -47,7 +47,7 @@ fn run(allocator: std.mem.Allocator, io: Io) !void {
 }
 
 fn testError(comptime fmt: []const u8, args: anytype) void {
-    var stderr_writer = std.fs.File.stderr().writer(&.{});
+    var stderr_writer = std.Io.File.stderr().writer(&.{});
     const stderr = &stderr_writer.interface;
     stderr.print("CHILD TEST ERROR: ", .{}) catch {};
     stderr.print(fmt, args) catch {};
diff --git a/test/standalone/child_process/main.zig b/test/standalone/child_process/main.zig
index 5970cdd952..b20a7fed49 100644
--- a/test/standalone/child_process/main.zig
+++ b/test/standalone/child_process/main.zig
@@ -62,7 +62,7 @@ pub fn main() !void {
 var parent_test_error = false;
 
 fn testError(comptime fmt: []const u8, args: anytype) void {
-    var stderr_writer = std.fs.File.stderr().writer(&.{});
+    var stderr_writer = std.Io.File.stderr().writer(&.{});
     const stderr = &stderr_writer.interface;
     stderr.print("PARENT TEST ERROR: ", .{}) catch {};
     stderr.print(fmt, args) catch {};
diff --git a/test/standalone/simple/cat/main.zig b/test/standalone/simple/cat/main.zig
index 9ea980aecc..dea528f4f7 100644
--- a/test/standalone/simple/cat/main.zig
+++ b/test/standalone/simple/cat/main.zig
@@ -1,5 +1,5 @@
 const std = @import("std");
-const fs = std.fs;
+const Io = std.Io;
 const mem = std.mem;
 const warn = std.log.warn;
 const fatal = std.process.fatal;
@@ -18,11 +18,11 @@ pub fn main() !void {
     const exe = args[0];
     var catted_anything = false;
     var stdout_buffer: [4096]u8 = undefined;
-    var stdout_writer = fs.File.stdout().writerStreaming(&stdout_buffer);
+    var stdout_writer = Io.File.stdout().writerStreaming(&stdout_buffer);
     const stdout = &stdout_writer.interface;
-    var stdin_reader = fs.File.stdin().readerStreaming(io, &.{});
+    var stdin_reader = Io.File.stdin().readerStreaming(io, &.{});
 
-    const cwd = fs.cwd();
+    const cwd = Io.Dir.cwd();
 
     for (args[1..]) |arg| {
         if (mem.eql(u8, arg, "-")) {
diff --git a/test/standalone/simple/guess_number/main.zig b/test/standalone/simple/guess_number/main.zig
index d477de2b78..25226ec1c8 100644
--- a/test/standalone/simple/guess_number/main.zig
+++ b/test/standalone/simple/guess_number/main.zig
@@ -2,9 +2,9 @@ const builtin = @import("builtin");
 const std = @import("std");
 
 pub fn main() !void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     const out = &stdout_writer.interface;
-    const stdin: std.fs.File = .stdin();
+    const stdin: std.Io.File = .stdin();
 
     try out.writeAll("Welcome to the Guess Number Game in Zig.\n");
 
diff --git a/test/standalone/simple/hello_world/hello.zig b/test/standalone/simple/hello_world/hello.zig
index 3b2b910687..37c5c4bb1b 100644
--- a/test/standalone/simple/hello_world/hello.zig
+++ b/test/standalone/simple/hello_world/hello.zig
@@ -1,5 +1,5 @@
 const std = @import("std");
 
 pub fn main() !void {
-    try std.fs.File.stdout().writeAll("Hello, World!\n");
+    try std.Io.File.stdout().writeAll("Hello, World!\n");
 }
diff --git a/test/standalone/windows_bat_args/echo-args.zig b/test/standalone/windows_bat_args/echo-args.zig
index 054c4a6975..7e73fa54a0 100644
--- a/test/standalone/windows_bat_args/echo-args.zig
+++ b/test/standalone/windows_bat_args/echo-args.zig
@@ -5,7 +5,7 @@ pub fn main() !void {
     defer arena_state.deinit();
     const arena = arena_state.allocator();
 
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     const stdout = &stdout_writer.interface;
     var args = try std.process.argsAlloc(arena);
     for (args[1..], 1..) |arg, i| {
diff --git a/test/standalone/windows_paths/relative.zig b/test/standalone/windows_paths/relative.zig
index 8301549667..7f87151ac8 100644
--- a/test/standalone/windows_paths/relative.zig
+++ b/test/standalone/windows_paths/relative.zig
@@ -13,7 +13,7 @@ pub fn main() !void {
     const relative = try std.fs.path.relative(allocator, args[1], args[2]);
     defer allocator.free(relative);
 
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     const stdout = &stdout_writer.interface;
     try stdout.writeAll(relative);
 }
diff --git a/test/standalone/windows_spawn/hello.zig b/test/standalone/windows_spawn/hello.zig
index fb4a827e23..e54bbe0386 100644
--- a/test/standalone/windows_spawn/hello.zig
+++ b/test/standalone/windows_spawn/hello.zig
@@ -1,7 +1,7 @@
 const std = @import("std");
 
 pub fn main() !void {
-    var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
+    var stdout_writer = std.Io.File.stdout().writerStreaming(&.{});
     const stdout = &stdout_writer.interface;
     try stdout.writeAll("hello from exe\n");
 }
diff --git a/test/standalone/windows_spawn/main.zig b/test/standalone/windows_spawn/main.zig
index 10ee35f4df..f388070097 100644
--- a/test/standalone/windows_spawn/main.zig
+++ b/test/standalone/windows_spawn/main.zig
@@ -1,4 +1,5 @@
 const std = @import("std");
+const Io = std.Io;
 
 const windows = std.os.windows;
 const utf16Literal = std.unicode.utf8ToUtf16LeStringLiteral;
@@ -218,7 +219,7 @@ fn testExecWithCwd(allocator: std.mem.Allocator, command: []const u8, cwd: ?[]co
     try std.testing.expectEqualStrings(expected_stdout, result.stdout);
 }
 
-fn renameExe(dir: std.fs.Dir, old_sub_path: []const u8, new_sub_path: []const u8) !void {
+fn renameExe(dir: Io.Dir, old_sub_path: []const u8, new_sub_path: []const u8) !void {
     var attempt: u5 = 0;
     while (true) break dir.rename(old_sub_path, new_sub_path) catch |err| switch (err) {
         error.AccessDenied => {
diff --git a/test/tests.zig b/test/tests.zig
index 0911ae2e46..2b0e8fb5d0 100644
--- a/test/tests.zig
+++ b/test/tests.zig
@@ -2629,10 +2629,11 @@ pub fn addCases(
 ) !void {
     const arena = b.allocator;
     const gpa = b.allocator;
+    const io = b.graph.io;
 
     var cases = @import("src/Cases.zig").init(gpa, arena);
 
-    var dir = try b.build_root.handle.openDir("test/cases", .{ .iterate = true });
+    var dir = try b.build_root.handle.openDir(io, "test/cases", .{ .iterate = true });
     defer dir.close();
 
     cases.addFromDir(dir, b);