Improve fs.Walker test

- Take into account that iteration order is undefined by checking against a map instead of relying on numerically sorted iteration order
- Check both path and basename for each entry instead of just path

lib/std/fs/test.zig

@@ -916,14 +916,30 @@ test "walker" {
     var tmp = tmpDir(.{});
     defer tmp.cleanup();
 
-    const nb_dirs = 8;
+    // iteration order of walker is undefined, so need lookup maps to check against
 
-    var i: usize = 0;
+    const expected_paths = std.ComptimeStringMap(void, .{
-    var sub_dir = tmp.dir;
+        .{"dir1"},
-    while (i < nb_dirs) : (i += 1) {
+        .{"dir2"},
-        const dir_name = try std.fmt.allocPrint(allocator, "{}", .{i});
+        .{"dir3"},
-        try sub_dir.makeDir(dir_name);
+        .{"dir4"},
-        sub_dir = try sub_dir.openDir(dir_name, .{});
+        .{"dir3" ++ std.fs.path.sep_str ++ "sub1"},
+        .{"dir3" ++ std.fs.path.sep_str ++ "sub2"},
+        .{"dir3" ++ std.fs.path.sep_str ++ "sub2" ++ std.fs.path.sep_str ++ "subsub1"},
+    });
+
+    const expected_basenames = std.ComptimeStringMap(void, .{
+        .{"dir1"},
+        .{"dir2"},
+        .{"dir3"},
+        .{"dir4"},
+        .{"sub1"},
+        .{"sub2"},
+        .{"subsub1"},
+    });
+
+    for (expected_paths.kvs) |kv| {
+        try tmp.dir.makePath(kv.key);
     }
 
     const tmp_path = try fs.path.join(allocator, &[_][]const u8{ "zig-cache", "tmp", tmp.sub_path[0..] });
@@ -932,18 +948,19 @@ test "walker" {
     var walker = try tmp_dir.walk(testing.allocator);
     defer walker.deinit();
 
-    i = 0;
+    var num_walked: usize = 0;
-    var expected_dir_name: []const u8 = "";
+    while (try walker.next()) |entry| {
-    while (i < nb_dirs) : (i += 1) {
+        testing.expect(expected_basenames.has(entry.basename)) catch |err| {
-        const name = try std.fmt.allocPrint(allocator, "{}", .{i});
+            std.debug.print("found unexpected basename: {s}\n", .{std.fmt.fmtSliceEscapeLower(entry.basename)});
-        expected_dir_name = if (expected_dir_name.len == 0)
+            return err;
-            name
+        };
-        else
+        testing.expect(expected_paths.has(entry.path)) catch |err| {
-            try fs.path.join(allocator, &[_][]const u8{ expected_dir_name, name });
+            std.debug.print("found unexpected path: {s}\n", .{std.fmt.fmtSliceEscapeLower(entry.path)});
-
+            return err;
-        var entry = (try walker.next()).?;
+        };
-        try testing.expectEqualStrings(expected_dir_name, entry.path);
+        num_walked += 1;
     }
+    try testing.expectEqual(expected_paths.kvs.len, num_walked);
 }
 
 test ". and .. in fs.Dir functions" {