path that requires canonicalization for unix and wasi

canonicalize_test_unix.zig

test "canonicalize path Unix" {
    if (builtin.os.tag == .windows) // symlinks are not portable
        return error.SkipZigTest;
    // TODO testing partial solution to https://github.com/ziglang/zig/issues/4812
    const alloc = testing.allocator;
    var tmp = testing.tmpDir(.{ .no_follow = true }); // ie zig-cache/tmp/8DLgoSEqz593PAEE
    defer tmp.cleanup();
    const tmpdirpath = try tmp.getFullPath(alloc);
    defer alloc.free(tmpdirpath);
    var cwd_buf: [fs.MAX_PATH_BYTES]u8 = undefined; // maximum size of a UTF-8 encoded file path
    const cwd = try std.process.getCwd(&cwd_buf);
    const s_symlink = "br" ++ ("u" ** 98);
    try tmp.dir.symLink(cwd, s_symlink, .{ .is_directory = true });
    var ultralong_path = try fs.path.join(alloc, &[_][]const u8{ tmpdirpath, s_symlink });
    defer alloc.free(ultralong_path);
    {
        // ensure symlink works
        var buffer: [fs.MAX_PATH_BYTES]u8 = undefined;
        const given = try tmp.dir.readLink(s_symlink, buffer[0..]);
        try testing.expect(mem.eql(u8, cwd, given));
    }
    const append_path = try fs.path.join(alloc, &[_][]const u8{
        "zig-cache",
        "tmp",
        tmp.sub_path[0..],
        s_symlink,
    });
    defer alloc.free(append_path);

    std.debug.assert(fs.MAX_PATH_BYTES > ultralong_path.len);
    var min_diff = fs.MAX_PATH_BYTES - ultralong_path.len;
    var i: usize = min_diff / append_path.len + 1;
    std.debug.print("ultralong_path needs {d} concatenations\n", .{i});
    while (i > 0) : (i -= 1) {
        // debug: add test here
        const tmp_var = try fs.path.join(alloc, &[_][]const u8{ ultralong_path, append_path });
        alloc.free(ultralong_path);
        ultralong_path = tmp_var;
    }
    std.debug.assert(fs.MAX_PATH_BYTES < ultralong_path.len);
    //std.debug.print("ultralong_path: {s}\n", .{ultralong_path});
    // TODO add final test here
    // const canon_path1 = canonicalize(alloc, absolute_path);
}