1pub fn main() !void {
 2    var arena_state: std.heap.ArenaAllocator = .init(std.heap.page_allocator);
 3    defer arena_state.deinit();
 4    const arena = arena_state.allocator();
 5
 6    const args = try std.process.argsAlloc(arena);
 7
 8    if (args.len != 3) return error.BadUsage;
 9    const actual_path = args[1];
10    const expected_path = args[2];
11
12    const actual = try std.fs.cwd().readFileAlloc(actual_path, arena, .limited(1024 * 1024));
13    const expected = try std.fs.cwd().readFileAlloc(expected_path, arena, .limited(1024 * 1024));
14
15    // The actual output starts with a comment which we should strip out before comparing.
16    const comment_str = "/* This file was generated by ConfigHeader using the Zig Build System. */\n";
17    if (!std.mem.startsWith(u8, actual, comment_str)) {
18        return error.MissingOrMalformedComment;
19    }
20    const actual_without_comment = actual[comment_str.len..];
21
22    if (!std.mem.eql(u8, actual_without_comment, expected)) {
23        return error.DoesNotMatch;
24    }
25}
26const std = @import("std");