made build.zig.

Has runner and tester for each day,
as well as a runner and tester for all the days.
Also has check step for zls.

.gitignore

@@ -1,5 +1,5 @@
 # ---> Zig
-zig-cache/
+.zig-cache/
 zig-out/
 build/
 build-*/

build.zig

@@ -0,0 +1,75 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build) !void {
+    const allocator = b.allocator;
+
+    const target = b.standardTargetOptions(.{});
+    const optimize = b.standardOptimizeOption(.{});
+
+    const run_all = b.step("run", "Run all days");
+    const test_all = b.step("test", "Test all days");
+    const check = b.step("check", "run checks");
+
+    const utils_mod = b.createModule(.{ .root_source_file = b.path("src/utils/mod.zig") });
+
+    var dirIt = (try std.fs.cwd().openDir(
+        "./src/days",
+        .{ .iterate = true },
+    )).iterate();
+
+    while (try dirIt.next()) |entry| {
+        if (entry.kind == .directory) {}
+        // each day entry will have a main.zig
+        const source_file = try std.fs.path.join(allocator, &.{ "src", "days", entry.name, "main.zig" });
+        defer allocator.free(source_file);
+        //make sure the main.zig exists
+        _ = std.fs.cwd().openFile(source_file, .{}) catch continue;
+
+        const exe = b.addExecutable(.{
+            .name = entry.name,
+            .root_source_file = b.path(source_file),
+            .target = target,
+            .optimize = optimize,
+        });
+        exe.root_module.addImport("utils", utils_mod);
+
+        b.installArtifact(exe);
+        const install_cmd = b.addInstallArtifact(exe, .{});
+        const install_step = b.step(
+            b.fmt("install_{s}", .{entry.name}),
+            b.fmt("install {s}", .{entry.name}),
+        );
+        install_step.dependOn(&install_cmd.step);
+        b.installArtifact(exe);
+
+        const run_cmd = b.addRunArtifact(exe);
+        const run_step = b.step(
+            b.fmt("run_{s}", .{entry.name}),
+            b.fmt("run {s}", .{entry.name}),
+        );
+        run_step.dependOn(&run_cmd.step);
+        run_all.dependOn(&run_cmd.step);
+
+        const exe_test = b.addTest(.{
+            .root_source_file = b.path(source_file),
+            .target = target,
+            .optimize = optimize,
+        });
+        const test_cmd = b.addRunArtifact(exe_test);
+        const test_step = b.step(
+            b.fmt("test_{s}", .{entry.name}),
+            b.fmt("test {s}", .{entry.name}),
+        );
+        test_step.dependOn(&test_cmd.step);
+        test_all.dependOn(&test_cmd.step);
+
+        const exe_check = b.addExecutable(.{
+            .name = entry.name,
+            .root_source_file = b.path(source_file),
+            .target = target,
+            .optimize = optimize,
+        });
+        exe_check.root_module.addImport("utils", utils_mod);
+        check.dependOn(&exe_check.step);
+    }
+}

build.zig.zon

@@ -0,0 +1,46 @@
+.{
+    // This is the default name used by packages depending on this one. For
+    // example, when a user runs `zig fetch --save <url>`, this field is used
+    // as the key in the `dependencies` table. Although the user can choose a
+    // different name, most users will stick with this provided value.
+    //
+    // It is redundant to include "zig" in this name because it is already
+    // within the Zig package namespace.
+    .name = .aoc2024,
+
+    // This is a [Semantic Version](https://semver.org/).
+    // In a future version of Zig it will be used for package deduplication.
+    .version = "0.0.1",
+
+    // Together with name, this represents a globally unique package
+    // identifier. This field is generated by the Zig toolchain when the
+    // package is first created, and then *never changes*. This allows
+    // unambiguous detection of one package being an updated version of
+    // another.
+    //
+    // When forking a Zig project, this id should be regenerated (delete the
+    // field and run `zig build`) if the upstream project is still maintained.
+    // Otherwise, the fork is *hostile*, attempting to take control over the
+    // original project's identity. Thus it is recommended to leave the comment
+    // on the following line intact, so that it shows up in code reviews that
+    // modify the field.
+    .fingerprint = 0x25105d4386327470, // Changing this has security and trust implications.
+
+    // Tracks the earliest Zig version that the package considers to be a
+    // supported use case.
+    .minimum_zig_version = "0.14.0",
+
+    // Specifies the set of files and directories that are included in this package.
+    // Only files and directories listed here are included in the `hash` that
+    // is computed for this package. Only files listed here will remain on disk
+    // when using the zig package manager. As a rule of thumb, one should list
+    // files required for compilation plus any license(s).
+    // Paths are relative to the build root. Use the empty string (`""`) to refer to
+    // the build root itself.
+    // A directory listed here means that all files within, recursively, are included.
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+        "src",
+    },
+}

days/template/main.zig

@@ -1,24 +0,0 @@
-const std = @import("std");
-
-pub fn main() !void {
-    // Prints to stderr (it's a shortcut based on `std.io.getStdErr()`)
-    std.debug.print("All your {s} are belong to us.\n", .{"codebase"});
-
-    // stdout is for the actual output of your application, for example if you
-    // are implementing gzip, then only the compressed bytes should be sent to
-    // stdout, not any debugging messages.
-    const stdout_file = std.io.getStdOut().writer();
-    var bw = std.io.bufferedWriter(stdout_file);
-    const stdout = bw.writer();
-
-    try stdout.print("Run `zig build test` to run the tests.\n", .{});
-
-    try bw.flush(); // don't forget to flush!
-}
-
-test "simple test" {
-    var list = std.ArrayList(i32).init(std.testing.allocator);
-    defer list.deinit(); // try commenting this out and see if zig detects the memory leak!
-    try list.append(42);
-    try std.testing.expectEqual(@as(i32, 42), list.pop());
-}

src/days/template/main.zig

@@ -0,0 +1,10 @@
+const std = @import("std");
+const part1 = @import("part1.zig");
+const part2 = @import("part2.zig");
+const input = @embedFile("input.txt");
+
+pub fn main() !void {
+    const stdout = std.io.getStdErr().writer();
+    try stdout.print("Part1: {d}\n", .{part1.solve(input)});
+    try stdout.print("Part2: {d}\n", .{part2.solve(input)});
+}

src/days/template/part1.zig

@@ -1,7 +1,8 @@
 const lib = @import("lib.zig");
 const std = @import("std");
+const utils = @import("utils");
 
-pub fn part1(comptime input: []const u8) i32 {
+pub fn solve(comptime input: []const u8) i32 {
     return input.len;
 }
 
@@ -9,5 +10,5 @@ test "part1 sample" {
     const input =
         \\0
     ;
-    try std.testing.expectEqual(part1(input), 11);
+    try std.testing.expectEqual(solve(input), 1);
 }

src/days/template/part2.zig

@@ -1,7 +1,8 @@
 const lib = @import("lib.zig");
 const std = @import("std");
+const utils = @import("utils");
 
-pub fn part2(comptime input: []const u8) i32 {
+pub fn solve(comptime input: []const u8) i32 {
     return input.len;
 }
 
@@ -9,5 +10,5 @@ test "part2 sample" {
     const input =
         \\0
     ;
-    try std.testing.expectEqual(part2(input), 1);
+    try std.testing.expectEqual(solve(input), 1);
 }

src/utils/mod.zig

@@ -0,0 +1 @@
+const std = @import("std");