diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9cef9f8..f4e4de4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -39,4 +39,4 @@ jobs:
       - name: Zig environment variables
         run: zig env
       - name: Test
-        run: zig build test
+        run: zig build test -Dall --summary all
diff --git a/build.zig b/build.zig
index cd090e8..e2dd39c 100644
--- a/build.zig
+++ b/build.zig
@@ -1,14 +1,13 @@
 const std = @import("std");
+var all: bool = false;
 
-pub fn build(b: *std.Build) void {
-    const target = b.standardTargetOptions(.{});
-    const optimize = b.standardOptimizeOption(.{});
-
+fn everythingForTargetAndOptimization(b: *std.Build, target: std.zig.CrossTarget, optimization: std.builtin.OptimizeMode, unit_tests: []const []const u8, test_step: *std.Build.Step) !void {
+    const name = if (all) try std.mem.concat(b.allocator, u8, &.{ "nativity_", @tagName(optimization) }) else "nativity";
     const exe = b.addExecutable(.{
-        .name = "compiler",
+        .name = name,
         .root_source_file = .{ .path = "src/main.zig" },
         .target = target,
-        .optimize = optimize,
+        .optimize = optimization,
     });
 
     b.installArtifact(exe);
@@ -26,26 +25,29 @@ pub fn build(b: *std.Build) void {
         run_cmd.addArgs(args);
     }
 
-    const run_step = b.step("run", "Run the app");
+    const run_step = b.step(if (all) try std.mem.concat(b.allocator, u8, &.{ "run_", @tagName(optimization) }) else "run", "Run the app");
     run_step.dependOn(&run_cmd.step);
 
     const debug_command = addDebugCommand(b, exe);
-    const debug_step = b.step("debug", "Debug the app");
+    const debug_step = b.step(if (all) try std.mem.concat(b.allocator, u8, &.{ "debug_", @tagName(optimization) }) else "debug", "Debug the app");
     debug_step.dependOn(&debug_command.step);
 
-    const unit_tests = b.addTest(.{
+    const zig_tests = b.addTest(.{
         .root_source_file = .{ .path = "src/main.zig" },
         .target = target,
-        .optimize = optimize,
+        .optimize = optimization,
     });
 
-    const run_unit_tests = b.addRunArtifact(unit_tests);
-    const test_step = b.step("test", "Run unit tests");
-    test_step.dependOn(&run_unit_tests.step);
+    const run_zig_tests = b.addRunArtifact(zig_tests);
+    run_zig_tests.has_side_effects = true;
+    test_step.dependOn(&run_zig_tests.step);
 
-    const debug_unit_tests_cmd = addDebugCommand(b, unit_tests);
-    const debug_test_step = b.step("debug_test", "Run the tests through the debugger");
-    debug_test_step.dependOn(&debug_unit_tests_cmd.step);
+    for (unit_tests) |unit_test_main_source_file| {
+        const unit_test = b.addRunArtifact(exe);
+        unit_test.has_side_effects = true;
+        unit_test.addArg(unit_test_main_source_file);
+        test_step.dependOn(&unit_test.step);
+    }
 }
 
 fn addDebugCommand(b: *std.Build, artifact: *std.Build.Step.Compile) *std.Build.Step.Run {
@@ -76,3 +78,39 @@ fn addDebugCommand(b: *std.Build, artifact: *std.Build.Step.Compile) *std.Build.
         else => @compileError("Operating system not supported"),
     };
 }
+
+pub fn build(b: *std.Build) !void {
+    all = b.option(bool, "all", "All") orelse false;
+
+    var unit_test_list = std.ArrayList([]const u8).init(b.allocator);
+    var test_dir = try std.fs.cwd().openIterableDir("test", .{ .access_sub_paths = true });
+    defer test_dir.close();
+
+    var test_dir_iterator = test_dir.iterate();
+
+    while (try test_dir_iterator.next()) |entry| {
+        switch (entry.kind) {
+            .directory => {
+                const dir_name = entry.name;
+                const main_unit_test_source_file = try std.mem.concat(b.allocator, u8, &.{ "test/", dir_name, "/main.nat" });
+                try unit_test_list.append(main_unit_test_source_file);
+            },
+            .file => {},
+            else => @panic("Don't put crap on test directory"),
+        }
+    }
+
+    const target = b.standardTargetOptions(.{});
+    const unit_tests = unit_test_list.items;
+    const test_step = b.step("test", "Test the Nativity compiler");
+
+    if (all) {
+        inline for (@typeInfo(std.builtin.OptimizeMode).Enum.fields) |enum_field| {
+            const optimization = @field(std.builtin.OptimizeMode, enum_field.name);
+            try everythingForTargetAndOptimization(b, target, optimization, unit_tests, test_step);
+        }
+    } else {
+        const optimization = b.standardOptimizeOption(.{});
+        _ = try everythingForTargetAndOptimization(b, target, optimization, unit_tests, test_step);
+    }
+}
diff --git a/src/main.zig b/src/main.zig
index 6ddc0b3..583297d 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -8,11 +8,16 @@ pub const seed = std.math.maxInt(u64);
 const default_src_file = "src/test/main.nat";
 
 pub fn main() !void {
-    try singleCompilation(default_src_file);
+    const allocator = std.heap.page_allocator;
+    const arguments = try std.process.argsAlloc(allocator);
+    if (arguments.len == 2) {
+        try singleCompilation(allocator, arguments[1]);
+    } else {
+        @panic("Wrong arguments");
+    }
 }
 
-fn singleCompilation(main_file_path: []const u8) !void {
-    const allocator = std.heap.page_allocator;
+fn singleCompilation(allocator: Allocator, main_file_path: []const u8) !void {
     const compilation = try Compilation.init(allocator);
 
     try compilation.compileModule(.{
@@ -23,7 +28,3 @@ fn singleCompilation(main_file_path: []const u8) !void {
 test {
     _ = Compilation;
 }
-
-test "basic" {
-    try singleCompilation(default_src_file);
-}
diff --git a/src/test/main.nat b/test/first/main.nat
similarity index 100%
rename from src/test/main.nat
rename to test/first/main.nat