Add cross-platform test targets

Author: femiagbabiaka

build.zig

@@ -1,5 +1,17 @@
 const std = @import("std");
 
+const test_targets = [_]std.Target.Query{
+    .{}, // native
+    .{
+        .cpu_arch = .x86_64,
+        .os_tag = .linux,
+    },
+    .{
+        .cpu_arch = .aarch64,
+        .os_tag = .macos,
+    },
+};
+
 pub fn build(b: *std.Build) void {
     const target = b.standardTargetOptions(.{});
     const optimize = b.standardOptimizeOption(.{});
@@ -29,9 +41,14 @@ pub fn build(b: *std.Build) void {
     });
     b.installArtifact(exe);
 
-    const getopt_lib_unit_tests = b.addTest(.{ .root_module = getopt_lib_mod });
-    const run_tests = b.addRunArtifact(getopt_lib_unit_tests);
-
     const test_step = b.step("test", "Run tests");
-    test_step.dependOn(&run_tests.step);
+    for (test_targets) |test_target| {
+        const unit_tests = b.addTest(.{
+            .root_module = getopt_lib_mod,
+            .target = b.resolveTargetQuery(test_target),
+        });
+
+        const run_unit_tests = b.addRunArtifact(unit_tests);
+        test_step.dependOn(&run_unit_tests.step);
+    }
 }