Add Entity tests for adding and checking tags

test/entity.zig

@@ -23,7 +23,6 @@ test "Entity_init_id" {
     defer world.deinit();
 
     const e = try world.entity(.{}, .{});
-    // try expect(e.raw != 0); -- Not necessary, world.entity() returns error if result would be 0.
     try expect(c.ecs_get_type(world.raw, e.raw) == null);
 }
 
@@ -33,7 +32,6 @@ test "Entity_init_id_name" {
     defer world.deinit();
 
     const e = try world.entity(.{ .name = "foo" }, .{});
-    // try expect(e.raw != 0); -- Not necessary, world.entity() returns error if result would be 0.
     try expectEqualStrings("foo", e.getName().?);
 
     const path2 = try e.getPath(flecs.allocator);
@@ -49,10 +47,38 @@ test "Entity_init_id_path" {
     const p = try Path.fromString("parent.child", null, flecs.allocator);
     defer p.deinit();
     const e = try world.entity(.{ .path = p }, .{});
-    // try expect(e.raw != 0); -- Not necessary, world.entity() returns error if result would be 0.
     try expectEqualStrings("child", e.getName().?);
 
     const path = try e.getPath(flecs.allocator);
     defer path.deinit();
     try expectFmt("parent.child", "{}", .{path});
 }
+
+test "Entity_init_id_add_1_comp" {
+    const TagA = struct {};
+
+    flecs.init(std.testing.allocator);
+    var world = try World.initMinimal();
+    defer world.deinit();
+
+    _ = try world.tag(TagA);
+
+    const e = try world.entity(.{}, .{TagA});
+    try expect(e.has(TagA));
+}
+
+test "Entity_init_id_add_2_comp" {
+    const TagA = struct {};
+    const TagB = struct {};
+
+    flecs.init(std.testing.allocator);
+    var world = try World.initMinimal();
+    defer world.deinit();
+
+    _ = try world.tag(TagA);
+    _ = try world.tag(TagB);
+
+    const e = try world.entity(.{}, .{ TagA, TagB });
+    try expect(e.has(TagA));
+    try expect(e.has(TagB));
+}