From e76971101b3968d8f3a803e8c481b0093a46ec6a Mon Sep 17 00:00:00 2001
From: Mike <mike@prime31.com>
Date: Sun, 14 Jun 2020 14:53:48 -0700
Subject: [PATCH] fixes and tests

---
 zig-ecs/src/ecs/registry.zig  |  2 +-
 zig-ecs/src/ecs/views.zig     | 10 ++++-----
 zig-ecs/tests/groups_test.zig | 42 +++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/zig-ecs/src/ecs/registry.zig b/zig-ecs/src/ecs/registry.zig
index a6c8e0d..58ed069 100644
--- a/zig-ecs/src/ecs/registry.zig
+++ b/zig-ecs/src/ecs/registry.zig
@@ -231,7 +231,7 @@ pub const Registry = struct {
 
     /// Returns the number of existing components of the given type
     pub fn len(self: *Registry, comptime T: type) usize {
-        self.assure(T).len();
+        return self.assure(T).len();
     }
 
     /// Increases the capacity of the registry or of the pools for the given component
diff --git a/zig-ecs/src/ecs/views.zig b/zig-ecs/src/ecs/views.zig
index 65506f4..44f12fa 100644
--- a/zig-ecs/src/ecs/views.zig
+++ b/zig-ecs/src/ecs/views.zig
@@ -43,12 +43,12 @@ pub fn BasicView(comptime T: type) type {
             return self.storage.getConst(entity);
         }
 
-        pub fn entityIterator(self: Self) utils.ReverseSliceIterator(Entity) {
-            return self.storage.set.reverseIterator();
+        pub fn iterator(self: Self) utils.ReverseSliceIterator(T) {
+            return utils.ReverseSliceIterator(T).init(self.storage.instances.items);
         }
 
-        pub fn componentIterator(self: Self) utils.ReverseSliceIterator(T) {
-            return utils.ReverseSliceIterator(T).init(self.storage.instances.items);
+        pub fn entityIterator(self: Self) utils.ReverseSliceIterator(Entity) {
+            return self.storage.set.reverseIterator();
         }
     };
 }
@@ -165,7 +165,7 @@ test "single basic view" {
     std.testing.expectEqual(view.len(), 2);
 
     var i: usize = 0;
-    var iter = view.componentIterator();
+    var iter = view.iterator();
     while (iter.next()) |comp| {
         if (i == 0) std.testing.expectEqual(comp, 50);
         if (i == 1) std.testing.expectEqual(comp, 30);
diff --git a/zig-ecs/tests/groups_test.zig b/zig-ecs/tests/groups_test.zig
index 39b3b4a..94c93f6 100644
--- a/zig-ecs/tests/groups_test.zig
+++ b/zig-ecs/tests/groups_test.zig
@@ -145,6 +145,48 @@ test "sort OwningGroup by Component" {
     }
 }
 
+test "sort OwningGroup by Component ensure unsorted non-matches" {
+    var reg = Registry.init(std.testing.allocator);
+    defer reg.deinit();
+
+    var group = reg.group(.{ Sprite, Renderable }, .{}, .{});
+
+    var i: usize = 0;
+    while (i < 5) : (i += 1) {
+        var e = reg.create();
+        reg.add(e, Sprite{ .x = @intToFloat(f32, i) });
+        reg.add(e, Renderable{ .x = @intToFloat(f32, i) });
+
+        var e2 = reg.create();
+        reg.add(e2, Sprite{ .x = @intToFloat(f32, i + 1 * 50) });
+    }
+
+    std.testing.expectEqual(group.len(), 5);
+    std.testing.expectEqual(reg.len(Sprite), 10);
+
+    const SortContext = struct {
+        fn sort(this: void, a: Sprite, b: Sprite) bool {
+            // sprites with x > 50 shouldnt match in the group
+            std.testing.expect(a.x < 50 and b.x < 50);
+            return a.x > b.x;
+        }
+    };
+    group.sort(Sprite, {}, SortContext.sort);
+
+    // all the
+    var view = reg.view(.{Sprite}, .{});
+    var count: usize = 0;
+    var iter = view.iterator();
+    while (iter.next()) |sprite| {
+        count += 1;
+
+        // all sprite.x > 50 should be at the end and we iterate backwards
+        if (count < 6) {
+            std.testing.expect(sprite.x >= 50);
+        }
+    }
+}
+
 test "nested OwningGroups add/remove components" {
     var reg = Registry.init(std.testing.allocator);
     defer reg.deinit();