Add tests for get_children of layouts

Partially-fixes: https://github.com/awesomeWM/awesome/issues/1672
Signed-off-by: Uli Schlachter <psychon@znc.in>

spec/wibox/layout/align_spec.lua

@@ -279,6 +279,28 @@ describe("wibox.layout.align", function()
             assert.is.equal(layout_changed, 0)
         end)
     end)
+
+    it("set_children", function()
+        local w1, w2, w3 = { w1 = true }, { w2 = true }, { w3 = true }
+        local layout = align.vertical()
+
+        assert.is.same({}, layout:get_children())
+
+        layout:set_second(w2)
+        assert.is.same({ w2 }, layout:get_children())
+
+        layout:set_first(w1)
+        assert.is.same({ w1, w2 }, layout:get_children())
+
+        layout:set_third(w3)
+        assert.is.same({ w1, w2, w3 }, layout:get_children())
+
+        layout:set_second(nil)
+        assert.is.same({ w1, w3 }, layout:get_children())
+
+        layout:reset()
+        assert.is.same({}, layout:get_children())
+    end)
 end)
 
 -- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80

spec/wibox/layout/fixed_spec.lua

@@ -134,6 +134,21 @@ describe("wibox.layout.fixed", function()
             assert.is.equal(layout_changed, 2)
         end)
     end)
+
+    it("set_children", function()
+        local w1, w2 = base.empty_widget(), base.empty_widget()
+
+        assert.is.same({}, layout:get_children())
+
+        layout:add(w1)
+        assert.is.same({ w1 }, layout:get_children())
+
+        layout:add(w2)
+        assert.is.same({ w1, w2 }, layout:get_children())
+
+        layout:reset()
+        assert.is.same({}, layout:get_children())
+    end)
 end)
 
 -- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80

spec/wibox/layout/flex_spec.lua

@@ -134,6 +134,21 @@ describe("wibox.layout.flex", function()
             assert.is.equal(layout_changed, 2)
         end)
     end)
+
+    it("set_children", function()
+        local w1, w2 = base.empty_widget(), base.empty_widget()
+
+        assert.is.same({}, layout:get_children())
+
+        layout:add(w1)
+        assert.is.same({ w1 }, layout:get_children())
+
+        layout:add(w2)
+        assert.is.same({ w1, w2 }, layout:get_children())
+
+        layout:reset()
+        assert.is.same({}, layout:get_children())
+    end)
 end)
 
 -- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80

spec/wibox/layout/grid_spec.lua

@@ -0,0 +1,30 @@
+---------------------------------------------------------------------------
+-- @author Uli Schlachter
+-- @copyright 2017 Uli Schlachter
+---------------------------------------------------------------------------
+
+local grid = require("wibox.layout.grid")
+local base = require("wibox.widget.base")
+
+describe("wibox.layout.grid", function()
+    it("set_children", function()
+        local layout = grid()
+        local w1, w2 = base.empty_widget(), base.empty_widget()
+
+        assert.is.same({}, layout:get_children())
+
+        layout:add(w1)
+        assert.is.same({ w1 }, layout:get_children())
+
+        layout:add_widget_at(w2, 2, 2)
+        assert.is.same({ w1, w2 }, layout:get_children())
+
+        layout:add_widget_at(w1, 1, 2)
+        assert.is.same({ w1, w2, w1 }, layout:get_children())
+
+        layout:reset()
+        assert.is.same({}, layout:get_children())
+    end)
+end)
+
+-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80