tests: Fix the tests then notify-send is not installed.

Fix #2684

tests/test-naughty-legacy.lua

@@ -92,21 +92,45 @@ local function destroyed_callback(n, reason)
     table.insert(destroyed, n)
 end
 
-naughty.connect_signal("destroyed", destroyed_callback)
+-- Test vertical overlapping
+local function test_overlap()
+    local wa = mouse.screen.workarea
 
+    for _, n1 in ipairs(active) do
+        assert(n1.box)
+        assert(n1.id)
+
+        -- Check for overlapping the workarea
+        assert(n1.box.y+default_height < wa.y+wa.height)
+        assert(n1.box.y >= wa.y)
+
+        -- Check for overlapping each other
+        for _, n2 in ipairs(active) do
+            assert(n2.box)
+            if n1 ~= n2 then
+                local geo1, geo2 = n1.box:geometry(), n2.box:geometry()
+                assert(geo1.height == geo2.height)
+                assert(geo1.height + 2*n1.box.border_width + naughty.config.spacing
+                    == default_height)
+
+                if n1.position == n2.position then
+                    assert(
+                        geo1.y >= geo2.y+default_height or
+                        geo2.y >= geo1.y+default_height
+                    )
+                end
+            end
+        end
+    end
+end
+
+-- Set the default size.
 table.insert(steps, function()
-    if not has_cmd_notify then return true end
 
-    spawn{ 'notify-send', 'title', 'message', '-t', '25000' }
-
-    return true
-end)
-
-table.insert(steps, function()
-    if not has_cmd_notify then return true end
-    if #active ~= 1 then return end
-
-    local n = active[1]
+    local n = naughty.notification {
+        title   = "title",
+        message = "message"
+    }
 
     assert(n.box)
     local offset = 2*n.box.border_width
@@ -116,6 +140,29 @@ table.insert(steps, function()
     assert(default_width  > 0)
     assert(default_height > 0)
 
+    n:destroy()
+
+    -- This one doesn't count.
+    active, destroyed, reasons, counter = {}, {}, {}, 0
+    return true
+end)
+
+naughty.connect_signal("destroyed", destroyed_callback)
+
+if has_cmd_notify then
+    table.insert(steps, function()
+        spawn{ 'notify-send', 'title', 'message', '-t', '25000' }
+
+        return true
+    end)
+
+    table.insert(steps, function()
+        if #active ~= 1 then return end
+
+        local n = active[1]
+
+        assert(n.box)
+
         -- Make sure the expiration timer is started
         assert(n.timer)
         assert(n.timer.started)
@@ -251,38 +298,6 @@ table.insert(steps, function()
         return true
     end)
 
--- Test vertical overlapping
-local function test_overlap()
-    local wa = mouse.screen.workarea
-
-    for _, n1 in ipairs(active) do
-        assert(n1.box)
-        assert(n1.id)
-
-        -- Check for overlapping the workarea
-        assert(n1.box.y+default_height < wa.y+wa.height)
-        assert(n1.box.y >= wa.y)
-
-        -- Check for overlapping each other
-        for _, n2 in ipairs(active) do
-            assert(n2.box)
-            if n1 ~= n2 then
-                local geo1, geo2 = n1.box:geometry(), n2.box:geometry()
-                assert(geo1.height == geo2.height)
-                assert(geo1.height + 2*n1.box.border_width + naughty.config.spacing
-                    == default_height)
-
-                if n1.position == n2.position then
-                    assert(
-                        geo1.y >= geo2.y+default_height or
-                        geo2.y >= geo1.y+default_height
-                    )
-                end
-            end
-        end
-    end
-end
-
     -- Check the lack of overlapping and the presence of the expected content.
     table.insert(steps, function()
         local wa = mouse.screen.workarea
@@ -322,6 +337,8 @@ table.insert(steps, function()
         return true
     end)
 
+end
+
 local positions = {
     "top_left"      , "top_middle"    , "top_right"     ,
     "bottom_left"   , "bottom_middle" , "bottom_right"  ,