tests: fix plenary after_each inconsistency (closes #1)

Author: mochaaP

test/minimal_init.lua

@@ -9,7 +9,8 @@ end
 function M.load(plugin)
     local name = plugin:match(".*/(.*)")
     local package_root = M.root(".tests/site/pack/deps/start/")
-    if not vim.uv.fs_stat(package_root .. name) then
+    local uv = vim.uv or vim.loop
+    if not uv.fs_stat(package_root .. name) then
         print("Installing " .. plugin)
         vim.fn.mkdir(package_root, "p")
         vim.fn.system({

test/spec/diagnostics_spec.lua

@@ -113,6 +113,19 @@ describe("diagnostics", function()
                     assert.stub(diagnostic_api.set).was_called(2)
                 end)
 
+                it("should call handler only once if buffer changed in between callbacks", function()
+                    diagnostics.handler(mock_params)
+
+                    local new_params = vim.deepcopy(mock_params)
+                    new_params.textDocument.version = 9999
+                    diagnostics.handler(new_params)
+
+                    generators.run_registered.calls[2].refs[1].after_each(mock_diagnostics, new_params, mock_generator)
+                    generators.run_registered.calls[1].refs[1].after_each(mock_diagnostics, mock_params, mock_generator)
+
+                    assert.stub(diagnostic_api.set).was_called(1)
+                end)
+
                 it("should call handler on each callback if buffer changed but method is different", function()
                     diagnostics.handler(mock_params)
                     generators.run_registered.calls[1].refs[1].after_each(mock_diagnostics, mock_params, mock_generator)