refactor(test): create an lsp-specific helpers.lua file

* move the code for creating fake rpc servers there

1 files changed, 178 insertions, 0 deletions

diff --git a/test/functional/plugin/lsp/helpers.lua b/test/functional/plugin/lsp/helpers.lua
new file mode 100644
index 0000000000..41b4db75cf
--- /dev/null
+++ b/test/functional/plugin/lsp/helpers.lua
@@ -0,0 +1,178 @@
+local helpers = require('test.functional.helpers')(after_each)
+
+local clear = helpers.clear
+local exec_lua = helpers.exec_lua
+local run = helpers.run
+local stop = helpers.stop
+local NIL = helpers.NIL
+
+local M = {}
+
+function M.clear_notrace()
+  -- problem: here be dragons
+  -- solution: don't look too closely for dragons
+  clear {env={
+    NVIM_LUA_NOTRACK="1";
+    VIMRUNTIME=os.getenv"VIMRUNTIME";
+  }}
+end
+
+M.create_server_definition = [[
+  function _create_server(opts)
+    opts = opts or {}
+    local server = {}
+    server.messages = {}
+
+    function server.cmd(dispatchers)
+      local closing = false
+      local handlers = opts.handlers or {}
+      local srv = {}
+
+      function srv.request(method, params, callback)
+        table.insert(server.messages, {
+          method = method,
+          params = params,
+        })
+        local handler = handlers[method]
+        if handler then
+          local response, err = handler(method, params)
+          if response then
+            callback(err, response)
+          end
+        elseif method == 'initialize' then
+          callback(nil, {
+            capabilities = opts.capabilities or {}
+          })
+        elseif method == 'shutdown' then
+          callback(nil, nil)
+        end
+        local request_id = #server.messages
+        return true, request_id
+      end
+
+      function srv.notify(method, params)
+        table.insert(server.messages, {
+          method = method,
+          params = params
+        })
+        if method == 'exit' then
+          dispatchers.on_exit(0, 15)
+        end
+      end
+
+      function srv.is_closing()
+        return closing
+      end
+
+      function srv.terminate()
+        closing = true
+      end
+
+      return srv
+    end
+
+    return server
+  end
+]]
+
+-- Fake LSP server.
+M.fake_lsp_code = 'test/functional/fixtures/fake-lsp-server.lua'
+M.fake_lsp_logfile = 'Xtest-fake-lsp.log'
+
+local function fake_lsp_server_setup(test_name, timeout_ms, options, settings)
+  exec_lua([=[
+    lsp = require('vim.lsp')
+    local test_name, fixture_filename, logfile, timeout, options, settings = ...
+    TEST_RPC_CLIENT_ID = lsp.start_client {
+      cmd_env = {
+        NVIM_LOG_FILE = logfile;
+        NVIM_LUA_NOTRACK = "1";
+      };
+      cmd = {
+        vim.v.progpath, '-Es', '-u', 'NONE', '--headless',
+        "-c", string.format("lua TEST_NAME = %q", test_name),
+        "-c", string.format("lua TIMEOUT = %d", timeout),
+        "-c", "luafile "..fixture_filename,
+      };
+      handlers = setmetatable({}, {
+        __index = function(t, method)
+          return function(...)
+            return vim.rpcrequest(1, 'handler', ...)
+          end
+        end;
+      });
+      workspace_folders = {{
+          uri = 'file://' .. vim.loop.cwd(),
+          name = 'test_folder',
+      }};
+      on_init = function(client, result)
+        TEST_RPC_CLIENT = client
+        vim.rpcrequest(1, "init", result)
+      end;
+      flags = {
+        allow_incremental_sync = options.allow_incremental_sync or false;
+        debounce_text_changes = options.debounce_text_changes or 0;
+      };
+      settings = settings;
+      on_exit = function(...)
+        vim.rpcnotify(1, "exit", ...)
+      end;
+    }
+  ]=], test_name, M.fake_lsp_code, M.fake_lsp_logfile, timeout_ms or 1e3, options or {}, settings or {})
+end
+
+function M.test_rpc_server(config)
+  if config.test_name then
+    M.clear_notrace()
+    fake_lsp_server_setup(config.test_name, config.timeout_ms or 1e3, config.options, config.settings)
+  end
+  local client = setmetatable({}, {
+    __index = function(_, name)
+      -- Workaround for not being able to yield() inside __index for Lua 5.1 :(
+      -- Otherwise I would just return the value here.
+      return function(...)
+        return exec_lua([=[
+        local name = ...
+        if type(TEST_RPC_CLIENT[name]) == 'function' then
+          return TEST_RPC_CLIENT[name](select(2, ...))
+        else
+          return TEST_RPC_CLIENT[name]
+        end
+        ]=], name, ...)
+      end
+    end;
+  })
+  local code, signal
+  local function on_request(method, args)
+    if method == "init" then
+      if config.on_init then
+        config.on_init(client, unpack(args))
+      end
+      return NIL
+    end
+    if method == 'handler' then
+      if config.on_handler then
+        config.on_handler(unpack(args))
+      end
+    end
+    return NIL
+  end
+  local function on_notify(method, args)
+    if method == 'exit' then
+      code, signal = unpack(args)
+      return stop()
+    end
+  end
+  --  TODO specify timeout?
+  --  run(on_request, on_notify, config.on_setup, 1000)
+  run(on_request, on_notify, config.on_setup)
+  if config.on_exit then
+    config.on_exit(code, signal)
+  end
+  stop()
+  if config.test_name then
+    exec_lua("vim.api.nvim_exec_autocmds('VimLeavePre', { modeline = false })")
+  end
+end
+
+return M