perf(helpers): only validate opts on first run

Author: Jose Alvarez

lua/null-ls/helpers.lua

@@ -50,31 +50,34 @@ local formats = {
 }
 
 M.generator_factory = function(opts)
+    local command, args, on_output, format, to_stderr, to_stdin, ignore_errors,
+          check_exit_code = opts.command, opts.args, opts.on_output,
+                            opts.format, opts.to_stderr, opts.to_stdin,
+                            opts.ignore_errors, opts.check_exit_code
+
+    local _validated
+    local validate_opts = function()
+        validate({
+            command = {command, "string"},
+            args = {args, "table", true},
+            on_output = {on_output, "function"},
+            format = {
+                format, function(a)
+                    return not a or vim.tbl_contains(vim.tbl_values(formats), a)
+                end, "raw, line, or json"
+            },
+            to_stderr = {to_stderr, "boolean", true},
+            to_stdin = {to_stdin, "boolean", true},
+            ignore_errors = {ignore_errors, "boolean", true},
+            check_exit_code = {check_exit_code, "function", true}
+        })
+
+        _validated = true
+    end
+
     return {
         fn = function(params, done)
-            local command, args, on_output, format, to_stderr, to_stdin,
-                  ignore_errors, check_exit_code = opts.command, opts.args,
-                                                   opts.on_output, opts.format,
-                                                   opts.to_stderr,
-                                                   opts.to_stdin,
-                                                   opts.ignore_errors,
-                                                   opts.check_exit_code
-
-            validate({
-                command = {command, "string"},
-                args = {args, "table", true},
-                on_output = {on_output, "function"},
-                format = {
-                    format, function(a)
-                        return not a or
-                                   vim.tbl_contains(vim.tbl_values(formats), a)
-                    end, "raw, line, or json"
-                },
-                to_stderr = {to_stderr, "boolean", true},
-                to_stdin = {to_stdin, "boolean", true},
-                ignore_errors = {ignore_errors, "boolean", true},
-                check_exit_code = {check_exit_code, "function", true}
-            })
+            if not _validated then validate_opts() end
 
             local wrapper = function(error_output, output)
                 if to_stderr then

test/spec/helpers_spec.lua

@@ -5,16 +5,19 @@ local test_utils = require("test.utils")
 
 describe("helpers", function()
     _G._TEST = true
-    local helpers = require("null-ls.helpers")
+
+    stub(vim, "validate")
 
     local done = stub.new()
     local on_output = stub.new()
 
     after_each(function()
         done:clear()
         on_output:clear()
+        vim.validate:clear()
     end)
 
+    local helpers = require("null-ls.helpers")
     describe("json_output_wrapper", function()
         it("should throw error if json decode fails", function()
             local bad_json = "this is not json"
@@ -88,8 +91,26 @@ describe("helpers", function()
         end)
 
         after_each(function()
-            vim.cmd("bufdo! bwipeout!")
             loop.spawn:clear()
+
+            vim.cmd("bufdo! bwipeout!")
+        end)
+
+        it("should validate opts on first run", function()
+            local generator = helpers.generator_factory(generator_args)
+
+            generator.fn({})
+
+            assert.stub(vim.validate).was_called()
+        end)
+
+        it("should not validate opts on subsequent runs", function()
+            local generator = helpers.generator_factory(generator_args)
+
+            generator.fn({})
+            generator.fn({})
+
+            assert.stub(vim.validate).was_called(1)
         end)
 
         it("should set async to true", function()