test config validation

pkg/cluster/BUILD.bazel

@@ -1,4 +1,4 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
@@ -24,3 +24,9 @@ filegroup(
     tags = ["automanaged"],
     visibility = ["//visibility:public"],
 )
+
+go_test(
+    name = "go_default_test",
+    srcs = ["config_test.go"],
+    embed = [":go_default_library"],
+)

pkg/cluster/config_test.go

@@ -0,0 +1,77 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cluster
+
+import "testing"
+
+func TestConfigValidate(t *testing.T) {
+	cases := []struct {
+		Name           string
+		Config         Config
+		ExpectedErrors int
+	}{
+		{
+			Name:           "Canonical config",
+			Config:         NewConfig("1"),
+			ExpectedErrors: 0,
+		},
+		{
+			Name: "Invalid name - commas",
+			Config: Config{
+				Name: ",,,,,,",
+			},
+			ExpectedErrors: 1,
+		},
+		{
+			Name: "Invalid name - zero length",
+			Config: Config{
+				Name: "",
+			},
+			ExpectedErrors: 1,
+		},
+		{
+			Name: "Invalid name - invalid character in the middle",
+			Config: Config{
+				Name: "almost-valid@nope",
+			},
+			ExpectedErrors: 1,
+		},
+	}
+
+	for _, tc := range cases {
+		err := tc.Config.Validate()
+		// the error can be:
+		// - nil, in which case we should expect no errors or fail
+		if err == nil {
+			if tc.ExpectedErrors != 0 {
+				t.Errorf("received no errors but expected errors for case %s", tc.Name)
+			}
+			continue
+		}
+		// - not castable to ConfigErrors, in which case we have the wrong error type ...
+		configErrors, ok := err.(ConfigErrors)
+		if !ok {
+			t.Errorf("config.Validate should only return nil or ConfigErrors{...}, got: %v for case: %s", err, tc.Name)
+			continue
+		}
+		// - ConfigErrors, in which case expect a certain number of errors
+		errors := configErrors.Errors()
+		if len(errors) != tc.ExpectedErrors {
+			t.Errorf("expected %d errors but got len(%v) = %d for case: %s", tc.ExpectedErrors, errors, len(errors), tc.Name)
+		}
+	}
+}