Add e2e tests for build/diff kustomization

Signed-off-by: Soule BA <soule@weave.works>

cmd/flux/build_kustomization_test.go

@@ -0,0 +1,83 @@
+//go:build unit
+// +build unit
+
+/*
+Copyright 2021 The Flux 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 main
+
+import (
+	"testing"
+)
+
+func setup(t *testing.T, tmpl map[string]string) {
+	t.Helper()
+	testEnv.CreateObjectFile("./testdata/build-kustomization/podinfo-source.yaml", tmpl, t)
+	testEnv.CreateObjectFile("./testdata/build-kustomization/podinfo-kustomization.yaml", tmpl, t)
+}
+
+func TestBuildKustomization(t *testing.T) {
+	tests := []struct {
+		name       string
+		args       string
+		resultFile string
+		assertFunc string
+	}{
+		{
+			name:       "no args",
+			args:       "build kustomization podinfo",
+			resultFile: "invalid resource path \"\"",
+			assertFunc: "assertError",
+		},
+		{
+			name:       "build podinfo",
+			args:       "build kustomization podinfo --path ./testdata/build-kustomization/podinfo",
+			resultFile: "./testdata/build-kustomization/podinfo-result.yaml",
+			assertFunc: "assertGoldenTemplateFile",
+		},
+		{
+			name:       "build podinfo without service",
+			args:       "build kustomization podinfo --path ./testdata/build-kustomization/delete-service",
+			resultFile: "./testdata/build-kustomization/podinfo-without-service-result.yaml",
+			assertFunc: "assertGoldenTemplateFile",
+		},
+	}
+
+	tmpl := map[string]string{
+		"fluxns": allocateNamespace("flux-system"),
+	}
+	setup(t, tmpl)
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var assert assertFunc
+
+			switch tt.assertFunc {
+			case "assertGoldenTemplateFile":
+				assert = assertGoldenTemplateFile(tt.resultFile, tmpl)
+			case "assertError":
+				assert = assertError(tt.resultFile)
+			}
+
+			cmd := cmdTestCase{
+				args:   tt.args + " -n " + tmpl["fluxns"],
+				assert: assert,
+			}
+
+			cmd.runTestCmd(t)
+		})
+	}
+}