Export scaffolding machinery

Signed-off-by: Adrian Orive <adrian.orive.oneca@gmail.com>

Makefile

@@ -97,7 +97,7 @@ test-unit: ## Run the unit tests
 .PHONY: test-coverage
 test-coverage: ## Run unit tests creating the output to report coverage
 	- rm -rf *.out  # Remove all coverage files if exists
-	go test -race -failfast -tags=integration -coverprofile=coverage-all.out -coverpkg="./pkg/cli/...,./pkg/config/...,./pkg/internal/...,./pkg/model/...,./pkg/plugin/...,./pkg/plugins/golang,./pkg/plugins/internal/..." ./pkg/...
+	go test -race -failfast -tags=integration -coverprofile=coverage-all.out -coverpkg="./pkg/cli/...,./pkg/config/...,./pkg/internal/...,./pkg/machinery/...,./pkg/model/...,./pkg/plugin/...,./pkg/plugins/golang" ./pkg/...
 
 .PHONY: test-integration
 test-integration: ## Run the integration tests

pkg/machinery/errors.go

@@ -0,0 +1,157 @@
+/*
+Copyright 2020 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 machinery
+
+import (
+	"fmt"
+
+	"sigs.k8s.io/kubebuilder/v3/pkg/model/file"
+)
+
+// This file contains the errors returned by the scaffolding machinery
+// They are exported to be able to check which kind of error was returned
+
+// ValidateError is a wrapper error that will be used for errors returned by RequiresValidation.Validate
+type ValidateError struct {
+	error
+}
+
+// Unwrap implements Wrapper interface
+func (e ValidateError) Unwrap() error {
+	return e.error
+}
+
+// SetTemplateDefaultsError is a wrapper error that will be used for errors returned by Template.SetTemplateDefaults
+type SetTemplateDefaultsError struct {
+	error
+}
+
+// Unwrap implements Wrapper interface
+func (e SetTemplateDefaultsError) Unwrap() error {
+	return e.error
+}
+
+// PluginError is a wrapper error that will be used for errors returned by model.Plugin.Pipe
+type PluginError struct {
+	error
+}
+
+// Unwrap implements Wrapper interface
+func (e PluginError) Unwrap() error {
+	return e.error
+}
+
+// ExistsFileError is a wrapper error that will be used for errors when checking for a file existence
+type ExistsFileError struct {
+	error
+}
+
+// Unwrap implements Wrapper interface
+func (e ExistsFileError) Unwrap() error {
+	return e.error
+}
+
+// OpenFileError is a wrapper error that will be used for errors when opening a file
+type OpenFileError struct {
+	error
+}
+
+// Unwrap implements Wrapper interface
+func (e OpenFileError) Unwrap() error {
+	return e.error
+}
+
+// CreateDirectoryError is a wrapper error that will be used for errors when creating a directory
+type CreateDirectoryError struct {
+	error
+}
+
+// Unwrap implements Wrapper interface
+func (e CreateDirectoryError) Unwrap() error {
+	return e.error
+}
+
+// CreateFileError is a wrapper error that will be used for errors when creating a file
+type CreateFileError struct {
+	error
+}
+
+// Unwrap implements Wrapper interface
+func (e CreateFileError) Unwrap() error {
+	return e.error
+}
+
+// ReadFileError is a wrapper error that will be used for errors when reading a file
+type ReadFileError struct {
+	error
+}
+
+// Unwrap implements Wrapper interface
+func (e ReadFileError) Unwrap() error {
+	return e.error
+}
+
+// WriteFileError is a wrapper error that will be used for errors when writing a file
+type WriteFileError struct {
+	error
+}
+
+// Unwrap implements Wrapper interface
+func (e WriteFileError) Unwrap() error {
+	return e.error
+}
+
+// CloseFileError is a wrapper error that will be used for errors when closing a file
+type CloseFileError struct {
+	error
+}
+
+// Unwrap implements Wrapper interface
+func (e CloseFileError) Unwrap() error {
+	return e.error
+}
+
+// ModelAlreadyExistsError is returned if the file is expected not to exist but a previous model does
+type ModelAlreadyExistsError struct {
+	path string
+}
+
+// Error implements error interface
+func (e ModelAlreadyExistsError) Error() string {
+	return fmt.Sprintf("failed to create %s: model already exists", e.path)
+}
+
+// UnknownIfExistsActionError is returned if the if-exists-action is unknown
+type UnknownIfExistsActionError struct {
+	path           string
+	ifExistsAction file.IfExistsAction
+}
+
+// Error implements error interface
+func (e UnknownIfExistsActionError) Error() string {
+	return fmt.Sprintf("unknown behavior if file exists (%d) for %s", e.ifExistsAction, e.path)
+}
+
+// FileAlreadyExistsError is returned if the file is expected not to exist but it does
+type FileAlreadyExistsError struct {
+	path string
+}
+
+// Error implements error interface
+func (e FileAlreadyExistsError) Error() string {
+	return fmt.Sprintf("failed to create %s: file already exists", e.path)
+}

pkg/machinery/errors_test.go

@@ -0,0 +1,56 @@
+/*
+Copyright 2020 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 machinery
+
+import (
+	"errors"
+	"path/filepath"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/ginkgo/extensions/table"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Errors", func() {
+	var (
+		path    = filepath.Join("path", "to", "file")
+		testErr = errors.New("test error")
+	)
+
+	DescribeTable("should contain the wrapped error",
+		func(err error) {
+			Expect(errors.Is(err, testErr)).To(BeTrue())
+		},
+		Entry("for validate errors", ValidateError{testErr}),
+		Entry("for set template defaults errors", SetTemplateDefaultsError{testErr}),
+		Entry("for plugin errors", PluginError{testErr}),
+		Entry("for file existence errors", ExistsFileError{testErr}),
+		Entry("for file opening errors", OpenFileError{testErr}),
+		Entry("for directory creation errors", CreateDirectoryError{testErr}),
+		Entry("for file creation errors", CreateFileError{testErr}),
+		Entry("for file reading errors", ReadFileError{testErr}),
+		Entry("for file writing errors", WriteFileError{testErr}),
+		Entry("for file closing errors", CloseFileError{testErr}),
+	)
+
+	// NOTE: the following test increases coverage
+	It("should print a descriptive error message", func() {
+		Expect(ModelAlreadyExistsError{path}.Error()).To(ContainSubstring("model already exists"))
+		Expect(UnknownIfExistsActionError{path, -1}.Error()).To(ContainSubstring("unknown behavior if file exists"))
+		Expect(FileAlreadyExistsError{path}.Error()).To(ContainSubstring("file already exists"))
+	})
+})