Test whether auto-generated conversions weren't manually edited

pkg/api/v1beta3/conversion.go

@@ -24,6 +24,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/conversion"
 )
 
+// AUTO-GENERATED FUNCTIONS START HERE
 func convert_v1beta3_AWSElasticBlockStoreVolumeSource_To_api_AWSElasticBlockStoreVolumeSource(in *AWSElasticBlockStoreVolumeSource, out *newer.AWSElasticBlockStoreVolumeSource, s conversion.Scope) error {
 	out.VolumeID = in.VolumeID
 	out.FSType = in.FSType
@@ -2914,6 +2915,8 @@ func convert_api_VolumeSource_To_v1beta3_VolumeSource(in *newer.VolumeSource, ou
 	return nil
 }
 
+// AUTO-GENERATED FUNCTIONS END HERE
+
 func init() {
 	err := newer.Scheme.AddGeneratedConversionFuncs(
 		convert_api_AWSElasticBlockStoreVolumeSource_To_v1beta3_AWSElasticBlockStoreVolumeSource,

pkg/conversion/code_generation_test.go

@@ -0,0 +1,151 @@
+/*
+Copyright 2015 Google Inc. All rights reserved.
+
+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 conversion_test
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/conversion"
+
+	"github.com/golang/glog"
+)
+
+func generateConversions(t *testing.T, version string) (bytes.Buffer, bytes.Buffer) {
+	g := conversion.NewGenerator(api.Scheme.Raw())
+	g.OverwritePackage(version, "")
+	g.OverwritePackage("api", "newer")
+	for _, knownType := range api.Scheme.KnownTypes(version) {
+		if err := g.GenerateConversionsForType(version, knownType); err != nil {
+			glog.Errorf("error while generating conversion functions for %v: %v", knownType, err)
+		}
+	}
+
+	var functions bytes.Buffer
+	functionsWriter := bufio.NewWriter(&functions)
+	if err := g.WriteConversionFunctions(functionsWriter); err != nil {
+		t.Fatalf("couldn't generate conversion functions: %v", err)
+	}
+	if err := functionsWriter.Flush(); err != nil {
+		t.Fatalf("error while flushing writer")
+	}
+
+	var names bytes.Buffer
+	namesWriter := bufio.NewWriter(&names)
+	if err := g.WriteConversionFunctionNames(namesWriter); err != nil {
+		t.Fatalf("couldn't generate conversion function names: %v", err)
+	}
+	if err := namesWriter.Flush(); err != nil {
+		t.Fatalf("error while flushing writer")
+	}
+
+	return functions, names
+}
+
+func readLinesUntil(t *testing.T, reader *bufio.Reader, stop string, buffer *bytes.Buffer) error {
+	for {
+		line, err := reader.ReadString('\n')
+		if err == io.EOF {
+			return fmt.Errorf("'%s' line not found", stop)
+		}
+		if err != nil {
+			t.Fatalf("error while reading file: %v", err)
+		}
+		if line == stop {
+			break
+		}
+		if buffer != nil {
+			if _, err := buffer.WriteString(line); err != nil {
+				t.Fatalf("error while buffering line")
+			}
+		}
+	}
+	return nil
+}
+
+func bufferExistingConversions(t *testing.T, fileName string) (bytes.Buffer, bytes.Buffer) {
+	file, err := os.Open(fileName)
+	if err != nil {
+		t.Fatalf("couldn't open file %s", fileName)
+	}
+	defer file.Close()
+
+	reader := bufio.NewReader(file)
+
+	functionsPrefix := "// AUTO-GENERATED FUNCTIONS START HERE\n"
+	functionsSuffix := "// AUTO-GENERATED FUNCTIONS END HERE\n"
+	if err := readLinesUntil(t, reader, functionsPrefix, nil); err != nil {
+		t.Fatalf("error while parsing file: %v", err)
+	}
+	var functions bytes.Buffer
+	if err := readLinesUntil(t, reader, functionsSuffix, &functions); err != nil {
+		t.Fatalf("error while parsing file: %v", err)
+	}
+
+	functionNamesPrefix := "\terr := newer.Scheme.AddGeneratedConversionFuncs(\n"
+	functionNamesSuffix := "\t)\n"
+	if err := readLinesUntil(t, reader, functionNamesPrefix, nil); err != nil {
+		t.Fatalf("error while parsing file: %v", err)
+	}
+	var names bytes.Buffer
+	if err := readLinesUntil(t, reader, functionNamesSuffix, &names); err != nil {
+		t.Fatalf("error while parsing file: %v", err)
+	}
+
+	return functions, names
+}
+
+func compareBuffers(t *testing.T, existing, generated bytes.Buffer) {
+	for {
+		existingLine, existingErr := existing.ReadString('\n')
+		generatedLine, generatedErr := generated.ReadString('\n')
+		if existingErr == io.EOF && generatedErr == io.EOF {
+			break
+		}
+		if existingErr != generatedErr {
+			t.Errorf("reading errors: existing %v generated %v", existingErr, generatedErr)
+			return
+		}
+		if existingErr != nil {
+			t.Errorf("error while reading: %v", existingErr)
+		}
+		if existingLine != generatedLine {
+			diff := fmt.Sprintf("first difference: expected %s, got %s", generatedLine, existingLine)
+			t.Errorf("please regenerate conversion functions; %s", diff)
+			return
+		}
+	}
+}
+
+func TestNoManualChangesToGenerateConversions(t *testing.T) {
+	versions := []string{"v1beta3"}
+
+	for _, version := range versions {
+		fileName := fmt.Sprintf("../../pkg/api/%s/conversion.go", version)
+
+		existingFunctions, existingNames := bufferExistingConversions(t, fileName)
+		generatedFunctions, generatedNames := generateConversions(t, version)
+
+		compareBuffers(t, existingFunctions, generatedFunctions)
+		compareBuffers(t, existingNames, generatedNames)
+	}
+}