Script for automatically generate conversions.

pkg/runtime/conversion_generation_test.go

@@ -33,7 +33,7 @@ import (
 	"github.com/golang/glog"
 )
 
-func generateConversions(t *testing.T, version string) (bytes.Buffer, bytes.Buffer) {
+func generateConversions(t *testing.T, version string) bytes.Buffer {
 	g := runtime.NewConversionGenerator(api.Scheme.Raw())
 	g.OverwritePackage(version, "")
 	g.OverwritePackage("api", "newer")
@@ -51,17 +51,14 @@ func generateConversions(t *testing.T, version string) (bytes.Buffer, bytes.Buff
 	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 {
+	if err := g.RegisterConversionFunctions(functionsWriter); err != nil {
 		t.Fatalf("couldn't generate conversion function names: %v", err)
 	}
-	if err := namesWriter.Flush(); err != nil {
+	if err := functionsWriter.Flush(); err != nil {
 		t.Fatalf("error while flushing writer")
 	}
 
-	return functions, names
+	return functions
 }
 
 func readLinesUntil(t *testing.T, reader *bufio.Reader, stop string, buffer *bytes.Buffer) error {
@@ -85,7 +82,7 @@ func readLinesUntil(t *testing.T, reader *bufio.Reader, stop string, buffer *byt
 	return nil
 }
 
-func bufferExistingConversions(t *testing.T, fileName string) (bytes.Buffer, bytes.Buffer) {
+func bufferExistingConversions(t *testing.T, fileName string) bytes.Buffer {
 	file, err := os.Open(fileName)
 	if err != nil {
 		t.Fatalf("couldn't open file %s", fileName)
@@ -103,18 +100,11 @@ func bufferExistingConversions(t *testing.T, fileName string) (bytes.Buffer, byt
 	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)
+	_, err = reader.ReadString('\n')
+	if err == nil || err != io.EOF {
+		t.Fatalf("end-of-file expected")
 	}
-	var names bytes.Buffer
-	if err := readLinesUntil(t, reader, functionNamesSuffix, &names); err != nil {
-		t.Fatalf("error while parsing file: %v", err)
-	}
-
-	return functions, names
+	return functions
 }
 
 func compareBuffers(t *testing.T, generatedFile string, existing, generated bytes.Buffer) bool {
@@ -150,20 +140,14 @@ func TestNoManualChangesToGenerateConversions(t *testing.T) {
 	for _, version := range versions {
 		fileName := fmt.Sprintf("../../pkg/api/%s/conversion_generated.go", version)
 
-		existingFunctions, existingNames := bufferExistingConversions(t, fileName)
-		generatedFunctions, generatedNames := generateConversions(t, version)
+		existingFunctions := bufferExistingConversions(t, fileName)
+		generatedFunctions := generateConversions(t, version)
 
 		functionsTxt := fmt.Sprintf("%s.functions.txt", version)
 		ioutil.WriteFile(functionsTxt, generatedFunctions.Bytes(), os.FileMode(0644))
 
-		namesTxt := fmt.Sprintf("%s.names.txt", version)
-		ioutil.WriteFile(namesTxt, generatedNames.Bytes(), os.FileMode(0644))
-
 		if ok := compareBuffers(t, functionsTxt, existingFunctions, generatedFunctions); ok {
 			os.Remove(functionsTxt)
 		}
-		if ok := compareBuffers(t, namesTxt, existingNames, generatedNames); ok {
-			os.Remove(namesTxt)
-		}
 	}
 }

pkg/runtime/conversion_generator.go

@@ -29,7 +29,7 @@ import (
 type ConversionGenerator interface {
 	GenerateConversionsForType(version string, reflection reflect.Type) error
 	WriteConversionFunctions(w io.Writer) error
-	WriteConversionFunctionNames(w io.Writer) error
+	RegisterConversionFunctions(w io.Writer) error
 	OverwritePackage(pkg, overwrite string)
 }
 
@@ -263,7 +263,22 @@ func (g *conversionGenerator) WriteConversionFunctions(w io.Writer) error {
 	return nil
 }
 
-func (g *conversionGenerator) WriteConversionFunctionNames(w io.Writer) error {
+func (g *conversionGenerator) writeRegisterHeader(b *buffer, indent int) {
+	b.addLine("func init() {\n", indent)
+	b.addLine("err := newer.Scheme.AddGeneratedConversionFuncs(\n", indent+1)
+}
+
+func (g *conversionGenerator) writeRegisterFooter(b *buffer, indent int) {
+	b.addLine(")\n", indent+1)
+	b.addLine("if err != nil {\n", indent+1)
+	b.addLine("// If one of the conversion functions is malformed, detect it immediately.\n", indent+2)
+	b.addLine("panic(err)\n", indent+2)
+	b.addLine("}\n", indent+1)
+	b.addLine("}\n", indent)
+	b.addLine("\n", indent)
+}
+
+func (g *conversionGenerator) RegisterConversionFunctions(w io.Writer) error {
 	// Write conversion function names alphabetically ordered.
 	var names []string
 	for inType, outType := range g.convertibles {
@@ -273,10 +288,12 @@ func (g *conversionGenerator) WriteConversionFunctionNames(w io.Writer) error {
 	sort.Strings(names)
 
 	buffer := newBuffer()
-	indent := 2
+	indent := 0
+	g.writeRegisterHeader(buffer, indent)
 	for _, name := range names {
-		buffer.addLine(fmt.Sprintf("%s,\n", name), indent)
+		buffer.addLine(fmt.Sprintf("%s,\n", name), indent+2)
 	}
+	g.writeRegisterFooter(buffer, indent)
 	if err := buffer.flushLines(w); err != nil {
 		return err
 	}