added basic test templates for request and response de and encoding

attribute_test.go

@@ -2,6 +2,7 @@ package ipp
 
 import (
 	"bytes"
+	"github.com/stretchr/testify/assert"
 	"testing"
 )
 
@@ -42,25 +43,18 @@ var attributeTestCases = []struct {
 	},
 }
 
-func TestAttributeEncoding(t *testing.T) {
+func TestAttributeDecoder_Decode(t *testing.T) {
 	buf := new(bytes.Buffer)
 	enc := NewAttributeEncoder(buf)
 
 	for _, c := range attributeTestCases {
-		if err := enc.Encode(c.Attribute, c.Value); err != nil {
-			t.Errorf("error while encoding attribute %s with value %v: %v", c.Attribute, c.Value, err)
-		}
-
-		result := buf.Bytes()
-		if !bytes.Equal(result, c.Bytes) {
-			t.Errorf("encoding result is not correct, expected %v, got %v", c.Bytes, result)
-		}
-
+		assert.Nil(t, enc.Encode(c.Attribute, c.Value))
+		assert.Equal(t, buf.Bytes(), c.Bytes, "encoding result is not correct")
 		buf.Reset()
 	}
 }
 
-func TestAttributeDecoder(t *testing.T) {
+func TestAttributeEncoder_Encode(t *testing.T) {
 	buf := new(bytes.Buffer)
 	dec := NewAttributeDecoder(buf)
 
@@ -70,17 +64,9 @@ func TestAttributeDecoder(t *testing.T) {
 		buf.Write(c.Bytes[1:])
 
 		attr, err := dec.Decode(tag)
-		if err != nil {
-			t.Errorf("error while decoding bytes %v: %v", c.Bytes, err)
-		}
-
-		if attr.Name != c.Attribute {
-			t.Errorf("decoded attribute is not correct, expected %v, got %v", c.Attribute, attr.Name)
-		}
-
-		if attr.Value != c.Value {
-			t.Errorf("decoded value is not correct, expected %v, got %v", c.Attribute, attr.Name)
-		}
+		assert.Nil(t, err)
+		assert.Equal(t, c.Attribute, attr.Name, "decoded attribute is not correct")
+		assert.Equal(t, c.Value, attr.Value, "decoded value is not correct")
 
 		buf.Reset()
 	}

cups-client.go

@@ -16,7 +16,7 @@ func NewCUPSClient(host string, port int, username, password string, useTLS bool
 	return &CUPSClient{ippClient}
 }
 
-// NewCUPSClient creates a new cups ipp client with given Adapter
+// NewCUPSClientWithAdapter creates a new cups ipp client with given Adapter
 func NewCUPSClientWithAdapter(username string, adapter Adapter) *CUPSClient {
 	ippClient := NewIPPClientWithAdapter(username, adapter)
 	return &CUPSClient{ippClient}
@@ -177,7 +177,7 @@ func (c *CUPSClient) CreatePrinter(name, deviceURI, ppd string, shared bool, err
 	req.PrinterAttributes[AttributeDeviceURI] = deviceURI
 	req.PrinterAttributes[AttributePrinterInfo] = information
 	req.PrinterAttributes[AttributePrinterLocation] = location
-	req.PrinterAttributes[AttributePrinterErrorPolicy] = string(errorPolicy)
+	req.PrinterAttributes[AttributePrinterErrorPolicy] = errorPolicy
 
 	_, err := c.SendRequest(c.adapter.GetHttpUri("admin", ""), req, nil)
 	return err
@@ -217,7 +217,7 @@ func (c *CUPSClient) SetPrinterIsShared(printer string, shared bool) error {
 func (c *CUPSClient) SetPrinterErrorPolicy(printer string, errorPolicy string) error {
 	req := NewRequest(OperationCupsAddModifyPrinter, 1)
 	req.OperationAttributes[AttributePrinterURI] = c.getPrinterUri(printer)
-	req.PrinterAttributes[AttributePrinterErrorPolicy] = string(errorPolicy)
+	req.PrinterAttributes[AttributePrinterErrorPolicy] = errorPolicy
 
 	_, err := c.SendRequest(c.adapter.GetHttpUri("admin", ""), req, nil)
 	return err

go.mod

@@ -1,3 +1,5 @@
 module github.com/phin1x/go-ipp
 
 go 1.13
+
+require github.com/stretchr/testify v1.8.4 // indirect

ipp-client.go

@@ -241,7 +241,7 @@ func (c *IPPClient) GetJobAttributes(jobID int, attributes []string) (Attributes
 // GetJobs returns jobs from a printer or class
 func (c *IPPClient) GetJobs(printer, class string, whichJobs string, myJobs bool, firstJobId, limit int, attributes []string) (map[int]Attributes, error) {
 	req := NewRequest(OperationGetJobs, 1)
-	req.OperationAttributes[AttributeWhichJobs] = string(whichJobs)
+	req.OperationAttributes[AttributeWhichJobs] = whichJobs
 	req.OperationAttributes[AttributeMyJobs] = myJobs
 
 	if printer != "" {

request.go

@@ -58,26 +58,28 @@ func (r *Request) Encode() ([]byte, error) {
 		return nil, err
 	}
 
-	if err := binary.Write(buf, binary.BigEndian, int8(TagOperation)); err != nil {
+	if err := binary.Write(buf, binary.BigEndian, TagOperation); err != nil {
 		return nil, err
 	}
 
-	if err := enc.Encode(AttributeCharset, Charset); err != nil {
-		return nil, err
+	if r.OperationAttributes == nil {
+		r.OperationAttributes = make(map[string]interface{}, 2)
 	}
 
-	if err := enc.Encode(AttributeNaturalLanguage, CharsetLanguage); err != nil {
-		return nil, err
+	if _, found := r.OperationAttributes[AttributeCharset]; !found {
+		r.OperationAttributes[AttributeCharset] = Charset
 	}
 
-	if len(r.OperationAttributes) > 0 {
-		if err := r.encodeOperationAttributes(enc); err != nil {
-			return nil, err
-		}
+	if _, found := r.OperationAttributes[AttributeNaturalLanguage]; !found {
+		r.OperationAttributes[AttributeNaturalLanguage] = CharsetLanguage
+	}
+
+	if err := r.encodeOperationAttributes(enc); err != nil {
+		return nil, err
 	}
 
 	if len(r.JobAttributes) > 0 {
-		if err := binary.Write(buf, binary.BigEndian, int8(TagJob)); err != nil {
+		if err := binary.Write(buf, binary.BigEndian, TagJob); err != nil {
 			return nil, err
 		}
 		for attr, value := range r.JobAttributes {
@@ -88,7 +90,7 @@ func (r *Request) Encode() ([]byte, error) {
 	}
 
 	if len(r.PrinterAttributes) > 0 {
-		if err := binary.Write(buf, binary.BigEndian, int8(TagPrinter)); err != nil {
+		if err := binary.Write(buf, binary.BigEndian, TagPrinter); err != nil {
 			return nil, err
 		}
 		for attr, value := range r.PrinterAttributes {
@@ -98,7 +100,7 @@ func (r *Request) Encode() ([]byte, error) {
 		}
 	}
 
-	if err := binary.Write(buf, binary.BigEndian, int8(TagEnd)); err != nil {
+	if err := binary.Write(buf, binary.BigEndian, TagEnd); err != nil {
 		return nil, err
 	}
 
@@ -127,6 +129,7 @@ func (r *Request) encodeOperationAttributes(enc *AttributeEncoder) error {
 			return err
 		}
 	}
+
 	return nil
 }
 

request_test.go

@@ -0,0 +1,59 @@
+package ipp
+
+import (
+	"bytes"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+var requestTestCases = []struct {
+	Request Request
+	Bytes   []byte
+	// some test cases are only for encoding, skip them in decoding tests
+	SkipDecoding bool
+}{
+	{
+		Request: Request{
+			ProtocolVersionMajor: ProtocolVersionMajor,
+			ProtocolVersionMinor: ProtocolVersionMinor,
+			Operation:            OperationPrintJob,
+			RequestId:            12345,
+		},
+		Bytes:        []byte{2, 0, 0, 2, 0, 0, 48, 57, 1, 71, 0, 18, 97, 116, 116, 114, 105, 98, 117, 116, 101, 115, 45, 99, 104, 97, 114, 115, 101, 116, 0, 5, 117, 116, 102, 45, 56, 72, 0, 27, 97, 116, 116, 114, 105, 98, 117, 116, 101, 115, 45, 110, 97, 116, 117, 114, 97, 108, 45, 108, 97, 110, 103, 117, 97, 103, 101, 0, 5, 101, 110, 45, 85, 83, 3},
+		SkipDecoding: true,
+	},
+	{
+		Request: Request{
+			ProtocolVersionMajor: ProtocolVersionMajor,
+			ProtocolVersionMinor: ProtocolVersionMinor,
+			Operation:            OperationPrintJob,
+			RequestId:            12345,
+			OperationAttributes: map[string]interface{}{
+				AttributeCharset:         Charset,
+				AttributeNaturalLanguage: CharsetLanguage,
+			},
+		},
+		Bytes:        []byte{2, 0, 0, 2, 0, 0, 48, 57, 1, 71, 0, 18, 97, 116, 116, 114, 105, 98, 117, 116, 101, 115, 45, 99, 104, 97, 114, 115, 101, 116, 0, 5, 117, 116, 102, 45, 56, 72, 0, 27, 97, 116, 116, 114, 105, 98, 117, 116, 101, 115, 45, 110, 97, 116, 117, 114, 97, 108, 45, 108, 97, 110, 103, 117, 97, 103, 101, 0, 5, 101, 110, 45, 85, 83, 3},
+		SkipDecoding: true,
+	},
+}
+
+func TestRequest_Encode(t *testing.T) {
+	for _, c := range requestTestCases {
+		data, err := c.Request.Encode()
+		assert.Nil(t, err)
+		assert.Equal(t, c.Bytes, data, "encoded request is not correct")
+	}
+}
+
+func TestRequestDecoder_Decode(t *testing.T) {
+	for _, c := range requestTestCases {
+		if c.SkipDecoding {
+			continue
+		}
+
+		request, err := NewRequestDecoder(bytes.NewReader(c.Bytes)).Decode(nil)
+		assert.Nil(t, err)
+		assert.Equal(t, &c.Request, request, "decoded request is not correct")
+	}
+}

response.go

@@ -74,44 +74,37 @@ func (r *Response) Encode() ([]byte, error) {
 		return nil, err
 	}
 
-	if err := binary.Write(buf, binary.BigEndian, int8(TagOperation)); err != nil {
+	if err := binary.Write(buf, binary.BigEndian, TagOperation); err != nil {
 		return nil, err
 	}
 
-	if err := enc.Encode(AttributeCharset, Charset); err != nil {
-		return nil, err
+	if r.OperationAttributes == nil {
+		r.OperationAttributes = make(Attributes, 0)
 	}
 
-	if err := enc.Encode(AttributeNaturalLanguage, CharsetLanguage); err != nil {
-		return nil, err
+	if _, found := r.OperationAttributes[AttributeCharset]; !found {
+		r.OperationAttributes[AttributeCharset] = []Attribute{
+			{
+				Value: Charset,
+			},
+		}
 	}
 
-	if len(r.OperationAttributes) > 0 {
-		for name, attr := range r.OperationAttributes {
-			if len(attr) == 0 {
-				continue
-			}
-
-			values := make([]interface{}, len(attr))
-			for i, v := range attr {
-				values[i] = v.Value
-			}
-
-			if len(values) == 1 {
-				if err := enc.Encode(name, values[0]); err != nil {
-					return nil, err
-				}
-			} else {
-				if err := enc.Encode(name, values); err != nil {
-					return nil, err
-				}
-			}
+	if _, found := r.OperationAttributes[AttributeNaturalLanguage]; !found {
+		r.OperationAttributes[AttributeNaturalLanguage] = []Attribute{
+			{
+				Value: CharsetLanguage,
+			},
 		}
 	}
 
+	if err := r.encodeOperationAttributes(enc); err != nil {
+		return nil, err
+	}
+
 	if len(r.PrinterAttributes) > 0 {
 		for _, printerAttr := range r.PrinterAttributes {
-			if err := binary.Write(buf, binary.BigEndian, int8(TagPrinter)); err != nil {
+			if err := binary.Write(buf, binary.BigEndian, TagPrinter); err != nil {
 				return nil, err
 			}
 
@@ -140,7 +133,7 @@ func (r *Response) Encode() ([]byte, error) {
 
 	if len(r.JobAttributes) > 0 {
 		for _, jobAttr := range r.JobAttributes {
-			if err := binary.Write(buf, binary.BigEndian, int8(TagJob)); err != nil {
+			if err := binary.Write(buf, binary.BigEndian, TagJob); err != nil {
 				return nil, err
 			}
 
@@ -174,6 +167,49 @@ func (r *Response) Encode() ([]byte, error) {
 	return buf.Bytes(), nil
 }
 
+func (r *Response) encodeOperationAttributes(enc *AttributeEncoder) error {
+	ordered := []string{
+		AttributeCharset,
+		AttributeNaturalLanguage,
+		AttributePrinterURI,
+		AttributeJobID,
+	}
+
+	for _, name := range ordered {
+		if attr, ok := r.OperationAttributes[name]; ok {
+			delete(r.OperationAttributes, name)
+			if err := encodeOperationAttribute(enc, name, attr); err != nil {
+				return err
+			}
+		}
+	}
+
+	for name, attr := range r.OperationAttributes {
+		if err := encodeOperationAttribute(enc, name, attr); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func encodeOperationAttribute(enc *AttributeEncoder, name string, attr []Attribute) error {
+	if len(attr) == 0 {
+		return nil
+	}
+
+	values := make([]interface{}, len(attr))
+	for i, v := range attr {
+		values[i] = v.Value
+	}
+
+	if len(values) == 1 {
+		return enc.Encode(name, values[0])
+	}
+
+	return enc.Encode(name, values)
+}
+
 // ResponseDecoder reads and decodes a response from a stream
 type ResponseDecoder struct {
 	reader io.Reader