Move ErrorCode logic to new errcode package

Make HTTP status codes match the ErrorCode by looking it up in the Descriptors

Signed-off-by: Doug Davis <dug@us.ibm.com>

docs/api/errcode/errors_test.go

@@ -0,0 +1,167 @@
+package errcode
+
+import (
+	"encoding/json"
+	// "reflect"
+	"testing"
+
+	// "github.com/docker/distribution/digest"
+)
+
+// TestErrorCodes ensures that error code format, mappings and
+// marshaling/unmarshaling. round trips are stable.
+func TestErrorCodes(t *testing.T) {
+	for _, desc := range errorDescriptors {
+		if desc.Code.String() != desc.Value {
+			t.Fatalf("error code string incorrect: %q != %q", desc.Code.String(), desc.Value)
+		}
+
+		if desc.Code.Message() != desc.Message {
+			t.Fatalf("incorrect message for error code %v: %q != %q", desc.Code, desc.Code.Message(), desc.Message)
+		}
+
+		// Serialize the error code using the json library to ensure that we
+		// get a string and it works round trip.
+		p, err := json.Marshal(desc.Code)
+
+		if err != nil {
+			t.Fatalf("error marshaling error code %v: %v", desc.Code, err)
+		}
+
+		if len(p) <= 0 {
+			t.Fatalf("expected content in marshaled before for error code %v", desc.Code)
+		}
+
+		// First, unmarshal to interface and ensure we have a string.
+		var ecUnspecified interface{}
+		if err := json.Unmarshal(p, &ecUnspecified); err != nil {
+			t.Fatalf("error unmarshaling error code %v: %v", desc.Code, err)
+		}
+
+		if _, ok := ecUnspecified.(string); !ok {
+			t.Fatalf("expected a string for error code %v on unmarshal got a %T", desc.Code, ecUnspecified)
+		}
+
+		// Now, unmarshal with the error code type and ensure they are equal
+		var ecUnmarshaled ErrorCode
+		if err := json.Unmarshal(p, &ecUnmarshaled); err != nil {
+			t.Fatalf("error unmarshaling error code %v: %v", desc.Code, err)
+		}
+
+		if ecUnmarshaled != desc.Code {
+			t.Fatalf("unexpected error code during error code marshal/unmarshal: %v != %v", ecUnmarshaled, desc.Code)
+		}
+	}
+}
+
+// TestErrorsManagement does a quick check of the Errors type to ensure that
+// members are properly pushed and marshaled.
+/*
+func TestErrorsManagement(t *testing.T) {
+	var errs Errors
+
+	errs.Push(ErrorCodeDigestInvalid)
+	errs.Push(ErrorCodeBlobUnknown,
+		map[string]digest.Digest{"digest": "sometestblobsumdoesntmatter"})
+
+	p, err := json.Marshal(errs)
+
+	if err != nil {
+		t.Fatalf("error marashaling errors: %v", err)
+	}
+
+	expectedJSON := "{\"errors\":[{\"code\":\"DIGEST_INVALID\",\"message\":\"provided digest did not match uploaded content\"},{\"code\":\"BLOB_UNKNOWN\",\"message\":\"blob unknown to registry\",\"detail\":{\"digest\":\"sometestblobsumdoesntmatter\"}}]}"
+
+	if string(p) != expectedJSON {
+		t.Fatalf("unexpected json: %q != %q", string(p), expectedJSON)
+	}
+
+	errs.Clear()
+	errs.Push(ErrorCodeUnknown)
+	expectedJSON = "{\"errors\":[{\"code\":\"UNKNOWN\",\"message\":\"unknown error\"}]}"
+	p, err = json.Marshal(errs)
+
+	if err != nil {
+		t.Fatalf("error marashaling errors: %v", err)
+	}
+
+	if string(p) != expectedJSON {
+		t.Fatalf("unexpected json: %q != %q", string(p), expectedJSON)
+	}
+}
+
+// TestMarshalUnmarshal ensures that api errors can round trip through json
+// without losing information.
+func TestMarshalUnmarshal(t *testing.T) {
+
+	var errors Errors
+
+	for _, testcase := range []struct {
+		description string
+		err         Error
+	}{
+		{
+			description: "unknown error",
+			err: Error{
+
+				Code:    ErrorCodeUnknown,
+				Message: ErrorCodeUnknown.Descriptor().Message,
+			},
+		},
+		{
+			description: "unknown manifest",
+			err: Error{
+				Code:    ErrorCodeManifestUnknown,
+				Message: ErrorCodeManifestUnknown.Descriptor().Message,
+			},
+		},
+		{
+			description: "unknown manifest",
+			err: Error{
+				Code:    ErrorCodeBlobUnknown,
+				Message: ErrorCodeBlobUnknown.Descriptor().Message,
+				Detail:  map[string]interface{}{"digest": "asdfqwerqwerqwerqwer"},
+			},
+		},
+	} {
+		fatalf := func(format string, args ...interface{}) {
+			t.Fatalf(testcase.description+": "+format, args...)
+		}
+
+		unexpectedErr := func(err error) {
+			fatalf("unexpected error: %v", err)
+		}
+
+		p, err := json.Marshal(testcase.err)
+		if err != nil {
+			unexpectedErr(err)
+		}
+
+		var unmarshaled Error
+		if err := json.Unmarshal(p, &unmarshaled); err != nil {
+			unexpectedErr(err)
+		}
+
+		if !reflect.DeepEqual(unmarshaled, testcase.err) {
+			fatalf("errors not equal after round trip: %#v != %#v", unmarshaled, testcase.err)
+		}
+
+		// Roll everything up into an error response envelope.
+		errors.PushErr(testcase.err)
+	}
+
+	p, err := json.Marshal(errors)
+	if err != nil {
+		t.Fatalf("unexpected error marshaling error envelope: %v", err)
+	}
+
+	var unmarshaled Errors
+	if err := json.Unmarshal(p, &unmarshaled); err != nil {
+		t.Fatalf("unexpected error unmarshaling error envelope: %v", err)
+	}
+
+	if !reflect.DeepEqual(unmarshaled, errors) {
+		t.Fatalf("errors not equal after round trip: %#v != %#v", unmarshaled, errors)
+	}
+}
+*/