Decouple from stellar/go monorepo

Cargo.toml

@@ -2,7 +2,8 @@
 resolver = "2"
 members = [
     "lib/ffi",
-    "lib/xdr2json"
+    "lib/xdr2json",
+    "scripts/generate-types"
 ]
 
 [workspace.package]

Makefile

@@ -23,5 +23,8 @@ build-libs: Cargo.lock
 		cp $(BUILD_DIR)/$$target/$(PROFILE)/*.a $(LIBS_DIR)/$$target/; \
 	done
 
+generate-types:
+	cargo run --bin generate-types | gofmt > xdr2json/types.go
+
 dist-clean:
 	@rm -rf $(BUILD_DIR) $(LIBS_DIR)

scripts/generate-types/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "generate-types"
+version = "0.0.0"
+edition = "2021"
+rust-version.workspace = true
+publish = false
+
+[dependencies]
+stellar-xdr = { workspace = true }

scripts/generate-types/src/main.rs

@@ -0,0 +1,18 @@
+use stellar_xdr::curr::TypeVariant;
+
+/// Generates a Go file that contains the types for the XDR-JSON schema as
+/// constants.
+fn main() {
+    println!("// Code generated by scripts/generate-types. DO NOT EDIT.");
+    println!();
+    println!("package xdr2json");
+    println!();
+    println!("type XdrType string");
+    println!();
+    println!("const (");
+    for typ in TypeVariant::variants() {
+        let name = typ.name();
+        println!("    {name} XdrType = \"{name}\"");
+    }
+    println!(")");
+}

xdr2json/conversion.go

@@ -16,54 +16,18 @@ package xdr2json
 import "C"
 
 import (
-	"encoding"
 	"encoding/json"
-	"github.com/pkg/errors"
-	"reflect"
 	"unsafe"
-)
-
-// ConvertBytes takes an XDR object (`xdr`) and its serialized bytes (`field`)
-// and returns the raw JSON-formatted serialization of that object.
-// It can be unmarshalled to a proper JSON structure, but the raw bytes are
-// returned to avoid unnecessary round-trips. If there is an
-// error, it returns an empty string.
-//
-// The `xdr` object does not need to actually be initialized/valid:
-// we only use it to determine the name of the structure. We could just
-// accept a string, but that would make mistakes likelier than passing the
-// structure itself (by reference).
-func ConvertBytes(xdr interface{}, field []byte) (json.RawMessage, error) {
-	if len(field) == 0 {
-		return []byte(""), nil
-	}
-
-	xdrTypeName := reflect.TypeOf(xdr).Name()
-	return convertAnyBytes(xdrTypeName, field)
-}
 
-// ConvertInterface takes a valid XDR object (`xdr`) and returns
-// the raw JSON-formatted serialization of that object. If there is an
-// error, it returns an empty string.
-//
-// Unlike `ConvertBytes`, the value here needs to be valid and
-// serializable.
-func ConvertInterface(xdr encoding.BinaryMarshaler) (json.RawMessage, error) {
-	xdrTypeName := reflect.TypeOf(xdr).Name()
-	data, err := xdr.MarshalBinary()
-	if err != nil {
-		return []byte(""), errors.Wrapf(err, "failed to serialize XDR type '%s'", xdrTypeName)
-	}
-
-	return convertAnyBytes(xdrTypeName, data)
-}
+	"github.com/pkg/errors"
+)
 
-func convertAnyBytes(xdrTypeName string, field []byte) (json.RawMessage, error) {
+func Decode(xdrTypeName XdrType, field []byte) (json.RawMessage, error) {
 	var jsonStr, errStr string
 	// scope just added to show matching alloc/frees
 	{
 		goRawXdr := CXDR(field)
-		b := C.CString(xdrTypeName)
+		b := C.CString(string(xdrTypeName))
 
 		result := C.xdr_to_json(b, goRawXdr)
 		C.free(unsafe.Pointer(b))

xdr2json/conversion_test.go

@@ -9,11 +9,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-// We just need similarly named structs as are defined in the
-type Asset struct{}
-type SorobanTransactionData struct{}
-
-func TestConversion(t *testing.T) {
+func TestDecode(t *testing.T) {
 	/* The base64-encoded string representing the asset
 	Created with:
 	$ stellar xdr encode --type Asset << -
@@ -25,7 +21,7 @@ func TestConversion(t *testing.T) {
 	rawBytes, err := base64.StdEncoding.DecodeString(encodedAsset)
 	require.NoError(t, err)
 
-	jsb, err := ConvertBytes(Asset{}, rawBytes)
+	jsb, err := Decode(Asset, rawBytes)
 	require.NoError(t, err)
 
 	var dest map[string]interface{}
@@ -45,7 +41,7 @@ func TestConversion(t *testing.T) {
 }
 
 func TestEmptyConversion(t *testing.T) {
-	js, err := ConvertBytes(SorobanTransactionData{}, []byte{})
+	js, err := Decode(SorobanTransactionData, []byte{})
 	require.NoError(t, err)
 	require.Equal(t, "", string(js))
 }