py: fix RunSrc to allow multiple top-level statements (#257)

py/run.go

@@ -131,7 +131,7 @@ func RunSrc(ctx Context, pySrc string, pySrcDesc string, inModule interface{}) (
 	if pySrcDesc == "" {
 		pySrcDesc = "<run>"
 	}
-	code, err := Compile(pySrc+"\n", pySrcDesc, SingleMode, 0, true)
+	code, err := Compile(pySrc+"\n", pySrcDesc, ExecMode, 0, true)
 	if err != nil {
 		return nil, err
 	}

pytest/runsrc_test.go

@@ -0,0 +1,64 @@
+// Copyright 2026 The go-python Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pytest
+
+import (
+	"testing"
+
+	"github.com/go-python/gpython/py"
+
+	_ "github.com/go-python/gpython/stdlib"
+)
+
+// Regression test for https://github.com/go-python/gpython/issues/257
+//
+// RunSrc used to compile in SingleMode which only accepts a single
+// interactive statement, so source containing more than one top-level
+// statement (e.g. two class definitions) failed with a SyntaxError.
+func TestRunSrcMultipleStatements(t *testing.T) {
+	for _, test := range []struct {
+		name string
+		src  string
+	}{
+		{
+			name: "two classes",
+			src: `
+class A:
+    pass
+
+
+class B:
+    pass
+`,
+		},
+		{
+			name: "two functions",
+			src: `
+def a():
+    return 1
+
+def b():
+    return 2
+`,
+		},
+		{
+			name: "assignments and expression",
+			src: `
+x = 1
+y = 2
+z = x + y
+`,
+		},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			ctx := py.NewContext(py.DefaultContextOpts())
+			defer ctx.Close()
+			_, err := py.RunSrc(ctx, test.src, "run", nil)
+			if err != nil {
+				t.Fatalf("RunSrc failed: %v", err)
+			}
+		})
+	}
+}