Implemented conn.go and hanshake.go + unit tests

conn_inmem_test.go

@@ -0,0 +1,44 @@
+// This file defines an in-memory implementation of the Conn interface that is
+// used ONLY by unit tests.
+//
+// The inmem_conn replaces a real WebSocket or network connection with simple
+// Go channels. This allows handshake, sequencing, and message logic to be
+// tested deterministically without spinning up a server, opening sockets,
+// or relying on timing.
+
+package ownwire_sdk
+
+import (
+	"context"
+)
+
+type inmem_conn struct {
+	write_ch chan string
+	read_ch  chan string
+}
+
+func new_inmem_conn() *inmem_conn {
+	return &inmem_conn{
+		write_ch: make(chan string, 16),
+		read_ch:  make(chan string, 16),
+	}
+}
+
+func (c *inmem_conn) WriteText(ctx context.Context, s string) error {
+	select {
+	case c.write_ch <- s:
+		return nil
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+}
+
+func (c *inmem_conn) ReadText(ctx context.Context) (string, error) {
+	select {
+	case s := <-c.read_ch:
+		return s, nil
+	case <-ctx.Done():
+		return "", ctx.Err()
+	}
+}
+