test(rhc-server): add unit tests for backend implementation

Add comprehensive unit tests for the Backend struct and its Test method
in cmd/rhc-server. Tests cover various input scenarios.

Signed-off-by: mjcr99 <[email protected]>
Assisted-by: Claude Code

Author: mjcr99

cmd/rhc-server/rhc-server_test.go

@@ -0,0 +1,96 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+
+	"github.com/redhatinsights/rhc/varlink/internalapi"
+)
+
+func TestNewBackend(t *testing.T) {
+	backend := NewBackend()
+
+	if backend == nil {
+		t.Fatal("NewBackend() returned nil")
+	}
+}
+
+func TestBackend_Test(t *testing.T) {
+	tests := []struct {
+		description string
+		input       *internalapi.TestIn
+		want        *internalapi.TestOut
+	}{
+		{
+			description: "simple message",
+			input: &internalapi.TestIn{
+				Input: "hello",
+			},
+			want: &internalapi.TestOut{
+				Output: "Echo from rhc-server: hello",
+			},
+		},
+		{
+			description: "empty string",
+			input: &internalapi.TestIn{
+				Input: "",
+			},
+			want: &internalapi.TestOut{
+				Output: "Echo from rhc-server: ",
+			},
+		},
+		{
+			description: "message with special characters",
+			input: &internalapi.TestIn{
+				Input: "hello!@#$%^&*()",
+			},
+			want: &internalapi.TestOut{
+				Output: "Echo from rhc-server: hello!@#$%^&*()",
+			},
+		},
+		{
+			description: "message with newlines",
+			input: &internalapi.TestIn{
+				Input: "line1\nline2\nline3",
+			},
+			want: &internalapi.TestOut{
+				Output: "Echo from rhc-server: line1\nline2\nline3",
+			},
+		},
+		{
+			description: "message with unicode",
+			input: &internalapi.TestIn{
+				Input: "Hello 世界 🌍",
+			},
+			want: &internalapi.TestOut{
+				Output: "Echo from rhc-server: Hello 世界 🌍",
+			},
+		},
+		{
+			description: "very long message",
+			input: &internalapi.TestIn{
+				Input: string(make([]byte, 10000)),
+			},
+			want: &internalapi.TestOut{
+				Output: "Echo from rhc-server: " + string(make([]byte, 10000)),
+			},
+		},
+	}
+
+	backend := NewBackend()
+
+	for _, test := range tests {
+		t.Run(test.description, func(t *testing.T) {
+			got, err := backend.Test(test.input)
+
+			if err != nil {
+				t.Errorf("Backend.Test(%v) unexpected error: %v", test.input, err)
+			}
+
+			if !cmp.Equal(got, test.want) {
+				t.Errorf("Backend.Test(%v) = %v; want %v", test.input, got, test.want)
+			}
+		})
+	}
+}