test: integration tests for imports

extension/examples/valid/sum.wacc

@@ -0,0 +1,27 @@
+# simple sum program
+
+# Output:
+# 15
+#
+
+# Exit:
+# 0
+
+# Program:
+
+begin
+  int sum(int a, int b) is 
+    return a + b
+  end
+
+  int main() is
+    int a = 5 ;
+    int b = 10 ;
+    int result = call sum(a, b) ;
+    println result ;
+    return 0
+  end
+
+  int result = call main() ;
+  exit result
+end