Adding a Code Generator

Currently, our compiler supports generating code for the Selenium library. We also have the option to serialize the Abstract Syntax Tree (AST) to JSON.

The Visitor Pattern

Our implementation should be straightforward if you are already familiar with the Visitor design pattern.

• The JsonASTVisitor serializer translates the source code's AST into a JSON format
• The Selenium code generation is achieved by the SeleniumASTVisitor
• The Decompiler visitor DecompilerASTVisitor to generate the corresponding source code from a serialized AST

Serialized AST with JSON

Compiling he GitHub example present in the home page with rnlc -t json produces the following JSON output. This feature is useful if you aim to use this compiler within another project to represent this test visually as seen here.

{
  "tests": [
    {
      "actions": [
        { "action": "visit", "url": "https://github.com" },
        {
          "action": "click",
          "description": "sign in present in the top right corner",
          "elementType": "link"
        },
        {
          "action": "check",
          "description": "GitHub logo",
          "elementType": "image",
          "state": true
        },
        {
          "action": "type",
          "content": "johndoe",
          "description": "the username input field",
          "elementType": "input"
        },
        {
          "action": "type",
          "content": "secretpassword",
          "description": "the password input filed",
          "elementType": "input"
        },
        {
          "action": "click",
          "description": "sign in button",
          "elementType": "button"
        }
      ],
      "testName": "githubSignIn"
    }
  ]
}

Supporting a New Target

To generate code for an unsupported library or format, you can create a new visitor class for your target which implements the ASTVisitor interface.

To achieve this you have to implement the following functions:

class ASTVisitor {
public:
    virtual string visit(const VisitNode& node) = 0;
    virtual string visit(const ClickNode& node) = 0;
    virtual string visit(const TypeNode& node) = 0;
    virtual string visit(const CheckNode& node) = 0;
    virtual string visit(const TestNode& node) = 0;
    virtual string visit(const AST& tree) = 0;
};