/tests/integration/test_js.py

from unittest.mock import patch

import pytest

from browser_harness import helpers


def _capture_cdp():
    captured = []
    def fake_cdp(method, **kwargs):
        captured.append((method, kwargs))
        return {"result": {"value": None}}
    return fake_cdp, captured


def _evaluated_expression(captured):
    return next(kw["expression"] for m, kw in captured if m == "Runtime.evaluate")


def test_simple_expression_passes_through():
    fake_cdp, captured = _capture_cdp()
    with patch("browser_harness.helpers.cdp", side_effect=fake_cdp):
        helpers.js("document.title")
    assert _evaluated_expression(captured) == "document.title"


def test_return_statement_gets_wrapped():
    fake_cdp, captured = _capture_cdp()
    with patch("browser_harness.helpers.cdp", side_effect=fake_cdp):
        helpers.js("const x = 1; return x")
    assert _evaluated_expression(captured) == "(function(){const x = 1; return x})()"


def test_iife_with_internal_return_is_not_double_wrapped():
    fake_cdp, captured = _capture_cdp()
    with patch("browser_harness.helpers.cdp", side_effect=fake_cdp):
        helpers.js("(function(){ return document.title; })()")
    assert _evaluated_expression(captured) == "(function(){ return document.title; })()"


def test_js_raises_on_syntax_error_exception_details():
    def fake_cdp(method, **kwargs):
        return {
            "result": {
                "type": "object",
                "subtype": "error",
                "description": "SyntaxError: Invalid or unexpected token",
            },
            "exceptionDetails": {
                "text": "Uncaught",
                "lineNumber": 1,
                "columnNumber": 12,
            },
        }

    with patch("browser_harness.helpers.cdp", side_effect=fake_cdp):
        with pytest.raises(RuntimeError, match="SyntaxError"):
            helpers.js('return "a\n\nb";')


def test_js_raises_on_runtime_error_exception_details():
    def fake_cdp(method, **kwargs):
        return {
            "result": {
                "type": "object",
                "subtype": "error",
                "description": "ReferenceError: missing is not defined",
            },
            "exceptionDetails": {
                "text": "Uncaught",
                "lineNumber": 0,
                "columnNumber": 17,
            },
        }

    with patch("browser_harness.helpers.cdp", side_effect=fake_cdp):
        with pytest.raises(RuntimeError, match="ReferenceError"):
            helpers.js("return missing.value")


def test_js_raises_on_error_result_without_exception_details():
    def fake_cdp(method, **kwargs):
        return {
            "result": {
                "type": "object",
                "subtype": "error",
                "description": "Error: evaluation failed",
            }
        }

    with patch("browser_harness.helpers.cdp", side_effect=fake_cdp):
        with pytest.raises(RuntimeError, match="evaluation failed"):
            helpers.js("throw new Error('evaluation failed')")