utilize Pattern Tree to decide the policy to use and modify HTTP response headers according to that policy

This commit also enhances the build script so that preprocessor conditionals can now use operators '&&' and '||'.
The features being developed are not yet included in the actual Haketilo build.
Some of the new source files contain similar functionality to other ones already existing in the source tree. At some point the latter will be removed.

1 files changed, 37 insertions, 36 deletions

diff --git a/test/unit/conftest.py b/test/unit/conftest.py
index f9a17f8..beffaf5 100644
--- a/test/unit/conftest.py
+++ b/test/unit/conftest.py
@@ -34,6 +34,7 @@ from selenium.webdriver.support import expected_conditions as EC
 from ..profiles           import firefox_safe_mode
 from ..server             import do_an_internet
 from ..extension_crafting import make_extension
+from ..world_wide_library import start_serving_script, dump_scripts
 
 @pytest.fixture(scope="package")
 def proxy():
@@ -77,55 +78,55 @@ def webextension(driver, request):
     driver.uninstall_addon(addon_id)
     ext_path.unlink()
 
-script_injecting_script = '''\
+script_injector_script = '''\
 /*
  * Selenium by default executes scripts in some weird one-time context. We want
  * separately-loaded scripts to be able to access global variables defined
  * before, including those declared with `const` or `let`. To achieve that, we
- * run our scripts by injecting them into the page inside a <script> tag. We use
- * custom properties of the `window` object to communicate with injected code.
+ * run our scripts by injecting them into the page with a <script> tag that runs
+ * javascript served by our proxy. We use custom properties of the `window`
+ * object to communicate with injected code.
  */
-
-const script_elem = document.createElement('script');
-script_elem.textContent = arguments[0];
-
-delete window.haketilo_selenium_return_value;
-delete window.haketilo_selenium_exception;
-window.returnval = (val => window.haketilo_selenium_return_value = val);
-window.arguments = arguments[1];
-
-document.body.append(script_elem);
-
-/*
- * To ease debugging, we want this script to signal all exceptions from the
- * injectee.
- */
-try {
+const inject = async () => {
+    delete window.haketilo_selenium_return_value;
+    delete window.haketilo_selenium_exception;
+    window.returnval = val => window.haketilo_selenium_return_value = val;
+
+    const injectee = document.createElement('script');
+    injectee.src = arguments[0];
+    injectee.type = "application/javascript";
+    injectee.async = true;
+    const prom = new Promise(cb => injectee.onload = cb);
+
+    window.arguments = arguments[1];
+    document.body.append(injectee);
+
+    await prom;
+
+    /*
+     * To ease debugging, we want this script to signal all exceptions from the
+     * injectee.
+     */
     if (window.haketilo_selenium_exception !== false)
-        throw 'Error in injected script! Check your geckodriver.log!';
-} finally {
-    script_elem.remove();
-}
+        throw ['haketilo_selenium_error',
+               'Error in injected script! Check your geckodriver.log and ./injected_scripts/!'];
 
-return window.haketilo_selenium_return_value;
+    return window.haketilo_selenium_return_value;
+}
+return inject();
 '''
 
 def _execute_in_page_context(driver, script, args):
     script = script + '\n;\nwindow.haketilo_selenium_exception = false;'
-    driver.loaded_scripts.append(script)
+    script_url = start_serving_script(script)
+
     try:
-        return driver.execute_script(script_injecting_script, script, args)
+        result = driver.execute_script(script_injector_script, script_url, args)
+        if type(result) == list and result[0] == 'haketilo_selenium_error':
+            raise Exception(result[1])
+        return result
     except Exception as e:
-        import sys
-
-        print("Scripts loaded since driver's last get() method call:",
-              file=sys.stderr)
-
-        for script in driver.loaded_scripts:
-            lines = enumerate(script.split('\n'), 1)
-            for err_info in [('===',), *lines]:
-                print(*err_info, file=sys.stderr)
-
+        dump_scripts()
         raise e from None
 
 # Some fixtures here just define functions that operate on driver. We should