[jsinterp] Implement `Function.prototype` resolving for `call` and `apply` (#10392)

Authored by: Grub4K

1 files changed, 18 insertions, 0 deletions

diff --git a/yt_dlp/jsinterp.py b/yt_dlp/jsinterp.py
index a0f32892f..851d4dc7b 100644
--- a/yt_dlp/jsinterp.py
+++ b/yt_dlp/jsinterp.py
@@ -636,6 +636,8 @@ class JSInterpreter:
                     raise self.Exception(f'{member} {msg}', expr)
 
             def eval_method():
+                nonlocal member
+
                 if (variable, member) == ('console', 'debug'):
                     if Debugger.ENABLED:
                         Debugger.write(self.interpret_expression(f'[{arg_str}]', local_vars, allow_recursion))
@@ -644,6 +646,7 @@ class JSInterpreter:
                 types = {
                     'String': str,
                     'Math': float,
+                    'Array': list,
                 }
                 obj = local_vars.get(variable, types.get(variable, NO_DEFAULT))
                 if obj is NO_DEFAULT:
@@ -667,6 +670,21 @@ class JSInterpreter:
                     self.interpret_expression(v, local_vars, allow_recursion)
                     for v in self._separate(arg_str)]
 
+                # Fixup prototype call
+                if isinstance(obj, type) and member.startswith('prototype.'):
+                    new_member, _, func_prototype = member.partition('.')[2].partition('.')
+                    assertion(argvals, 'takes one or more arguments')
+                    assertion(isinstance(argvals[0], obj), f'needs binding to type {obj}')
+                    if func_prototype == 'call':
+                        obj, *argvals = argvals
+                    elif func_prototype == 'apply':
+                        assertion(len(argvals) == 2, 'takes two arguments')
+                        obj, argvals = argvals
+                        assertion(isinstance(argvals, list), 'second argument needs to be a list')
+                    else:
+                        raise self.Exception(f'Unsupported Function method {func_prototype}', expr)
+                    member = new_member
+
                 if obj is str:
                     if member == 'fromCharCode':
                         assertion(argvals, 'takes one or more arguments')