Moved py.code code over to py.test

Fix #103

Author: nicoddemus

_pytest/_code/__init__.py

@@ -0,0 +1,17 @@
+""" python inspection/code generation API """
+from .assertion import AssertionError as _AssertionError  # noqa
+from .assertion import _format_explanation  # noqa
+from .assertion import _reprcompare  # noqa
+from .assertion import reinterpret as _reinterpret  # noqa
+from .assertion import reinterpret_old as _reinterpret_old  # noqa
+from .code import Code  # noqa
+from .code import ExceptionInfo  # noqa
+from .code import Frame  # noqa
+from .code import Traceback  # noqa
+from .code import getrawcode  # noqa
+from .code import patch_builtins  # noqa
+from .code import unpatch_builtins  # noqa
+from .source import Source  # noqa
+from .source import compile_ as compile  # noqa
+from .source import getfslineno  # noqa
+

_pytest/_code/_assertionnew.py

@@ -0,0 +1,339 @@
+"""
+Find intermediate evalutation results in assert statements through builtin AST.
+This should replace _assertionold.py eventually.
+"""
+
+import ast
+import sys
+
+from .assertion import _format_explanation, BuiltinAssertionError
+
+if sys.platform.startswith("java") and sys.version_info < (2, 5, 2):
+    # See http://bugs.jython.org/issue1497
+    _exprs = ("BoolOp", "BinOp", "UnaryOp", "Lambda", "IfExp", "Dict",
+              "ListComp", "GeneratorExp", "Yield", "Compare", "Call",
+              "Repr", "Num", "Str", "Attribute", "Subscript", "Name",
+              "List", "Tuple")
+    _stmts = ("FunctionDef", "ClassDef", "Return", "Delete", "Assign",
+              "AugAssign", "Print", "For", "While", "If", "With", "Raise",
+              "TryExcept", "TryFinally", "Assert", "Import", "ImportFrom",
+              "Exec", "Global", "Expr", "Pass", "Break", "Continue")
+    _expr_nodes = set(getattr(ast, name) for name in _exprs)
+    _stmt_nodes = set(getattr(ast, name) for name in _stmts)
+    def _is_ast_expr(node):
+        return node.__class__ in _expr_nodes
+    def _is_ast_stmt(node):
+        return node.__class__ in _stmt_nodes
+else:
+    def _is_ast_expr(node):
+        return isinstance(node, ast.expr)
+    def _is_ast_stmt(node):
+        return isinstance(node, ast.stmt)
+
+
+class Failure(Exception):
+    """Error found while interpreting AST."""
+
+    def __init__(self, explanation=""):
+        self.cause = sys.exc_info()
+        self.explanation = explanation
+
+
+def interpret(source, frame, should_fail=False):
+    mod = ast.parse(source)
+    visitor = DebugInterpreter(frame)
+    try:
+        visitor.visit(mod)
+    except Failure:
+        failure = sys.exc_info()[1]
+        return getfailure(failure)
+    if should_fail:
+        return ("(assertion failed, but when it was re-run for "
+                "printing intermediate values, it did not fail.  Suggestions: "
+                "compute assert expression before the assert or use --no-assert)")
+
+def run(offending_line, frame=None):
+    from .code import Frame
+    if frame is None:
+        frame = Frame(sys._getframe(1))
+    return interpret(offending_line, frame)
+
+def getfailure(failure):
+    explanation = _format_explanation(failure.explanation)
+    value = failure.cause[1]
+    if str(value):
+        lines = explanation.splitlines()
+        if not lines:
+            lines.append("")
+        lines[0] += " << %s" % (value,)
+        explanation = "\n".join(lines)
+    text = "%s: %s" % (failure.cause[0].__name__, explanation)
+    if text.startswith("AssertionError: assert "):
+        text = text[16:]
+    return text
+
+
+operator_map = {
+    ast.BitOr : "|",
+    ast.BitXor : "^",
+    ast.BitAnd : "&",
+    ast.LShift : "<<",
+    ast.RShift : ">>",
+    ast.Add : "+",
+    ast.Sub : "-",
+    ast.Mult : "*",
+    ast.Div : "/",
+    ast.FloorDiv : "//",
+    ast.Mod : "%",
+    ast.Eq : "==",
+    ast.NotEq : "!=",
+    ast.Lt : "<",
+    ast.LtE : "<=",
+    ast.Gt : ">",
+    ast.GtE : ">=",
+    ast.Pow : "**",
+    ast.Is : "is",
+    ast.IsNot : "is not",
+    ast.In : "in",
+    ast.NotIn : "not in"
+}
+
+unary_map = {
+    ast.Not : "not %s",
+    ast.Invert : "~%s",
+    ast.USub : "-%s",
+    ast.UAdd : "+%s"
+}
+
+
+class DebugInterpreter(ast.NodeVisitor):
+    """Interpret AST nodes to gleam useful debugging information. """
+
+    def __init__(self, frame):
+        self.frame = frame
+
+    def generic_visit(self, node):
+        # Fallback when we don't have a special implementation.
+        if _is_ast_expr(node):
+            mod = ast.Expression(node)
+            co = self._compile(mod)
+            try:
+                result = self.frame.eval(co)
+            except Exception:
+                raise Failure()
+            explanation = self.frame.repr(result)
+            return explanation, result
+        elif _is_ast_stmt(node):
+            mod = ast.Module([node])
+            co = self._compile(mod, "exec")
+            try:
+                self.frame.exec_(co)
+            except Exception:
+                raise Failure()
+            return None, None
+        else:
+            raise AssertionError("can't handle %s" %(node,))
+
+    def _compile(self, source, mode="eval"):
+        return compile(source, "<assertion interpretation>", mode)
+
+    def visit_Expr(self, expr):
+        return self.visit(expr.value)
+
+    def visit_Module(self, mod):
+        for stmt in mod.body:
+            self.visit(stmt)
+
+    def visit_Name(self, name):
+        explanation, result = self.generic_visit(name)
+        # See if the name is local.
+        source = "%r in locals() is not globals()" % (name.id,)
+        co = self._compile(source)
+        try:
+            local = self.frame.eval(co)
+        except Exception:
+            # have to assume it isn't
+            local = False
+        if not local:
+            return name.id, result
+        return explanation, result
+
+    def visit_Compare(self, comp):
+        left = comp.left
+        left_explanation, left_result = self.visit(left)
+        for op, next_op in zip(comp.ops, comp.comparators):
+            next_explanation, next_result = self.visit(next_op)
+            op_symbol = operator_map[op.__class__]
+            explanation = "%s %s %s" % (left_explanation, op_symbol,
+                                        next_explanation)
+            source = "__exprinfo_left %s __exprinfo_right" % (op_symbol,)
+            co = self._compile(source)
+            try:
+                result = self.frame.eval(co, __exprinfo_left=left_result,
+                                         __exprinfo_right=next_result)
+            except Exception:
+                raise Failure(explanation)
+            try:
+                if not result:
+                    break
+            except KeyboardInterrupt:
+                raise
+            except:
+                break
+            left_explanation, left_result = next_explanation, next_result
+
+        import _pytest._code
+        rcomp = _pytest._code._reprcompare
+        if rcomp:
+            res = rcomp(op_symbol, left_result, next_result)
+            if res:
+                explanation = res
+        return explanation, result
+
+    def visit_BoolOp(self, boolop):
+        is_or = isinstance(boolop.op, ast.Or)
+        explanations = []
+        for operand in boolop.values:
+            explanation, result = self.visit(operand)
+            explanations.append(explanation)
+            if result == is_or:
+                break
+        name = is_or and " or " or " and "
+        explanation = "(" + name.join(explanations) + ")"
+        return explanation, result
+
+    def visit_UnaryOp(self, unary):
+        pattern = unary_map[unary.op.__class__]
+        operand_explanation, operand_result = self.visit(unary.operand)
+        explanation = pattern % (operand_explanation,)
+        co = self._compile(pattern % ("__exprinfo_expr",))
+        try:
+            result = self.frame.eval(co, __exprinfo_expr=operand_result)
+        except Exception:
+            raise Failure(explanation)
+        return explanation, result
+
+    def visit_BinOp(self, binop):
+        left_explanation, left_result = self.visit(binop.left)
+        right_explanation, right_result = self.visit(binop.right)
+        symbol = operator_map[binop.op.__class__]
+        explanation = "(%s %s %s)" % (left_explanation, symbol,
+                                      right_explanation)
+        source = "__exprinfo_left %s __exprinfo_right" % (symbol,)
+        co = self._compile(source)
+        try:
+            result = self.frame.eval(co, __exprinfo_left=left_result,
+                                     __exprinfo_right=right_result)
+        except Exception:
+            raise Failure(explanation)
+        return explanation, result
+
+    def visit_Call(self, call):
+        func_explanation, func = self.visit(call.func)
+        arg_explanations = []
+        ns = {"__exprinfo_func" : func}
+        arguments = []
+        for arg in call.args:
+            arg_explanation, arg_result = self.visit(arg)
+            arg_name = "__exprinfo_%s" % (len(ns),)
+            ns[arg_name] = arg_result
+            arguments.append(arg_name)
+            arg_explanations.append(arg_explanation)
+        for keyword in call.keywords:
+            arg_explanation, arg_result = self.visit(keyword.value)
+            arg_name = "__exprinfo_%s" % (len(ns),)
+            ns[arg_name] = arg_result
+            keyword_source = "%s=%%s" % (keyword.arg)
+            arguments.append(keyword_source % (arg_name,))
+            arg_explanations.append(keyword_source % (arg_explanation,))
+        if call.starargs:
+            arg_explanation, arg_result = self.visit(call.starargs)
+            arg_name = "__exprinfo_star"
+            ns[arg_name] = arg_result
+            arguments.append("*%s" % (arg_name,))
+            arg_explanations.append("*%s" % (arg_explanation,))
+        if call.kwargs:
+            arg_explanation, arg_result = self.visit(call.kwargs)
+            arg_name = "__exprinfo_kwds"
+            ns[arg_name] = arg_result
+            arguments.append("**%s" % (arg_name,))
+            arg_explanations.append("**%s" % (arg_explanation,))
+        args_explained = ", ".join(arg_explanations)
+        explanation = "%s(%s)" % (func_explanation, args_explained)
+        args = ", ".join(arguments)
+        source = "__exprinfo_func(%s)" % (args,)
+        co = self._compile(source)
+        try:
+            result = self.frame.eval(co, **ns)
+        except Exception:
+            raise Failure(explanation)
+        pattern = "%s\n{%s = %s\n}"
+        rep = self.frame.repr(result)
+        explanation = pattern % (rep, rep, explanation)
+        return explanation, result
+
+    def _is_builtin_name(self, name):
+        pattern = "%r not in globals() and %r not in locals()"
+        source = pattern % (name.id, name.id)
+        co = self._compile(source)
+        try:
+            return self.frame.eval(co)
+        except Exception:
+            return False
+
+    def visit_Attribute(self, attr):
+        if not isinstance(attr.ctx, ast.Load):
+            return self.generic_visit(attr)
+        source_explanation, source_result = self.visit(attr.value)
+        explanation = "%s.%s" % (source_explanation, attr.attr)
+        source = "__exprinfo_expr.%s" % (attr.attr,)
+        co = self._compile(source)
+        try:
+            result = self.frame.eval(co, __exprinfo_expr=source_result)
+        except Exception:
+            raise Failure(explanation)
+        explanation = "%s\n{%s = %s.%s\n}" % (self.frame.repr(result),
+                                              self.frame.repr(result),
+                                              source_explanation, attr.attr)
+        # Check if the attr is from an instance.
+        source = "%r in getattr(__exprinfo_expr, '__dict__', {})"
+        source = source % (attr.attr,)
+        co = self._compile(source)
+        try:
+            from_instance = self.frame.eval(co, __exprinfo_expr=source_result)
+        except Exception:
+            from_instance = True
+        if from_instance:
+            rep = self.frame.repr(result)
+            pattern = "%s\n{%s = %s\n}"
+            explanation = pattern % (rep, rep, explanation)
+        return explanation, result
+
+    def visit_Assert(self, assrt):
+        test_explanation, test_result = self.visit(assrt.test)
+        if test_explanation.startswith("False\n{False =") and \
+                test_explanation.endswith("\n"):
+            test_explanation = test_explanation[15:-2]
+        explanation = "assert %s" % (test_explanation,)
+        if not test_result:
+            try:
+                raise BuiltinAssertionError
+            except Exception:
+                raise Failure(explanation)
+        return explanation, test_result
+
+    def visit_Assign(self, assign):
+        value_explanation, value_result = self.visit(assign.value)
+        explanation = "... = %s" % (value_explanation,)
+        name = ast.Name("__exprinfo_expr", ast.Load(),
+                        lineno=assign.value.lineno,
+                        col_offset=assign.value.col_offset)
+        new_assign = ast.Assign(assign.targets, name, lineno=assign.lineno,
+                                col_offset=assign.col_offset)
+        mod = ast.Module([new_assign])
+        co = self._compile(mod, "exec")
+        try:
+            self.frame.exec_(co, __exprinfo_expr=value_result)
+        except Exception:
+            raise Failure(explanation)
+        return explanation, value_result