Merge 5639625 into 33def2a

deal/linter/_contract.py

@@ -12,6 +12,7 @@
 
 
 class Category(enum.Enum):
+    PRE = 'pre'
     POST = 'post'
     RAISES = 'raises'
     SILENT = 'silent'

deal/linter/_extractors/__init__.py

@@ -6,6 +6,7 @@
 from .exceptions_stubs import get_exceptions_stubs
 from .globals import get_globals
 from .imports import get_imports
+from .pre import get_pre
 from .prints import get_prints
 from .returns import get_returns, has_returns
 from .value import get_value
@@ -19,6 +20,7 @@
     'get_globals',
     'get_imports',
     'get_name',
+    'get_pre',
     'get_prints',
     'get_returns',
     'get_value',

deal/linter/_extractors/common.py

@@ -11,6 +11,7 @@
 
 TOKENS = SimpleNamespace(
     ASSERT=(ast.Assert, astroid.Assert),
+    ASSIGN=(ast.Assign, astroid.Assign),
     ATTR=(ast.Attribute, astroid.Attribute),
     BIN_OP=(ast.BinOp, astroid.BinOp),
     CALL=(ast.Call, astroid.Call),
@@ -23,7 +24,6 @@
     NONLOCAL=(ast.Nonlocal, astroid.Nonlocal),
     RAISE=(ast.Raise, astroid.Raise),
     RETURN=(ast.Return, astroid.Return),
-    # TRY=(ast.Try, astroid.TryExcept, astroid.TryFinally),
     UNARY_OP=(ast.UnaryOp, astroid.UnaryOp),
     WITH=(ast.With, astroid.With),
     YIELD=(ast.Yield, astroid.Yield),
@@ -38,15 +38,17 @@ class Token(NamedTuple):
 
 def traverse(body: List) -> Iterator:
     for expr in body:
-        # breaking apart
+        # breaking apart statements
         if isinstance(expr, TOKENS.EXPR):
             yield expr.value
+            yield from _travers_expr(expr=expr.value)
             continue
         if isinstance(expr, TOKENS.IF + TOKENS.FOR):
             yield from traverse(body=expr.body)
             yield from traverse(body=expr.orelse)
             continue
 
+        # breaking apart try-except
         if isinstance(expr, (ast.Try, astroid.TryExcept)):
             for handler in expr.handlers:
                 yield from traverse(body=handler.body)
@@ -58,11 +60,19 @@ def traverse(body: List) -> Iterator:
         # extracting things
         if isinstance(expr, TOKENS.WITH):
             yield from traverse(body=expr.body)
-        if isinstance(expr, TOKENS.RETURN):
+        elif isinstance(expr, TOKENS.RETURN + TOKENS.ASSIGN):
             yield expr.value
         yield expr
 
 
+def _travers_expr(expr):
+    if isinstance(expr, TOKENS.CALL):
+        for subnode in expr.args:
+            yield from traverse(body=[subnode])
+        for subnode in (expr.keywords or ()):
+            yield from traverse(body=[subnode.value])
+
+
 def get_name(expr) -> Optional[str]:
     if isinstance(expr, ast.Name):
         return expr.id
@@ -84,6 +94,8 @@ def get_name(expr) -> Optional[str]:
 
 
 def infer(expr) -> Tuple:
+    if not isinstance(expr, astroid.node_classes.NodeNG):
+        return tuple()
     with suppress(astroid.exceptions.InferenceError, RecursionError):
         return tuple(g for g in expr.infer() if type(g) is not astroid.Uninferable)
     return tuple()

deal/linter/_extractors/contracts.py

@@ -8,7 +8,7 @@
 from .common import TOKENS, get_name
 
 
-SUPPORTED_CONTRACTS = {'deal.post', 'deal.raises', 'deal.silent', 'deal.pure'}
+SUPPORTED_CONTRACTS = {'deal.pre', 'deal.post', 'deal.raises', 'deal.silent', 'deal.pure'}
 SUPPORTED_MARKERS = {'deal.silent', 'deal.pure'}
 
 

deal/linter/_extractors/exceptions.py

@@ -70,56 +70,28 @@ def handle_call(expr, dive: bool = True) -> Optional[Union[Token, Iterator[Token
             return Token(value=SystemExit, **token_info)
     # infer function call and check the function body for raises
     if dive:
-        return _exceptions_from_funcs(expr=expr)
+        return _exceptions_from_func(expr=expr)
     return None
 
 
-@get_exceptions.register(astroid.Assign)
-def handle_assign(expr: astroid.Assign, dive: bool = True) -> Iterator[Token]:
-    # infer function call and check the function body for raises
-    if dive:
-        yield from _exceptions_from_funcs(expr=expr)
-
-
-def _exceptions_from_funcs(expr) -> Iterator[Token]:
-    for name_node in get_names(expr):
-        # node have to be a name
-        if type(name_node) is not astroid.Name:
+def _exceptions_from_func(expr) -> Iterator[Token]:
+    for value in infer(expr.func):
+        if type(value) is not astroid.FunctionDef:
             continue
 
-        extra = dict(
-            line=name_node.lineno,
-            col=name_node.col_offset,
-        )
-        for value in infer(name_node):
-            if type(value) is not astroid.FunctionDef:
-                continue
+        # recursively infer exceptions from the function body
+        for error in get_exceptions(body=value.body, dive=False):
+            yield Token(value=error.value, line=expr.lineno, col=expr.col_offset)
 
-            # recursively infer exceptions from the function body
-            for error in get_exceptions(body=value.body, dive=False):
-                yield Token(value=error.value, **extra)
-
-            # get explicitly specified exceptions from `@deal.raises`
-            if not value.decorators:
+        # get explicitly specified exceptions from `@deal.raises`
+        if not value.decorators:
+            continue
+        for category, args in get_contracts(value.decorators.nodes):
+            if category != 'raises':
                 continue
-            for category, args in get_contracts(value.decorators.nodes):
-                if category != 'raises':
+            for arg in args:
+                name = get_name(arg)
+                if name is None:
                     continue
-                for arg in args:
-                    name = get_name(arg)
-                    if name is None:
-                        continue
-                    yield Token(value=name, **extra)
+                yield Token(value=name, line=expr.lineno, col=expr.col_offset)
     return None
-
-
-def get_names(expr) -> Iterator:
-    if isinstance(expr, astroid.Assign):
-        yield from get_names(expr.value)
-    if isinstance(expr, TOKENS.CALL):
-        if isinstance(expr.func, TOKENS.NAME):
-            yield expr.func
-        for subnode in expr.args:
-            yield from get_names(subnode)
-        for subnode in (expr.keywords or ()):
-            yield from get_names(subnode.value)

deal/linter/_extractors/pre.py

@@ -0,0 +1,67 @@
+# built-in
+import ast
+from typing import Iterator
+
+# external
+import astroid
+
+# app
+from .common import Extractor, Token, infer
+from .contracts import get_contracts
+from .value import UNKNOWN, get_value
+
+
+get_pre = Extractor()
+
+
+@get_pre.register(astroid.Call)
+def handle_call(expr: astroid.Call) -> Iterator[Token]:
+    from .._contract import Contract, Category
+
+    args = []
+    for subnode in expr.args:
+        value = get_value(expr=subnode)
+        if value is UNKNOWN:
+            return
+        args.append(value)
+
+    kwargs = {}
+    for subnode in (expr.keywords or ()):
+        value = get_value(expr=subnode.value)
+        if value is UNKNOWN:
+            return
+        kwargs[subnode.arg] = value
+
+    for func in infer(expr.func):
+        if type(func) is not astroid.FunctionDef:
+            continue
+        if not func.decorators:
+            continue
+        code = 'def f({}):0'.format(func.args.as_string())
+        func_args = ast.parse(code).body[0].args  # type: ignore
+
+        for category, contract_args in get_contracts(func.decorators.nodes):
+            if category != 'pre':
+                continue
+
+            contract = Contract(
+                args=contract_args,
+                category=Category.PRE,
+                func_args=func_args,
+            )
+            try:
+                result = contract.run(*args, **kwargs)
+            except NameError:
+                continue
+            if result is False or type(result) is str:
+                msg = _format_message(args, kwargs)
+                yield Token(value=msg, line=expr.lineno, col=expr.col_offset)
+
+
+def _format_message(args: list, kwargs: dict) -> str:
+    sep = ', '
+    args_s = sep.join(map(repr, args))
+    kwargs_s = sep.join(['{}={!r}'.format(k, v) for k, v in kwargs.items()])
+    if args and kwargs:
+        return args_s + sep + kwargs_s
+    return args_s + kwargs_s

deal/linter/_extractors/value.py

@@ -19,9 +19,11 @@ def get_value(expr):
             return ast.literal_eval(expr)
 
     if isinstance(expr, astroid.node_classes.NodeNG):
-        renderred = expr.as_string()
-        with suppress(ValueError, SyntaxError):
-            return ast.literal_eval(renderred)
+        # AttributeError: 'AsStringVisitor3' object has no attribute 'visit_unknown'
+        with suppress(AttributeError):  # pragma: no cover
+            renderred = expr.as_string()
+            with suppress(ValueError, SyntaxError):
+                return ast.literal_eval(renderred)
 
     handler = inner_extractor.handlers.get(type(expr))
     if handler:

deal/linter/_rules.py

@@ -9,7 +9,7 @@
 from ._error import Error
 from ._extractors import (
     get_asserts, get_exceptions, get_exceptions_stubs, get_globals,
-    get_imports, get_prints, get_returns, has_returns,
+    get_imports, get_pre, get_prints, get_returns, has_returns,
 )
 from ._func import Func
 from ._stub import StubsManager
@@ -48,9 +48,27 @@ def __call__(self, tree: ast.Module) -> Iterator[Error]:
 
 
 @register
-class CheckReturns:
+class CheckPre:
     __slots__ = ()
     code = 11
+    message = 'pre contract error'
+    required = Required.FUNC
+
+    def __call__(self, func: Func, stubs: StubsManager = None) -> Iterator[Error]:
+        for token in get_pre(body=func.body):
+            yield Error(
+                code=self.code,
+                text=self.message,
+                value=token.value,  # type: ignore
+                row=token.line,
+                col=token.col,
+            )
+
+
+@register
+class CheckReturns:
+    __slots__ = ()
+    code = 12
     message = 'post contract error'
     required = Required.FUNC
 
@@ -84,7 +102,7 @@ def _check(self, func: Func, contract: Contract) -> Iterator[Error]:
 @register
 class CheckRaises:
     __slots__ = ()
-    code = 12
+    code = 21
     message = 'raises contract error'
     required = Required.FUNC
 
@@ -120,7 +138,7 @@ def _check(self, func: Func, contract: Contract, stubs: StubsManager = None) ->
 @register
 class CheckPrints:
     __slots__ = ()
-    code = 13
+    code = 22
     message = 'silent contract error'
     required = Required.FUNC
 
@@ -146,7 +164,7 @@ def _check(self, func: Func, stubs: StubsManager = None) -> Iterator[Error]:
 @register
 class CheckPure:
     __slots__ = ()
-    code = 14
+    code = 23
     message = 'pure contract error'
     required = Required.FUNC
 
@@ -179,7 +197,7 @@ def _check(self, func: Func, stubs: StubsManager = None) -> Iterator[Error]:
 @register
 class CheckAsserts:
     __slots__ = ()
-    code = 15
+    code = 31
     message = 'assert error'
     required = Required.FUNC
 

docs/commands/lint.md

@@ -11,8 +11,9 @@ Another option is to use built-in CLI from deal: `python3 -m deal lint`. I has b
 | Code    | Message               |
 | ------- | --------------------- |
 | DEAL001 | do not use `from deal import ...`, use `import deal` instead |
-| DEAL011 | post contract error   |
-| DEAL012 | raises contract error |
-| DEAL013 | silent contract error |
-| DEAL014 | pure contract error   |
-| DEAL015 | assert error          |
+| DEAL011 | pre contract error    |
+| DEAL012 | post contract error   |
+| DEAL021 | raises contract error |
+| DEAL022 | silent contract error |
+| DEAL023 | pure contract error   |
+| DEAL031 | assert error          |

tests/test_cli/test_lint.py

@@ -38,7 +38,7 @@ def test_get_errors(tmp_path: Path):
     (tmp_path / 'example.py').write_text(TEXT)
     errors = list(get_errors(paths=[tmp_path]))
     assert len(errors) == 1
-    assert errors[0]['code'] == 11
+    assert errors[0]['code'] == 12
     assert errors[0]['content'] == '    return -1'
 
 

tests/test_linter/test_checker.py

@@ -24,9 +24,9 @@ def test2():
 """.strip()
 
 EXPECTED = [
-    (6, 11, 'DEAL011 post contract error (-1)', Checker),
-    (11, 8, 'DEAL012 raises contract error (ZeroDivisionError)', Checker),
-    (13, 10, 'DEAL012 raises contract error (KeyError)', Checker),
+    (6, 11, 'DEAL012 post contract error (-1)', Checker),
+    (11, 8, 'DEAL021 raises contract error (ZeroDivisionError)', Checker),
+    (13, 10, 'DEAL021 raises contract error (KeyError)', Checker),
 ]