Merge 54d36e5 into fe27139

deal/linter/_contract.py

@@ -20,6 +20,7 @@ class Category(enum.Enum):
     POST = 'post'
     RAISES = 'raises'
     SILENT = 'silent'
+    PURE = 'pure'
 
 
 class Contract:

deal/linter/_extractors/__init__.py

@@ -2,6 +2,7 @@
 from .common import get_name
 from .contracts import get_contracts
 from .exceptions import get_exceptions
+from .globals import get_globals
 from .imports import get_imports
 from .prints import get_prints
 from .returns import get_returns
@@ -10,6 +11,7 @@
 __all__ = [
     'get_contracts',
     'get_exceptions',
+    'get_globals',
     'get_imports',
     'get_name',
     'get_prints',

deal/linter/_extractors/common.py

@@ -8,20 +8,22 @@
 
 
 TOKENS = SimpleNamespace(
-    ATTR=(ast.Attribute, astroid.Attribute),
     ASSERT=(ast.Assert, astroid.Assert),
+    ATTR=(ast.Attribute, astroid.Attribute),
     BIN_OP=(ast.BinOp, astroid.BinOp),
     CALL=(ast.Call, astroid.Call),
     EXPR=(ast.Expr, astroid.Expr),
     FOR=(ast.For, astroid.For),
+    FUNC=(ast.FunctionDef, astroid.FunctionDef),
+    GLOBAL=(ast.Global, astroid.Global),
     IF=(ast.If, astroid.If),
     NAME=(ast.Name, astroid.Name),
+    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),
-    FUNC=(ast.FunctionDef, astroid.FunctionDef),
 )
 
 

deal/linter/_extractors/contracts.py

@@ -8,8 +8,8 @@
 from .common import TOKENS, get_name
 
 
-SUPPORTED_CONTRACTS = {'deal.post', 'deal.raises', 'deal.silent'}
-SUPPORTED_MARKERS = {'deal.silent'}
+SUPPORTED_CONTRACTS = {'deal.post', 'deal.raises', 'deal.silent', 'deal.pure'}
+SUPPORTED_MARKERS = {'deal.silent', 'deal.pure'}
 
 
 def get_contracts(decorators: list) -> Iterator[Tuple[str, list]]:

deal/linter/_extractors/globals.py

@@ -0,0 +1,36 @@
+# built-in
+import ast
+from typing import Iterator
+
+# external
+import astroid
+
+# app
+from .common import TOKENS, Token, traverse
+
+
+def get_globals(body: list) -> Iterator[Token]:
+    for expr in traverse(body):
+        if isinstance(expr, TOKENS.GLOBAL):
+            yield Token(value='global', line=expr.lineno, col=expr.col_offset)
+            continue
+
+        if isinstance(expr, TOKENS.NONLOCAL):
+            yield Token(value='nonlocal', line=expr.lineno, col=expr.col_offset)
+            continue
+
+        if type(expr) is ast.Import:
+            yield Token(value='import', line=expr.lineno, col=expr.col_offset)
+            continue
+
+        if type(expr) is astroid.Import:
+            yield Token(value='import', line=expr.lineno, col=expr.col_offset)
+            continue
+
+        if type(expr) is ast.ImportFrom:
+            yield Token(value='import', line=expr.lineno, col=expr.col_offset)
+            continue
+
+        if type(expr) is astroid.ImportFrom:
+            yield Token(value='import', line=expr.lineno, col=expr.col_offset)
+            continue

deal/linter/_rules.py

@@ -6,7 +6,7 @@
 # app
 from ._contract import Category, Contract
 from ._error import Error
-from ._extractors import get_exceptions, get_imports, get_prints, get_returns
+from ._extractors import get_exceptions, get_imports, get_prints, get_returns, get_globals
 from ._func import Func
 
 
@@ -116,11 +116,11 @@ def __call__(self, func: Func) -> Iterator[Error]:
         for contract in func.contracts:
             if contract.category != Category.SILENT:
                 continue
-            yield from self._check(func=func, contract=contract)
+            yield from self._check(func=func)
             # if `@deal.silent` is duplicated, check the function only once
             return
 
-    def _check(self, func: Func, contract: Contract) -> Iterator[Error]:
+    def _check(self, func: Func) -> Iterator[Error]:
         for token in get_prints(body=func.body):
             yield Error(
                 code=self.code,
@@ -129,3 +129,27 @@ def _check(self, func: Func, contract: Contract) -> Iterator[Error]:
                 row=token.line,
                 col=token.col,
             )
+
+
+@register
+class CheckPure:
+    code = 14
+    message = 'pure contract error'
+    required = Required.FUNC
+
+    def __call__(self, func: Func) -> Iterator[Error]:
+        for contract in func.contracts:
+            if contract.category != Category.PURE:
+                continue
+            yield from self._check(func=func)
+            return
+
+    def _check(self, func: Func) -> Iterator[Error]:
+        for token in get_globals(body=func.body):
+            yield Error(
+                code=self.code,
+                text=self.message,
+                value=str(token.value),
+                row=token.line,
+                col=token.col,
+            )

docs/decorators/pure.md

@@ -1,6 +1,6 @@
 # pure
 
-Pure function cannot do network requests, write anything into stdout or raise any exceptions. It gets some parameters and returns some result. That's all. This is alias for `chain(safe, silent, offline)`.
+Pure function cannot do network requests, write anything into stdout or raise any exceptions. It gets some parameters and returns some result. That's all. In runtime, it does the same checks as `chain(safe, silent, offline)`. However, [linter](../linter.html) checks a bit more, like no `import`, `global`, `nonlocal`, etc.
 
 ```python
 @deal.pure

docs/linter.md

@@ -14,3 +14,4 @@ Another option is to use built-in CLI from deal: `python3 -m deal.linter`. I has
 | DEAL011 | post contract error   |
 | DEAL012 | raises contract error |
 | DEAL013 | silent contract error |
+| DEAL014 | pure contract error   |

tests/test_linter/test_extractors/test_globals.py

@@ -0,0 +1,35 @@
+# built-in
+import ast
+
+# external
+import astroid
+import pytest
+
+# project
+from deal.linter._extractors import get_globals
+
+
+@pytest.mark.parametrize('text, expected', [
+    ('global a', ('global', )),
+    ('global a, b, c', ('global', )),
+
+    ('nonlocal a', ('nonlocal', )),
+    ('nonlocal a, b, c', ('nonlocal', )),
+
+    ('import a', ('import', )),
+    ('import a as b', ('import', )),
+    ('import a as b, c', ('import', )),
+
+    ('from a import b', ('import', )),
+    ('from a import b as c', ('import', )),
+])
+def test_get_globals_simple(text, expected):
+    tree = astroid.parse(text)
+    print(tree.repr_tree())
+    globals = tuple(r.value for r in get_globals(body=tree.body))
+    assert globals == expected
+
+    tree = ast.parse(text)
+    print(ast.dump(tree))
+    globals = tuple(r.value for r in get_globals(body=tree.body))
+    assert globals == expected

tests/test_linter/test_rules.py

@@ -7,7 +7,17 @@
 
 # project
 from deal.linter._func import Func
-from deal.linter._rules import CheckImports, CheckPrints, CheckRaises, CheckReturns
+from deal.linter._rules import rules, CheckImports, CheckPrints, CheckRaises, CheckReturns, CheckPure
+
+
+def test_error_codes():
+    codes = [rule.code for rule in rules]
+    assert len(codes) == len(set(codes))
+
+
+def test_error_messages():
+    messages = [rule.message for rule in rules]
+    assert len(messages) == len(set(messages))
 
 
 def test_check_returns():
@@ -129,6 +139,22 @@ def test(a):
         assert actual == expected
 
 
+def test_check_pure():
+    checker = CheckPure()
+    text = """
+    @deal.pure
+    def test(a):
+        global b
+    """
+    text = dedent(text).strip()
+    funcs1 = Func.from_ast(ast.parse(text))
+    funcs2 = Func.from_astroid(astroid.parse(text))
+    for func in (funcs1[0], funcs2[0]):
+        actual = [tuple(err) for err in checker(func)]
+        expected = [(3, 4, 'DEAL014: pure contract error (global)')]
+        assert actual == expected
+
+
 def test_check_imports():
     checker = CheckImports()
     text = """