From ac75e377b8c6213f549fccc45a4d34db2c73404c Mon Sep 17 00:00:00 2001
From: Sam Wellander <samwellander@gmail.com>
Date: Thu, 21 Oct 2021 21:56:55 -0700
Subject: [PATCH] feat!: add prefer `TypeError` analyzer

---
 src/tryceratops/analyzers/__init__.py    |  3 +-
 src/tryceratops/analyzers/conditional.py | 64 ++++++++++++++++++++++++
 src/tryceratops/violations/codes.py      |  1 +
 3 files changed, 67 insertions(+), 1 deletion(-)
 create mode 100644 src/tryceratops/analyzers/conditional.py

diff --git a/src/tryceratops/analyzers/__init__.py b/src/tryceratops/analyzers/__init__.py
index 0cc5929..db8ac17 100644
--- a/src/tryceratops/analyzers/__init__.py
+++ b/src/tryceratops/analyzers/__init__.py
@@ -2,7 +2,7 @@
 
 from typing import TYPE_CHECKING, Set
 
-from . import call, exception_block, try_block
+from . import call, conditional, exception_block, try_block
 from .base import BaseAnalyzer
 
 if TYPE_CHECKING:
@@ -14,6 +14,7 @@
     call.CallRaiseVanillaAnalyzer,  # type: ignore
     call.CallRaiseLongArgsAnalyzer,  # type: ignore
     call.CallAvoidCheckingToContinueAnalyzer,  # type: ignore
+    conditional.PreferTypeErrorAnalyzer,
     exception_block.ExceptReraiseWithoutCauseAnalyzer,
     exception_block.ExceptVerboseReraiseAnalyzer,
     exception_block.ExceptBroadPassAnalyzer,
diff --git a/src/tryceratops/analyzers/conditional.py b/src/tryceratops/analyzers/conditional.py
new file mode 100644
index 0000000..710ac7f
--- /dev/null
+++ b/src/tryceratops/analyzers/conditional.py
@@ -0,0 +1,64 @@
+import ast
+from typing import Union
+
+from tryceratops.violations import codes
+
+from .base import BaseAnalyzer
+
+STANDARD_NON_TYPE_ERROR_IDS = (
+    "ArithmeticError",
+    "AssertionError",
+    "AttributeError",
+    "BufferError",
+    "EOFError",
+    "Exception",
+    "ImportError",
+    "LookupError",
+    "MemoryError",
+    "NameError",
+    "ReferenceError",
+    "RuntimeError",
+    "SyntaxError",
+    "SystemError",
+    "ValueError",
+)
+
+
+class PreferTypeErrorAnalyzer(BaseAnalyzer):
+    violation_code = codes.PREFER_TYPE_ERROR
+
+    def _is_checking_type(self, node: Union[ast.stmt, ast.expr]) -> bool:
+        if isinstance(node, ast.If):
+            return self._is_checking_type(node.test) and all(
+                [self._is_checking_type(stm) for stm in node.orelse if isinstance(stm, ast.If)]
+            )
+        if isinstance(node, ast.UnaryOp):
+            return self._is_checking_type(node.operand)
+        if isinstance(node, ast.BoolOp):
+            return all([self._is_checking_type(value) for value in node.values])
+        if isinstance(node, ast.Call):
+            if isinstance(node.func, ast.Name):
+                if node.func.id in ("isinstance", "issubclass", "callable"):
+                    return True
+        return False
+
+    def _check_is_raise_other_than_typeerror(self, node: ast.Raise) -> None:
+        if isinstance(node.exc, ast.Call):
+            if isinstance(node.exc.func, ast.Name):
+                if node.exc.func.id in STANDARD_NON_TYPE_ERROR_IDS:
+                    self._mark_violation(node.exc.func)
+        elif isinstance(node.exc, ast.Name):
+            if node.exc.id in STANDARD_NON_TYPE_ERROR_IDS:
+                self._mark_violation(node.exc)
+
+    def _check_for_raises(self, node):
+        for stm in ast.iter_child_nodes(node):
+            if isinstance(stm, ast.Raise):
+                self._check_is_raise_other_than_typeerror(stm)
+        if isinstance(node, ast.If):
+            for stm in node.orelse:
+                self._check_for_raises(stm)
+
+    def visit_If(self, node: ast.If) -> None:
+        if self._is_checking_type(node):
+            self._check_for_raises(node)
diff --git a/src/tryceratops/violations/codes.py b/src/tryceratops/violations/codes.py
index 4b02d30..4a625fe 100644
--- a/src/tryceratops/violations/codes.py
+++ b/src/tryceratops/violations/codes.py
@@ -4,6 +4,7 @@
     "TC003",
     "Avoid specifying long messages outside the exception class",
 )
+PREFER_TYPE_ERROR = ("TC004", "Prefer TypeError exception for invalid type")
 
 # TC1xx - General
 CHECK_TO_CONTINUE = (