fix: make max_conditional iterative (#258)

context: #243

User ran into `RecursionError: maximum recursion depth exceeded` running
`_get_max_nested_conditional`.

By removing the recursion from the function we hopefully fix this issue.
So now it's using text-book definition of BFS to go about finding the max depth.

Notice we do have to go through all nodes of the function because we don't know if a node that is not
of type conditional doesn't have another conditional inside of it (think block nodes, for example).
And we only increase the level when we pass through one conditional, not when we go to the next child.

close #243

Author: giovanni-guidini

codecov_cli/services/staticanalysis/analyzers/general.py

@@ -1,4 +1,5 @@
 import hashlib
+from collections import deque
 
 
 class BaseAnalyzer(object):
@@ -16,10 +17,26 @@ def _count_elements(self, node, types):
             count += 1
         return count
 
-    def _get_max_nested_conditional(self, node):
-        return (1 if node.type in self.condition_statements else 0) + max(
-            (self._get_max_nested_conditional(x) for x in node.children), default=0
-        )
+    def _get_max_nested_conditional(self, head):
+        """Iterates over all nodes in a function body and returns the max nested conditional depth.
+        Uses BFS to avoid recursion calls (so we don't throw RecursionError)
+        """
+        nodes_to_visit = deque()
+        nodes_to_visit.append([head, int(head.type in self.condition_statements)])
+        max_nested_depth = 0
+
+        while nodes_to_visit:
+            curr_node, curr_depth = nodes_to_visit.popleft()
+            max_nested_depth = max(max_nested_depth, curr_depth)
+            # Here is where the depth might change
+            # If the current node is a conditional
+            is_curr_conditional = curr_node.type in self.condition_statements
+
+            # Enqueue all child nodes of the curr_node
+            for child in curr_node.children:
+                nodes_to_visit.append([child, curr_depth + is_curr_conditional])
+
+        return max_nested_depth
 
     def _get_complexity_metrics(self, body_node):
         number_conditions = self._count_elements(

samples/inputs/sample_002.py

@@ -27,3 +27,9 @@ def single_line_minecraft(bb):
 c = 0
 while c < 1:
     print("b")
+
+def nested_conditionals(val):
+    if val > 10:
+        if val > 100:
+            if val > 1000:
+                return 'large value'

samples/outputs/sample_002.json

@@ -45,10 +45,22 @@
                     "returns": 0,
                     "max_nested_conditional": 0
                 }
+            },
+            {
+                "identifier": "nested_conditionals",
+                "start_line": 31,
+                "end_line": 35,
+                "code_hash": "9ee2ce7f737ad1adf8e8e6be70be534b",
+                "complexity_metrics": {
+                    "conditions": 3,
+                    "max_nested_conditional": 3,
+                    "mccabe_cyclomatic_complexity": 4,
+                    "returns": 1
+                }
             }
         ],
-        "hash": "97be1c2949c8f328b8ba5673eba21a84",
-        "number_lines": 30,
+        "hash": "9fb6bbc43350a18531adfb399f5cc0ae",
+        "number_lines": 35,
         "statements": [
             [
                 9,
@@ -199,6 +211,46 @@
                     "len": 0,
                     "extra_connected_lines": []
                 }
+            ],
+            [
+                32,
+                {
+                    "extra_connected_lines": [],
+                    "len": 3,
+                    "line_hash": "9ee2ce7f737ad1adf8e8e6be70be534b",
+                    "line_surety_ancestorship": null,
+                    "start_column": 4
+                }
+            ],
+            [
+                33,
+                {
+                    "extra_connected_lines": [],
+                    "len": 2,
+                    "line_hash": "3d1fa1be2935c716122a2a63eb0070f3",
+                    "line_surety_ancestorship": 32,
+                    "start_column": 8
+                }
+            ],
+            [
+                34,
+                {
+                    "extra_connected_lines": [],
+                    "len": 1,
+                    "line_hash": "20a6f68248783caeab8abb2ccda43cb3",
+                    "line_surety_ancestorship": 33,
+                    "start_column": 12
+                }
+            ],
+            [
+                35,
+                {
+                    "extra_connected_lines": [],
+                    "len": 0,
+                    "line_hash": "6c92ccd39eaa87eb873f2de3e475db82",
+                    "line_surety_ancestorship": 34,
+                    "start_column": 16
+                }
             ]
         ],
         "definition_lines": [
@@ -213,6 +265,10 @@
             [
                 17,
                 1
+            ],
+            [
+                31,
+                4
             ]
         ],
         "import_lines": [