Fix: Exclude property getters/setters from function discovery

**Problem:**
When functions are defined as property getters/setters (e.g., inside
Object.defineProperty with `get: function getrouter() {...}`), they were
being discovered as optimizable functions. This caused test generation
to fail because:

1. Tests tried to call the getter function directly (e.g., `obj.getrouter()`)
2. But getters are not accessible by function name - only via property access
3. This resulted in "TypeError: Cannot read properties of undefined (reading 'bind')"

**Root Cause:**
The tree-sitter function discovery in `treesitter.py` was finding all
function_expression nodes, including those used as property getters/setters.
These are not standalone functions and cannot be called directly.

**Solution:**
Added a check in `_walk_tree_for_functions` to exclude function_expression
nodes that are:
- Inside a `pair` node (key-value pair in object literal)
- Where the key is "get" or "set" (property accessor pattern)

**Affected Trace IDs (from logs):**
- 11b5475c-91d9-43b1-a317-33b7f4811c52 (init.getrouter)
- 78d8f1de-541a-4208-85c7-77194c70ec72 (createETagGenerator.generateETag)
- And others with similar patterns

**Testing:**
- Added comprehensive test suite in test_property_getter_exclusion.py
- Verified fix on actual Express.js application.js (getrouter no longer discovered)
- All existing JavaScript function discovery tests pass
- Linting (prek) passes

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: Codeflash Bot

codeflash/languages/javascript/treesitter.py

@@ -290,6 +290,18 @@ def _walk_tree_for_functions(
                 if func_info.is_method and node.parent and node.parent.type == "object":
                     should_include = False
 
+                # Skip property getters/setters (e.g., get: function foo() {})
+                # These are defined inside Object.defineProperty or object literals
+                # and cannot be called directly - they're accessed via property names.
+                # Tests would fail trying to call obj.getterFuncName() instead of obj.propertyName
+                if node.type == "function_expression" and node.parent and node.parent.type == "pair":
+                    # Check if this is a getter or setter by looking at the property name
+                    property_name_node = node.parent.child_by_field_name("key")
+                    if property_name_node:
+                        property_name = self.get_node_text(property_name_node, source_bytes)
+                        if property_name in ("get", "set"):
+                            should_include = False
+
                 if should_include:
                     functions.append(func_info)
 

tests/test_property_getter_exclusion.py

@@ -0,0 +1,135 @@
+"""Test that property getters are excluded from optimization.
+
+Property getters defined via Object.defineProperty should not be
+optimized because they're not directly callable and tests cannot
+access them by the function name.
+
+Relates to bug: Generated tests try to call getters directly
+(e.g., `obj.getterFunc()`) when they should access the property
+(e.g., `obj.propertyName`).
+"""
+
+from pathlib import Path
+
+from codeflash.discovery.functions_to_optimize import find_all_functions_in_file
+
+
+class TestPropertyGetterExclusion:
+    """Tests for excluding property getters from function discovery."""
+
+    def test_object_define_property_getter_excluded(self, tmp_path: Path) -> None:
+        """Test that functions used as property getters are excluded.
+
+        When a function is defined as `get: function foo() {...}` inside
+        Object.defineProperty, it should not be discovered as an optimizable
+        function because:
+        1. It's not directly accessible by the function name
+        2. Generated tests would fail trying to call it directly
+        3. Property access patterns are different from function calls
+
+        This reproduces the Express.js pattern where getrouter is defined
+        as a property getter inside the init function.
+        """
+        js_file = tmp_path / "app.js"
+        js_file.write_text("""
+const app = {};
+
+// Express pattern: getter nested inside a function
+app.init = function init() {
+  var router = null;
+
+  // Property getter pattern (like express application.js line 72)
+  Object.defineProperty(this, 'router', {
+    configurable: true,
+    get: function getrouter() {
+      if (router === null) {
+        router = { use: () => {} };
+      }
+      return router;
+    }
+  });
+};
+
+// Normal exported function (should be found)
+export function normalFunction() {
+  return 42;
+}
+
+module.exports = app;
+""")
+
+        functions = find_all_functions_in_file(js_file)
+        function_names = {fn.function_name for fn in functions.get(js_file, [])}
+
+        # Property getter should NOT be found
+        assert "getrouter" not in function_names, (
+            "Property getter 'getrouter' should be excluded from optimization. "
+            "Tests cannot access it as init.getrouter() - they would need to access "
+            "the 'router' property via an instance instead."
+        )
+
+        # Normal exported function should be found
+        assert "normalFunction" in function_names
+
+    def test_object_define_property_setter_excluded(self, tmp_path: Path) -> None:
+        """Test that functions used as property setters are also excluded."""
+        js_file = tmp_path / "app.js"
+        js_file.write_text("""
+const app = {};
+
+Object.defineProperty(app, 'value', {
+  set: function setvalue(val) {
+    this._value = val;
+  },
+  get: function getvalue() {
+    return this._value;
+  }
+});
+
+export function helper() {
+  return 1;
+}
+""")
+
+        functions = find_all_functions_in_file(js_file)
+        function_names = {fn.function_name for fn in functions.get(js_file, [])}
+
+        # Neither getter nor setter should be found
+        assert "setvalue" not in function_names
+        assert "getvalue" not in function_names
+
+        # Helper function should still be found
+        assert "helper" in function_names
+
+    def test_object_literal_getter_excluded(self, tmp_path: Path) -> None:
+        """Test that getter methods in object literals are excluded."""
+        js_file = tmp_path / "obj.js"
+        js_file.write_text("""
+const obj = {
+  get router() {
+    return this._router;
+  },
+
+  // Regular method should be excluded too (it's in an object literal)
+  method() {
+    return 1;
+  }
+};
+
+export function exported() {
+  return obj;
+}
+""")
+
+        functions = find_all_functions_in_file(js_file)
+        function_names = {fn.function_name for fn in functions.get(js_file, [])}
+
+        # Getter in object literal should not be found
+        assert "router" not in function_names
+
+        # Regular method in object literal should also not be found
+        # (per existing code logic)
+        assert "method" not in function_names
+
+        # Exported function should be found
+        assert "exported" in function_names