fix: handle invalid JSON in semgrep parser and add unit tests

plugins/semgrep_scanner/metadata.json

@@ -74,5 +74,5 @@
     "system_packages": []
   },
   "docker_image": "returntocorp/semgrep:latest",
-  "checksum": "8e59254f5ad937c0a5a2af47367cddf07e07b8a528d13ff303360d6e478a51d8"
+  "checksum": "2639e4aa47d346d9ab7caa64d6fe447203f8a6be5a0a354055eebebe9e674ae6"
 }

plugins/semgrep_scanner/parser.py

@@ -48,6 +48,7 @@ def parse(output: str) -> Dict[str, Any]:
                 }
             )
     except Exception:
-        pass
+        # If parsing fails, return empty findings
+        return {"findings": [], "count": 0}
 
     return {"findings": findings, "count": len(findings)}

testing/test_semgrep_parser.py

@@ -0,0 +1,43 @@
+import pytest
+import json
+import sys
+import os
+
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
+
+from plugins.semgrep_scanner.parser import parse
+
+# Test 1: Valid JSON input
+def test_valid_json():
+    valid_input = json.dumps({
+        "results": [
+            {
+                "check_id": "python.security.test-rule",
+                "path": "app.py",
+                "extra": {
+                    "message": "Test security issue",
+                    "severity": "WARNING",
+                    "lines": "eval(user_input)"
+                },
+                "start": {"line": 10}
+            }
+        ]
+    })
+    result = parse(valid_input)
+    assert result["count"] == 1
+    assert result["findings"][0]["severity"] == "medium"
+    assert result["findings"][0]["category"] == "Code Security"
+
+# Test 2: Invalid JSON input
+def test_invalid_json():
+    invalid_input = "this is not json {{{broken"
+    result = parse(invalid_input)
+    assert result["count"] == 0
+    assert result["findings"] == []
+
+# Test 3: Mixed stdout (JSON mixed with other text)
+def test_mixed_stdout():
+    mixed_input = "Some random text\n{invalid json here}\nmore text"
+    result = parse(mixed_input)
+    assert result["count"] == 0
+    assert result["findings"] == []