fix: resolve 13 pre-existing pytest failures

src/client/python/agentguard/cli.py

@@ -97,7 +97,7 @@ def _cmd_check(args: argparse.Namespace) -> int:
     except PolicyError as exc:
         print(str(exc), file=sys.stderr)
         return 1
-    print(f"ok: {target} ({len(rules)} rules)")
+    print(f"ok: {target.as_posix()} ({len(rules)} rules)")
     return 0
 
 
@@ -121,11 +121,11 @@ def _check_rules_file(path: Path) -> tuple[bool, int]:
 
     _, report = parse_legacy_rules(source)
     if report.ok:
-        print(f"ok: {path} ({report.rule_count} rule block(s))")
+        print(f"ok: {path.as_posix()} ({report.rule_count} rule block(s))")
         return True, report.rule_count
 
     for error in report.errors:
-        print(f"error: {path}: {error['message']}", file=sys.stderr)
+        print(f"error: {path.as_posix()}: {error['message']}", file=sys.stderr)
     return False, report.rule_count
 
 

src/client/python/agentguard/rules/loader.py

@@ -29,17 +29,22 @@ def load_rules_file(path: str | Path) -> list[PolicyRule]:
     p = Path(path)
     if not p.exists():
         raise PolicyError(f"rule file not found: {p}")
-    if p.suffix.lower() == ".rules":
-        try:
-            parsed, report = parse_legacy_rules(p.read_text(encoding="utf-8"))
-        except OSError as exc:
-            raise PolicyError(f"cannot read rule file {p}: {exc}") from exc
+    try:
+        text = p.read_text(encoding="utf-8")
+    except OSError as exc:
+        raise PolicyError(f"cannot read rule file {p}: {exc}") from exc
+    # `.rules` is the legacy text-DSL extension, but some callers write plain
+    # JSON rule lists to a `.rules`-suffixed path; sniff the content rather
+    # than trusting the suffix so both work.
+    looks_like_json = text.lstrip()[:1] in ("[", "{")
+    if p.suffix.lower() == ".rules" and not looks_like_json:
+        parsed, report = parse_legacy_rules(text)
         if not report.ok:
             raise PolicyError(f"cannot parse rule file {p}: {report.errors[0]['message']}")
         return [PolicyRule.from_dict(rule.to_dict()) for rule in parsed]
     try:
-        data = json.loads(p.read_text(encoding="utf-8"))
-    except (OSError, json.JSONDecodeError) as exc:
+        data = json.loads(text)
+    except json.JSONDecodeError as exc:
         raise PolicyError(f"cannot read rule file {p}: {exc}") from exc
     return _coerce_rules(data)