Merge pull request 'feat: structural schema lint for server definitions (#54)' (#58) from feat/54-schema-lint into main

bcc_core.py

@@ -1256,6 +1256,63 @@ def validate_servers(servers: list[ServerEntry]) -> list[str]:
     return problems
 
 
+def lint_server(name: str, data: dict) -> list[str]:
+    """Return non-blocking structural warnings for a single server definition.
+
+    Unlike validate_servers, nothing here blocks Save -- these are advisory
+    notes about shapes that will round-trip through JSON fine but are
+    probably not what the user intended (args given as a plain string
+    instead of a list, an env value that isn't a string, an unrecognized
+    `type`, unknown top-level fields, etc.).
+    """
+    nm = name.strip() or "(unnamed)"
+    warnings: list[str] = []
+
+    if "command" in data and not isinstance(data["command"], str):
+        warnings.append(f"'{nm}': 'command' should be a string")
+
+    if "args" in data:
+        args = data["args"]
+        if not isinstance(args, list):
+            warnings.append(f"'{nm}': 'args' should be a list (one argument per item)")
+        elif any(not isinstance(a, str) for a in args):
+            warnings.append(
+                f"'{nm}': 'args' contains non-string values "
+                "(they will be saved as-is; Claude expects strings)"
+            )
+
+    for field in ("env", "headers"):
+        if field not in data:
+            continue
+        val = data[field]
+        if not isinstance(val, dict):
+            warnings.append(f"'{nm}': '{field}' should be an object of string key/value pairs")
+        elif any(not isinstance(v, str) for v in val.values()):
+            warnings.append(
+                f"'{nm}': '{field}' contains non-string values "
+                "(they will be saved as-is; Claude expects strings)"
+            )
+
+    if "type" in data:
+        t = data["type"]
+        if t not in ("http", "sse", "stdio"):
+            warnings.append(f"'{nm}': 'type' should be one of http, sse, stdio (found {t!r})")
+
+    extra = sorted(k for k in data if k not in KNOWN_FIELDS)
+    if extra:
+        warnings.append(f"'{nm}': extra fields preserved as-is: {', '.join(extra)}")
+
+    return warnings
+
+
+def lint_servers(servers: list[ServerEntry]) -> list[str]:
+    """Concatenate lint_server warnings across every entry, in order."""
+    out: list[str] = []
+    for s in servers:
+        out.extend(lint_server(s.name, s.data))
+    return out
+
+
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