[FIX] validation: validate schema keys

This commit adds validation for the schema object itself, to ensure that
only recognized keys are set on it.

This is done to avoid typos when writing validation schemas
(e.g. `{ type: Array, element*S*: String  }`).

Author: jum-odoo

src/runtime/validation.ts

@@ -60,6 +60,8 @@ function toSchema(spec: SimplifiedSchema): NormalizedSchema {
   );
 }
 
+const SCHEMA_KEYS = new Set(["element", "shape", "type", "validate", "values"]);
+
 /**
  * Main validate function
  */
@@ -141,35 +143,42 @@ export function validateType(key: string, value: any, descr: TypeDescription): s
     let validDescr = descr.find((p) => !validateType(key, value, p));
     return validDescr ? null : `'${key}' is not a ${describe(descr)}`;
   }
-  let result: string | null = null;
+  const invalidKeys = Reflect.ownKeys(descr).filter((key) => !SCHEMA_KEYS.has(String(key)));
+  if (invalidKeys.length) {
+    return `invalid schema for '${key}': unknown keys ${invalidKeys
+      .map((key) => `"${String(key)}"`)
+      .join(", ")}`;
+  }
   if ("element" in descr) {
-    result = validateArrayType(key, value, descr.element!);
-  } else if ("shape" in descr) {
+    return validateArrayType(key, value, descr.element!);
+  }
+  if ("shape" in descr) {
     if (typeof value !== "object" || Array.isArray(value)) {
-      result = `'${key}' is not an object`;
+      return `'${key}' is not an object`;
     } else {
       const errors = validateSchema(value, descr.shape!);
       if (errors.length) {
-        result = `'${key}' doesn't have the correct shape (${errors.join(", ")})`;
+        return `'${key}' doesn't have the correct shape (${errors.join(", ")})`;
       }
     }
-  } else if ("values" in descr) {
+  }
+  if ("values" in descr) {
     if (typeof value !== "object" || Array.isArray(value)) {
-      result = `'${key}' is not an object`;
+      return `'${key}' is not an object`;
     } else {
       const errors = Object.entries(value)
         .map(([key, value]) => validateType(key, value, descr.values!))
         .filter(Boolean);
       if (errors.length) {
-        result = `some of the values in '${key}' are invalid (${errors.join(", ")})`;
+        return `some of the values in '${key}' are invalid (${errors.join(", ")})`;
       }
     }
   }
-  if ("type" in descr && !result) {
-    result = validateType(key, value, descr.type!);
+  if ("type" in descr) {
+    return validateType(key, value, descr.type!);
   }
-  if ("validate" in descr && !result) {
-    result = !descr.validate!(value) ? `'${key}' is not valid` : null;
+  if ("validate" in descr) {
+    return !descr.validate!(value) ? `'${key}' is not valid` : null;
   }
-  return result;
+  return null;
 }

tests/validation.test.ts

@@ -308,4 +308,13 @@ describe("validateSchema", () => {
     ]);
     expect(validateSchema({ a: "string" }, { a: [String, { value: false }] })).toEqual([]);
   });
+
+  test("validate schema's own keys", () => {
+    expect(validateSchema({ arr: [] }, { arr: { type: Array, elements: String } as any })).toEqual([
+      `invalid schema for 'arr': unknown keys "elements"`,
+    ]);
+    expect(validateSchema({ obj: {} }, { obj: { type: Object, shapes: String } as any })).toEqual([
+      `invalid schema for 'obj': unknown keys "shapes"`,
+    ]);
+  });
 });