Update test framework: fix run_tests.py to support all test files, add auto-import-check for test files

node_modules/form-data-encoder/lib/esm/util/isPlainObject.js

@@ -0,0 +1,13 @@
+const getType = (value) => (Object.prototype.toString.call(value).slice(8, -1).toLowerCase());
+function isPlainObject(value) {
+    if (getType(value) !== "object") {
+        return false;
+    }
+    const pp = Object.getPrototypeOf(value);
+    if (pp === null || pp === undefined) {
+        return true;
+    }
+    const Ctor = pp.constructor && pp.constructor.toString();
+    return Ctor === Object.toString();
+}
+export default isPlainObject;