add transform_object_properties in jerryx/arg (#1879)

Add a function in jerryx/arg.
jerryx_arg_transform_object_properties, it will validate the properties of a JS object, and convert those properties into native type.

JerryScript-DCO-1.0-Signed-off-by: Zidong Jiang zidong.jiang@intel.com

jerry-ext/include/jerryscript-ext/arg.h

@@ -16,7 +16,6 @@
 #ifndef JERRYX_ARG_H
 #define JERRYX_ARG_H
 
-#include <assert.h>
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
@@ -43,6 +42,17 @@ typedef struct jerryx_arg_js_iterator_t jerryx_arg_js_iterator_t;
 typedef jerry_value_t (*jerryx_arg_transform_func_t) (jerryx_arg_js_iterator_t *js_arg_iter_p, /**< available JS args */
                                                       const jerryx_arg_t *c_arg_p); /**< native arg */
 
+/**
+ * The structure used in jerryx_arg_object_properties
+ */
+typedef struct
+{
+  const jerry_char_t **name_p; /**< property name list of the JS object */
+  jerry_length_t name_cnt; /**< count of the name list */
+  const jerryx_arg_t *c_arg_p; /**< points to the array of transformation steps */
+  jerry_length_t c_arg_cnt; /**< the count of the `c_arg_p` array */
+} jerryx_arg_object_props_t;
+
 /**
  * The structure defining a single validation & transformation step.
  */
@@ -64,6 +74,12 @@ jerry_value_t jerryx_arg_transform_args (const jerry_value_t *js_arg_p,
                                          const jerryx_arg_t *c_arg_p,
                                          jerry_length_t c_arg_cnt);
 
+jerry_value_t jerryx_arg_transform_object_properties (const jerry_value_t obj_val,
+                                                      const jerry_char_t **name_p,
+                                                      const jerry_length_t name_cnt,
+                                                      const jerryx_arg_t *c_arg_p,
+                                                      jerry_length_t c_arg_cnt);
+
 /**
  * Indicates whether an argument is allowed to be coerced into the expected JS type.
  */
@@ -105,6 +121,8 @@ static inline jerryx_arg_t
 jerryx_arg_ignore (void);
 static inline jerryx_arg_t
 jerryx_arg_custom (void *dest, uintptr_t extra_info, jerryx_arg_transform_func_t func);
+static inline jerryx_arg_t
+jerryx_arg_object_properties (const jerryx_arg_object_props_t *object_props_p, jerryx_arg_optional_t opt_flag);
 
 jerry_value_t
 jerryx_arg_transform_optional (jerryx_arg_js_iterator_t *js_arg_iter_p,

jerry-ext/include/jerryscript-ext/arg.impl.h

@@ -51,6 +51,10 @@ jerry_value_t jerryx_arg_transform_native_pointer_optional (jerryx_arg_js_iterat
                                                             const jerryx_arg_t *c_arg_p);
 jerry_value_t jerryx_arg_transform_ignore (jerryx_arg_js_iterator_t *js_arg_iter_p,
                                            const jerryx_arg_t *c_arg_p);
+jerry_value_t jerryx_arg_transform_object_props (jerryx_arg_js_iterator_t *js_arg_iter_p,
+                                                 const jerryx_arg_t *c_arg_p);
+jerry_value_t jerryx_arg_transform_object_props_optional (jerryx_arg_js_iterator_t *js_arg_iter_p,
+                                                          const jerryx_arg_t *c_arg_p);
 
 /**
  * Create a validation/transformation step (`jerryx_arg_t`) that expects to
@@ -213,7 +217,7 @@ jerryx_arg_function (jerry_value_t *dest, /**< pointer to the jerry_value_t wher
 
 /**
  * Create a validation/transformation step (`jerryx_arg_t`) that expects to
- * consume one `Object` JS argument that is 'backed' with a native pointer with
+ * consume one `object` JS argument that is 'backed' with a native pointer with
  * a given type info. In case the native pointer info matches, the transform
  * will succeed and the object's native pointer will be assigned to *dest.
  *
@@ -275,4 +279,32 @@ jerryx_arg_custom (void *dest, /**< pointer to the native argument where the res
   };
 } /* jerryx_arg_custom */
 
+/**
+ * Create a jerryx_arg_t instance for object properties.
+ *
+ * @return a jerryx_arg_t instance.
+ */
+static inline jerryx_arg_t
+jerryx_arg_object_properties (const jerryx_arg_object_props_t *object_props, /**< pointer to object property mapping */
+                              jerryx_arg_optional_t opt_flag) /**< whether the argument is optional */
+{
+  jerryx_arg_transform_func_t func;
+
+  if (opt_flag == JERRYX_ARG_OPTIONAL)
+  {
+    func = jerryx_arg_transform_object_props_optional;
+  }
+  else
+  {
+    func = jerryx_arg_transform_object_props;
+  }
+
+  return (jerryx_arg_t)
+  {
+    .func = func,
+    .dest = NULL,
+    .extra_info = (uintptr_t) object_props
+  };
+} /* jerryx_arg_object_properties */
+
 #endif /* !JERRYX_ARG_IMPL_H */