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Added new 'jerry_value_instanceof' API function. #2723

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78 changes: 78 additions & 0 deletions docs/02.API-REFERENCE.md
Original file line number Diff line number Diff line change
Expand Up @@ -1084,6 +1084,84 @@ jerry_get_global_object (void);

Functions to check the type of an API value ([jerry_value_t](#jerry_value_t)).


## jerry_instanceof

**Summary**

Returns whether the given `jerry_value_t` is an instance of the given prototype.
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Isn't there any difference between the es5.1 vs es2015 instanceof internal workings? Could that affect the api workings?

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It should not affect the api workings, but may affect the internal workings (e.g.: instance of classes).

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Classes are simple functions, the only specializations they have is a bytecode status flag, so I think it couldn't have any affect on it.


**Prototype**

```c
jerry_value_t
jerry_instanceof (const jerry_value_t value, const jerry_value_t prototype);
```

- `value` - api value of instance object
- `prototype` - api value of prototype
- return value
- error, if value argument is not an object or prototype argument is not a function
- true, if the specified value is an instance of the given prototype
- false, otherwise

**Example**

[doctest]: # ()

```c
#include "jerryscript.h"

static jerry_value_t
my_constructor (const jerry_value_t func_val,
const jerry_value_t this_val,
const jerry_value_t argv[],
const jerry_length_t argc)
{
return jerry_create_undefined ();
}

int
main (void)
{
jerry_init (JERRY_INIT_EMPTY);

jerry_value_t base_obj = jerry_create_object ();
jerry_value_t constructor = jerry_create_external_function (my_constructor);

/* External functions does not have a prototype by default, so we need to create one */
jerry_value_t prototype_str = jerry_create_string ((const jerry_char_t *) ("prototype"));
jerry_release_value (jerry_set_property (constructor, prototype_str, base_obj));
jerry_release_value (prototype_str);

/* Construct the instance. */
jerry_value_t instance_val = jerry_construct_object (constructor, NULL, 0);

/* Call the API function of 'instanceof'. */
jerry_value_t is_instance = jerry_instanceof (instance_val, constructor);
if (!jerry_value_is_error (is_instance)
&& jerry_get_boolean_value (is_instance) == true)
{
/* ... */
}

/* Free all of the jerry values and cleanup the engine. */
jerry_release_value (base_obj);
jerry_release_value (constructor);
jerry_release_value (instance_val);
jerry_release_value (is_instance);

jerry_cleanup ();
return 0;
}
```

**See also**

- [jerry_construct_object](#jerry_construct_object)
- [jerry_create_external_function](#jerry_create_external_function)


## jerry_value_is_abort

**Summary**
Expand Down
35 changes: 35 additions & 0 deletions jerry-core/api/jerry.c
Original file line number Diff line number Diff line change
Expand Up @@ -601,6 +601,41 @@ jerry_get_global_object (void)
return ecma_make_object_value (global_obj_p);
} /* jerry_get_global_object */

/**
* Check if the specified value is an instance of the given prototype.
*
* See also ECMA-262 v5.1, 11.8.6
*
* Note:
* returned value must be freed with jerry_release_value, when it is no longer needed.
*
* @return true - if the specified value is an instance of the given prototype
* false - otherwise
* error - if value argument is not an object or prototype argument is not a function.
*
*/
jerry_value_t
jerry_instanceof (const jerry_value_t value, /**< object value */
const jerry_value_t prototype) /**< prototpye function */
{
jerry_assert_api_available ();

if (ecma_is_value_error_reference (value)
|| ecma_is_value_error_reference (prototype))
{
return jerry_throw (ecma_raise_type_error (ECMA_ERR_MSG (error_value_msg_p)));
}

if (!ecma_is_value_object (value)
|| !ecma_op_is_callable (prototype))
{
return jerry_throw (ecma_raise_type_error (ECMA_ERR_MSG (wrong_args_msg_p)));
}

ecma_object_t *proto_obj_p = ecma_get_object_from_value (prototype);
return jerry_return (ecma_op_object_has_instance (proto_obj_p, value));
} /* jerry_instanceof */

/**
* Check if the specified value is an abort value.
*
Expand Down
3 changes: 2 additions & 1 deletion jerry-core/ecma/operations/ecma-function-object.c
Original file line number Diff line number Diff line change
Expand Up @@ -327,7 +327,8 @@ ecma_op_arrow_function_get_compiled_code (ecma_arrow_function_t *arrow_function_
/**
* 15.3.5.3 implementation of [[HasInstance]] for Function objects
*
* @return ecma value
* @return true/false - if arguments are valid
* error - otherwise
* Returned value must be freed with ecma_free_value
*/
ecma_value_t
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1 change: 1 addition & 0 deletions jerry-core/include/jerryscript-core.h
Original file line number Diff line number Diff line change
Expand Up @@ -343,6 +343,7 @@ jerry_value_t jerry_get_global_object (void);
/**
* Checker functions of 'jerry_value_t'.
*/
jerry_value_t jerry_instanceof (const jerry_value_t value, const jerry_value_t prototype);
bool jerry_value_is_abort (const jerry_value_t value);
bool jerry_value_is_array (const jerry_value_t value);
bool jerry_value_is_boolean (const jerry_value_t value);
Expand Down
118 changes: 118 additions & 0 deletions tests/unit-core/test-api-instaceof.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,118 @@
/* Copyright JS Foundation and other contributors, http://js.foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

#include "jerryscript.h"

#include "test-common.h"

#define T(lhs, rhs, res) \
{ lhs, rhs, res }

typedef struct
{
jerry_value_t lhs;
jerry_value_t rhs;
bool expected;
} test_entry_t;

static jerry_value_t
my_constructor (const jerry_value_t func_val, /**< function */
const jerry_value_t this_val, /**< this */
const jerry_value_t argv[], /**< arguments */
const jerry_length_t argc) /**< number of arguments */
{
(void) func_val;
(void) this_val;
(void) argv;
(void) argc;
return jerry_create_undefined ();
} /* my_constructor */

int
main (void)
{
TEST_INIT ();

jerry_init (JERRY_INIT_EMPTY);

jerry_value_t base_obj = jerry_create_object ();
jerry_value_t constructor = jerry_create_external_function (my_constructor);

jerry_value_t no_proto_instance_val = jerry_construct_object (constructor, NULL, 0);

jerry_value_t prototype_str = jerry_create_string ((const jerry_char_t *) "prototype");
jerry_value_t res = jerry_set_property (constructor, prototype_str, base_obj);
jerry_release_value (prototype_str);
TEST_ASSERT (!jerry_value_is_error (res));
jerry_release_value (res);

jerry_value_t instance_val = jerry_construct_object (constructor, NULL, 0);

jerry_value_t error = jerry_create_error_from_value (base_obj, false);

test_entry_t bool_tests[] =
{
T (jerry_acquire_value (instance_val), jerry_acquire_value (constructor), true),
T (jerry_acquire_value (no_proto_instance_val), jerry_acquire_value (constructor), false),
T (jerry_acquire_value (base_obj), jerry_acquire_value (constructor), false)
};

for (uint32_t idx = 0; idx < sizeof (bool_tests) / sizeof (test_entry_t); idx++)
{
jerry_value_t result = jerry_instanceof (bool_tests[idx].lhs, bool_tests[idx].rhs);
TEST_ASSERT (!jerry_value_is_error (result));
TEST_ASSERT (jerry_get_boolean_value (result) == bool_tests[idx].expected);
jerry_release_value (bool_tests[idx].lhs);
jerry_release_value (bool_tests[idx].rhs);
jerry_release_value (result);
}

test_entry_t error_tests[] =
{
T (jerry_acquire_value (constructor), jerry_acquire_value (instance_val), true),
T (jerry_create_undefined (), jerry_acquire_value (constructor), true),
T (jerry_acquire_value (instance_val), jerry_create_undefined (), true),
T (jerry_acquire_value (instance_val), jerry_acquire_value (base_obj), true),
T (jerry_acquire_value (error), jerry_acquire_value (constructor), true),
T (jerry_acquire_value (instance_val), jerry_acquire_value (error), true),
T (jerry_create_string ((const jerry_char_t *) ""), jerry_create_string ((const jerry_char_t *) ""), true),
T (jerry_create_string ((const jerry_char_t *) ""), jerry_create_number (5.0), true),
T (jerry_create_number (5.0), jerry_create_string ((const jerry_char_t *) ""), true),
T (jerry_create_array (1), jerry_create_array (1), true),
T (jerry_create_array (1), jerry_create_object (), true),
T (jerry_create_object (), jerry_create_array (1), true),
T (jerry_create_null (), jerry_create_object (), true),
T (jerry_create_object (), jerry_create_string ((const jerry_char_t *) ""), true)
};

for (uint32_t idx = 0; idx < sizeof (error_tests) / sizeof (test_entry_t); idx++)
{
jerry_value_t result = jerry_instanceof (error_tests[idx].lhs, error_tests[idx].rhs);
TEST_ASSERT (jerry_value_is_error (result) == error_tests[idx].expected);
jerry_release_value (error_tests[idx].lhs);
jerry_release_value (error_tests[idx].rhs);
jerry_release_value (result);
}

jerry_release_value (base_obj);
jerry_release_value (constructor);
jerry_release_value (error);
jerry_release_value (instance_val);
jerry_release_value (no_proto_instance_val);

jerry_cleanup ();

return 0;
} /* main */