#include <file_valid.h>

Definition

The file_valid class contains a collection of static methods that implement the most file assertions used in xtd::tUnit.

Namespace: xtd::tunit

Library: xtd.tunit

Remarks: Validations are the same as assertions with the difference, no exception is thrown, but an error is generated.; If a validation fails, he test can be continued to the end or to an assertion is generated.

Examples: This example show how to used some methods :
#include <xtd/xtd.tunit>
#include <stdexcept>
using namespace xtd::tunit;
namespace unit_tests {
// The class test must be declared with test_class_ helper.
class test_class_(test) {
public:
void test_method_(test_case1) {
assert::is_true(true);
}

void test_method_(test_case2) {
assert::is_false(true);
}

void test_method_(test_case3) {
assert::does_not_throw([] {throw std::range_error("error");});
}
};
}
auto main()->int {
return console_unit_test().run();
}
// This code can produce the following output:
//
// Start 3 tests from 1 test case
// Run tests:
// SUCCEED test.test_case1 (0 ms total)
// FAILED test.test_case2 (0 ms total)
// Expected: false
// But was: true
// Stack Trace: in |---OMITTED---|/assert.cpp:14
// FAILED test.test_case3 (0 ms total)
// Expected: No Exception to be thrown
// But was: <std::range_error>
// Stack Trace: in |---OMITTED---|/assert.cpp:18
//
// Test results:
// SUCCEED 1 test.
// FAILED 2 tests.
// End 3 tests from 1 test case ran. (0 ms total)

Methods
template<typename char_t >
static void	are_equal (const std::basic_istream< char_t > &expected, const std::basic_istream< char_t > &actual)
	Validate that two files are equal. More...

template<typename char_t >
static void	are_equal (const std::basic_istream< char_t > &expected, const std::basic_istream< char_t > &actual, const xtd::diagnostics::stack_frame &stack_frame)
	Validate that two files are equal. More...

template<typename char_t >
static void	are_equal (const std::basic_istream< char_t > &expected, const std::basic_istream< char_t > &actual, const std::string &message)
	Validate that two files are equal. More...

template<typename char_t >
static void	are_equal (const std::basic_istream< char_t > &expected, const std::basic_istream< char_t > &actual, const std::string &message, const xtd::diagnostics::stack_frame &stack_frame)
	Validate that two files are equal. More...

template<typename char_t >
static void	are_equal (const std::basic_string< char_t > &expected, const std::basic_string< char_t > &actual)
	Validate that two files are equal. More...

template<typename char_t >
static void	are_equal (const std::basic_string< char_t > &expected, const std::basic_string< char_t > &actual, const xtd::diagnostics::stack_frame &stack_frame)
	Validate that two files are equal. More...

template<typename char_t >
static void	are_equal (const std::basic_string< char_t > &expected, const std::basic_string< char_t > &actual, const std::string &message)
	Validate that two files are equal. More...

template<typename char_t >
static void	are_equal (const std::basic_string< char_t > &expected, const std::basic_string< char_t > &actual, const std::string &message, const xtd::diagnostics::stack_frame &stack_frame)
	Validate that two files are equal. More...

template<typename char_t >
static void	are_not_equal (const std::basic_istream< char_t > &expected, const std::basic_istream< char_t > &actual)
	Validate that two files are not equal. More...

template<typename char_t >
static void	are_not_equal (const std::basic_istream< char_t > &expected, const std::basic_istream< char_t > &actual, const xtd::diagnostics::stack_frame &stack_frame)
	Validate that two files are not equal. More...

template<typename char_t >
static void	are_not_equal (const std::basic_istream< char_t > &expected, const std::basic_istream< char_t > &actual, const std::string &message)
	Validate that two files are not equal. More...

template<typename char_t >
static void	are_not_equal (const std::basic_istream< char_t > &expected, const std::basic_istream< char_t > &actual, const std::string &message, const xtd::diagnostics::stack_frame &stack_frame)
	Validate that two files are not equal. More...

template<typename char_t >
static void	are_not_equal (const std::basic_string< char_t > &expected, const std::basic_string< char_t > &actual)
	Validate that two files are not equal. More...

template<typename char_t >
static void	are_not_equal (const std::basic_string< char_t > &expected, const std::basic_string< char_t > &actual, const xtd::diagnostics::stack_frame &stack_frame)
	Validate that two files are not equal. More...

template<typename char_t >
static void	are_not_equal (const std::basic_string< char_t > &expected, const std::basic_string< char_t > &actual, const std::string &message)
	Validate that two files are not equal. More...

template<typename char_t >
static void	are_not_equal (const std::basic_string< char_t > &expected, const std::basic_string< char_t > &actual, const std::string &message, const xtd::diagnostics::stack_frame &stack_frame)
	Validate that two files are not equal. More...

template<typename char_t >
static void	exists (const std::basic_string< char_t > &file)
	Validate that file exists. More...

template<typename char_t >
static void	exists (const std::basic_string< char_t > &file, const xtd::diagnostics::stack_frame &stack_frame)
	Validate that file exists. More...

template<typename char_t >
static void	exists (const std::basic_string< char_t > &file, const std::string &message)
	Validate that file exists. More...

template<typename char_t >
static void	exists (const std::basic_string< char_t > &file, const std::string &message, const xtd::diagnostics::stack_frame &stack_frame)
	Validate that file exists. More...

template<typename char_t >
static void	does_not_exist (const std::basic_string< char_t > &file)
	Validate that file not exists. More...

template<typename char_t >
static void	does_not_exist (const std::basic_string< char_t > &file, const xtd::diagnostics::stack_frame &stack_frame)
	Validate that file not exists. More...

template<typename char_t >
static void	does_not_exist (const std::basic_string< char_t > &file, const std::string &message)
	Validate that file not exists. More...

template<typename char_t >
static void	does_not_exist (const std::basic_string< char_t > &file, const std::string &message, const xtd::diagnostics::stack_frame &stack_frame)
	Validate that file not exists. More...

Member Function Documentation

◆ are_equal() [1/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_equal	(	const std::basic_istream< char_t > &	expected,
		const std::basic_istream< char_t > &	actual
	)

inlinestatic

Validate that two files are equal.

Parameters

expected	the expected value.
actual	the actual value.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1); // test ok.
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1); // test fails

◆ are_equal() [2/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_equal	(	const std::basic_istream< char_t > &	expected,
		const std::basic_istream< char_t > &	actual,
		const xtd::diagnostics::stack_frame &	stack_frame
	)

inlinestatic

Validate that two files are equal.

Parameters

expected	the expected value.
actual	the actual value.
stack_frame	Contains information about current file and current line.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1, csf_); // test ok.
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1, csf_); // test fails

◆ are_equal() [3/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_equal	(	const std::basic_istream< char_t > &	expected,
		const std::basic_istream< char_t > &	actual,
		const std::string &	message
	)

inlinestatic

Validate that two files are equal.

Parameters

expected	the expected value.
actual	the actual value.
message	A user message to display if the assertion fails. This message can be seen in the unit test results.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1, "User message..."); // test ok.
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1, "User message..."); // test fails

◆ are_equal() [4/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_equal	(	const std::basic_istream< char_t > &	expected,
		const std::basic_istream< char_t > &	actual,
		const std::string &	message,
		const xtd::diagnostics::stack_frame &	stack_frame
	)

inlinestatic

Validate that two files are equal.

Parameters

expected	the expected value.
actual	the actual value.
message	A user message to display if the assertion fails. This message can be seen in the unit test results.
stack_frame	Contains information about current file and current line.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1, "User message...", csf_); // test ok.
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1, "User message...", csf_); // test fails

◆ are_equal() [5/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_equal	(	const std::basic_string< char_t > &	expected,
		const std::basic_string< char_t > &	actual
	)

inlinestatic

Validate that two files are equal.

Parameters

expected	the expected value.
actual	the actual value.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1); // test ok.
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1); // test fails

◆ are_equal() [6/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_equal	(	const std::basic_string< char_t > &	expected,
		const std::basic_string< char_t > &	actual,
		const xtd::diagnostics::stack_frame &	stack_frame
	)

inlinestatic

Validate that two files are equal.

Parameters

expected	the expected value.
actual	the actual value.
stack_frame	Contains information about current file and current line.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1, csf_); // test ok.
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1, csf_); // test fails

◆ are_equal() [7/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_equal	(	const std::basic_string< char_t > &	expected,
		const std::basic_string< char_t > &	actual,
		const std::string &	message
	)

inlinestatic

Validate that two files are equal.

Parameters

expected	the expected value.
actual	the actual value.
message	A user message to display if the assertion fails. This message can be seen in the unit test results.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1, "User message..."); // test ok.
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1, "User message..."); // test fails

◆ are_equal() [8/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_equal	(	const std::basic_string< char_t > &	expected,
		const std::basic_string< char_t > &	actual,
		const std::string &	message,
		const xtd::diagnostics::stack_frame &	stack_frame
	)

inlinestatic

Validate that two files are equal.

Parameters

expected	the expected value.
actual	the actual value.
message	A user message to display if the assertion fails. This message can be seen in the unit test results.
stack_frame	Contains information about current file and current line.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1, "User message...", csf_); // test ok.
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_equal(s2, s1, "User message...", csf_); // test fails

◆ are_not_equal() [1/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_not_equal	(	const std::basic_istream< char_t > &	expected,
		const std::basic_istream< char_t > &	actual
	)

inlinestatic

Validate that two files are not equal.

Parameters

expected	the expected value.
actual	the actual value.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1); // test ok.
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1); // test fails

◆ are_not_equal() [2/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_not_equal	(	const std::basic_istream< char_t > &	expected,
		const std::basic_istream< char_t > &	actual,
		const xtd::diagnostics::stack_frame &	stack_frame
	)

inlinestatic

Validate that two files are not equal.

Parameters

expected	the expected value.
actual	the actual value.
stack_frame	Contains information about current file and current line.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1, csf_); // test ok.
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1, csf_); // test fails

◆ are_not_equal() [3/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_not_equal	(	const std::basic_istream< char_t > &	expected,
		const std::basic_istream< char_t > &	actual,
		const std::string &	message
	)

inlinestatic

Validate that two files are not equal.

Parameters

expected	the expected value.
actual	the actual value.
message	A user message to display if the assertion fails. This message can be seen in the unit test results.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1, "User message..."); // test ok.
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1, "User message..."); // test fails

◆ are_not_equal() [4/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_not_equal	(	const std::basic_istream< char_t > &	expected,
		const std::basic_istream< char_t > &	actual,
		const std::string &	message,
		const xtd::diagnostics::stack_frame &	stack_frame
	)

inlinestatic

Validate that two files are not equal.

Parameters

expected	the expected value.
actual	the actual value.
message	A user message to display if the assertion fails. This message can be seen in the unit test results.
stack_frame	Contains information about current file and current line.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1, "User message...", csf_); // test ok.
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1, "User message...", csf_); // test fails

◆ are_not_equal() [5/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_not_equal	(	const std::basic_string< char_t > &	expected,
		const std::basic_string< char_t > &	actual
	)

inlinestatic

Validate that two files are not equal.

Parameters

expected	the expected value.
actual	the actual value.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1); // test ok.
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1); // test fails

◆ are_not_equal() [6/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_not_equal	(	const std::basic_string< char_t > &	expected,
		const std::basic_string< char_t > &	actual,
		const xtd::diagnostics::stack_frame &	stack_frame
	)

inlinestatic

Validate that two files are not equal.

Parameters

expected	the expected value.
actual	the actual value.
stack_frame	Contains information about current file and current line.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1, csf_); // test ok.
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1, csf_); // test fails

◆ are_not_equal() [7/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_not_equal	(	const std::basic_string< char_t > &	expected,
		const std::basic_string< char_t > &	actual,
		const std::string &	message
	)

inlinestatic

Validate that two files are not equal.

Parameters

expected	the expected value.
actual	the actual value.
message	A user message to display if the assertion fails. This message can be seen in the unit test results.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1, "User message..."); // test ok.
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1, "User message..."); // test fails

◆ are_not_equal() [8/8]

template<typename char_t >

static void xtd::tunit::file_valid::are_not_equal	(	const std::basic_string< char_t > &	expected,
		const std::basic_string< char_t > &	actual,
		const std::string &	message,
		const xtd::diagnostics::stack_frame &	stack_frame
	)

inlinestatic

Validate that two files are not equal.

Parameters

expected	the expected value.
actual	the actual value.
message	A user message to display if the assertion fails. This message can be seen in the unit test results.
stack_frame	Contains information about current file and current line.

Examples: std::stringstream s1;
s1 << "Test";
s1.seekg(0, std::ios::beg);
std::stringstream s2;
s2 << "Test2";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1, "User message...", csf_); // test ok.
s2 << "Test";
s2.seekg(0, std::ios::beg);
xtd::tunit::file_valid::are_not_equal(s2, s1, "User message...", csf_); // test fails

◆ does_not_exist() [1/4]

template<typename char_t >

static void xtd::tunit::file_valid::does_not_exist ( const std::basic_string< char_t > & file )

inlinestatic

Validate that file not exists.

Parameters

expected	the expected value.
actual	the actual value.

Examples: std::ifstream f1("Test1.txt");
f1.close();
xtd::tunit::file_valid::does_not_exist("Test2.txt"); // test ok.
xtd::tunit::file_valid::does_not_exist("Test1.txt"); // test fails

◆ does_not_exist() [2/4]

template<typename char_t >

static void xtd::tunit::file_valid::does_not_exist	(	const std::basic_string< char_t > &	file,
		const xtd::diagnostics::stack_frame &	stack_frame
	)

inlinestatic

Validate that file not exists.

Parameters

expected	the expected value.
actual	the actual value.
stack_frame	Contains information about current file and current line.

Examples: std::ifstream f1("Test1.txt");
f1.close();
xtd::tunit::file_valid::does_not_exist("Test2.txt", csf_); // test ok.
xtd::tunit::file_valid::does_not_exist("Test1.txt", csf_); // test fails

◆ does_not_exist() [3/4]

template<typename char_t >

static void xtd::tunit::file_valid::does_not_exist	(	const std::basic_string< char_t > &	file,
		const std::string &	message
	)

inlinestatic

Validate that file not exists.

Parameters

expected	the expected value.
actual	the actual value.
message	A user message to display if the assertion fails. This message can be seen in the unit test results.

Examples: std::ifstream f1("Test1.txt");
f1.close();
xtd::tunit::file_valid::does_not_exist("Test2.txt", "User message..."); // test ok.
xtd::tunit::file_valid::does_not_exist("Test1.txt", "User message..."); // test fails

◆ does_not_exist() [4/4]

template<typename char_t >

static void xtd::tunit::file_valid::does_not_exist	(	const std::basic_string< char_t > &	file,
		const std::string &	message,
		const xtd::diagnostics::stack_frame &	stack_frame
	)

inlinestatic

Validate that file not exists.

Parameters

expected	the expected value.
actual	the actual value.
message	A user message to display if the assertion fails. This message can be seen in the unit test results.
stack_frame	Contains information about current file and current line.

Examples: std::ifstream f1("Test1.txt");
f1.close();
xtd::tunit::file_valid::does_not_exist("Test2.txt" "User message...", csf_); // test ok.
xtd::tunit::file_valid::does_not_exist("Test1.txt", "User message...", csf_); // test fails

◆ exists() [1/4]

template<typename char_t >

static void xtd::tunit::file_valid::exists ( const std::basic_string< char_t > & file )

inlinestatic

Validate that file exists.

Parameters

expected	the expected value.
actual	the actual value.

Examples: std::ifstream f1("Test1.txt");
f1.close();
xtd::tunit::file_valid::exists("Test1.txt"); // test ok.
xtd::tunit::file_valid::exists("Test2.txt"); // test fails

◆ exists() [2/4]

template<typename char_t >

static void xtd::tunit::file_valid::exists	(	const std::basic_string< char_t > &	file,
		const xtd::diagnostics::stack_frame &	stack_frame
	)

inlinestatic

Validate that file exists.

Parameters

expected	the expected value.
actual	the actual value.
stack_frame	Contains information about current file and current line.

Examples: std::ifstream f1("Test1.txt");
f1.close();
xtd::tunit::file_valid::exists("Test1.txt", csf_); // test ok.
xtd::tunit::file_valid::exists("Test2.txt", csf_); // test fails

◆ exists() [3/4]

template<typename char_t >

static void xtd::tunit::file_valid::exists	(	const std::basic_string< char_t > &	file,
		const std::string &	message
	)

inlinestatic

Validate that file exists.

Parameters

expected	the expected value.
actual	the actual value.
message	A user message to display if the assertion fails. This message can be seen in the unit test results.

Examples: std::ifstream f1("Test1.txt");
f1.close();
xtd::tunit::file_valid::exists("Test1.txt", "User message..."); // test ok.
xtd::tunit::file_valid::exists("Test2.txt", "User message..."); // test fails

◆ exists() [4/4]

template<typename char_t >

static void xtd::tunit::file_valid::exists	(	const std::basic_string< char_t > &	file,
		const std::string &	message,
		const xtd::diagnostics::stack_frame &	stack_frame
	)

inlinestatic

Validate that file exists.

Parameters

expected	the expected value.
actual	the actual value.
message	A user message to display if the assertion fails. This message can be seen in the unit test results.
stack_frame	Contains information about current file and current line.

Examples: std::ifstream f1("Test1.txt");
f1.close();
xtd::tunit::file_valid::exists("Test1.txt" "User message...", csf_); // test ok.
xtd::tunit::file_valid::exists("Test2.txt", "User message...", csf_); // test fails

The documentation for this class was generated from the following file:

xtd.tunit/include/xtd/tunit/file_valid.h

Definition

Methods

Member Function Documentation

◆ are_equal() [1/8]

◆ are_equal() [2/8]

◆ are_equal() [3/8]

◆ are_equal() [4/8]

◆ are_equal() [5/8]

◆ are_equal() [6/8]

◆ are_equal() [7/8]

◆ are_equal() [8/8]

◆ are_not_equal() [1/8]

◆ are_not_equal() [2/8]

◆ are_not_equal() [3/8]

◆ are_not_equal() [4/8]

◆ are_not_equal() [5/8]

◆ are_not_equal() [6/8]

◆ are_not_equal() [7/8]

◆ are_not_equal() [8/8]

◆ does_not_exist() [1/4]

◆ does_not_exist() [2/4]

◆ does_not_exist() [3/4]

◆ does_not_exist() [4/4]

◆ exists() [1/4]

◆ exists() [2/4]

◆ exists() [3/4]

◆ exists() [4/4]