tanya/source/tanya/test/assertion.d
2017-10-12 07:41:35 +02:00

106 lines
3.0 KiB
D

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/**
* Additional assertions.
*
* This module provides functions that assert whether a given expression
* satisfies some complex condition, that can't be tested with
* $(D_KEYWORD assert) in a single line. Internally all the functions
* just evaluate the expression and call $(D_KEYWORD assert).
*
* The functions can cause segmentation fault if the module is compiled
* in production mode and the condition fails.
*
* Copyright: Eugene Wissner 2017.
* License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
* Mozilla Public License, v. 2.0).
* Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
* Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/test/assertion.d,
* tanya/test/assertion.d)
*/
module tanya.test.assertion;
import tanya.memory;
import tanya.meta.trait;
/**
* Asserts whether the function $(D_PARAM expr) throws an exception of type
* $(D_PARAM E). If it does, the exception is catched and properly destroyed.
* If it doesn't, an assertion error is thrown. If the exception doesn't match
* $(D_PARAM E) type, it isn't catched and escapes.
*
* Params:
* E = Expected exception type.
* T = Throwing function type.
* Args = Argument types of the throwing function.
* expr = Throwing function.
* args = Arguments for $(D_PARAM expr).
*/
void assertThrown(E : Exception, T, Args...)(T expr, auto ref Args args)
if (isSomeFunction!T)
{
try
{
cast(void) expr(args);
assert(false, "Expected exception not thrown");
}
catch (E exception)
{
defaultAllocator.dispose(exception);
}
}
///
@nogc nothrow pure @safe unittest
{
// If you want to test that an expression throws, you can wrap it into an
// arrow function.
static struct CtorThrows
{
this(int i) @nogc pure @safe
{
throw defaultAllocator.make!Exception();
}
}
assertThrown!Exception(() => CtorThrows(8));
}
/**
* Asserts that the function $(D_PARAM expr) doesn't throw.
*
* If it does, the thrown exception is catched, properly destroyed and an
* assertion error is thrown instead.
*
* Params:
* T = Tested function type.
* Args = Argument types of $(D_PARAM expr).
* expr = Tested function.
* args = Arguments for $(D_PARAM expr).
*/
void assertNotThrown(T, Args...)(T expr, auto ref Args args)
if (isSomeFunction!T)
{
try
{
cast(void) expr(args);
}
catch (Exception exception)
{
defaultAllocator.dispose(exception);
assert(false, "Unexpected exception thrown");
}
}
///
@nogc nothrow pure @safe unittest
{
// If you want to test that an expression doesn't throw, you can wrap it
// into an arrow function.
static struct S
{
}
assertNotThrown(() => S());
}