Break out assert macros from eunit to stdlib assert.hrl

Several people have requested that the assert macros in EUnit should be
moved out to a separate header file. This patch puts them in
stdlib/include/assert.hrl, which gets included by the eunit.hrl file.
Thus, nothing changes for eunit users, but the asserts can now also be
included separately.

1 files changed, 160 insertions, 0 deletions

diff --git a/lib/stdlib/doc/src/assert_hrl.xml b/lib/stdlib/doc/src/assert_hrl.xml
new file mode 100644
index 0000000000..d812ee16dc
--- /dev/null
+++ b/lib/stdlib/doc/src/assert_hrl.xml
@@ -0,0 +1,160 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE fileref SYSTEM "fileref.dtd">
+
+<fileref>
+  <header>
+    <copyright>
+      <year>2012</year><year>2015</year>
+      <holder>Ericsson AB. All Rights Reserved.</holder>
+    </copyright>
+    <legalnotice>
+      The contents of this file are subject to the Erlang Public License,
+      Version 1.1, (the "License"); you may not use this file except in
+      compliance with the License. You should have received a copy of the
+      Erlang Public License along with this software. If not, it can be
+      retrieved online at http://www.erlang.org/.
+
+      Software distributed under the License is distributed on an "AS IS"
+      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+      the License for the specific language governing rights and limitations
+      under the License.
+
+    </legalnotice>
+
+    <title>assert.hrl</title>
+    <prepared></prepared>
+    <docno></docno>
+    <date></date>
+    <rev></rev>
+  </header>
+  <file>assert.hrl</file>
+  <filesummary>Assert Macros</filesummary>
+  <description>
+    <p>The include file <c>assert.hrl</c> provides macros for inserting
+    assertions in your program code.</p>
+    <p>These macros are defined in the Stdlib include file
+       <c>assert.hrl</c>. Include the following directive in the module
+       from which the function is called:</p>
+        <code type="none">
+-include_lib("stdlib/include/assert.hrl").</code>
+    <p>When an assertion succeeds, the assert macro yields the atom
+    <c>ok</c>. When an assertion fails, an exception of type <c>error</c> is
+    instead generated. The associated error term will have the form
+    <c>{Macro, Info}</c>, where <c>Macro</c> is the name of the macro, for
+    example <c>assertEqual</c>, and <c>Info</c> will be a list of tagged
+    values such as <c>[{module, M}, {line, L}, ...]</c> giving more
+    information about the location and cause of the exception. All entries
+    in the <c>Info</c> list are optional, and you should not rely
+    programatically on any of them being present.</p>
+
+    <p>If the macro <c>NOASSERT</c> is defined when the <c>assert.hrl</c>
+    include file is read by the compiler, the macros will be defined as
+    equivalent to the atom <c>ok</c>. The test will not be performed, and
+    there will be no cost at runtime.</p>
+
+    <p>For example, using <c>erlc</c> to compile your modules, the following
+    will disable all assertions:</p>
+        <code type="none">
+erlc -DNOASSERT=true *.erl</code>
+    <p>(The value of <c>NOASSERT</c> does not matter, only the fact that it
+    is defined.)</p>
+    <p>A few other macros also have effect on the enabling or disabling of
+    assertions:</p>
+    <list type="bulleted">
+      <item>If <c>NODEBUG</c> is defined, it implies <c>NOASSERT</c>, unless
+      <c>DEBUG</c> is also defined, which is assumed to take
+      precedence.</item>
+      <item>If <c>ASSERT</c> is defined, it overrides <c>NOASSERT</c>, that
+      is, the assertions will remain enabled.</item>
+    </list>
+    <p>If you prefer, you can thus use only <c>DEBUG</c>/<c>NODEBUG</c> as
+    the main flags to control the behaviour of the assertions (which is
+    useful if you have other compiler conditionals or debugging macros
+    controlled by those flags), or you can use <c>ASSERT</c>/<c>NOASSERT</c>
+    to control only the assert macros.</p>
+
+  </description>
+
+  <section>
+  </section>
+
+  <section>
+    <title>Macros</title>
+    <taglist>
+      <tag><c>assert(BoolExpr)</c></tag>
+      <item><p>Tests that <c>BoolExpr</c> completes normally returning
+      <c>true</c>.</p>
+      </item>
+
+      <tag><c>assertNot(BoolExpr)</c></tag>
+      <item><p>Tests that <c>BoolExpr</c> completes normally returning
+      <c>false</c>.</p>
+      </item>
+
+      <tag><c>assertMatch(GuardedPattern, Expr)</c></tag>
+      <item><p>Tests that <c>Expr</c> completes normally yielding a value
+      that matches <c>GuardedPattern</c>. For example:
+        <code type="none">
+    ?assertMatch({bork, _}, f())</code></p>
+      <p>Note that a guard <c>when ...</c> can be included:
+        <code type="none">
+    ?assertMatch({bork, X} when X > 0, f())</code></p>
+      </item>
+
+      <tag><c>assertNotMatch(GuardedPattern, Expr)</c></tag>
+      <item><p>Tests that <c>Expr</c> completes normally yielding a value
+      that does not match <c>GuardedPattern</c>.</p>
+      <p>As in <c>assertMatch</c>, <c>GuardedPattern</c> can have a
+      <c>when</c> part.</p>
+      </item>
+
+      <tag><c>assertEqual(ExpectedValue, Expr)</c></tag>
+      <item><p>Tests that <c>Expr</c> completes normally yielding a value
+      that is exactly equal to <c>ExpectedValue</c>.</p>
+      </item>
+
+      <tag><c>assertNotEqual(ExpectedValue, Expr)</c></tag>
+      <item><p>Tests that <c>Expr</c> completes normally yielding a value
+      that is not exactly equal to <c>ExpectedValue</c>.</p>
+      </item>
+
+      <tag><c>assertException(Class, Term, Expr)</c></tag>
+      <item><p>Tests that <c>Expr</c> completes abnormally with an exception
+      of type <c>Class</c> and with the associated <c>Term</c>. The
+      assertion fails if <c>Expr</c> raises a different exception or if it
+      completes normally returning any value.</p>
+      <p>Note that both <c>Class</c> and <c>Term</c> can be guarded
+      patterns, as in <c>assertMatch</c>.</p>
+      </item>
+
+      <tag><c>assertNotException(Class, Term, Expr)</c></tag>
+      <item><p>Tests that <c>Expr</c> does not evaluate abnormally with an
+      exception of type <c>Class</c> and with the associated <c>Term</c>.
+      The assertion succeeds if <c>Expr</c> raises a different exception or
+      if it completes normally returning any value.</p>
+      <p>As in <c>assertException</c>, both <c>Class</c> and <c>Term</c>
+      can be guarded patterns.</p>
+      </item>
+
+      <tag><c>assertError(Term, Expr)</c></tag>
+      <item><p>Equivalent to <c>assertException(error, Term,
+      Expr)</c></p>
+      </item>
+
+      <tag><c>assertExit(Term, Expr)</c></tag>
+      <item><p>Equivalent to <c>assertException(exit, Term, Expr)</c></p>
+      </item>
+
+      <tag><c>assertThrow(Term, Expr)</c></tag>
+      <item><p>Equivalent to <c>assertException(throw, Term, Expr)</c></p>
+      </item>
+
+    </taglist>
+  </section>
+
+  <section>
+    <title>SEE ALSO</title>
+    <p><seealso marker="compiler:compile">compile(3)</seealso></p>
+    <p><seealso marker="erts:erlc">erlc(3)</seealso></p>
+  </section>
+</fileref>