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.

7 files changed, 491 insertions, 3 deletions

diff --git a/lib/stdlib/doc/src/Makefile b/lib/stdlib/doc/src/Makefile
index a4a2ed9931..d41f91250e 100644
--- a/lib/stdlib/doc/src/Makefile
+++ b/lib/stdlib/doc/src/Makefile
@@ -102,7 +102,7 @@ XML_REF3_FILES = \
 XML_REF6_FILES = stdlib_app.xml
 
 XML_PART_FILES = part.xml part_notes.xml part_notes_history.xml
-XML_CHAPTER_FILES = io_protocol.xml unicode_usage.xml notes.xml notes_history.xml
+XML_CHAPTER_FILES = io_protocol.xml unicode_usage.xml notes.xml notes_history.xml assert_hrl.xml
 
 BOOK_FILES = book.xml
 
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>
diff --git a/lib/stdlib/doc/src/ref_man.xml b/lib/stdlib/doc/src/ref_man.xml
index eee4a68ca1..cae62612aa 100644
--- a/lib/stdlib/doc/src/ref_man.xml
+++ b/lib/stdlib/doc/src/ref_man.xml
@@ -35,6 +35,7 @@
   </description>
   <xi:include href="stdlib_app.xml"/>
   <xi:include href="array.xml"/>
+  <xi:include href="assert_hrl.xml"/>
   <xi:include href="base64.xml"/>
   <xi:include href="beam_lib.xml"/>
   <xi:include href="binary.xml"/>
diff --git a/lib/stdlib/include/assert.hrl b/lib/stdlib/include/assert.hrl
new file mode 100644
index 0000000000..239d19a6dc
--- /dev/null
+++ b/lib/stdlib/include/assert.hrl
@@ -0,0 +1,260 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright (C) 2004-2014 Richard Carlsson, Mickaël Rémond
+%%
+%% 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.
+%%
+%% %CopyrightEnd%
+%%
+
+-ifndef(ASSERT_HRL).
+-define(ASSERT_HRL, true).
+
+%% Asserts are enabled unless NOASSERT is defined, and ASSERT can be used to
+%% override it: if both ASSERT and NOASSERT are defined, then ASSERT takes
+%% precedence, and NOASSERT will become undefined.
+%%
+%% Furthermore, if NODEBUG is defined, it implies NOASSERT, unless DEBUG or
+%% ASSERT are defined.
+%%
+%% If asserts are disabled, all assert macros are defined to be the atom
+%% 'ok'. If asserts are enabled, all assert macros are defined to yield 'ok'
+%% as the result if the test succeeds, and raise an error exception if the
+%% test fails. The error term will then have the form {Name, Info} where
+%% Name is the name of the macro and Info is a list of tagged tuples.
+
+%% allow NODEBUG to imply NOASSERT, unless DEBUG
+-ifdef(NODEBUG).
+-ifndef(DEBUG).
+-ifndef(NOASSERT).
+-define(NOASSERT, true).
+-endif.
+-endif.
+-endif.
+
+%% allow ASSERT to override NOASSERT
+-ifdef(ASSERT).
+-undef(NOASSERT).
+-endif.
+
+%% Assert macros must not depend on any non-kernel or stdlib libraries.
+%%
+%% We must use fun-call wrappers ((fun () -> ... end)()) to avoid
+%% exporting local variables, and furthermore we only use variable names
+%% prefixed with "__", that hopefully will not be bound outside the fun.
+%% It is not possible to nest assert macros.
+
+-ifdef(NOASSERT).
+-define(assert(BoolExpr),ok).
+-else.
+%% The assert macro is written the way it is so as not to cause warnings
+%% for clauses that cannot match, even if the expression is a constant.
+-define(assert(BoolExpr),
+        begin
+        ((fun () ->
+            case (BoolExpr) of
+                true -> ok;
+                __V -> erlang:error({assert,
+                                     [{module, ?MODULE},
+                                      {line, ?LINE},
+                                      {expression, (??BoolExpr)},
+                                      {expected, true},
+                                      case __V of false -> {value, __V};
+                                          _ -> {not_boolean,__V}
+                                      end]})
+            end
+          end)())
+        end).
+-endif.
+
+%% This is the inverse case of assert, for convenience.
+-ifdef(NOASSERT).
+-define(assertNot(BoolExpr),ok).
+-else.
+-define(assertNot(BoolExpr),
+        begin
+        ((fun () ->
+            case (BoolExpr) of
+                false -> ok;
+                __V -> erlang:error({assert,
+                                     [{module, ?MODULE},
+                                      {line, ?LINE},
+                                      {expression, (??BoolExpr)},
+                                      {expected, false},
+                                      case __V of true -> {value, __V};
+                                          _ -> {not_boolean,__V}
+                                      end]})
+            end
+          end)())
+        end).
+-endif.
+
+%% This is mostly a convenience which gives more detailed reports.
+%% Note: Guard is a guarded pattern, and can not be used for value.
+-ifdef(NOASSERT).
+-define(assertMatch(Guard, Expr), ok).
+-else.
+-define(assertMatch(Guard, Expr),
+        begin
+        ((fun () ->
+            case (Expr) of
+                Guard -> ok;
+                __V -> erlang:error({assertMatch,
+                                     [{module, ?MODULE},
+                                      {line, ?LINE},
+                                      {expression, (??Expr)},
+                                      {pattern, (??Guard)},
+                                      {value, __V}]})
+            end
+          end)())
+        end).
+-endif.
+
+%% This is the inverse case of assertMatch, for convenience.
+-ifdef(NOASSERT).
+-define(assertNotMatch(Guard, Expr), ok).
+-else.
+-define(assertNotMatch(Guard, Expr),
+        begin
+        ((fun () ->
+            __V = (Expr),
+            case __V of
+                Guard -> erlang:error({assertNotMatch,
+                                       [{module, ?MODULE},
+                                        {line, ?LINE},
+                                        {expression, (??Expr)},
+                                        {pattern, (??Guard)},
+                                        {value, __V}]});
+                _ -> ok
+            end
+          end)())
+        end).
+-endif.
+
+%% This is a convenience macro which gives more detailed reports when
+%% the expected LHS value is not a pattern, but a computed value
+-ifdef(NOASSERT).
+-define(assertEqual(Expect, Expr), ok).
+-else.
+-define(assertEqual(Expect, Expr),
+        begin
+        ((fun (__X) ->
+            case (Expr) of
+                __X -> ok;
+                __V -> erlang:error({assertEqual,
+                                     [{module, ?MODULE},
+                                      {line, ?LINE},
+                                      {expression, (??Expr)},
+                                      {expected, __X},
+                                      {value, __V}]})
+            end
+          end)(Expect))
+        end).
+-endif.
+
+%% This is the inverse case of assertEqual, for convenience.
+-ifdef(NOASSERT).
+-define(assertNotEqual(Unexpected, Expr), ok).
+-else.
+-define(assertNotEqual(Unexpected, Expr),
+        begin
+        ((fun (__X) ->
+            case (Expr) of
+                __X -> erlang:error({assertNotEqual,
+                                     [{module, ?MODULE},
+                                      {line, ?LINE},
+                                      {expression, (??Expr)},
+                                      {value, __X}]});
+                _ -> ok
+            end
+          end)(Unexpected))
+        end).
+-endif.
+
+%% Note: Class and Term are patterns, and can not be used for value.
+%% Term can be a guarded pattern, but Class cannot.
+-ifdef(NOASSERT).
+-define(assertException(Class, Term, Expr), ok).
+-else.
+-define(assertException(Class, Term, Expr),
+        begin
+        ((fun () ->
+            try (Expr) of
+                __V -> erlang:error({assertException,
+                                      [{module, ?MODULE},
+                                       {line, ?LINE},
+                                       {expression, (??Expr)},
+                                       {pattern,
+                                        "{ "++(??Class)++" , "++(??Term)
+                                        ++" , [...] }"},
+                                       {unexpected_success, __V}]})
+            catch
+                Class:Term -> ok;
+                __C:__T ->
+                    erlang:error({assertException,
+                                  [{module, ?MODULE},
+                                   {line, ?LINE},
+                                   {expression, (??Expr)},
+                                   {pattern,
+                                    "{ "++(??Class)++" , "++(??Term)
+                                    ++" , [...] }"},
+                                   {unexpected_exception,
+                                    {__C, __T,
+                                     erlang:get_stacktrace()}}]})
+            end
+          end)())
+        end).
+-endif.
+
+-define(assertError(Term, Expr), ?assertException(error, Term, Expr)).
+-define(assertExit(Term, Expr), ?assertException(exit, Term, Expr)).
+-define(assertThrow(Term, Expr), ?assertException(throw, Term, Expr)).
+
+%% This is the inverse case of assertException, for convenience.
+%% Note: Class and Term are patterns, and can not be used for value.
+%% Both Class and Term can be guarded patterns.
+-ifdef(NOASSERT).
+-define(assertNotException(Class, Term, Expr), ok).
+-else.
+-define(assertNotException(Class, Term, Expr),
+        begin
+        ((fun () ->
+            try (Expr) of
+                _ -> ok
+            catch
+                __C:__T ->
+                    case __C of
+                        Class ->
+                            case __T of
+                                Term ->
+                                    erlang:error({assertNotException,
+                                                  [{module, ?MODULE},
+                                                   {line, ?LINE},
+                                                   {expression, (??Expr)},
+                                                   {pattern,
+                                                    "{ "++(??Class)++" , "
+                                                    ++(??Term)++" , [...] }"},
+                                                   {unexpected_exception,
+                                                    {__C, __T,
+                                                     erlang:get_stacktrace()
+                                                    }}]});
+                                _ -> ok
+                            end;
+                        _ -> ok
+                    end
+            end
+          end)())
+        end).
+-endif.
+
+-endif. % ASSERT_HRL
diff --git a/lib/stdlib/src/Makefile b/lib/stdlib/src/Makefile
index 55bda60da5..344a5dc099 100644
--- a/lib/stdlib/src/Makefile
+++ b/lib/stdlib/src/Makefile
@@ -122,6 +122,7 @@ MODULES= \
 	zip
 
 HRL_FILES= \
+	../include/assert.hrl \
 	../include/erl_compile.hrl \
 	../include/erl_bits.hrl \
 	../include/ms_transform.hrl \
diff --git a/lib/stdlib/test/Makefile b/lib/stdlib/test/Makefile
index 61eb34d565..d4ab674486 100644
--- a/lib/stdlib/test/Makefile
+++ b/lib/stdlib/test/Makefile
@@ -107,7 +107,8 @@ RELSYSDIR = $(RELEASE_PATH)/stdlib_test
 
 ERL_MAKE_FLAGS +=
 ERL_COMPILE_FLAGS += -I$(ERL_TOP)/lib/test_server/include \
-		-I$(ERL_TOP)/lib/kernel/include
+		-I$(ERL_TOP)/lib/kernel/include \
+		-I$(ERL_TOP)/lib/stdlib/include
 
 EBIN = .
 
diff --git a/lib/stdlib/test/stdlib_SUITE.erl b/lib/stdlib/test/stdlib_SUITE.erl
index 206eb4fd74..8ab30eb62b 100644
--- a/lib/stdlib/test/stdlib_SUITE.erl
+++ b/lib/stdlib/test/stdlib_SUITE.erl
@@ -30,7 +30,7 @@
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
 all() -> 
-    [app_test, appup_test, {group,upgrade}].
+    [app_test, appup_test, assert_test, {group,upgrade}].
 
 groups() -> 
     [{upgrade,[minor_upgrade,major_upgrade]}].
@@ -185,3 +185,68 @@ upgrade_upgraded(_CtData,State) ->
     State.
 upgrade_downgraded(_CtData,State) ->
     State.
+
+
+-include_lib("stdlib/include/assert.hrl").
+-include_lib("stdlib/include/assert.hrl"). % test repeated inclusion
+assert_test(suite) ->
+    [];
+assert_test(doc) ->
+    ["Assert macros test."];
+assert_test(_Config) ->
+    ok = ?assert(true),
+    {'EXIT',{{assert, _},_}} = (catch ?assert(false)),
+    {'EXIT',{{assert, Info1},_}} = (catch ?assert(0)),
+    {not_boolean,0} = lists:keyfind(not_boolean,1,Info1),
+
+    ok = ?assertNot(false),
+    {'EXIT',{{assert, _},_}} = (catch ?assertNot(true)),
+    {'EXIT',{{assert, Info2},_}} = (catch ?assertNot(0)),
+    {not_boolean,0} = lists:keyfind(not_boolean,1,Info2),
+
+    ok = ?assertMatch({foo,_}, {foo,bar}),
+    {'EXIT',{{assertMatch,_},_}} =
+        (catch ?assertMatch({foo,_}, {foo})),
+
+    ok = ?assertMatch({foo,N} when N > 0, {foo,1}),
+    {'EXIT',{{assertMatch,_},_}} =
+        (catch ?assertMatch({foo,N} when N > 0, {foo,0})),
+
+    ok = ?assertNotMatch({foo,_}, {foo,bar,baz}),
+    {'EXIT',{{assertNotMatch,_},_}} =
+        (catch ?assertNotMatch({foo,_}, {foo,baz})),
+
+    ok = ?assertNotMatch({foo,N} when N > 0, {foo,0}),
+    {'EXIT',{{assertNotMatch,_},_}} =
+        (catch ?assertNotMatch({foo,N} when N > 0, {foo,1})),
+
+    ok = ?assertEqual(1.0, 1.0),
+    {'EXIT',{{assertEqual,_},_}} = (catch ?assertEqual(1, 1.0)),
+
+    ok = ?assertNotEqual(1, 1.0),
+    {'EXIT',{{assertNotEqual,_},_}} = (catch ?assertNotEqual(1.0, 1.0)),
+
+    ok = ?assertException(error, badarith, 1/0),
+    ok = ?assertException(exit, foo, exit(foo)),
+    ok = ?assertException(throw, foo, throw(foo)),
+    ok = ?assertException(throw, {foo,_}, throw({foo,bar})),
+    ok = ?assertException(throw, {foo,N} when N > 0, throw({foo,1})),
+    {'EXIT',{{assertException,Why1},_}} =
+        (catch ?assertException(error, badarith, 0/1)),
+    true = lists:keymember(unexpected_success,1,Why1),
+    {'EXIT',{{assertException,Why2},_}} =
+        (catch ?assertException(error, badarith, 1/length(0))),
+    true = lists:keymember(unexpected_exception,1,Why2),
+    {'EXIT',{{assertException,Why3},_}} =
+        (catch ?assertException(throw, {foo,N} when N > 0, throw({foo,0}))),
+    true = lists:keymember(unexpected_exception,1,Why3),
+
+    ok = ?assertNotException(throw, {foo,baz}, throw({foo,bar})),
+    {'EXIT',{{assertNotException,Why4},_}} =
+        (catch ?assertNotException(throw, {foo,bar}, throw({foo,bar}))),
+    true = lists:keymember(unexpected_exception,1,Why4),
+
+    ok = ?assertError(badarith, 1/0),
+    ok = ?assertExit(foo, exit(foo)),
+    ok = ?assertThrow(foo, throw(foo)),
+    ok.