Increase depth of error messages in Eunit Surefire reports

Currently, error messages in Eunit Surefire reports are shortened just
like when written to a terminal.  However, the space limitations that
constrain terminal output do not apply here, so it's more useful to
include more of the error message.  Getting the full error message can
be particularly helpful when an assertMatch fails because of a long
and deep error term.

The new depth of 100 should be enough for most cases, while protecting
against runaway errors.

lib/eunit/src/eunit_lib.erl

@@ -33,7 +33,7 @@
 -export([dlist_next/1, uniq/1, fun_parent/1, is_string/1, command/1,
 	 command/2, command/3, trie_new/0, trie_store/2, trie_match/2,
 	 split_node/1, consult_file/1, list_dir/1, format_exit_term/1,
-	 format_exception/1, format_error/1]).
+	 format_exception/1, format_exception/2, format_error/1]).
 
 
 %% Type definitions for describing exceptions
@@ -55,21 +55,23 @@
 
 %% ---------------------------------------------------------------------
 %% Formatting of error descriptors
+format_exception(Exception) ->
+    format_exception(Exception, 20).
 
-format_exception({Class,Term,Trace})
+format_exception({Class,Term,Trace}, Depth)
   when is_atom(Class), is_list(Trace) ->
     case is_stacktrace(Trace) of
 	true ->
 	    io_lib:format("~w:~P\n~s",
-			  [Class, Term, 20, format_stacktrace(Trace)]);
+			  [Class, Term, Depth, format_stacktrace(Trace)]);
 	false ->
-	    format_term(Term)
+	    format_term(Term, Depth)
     end;
-format_exception(Term) ->
-    format_term(Term).
+format_exception(Term, Depth) ->
+    format_term(Term, Depth).
 
-format_term(Term) ->
-    io_lib:format("~P\n", [Term, 15]).
+format_term(Term, Depth) ->
+    io_lib:format("~P\n", [Term, Depth]).
 
 format_exit_term(Term) ->
     {Reason, Trace} = analyze_exit_term(Term),

lib/eunit/src/eunit_surefire.erl

@@ -323,15 +323,15 @@ write_testcase(
 format_testcase_result(ok) -> [<<>>];
 format_testcase_result({failed, {error, {Type, _}, _} = Exception}) when is_atom(Type) ->
     [?INDENT, ?INDENT, <<"<failure type=\"">>, escape_attr(atom_to_list(Type)), <<"\">">>, ?NEWLINE,
-    <<"::">>, escape_text(eunit_lib:format_exception(Exception)),
+    <<"::">>, escape_text(eunit_lib:format_exception(Exception, 100)),
     ?INDENT, ?INDENT, <<"</failure>">>, ?NEWLINE];
 format_testcase_result({failed, Term}) ->
     [?INDENT, ?INDENT, <<"<failure type=\"unknown\">">>, ?NEWLINE,
     escape_text(io_lib:write(Term)),
     ?INDENT, ?INDENT, <<"</failure>">>, ?NEWLINE];
 format_testcase_result({aborted, {Class, _Term, _Trace} = Exception}) when is_atom(Class) ->
     [?INDENT, ?INDENT, <<"<error type=\"">>, escape_attr(atom_to_list(Class)), <<"\">">>, ?NEWLINE,
-    <<"::">>, escape_text(eunit_lib:format_exception(Exception)),
+    <<"::">>, escape_text(eunit_lib:format_exception(Exception, 100)),
     ?INDENT, ?INDENT, <<"</error>">>, ?NEWLINE];
 format_testcase_result({aborted, Term}) ->
     [?INDENT, ?INDENT, <<"<error type=\"unknown\">">>, ?NEWLINE,