Tests for custom callbacks

t/01-runtime-control.t

@@ -3,7 +3,7 @@ use warnings;
 
 use Test::More;
 
-plan tests => 9;
+plan tests => 13;
 
 use Config;
 
@@ -59,3 +59,18 @@ like($output, qr/^>> \d+ main, .*mem_enable.pl \(10\) used 2048 bytes$/m,
 
 like($output, qr/hello world/, 'program ran successfully');
 
+# Test custom callback
+$ENV{MEMORYTRACE_LIGHT} = $p_arg;
+
+$output = `$perlbin $includes -d:MemoryTrace::Light t/bin/mem_callback.pl 2>&1`;
+
+like($output, qr/^>> \d+ main, .*mem_callback.pl \(12\) used 1 bytes$/m,
+	'program printed default trace output');
+
+like($output, qr/^I caught main .*mem_callback.pl 16 2 !$/m,
+	'program printed custom callback output after set_callback');
+
+like($output, qr/^>> \d+ main, .*mem_callback.pl \(20\) used 4 bytes$/m,
+	'program printed default trace output after restore_callback');
+
+like($output, qr/hello world/, 'program ran successfully');

t/bin/mem_callback.pl

@@ -0,0 +1,22 @@
+# Basic callback test case
+use lib 't/lib/';
+
+use Devel::MemoryTrace::Light;
+
+use DMTraceProviderNextMem;
+
+sub c_callback {
+	print "I caught @_ !\n";
+}
+
+$DMTraceProviderNextMem::mem = 1;
+
+DB::set_callback(\&c_callback);
+
+$DMTraceProviderNextMem::mem += 2;
+
+DB::restore_callback();
+
+$DMTraceProviderNextMem::mem += 4;
+
+print "hello world\n";