Add Observers, useful class for notifying listeners

3 files changed, 109 insertions, 1 deletions

diff --git a/test/Makefile.am b/test/Makefile.am
index c23bd9f..4daf511 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -2,7 +2,8 @@ MAINTAINERCLEANFILES = Makefile.in
 
 AM_CXXFLAGS = @DEFINES@
 
-TESTS = test-url test-http test-args test-xdg test-paths test-strings
+TESTS = test-url test-http test-args test-xdg test-paths test-strings \
+        test-observers
 
 check_PROGRAMS = $(TESTS)
 
@@ -23,3 +24,5 @@ test_strings_LDADD = $(top_builddir)/src/libtp.a
 
 test_paths_SOURCES = test-paths.cc
 test_paths_LDADD = $(top_builddir)/src/libtp.a
+
+test_observers_SOURCES = test-observers.cc
diff --git a/test/test-observers.cc b/test/test-observers.cc
new file mode 100644
index 0000000..be1418d
--- /dev/null
+++ b/test/test-observers.cc
@@ -0,0 +1,94 @@
+// -*- mode: c++; c-basic-offset: 2; -*-
+
+#include "common.hh"
+#include "test.hh"
+
+#include "observers.hh"
+
+namespace {
+
+bool test_sanity() {
+  Observers<int> obs;
+  ASSERT_EQ(false, obs.notify().has_next());
+  obs.insert(1);
+  auto it = obs.notify();
+  ASSERT_EQ(true, it.has_next());
+  ASSERT_EQ(1, it.next());
+  ASSERT_EQ(false, it.has_next());
+  obs.erase(2);
+  it = obs.notify();
+  ASSERT_EQ(true, it.has_next());
+  ASSERT_EQ(1, it.next());
+  obs.erase(1);
+  ASSERT_EQ(false, obs.notify().has_next());
+  return true;
+}
+
+bool test_insert() {
+  Observers<int> obs;
+  auto it = obs.notify();
+  ASSERT_EQ(false, it.has_next());
+  obs.insert(1);
+  ASSERT_EQ(true, it.has_next());
+  ASSERT_EQ(1, it.next());
+  obs.insert(2);
+  ASSERT_EQ(false, it.has_next());
+  it = obs.notify();
+  ASSERT_EQ(true, it.has_next());
+  int other;
+  switch (it.next()) {
+  case 1:
+    other = 2;
+    break;
+  case 2:
+    other = 1;
+    break;
+  default:
+    ASSERT_TRUE(false);
+  }
+  ASSERT_EQ(true, it.has_next());
+  ASSERT_EQ(other, it.next());
+  return true;
+}
+
+bool test_erase() {
+  Observers<int> obs;
+  auto it = obs.notify();
+  ASSERT_EQ(false, it.has_next());
+  obs.insert(1);
+  ASSERT_EQ(true, it.has_next());
+  ASSERT_EQ(1, it.next());
+  ASSERT_EQ(false, it.has_next());
+  obs.erase(1);
+  auto it2 = obs.notify();
+  ASSERT_EQ(false, it2.has_next());
+  it = it2;
+
+  obs.insert(4);
+  obs.insert(3);
+  obs.insert(2);
+  it = obs.notify();
+  ASSERT_EQ(true, it.has_next());
+  ASSERT_EQ(2, it.next());
+  obs.erase(2);
+  it2 = obs.notify();
+  ASSERT_EQ(true, it2.has_next());
+  ASSERT_EQ(3, it2.next());
+  obs.erase(3);
+  ASSERT_EQ(true, it.has_next());
+  ASSERT_EQ(4, it.next());
+  ASSERT_EQ(true, it2.has_next());
+  ASSERT_EQ(4, it2.next());
+
+  return true;
+}
+
+}  // namespace
+
+int main(void) {
+  BEFORE;
+  RUN(test_sanity());
+  RUN(test_insert());
+  RUN(test_erase());
+  AFTER;
+}
diff --git a/test/test.hh b/test/test.hh
index 8d1f661..153a5b3 100644
--- a/test/test.hh
+++ b/test/test.hh
@@ -34,6 +34,17 @@
     }                                                                   \
   } while (false)
 
+#define ASSERT_TRUE(actual)                                             \
+  do {                                                                  \
+    auto a_ = (actual);                                                 \
+    if (!a_) {                                                          \
+      std::cerr << __FILE__ << ':' << __LINE__ << ": "                  \
+                << __FUNCTION__ << ": Expected " << a_                  \
+                << " to be true" << std::endl;                          \
+      return false;                                                     \
+    }                                                                   \
+  } while (false)
+
 #define ASSERT_STREQ(expected, actual)                                  \
   do {                                                                  \
     auto e_ = (expected);                                               \