Add test that shows that pattern_layout calls into logging::format.

TODO: logging::format is only really part of pattern_layout, so it should be moved into pattern_layout, as well as all of its tests.

logger.xcodeproj/project.pbxproj

@@ -23,6 +23,7 @@
 		CD6F7406225187F40081ED74 /* liblogging.dylib in Frameworks */ = {isa = PBXBuildFile; fileRef = 0ECAC4AF1BC00AC500FDAE14 /* liblogging.dylib */; };
 		CD6F740C225187FD0081ED74 /* logger_test.cxx in Sources */ = {isa = PBXBuildFile; fileRef = CD6F73FC225187E10081ED74 /* logger_test.cxx */; };
 		CD6F746C22518A2C0081ED74 /* GoogleMock.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = CD6F746B22518A2C0081ED74 /* GoogleMock.framework */; };
+		CD760CB922621776008A62DE /* pattern_layout_test.cxx in Sources */ = {isa = PBXBuildFile; fileRef = CD760CB822621776008A62DE /* pattern_layout_test.cxx */; };
 		CD88E9572252BDFC00927F40 /* log_manager.cxx in Sources */ = {isa = PBXBuildFile; fileRef = CD88E9552252BDFC00927F40 /* log_manager.cxx */; };
 		CD88E95F2252D3EF00927F40 /* c_logger.cxx in Sources */ = {isa = PBXBuildFile; fileRef = CD88E95D2252D3EF00927F40 /* c_logger.cxx */; };
 		CD88E9632252D67A00927F40 /* common.cxx in Sources */ = {isa = PBXBuildFile; fileRef = CD88E9612252D67A00927F40 /* common.cxx */; };
@@ -90,6 +91,7 @@
 		CD6F742D225189290081ED74 /* libcfmt_logger.dylib */ = {isa = PBXFileReference; explicitFileType = "compiled.mach-o.dylib"; path = libcfmt_logger.dylib; sourceTree = BUILT_PRODUCTS_DIR; };
 		CD6F742F225189470081ED74 /* GoogleMock.xcodeproj */ = {isa = PBXFileReference; lastKnownFileType = "wrapper.pb-project"; name = GoogleMock.xcodeproj; path = "../../../gmock-xcode-master/GoogleMock.xcodeproj"; sourceTree = "<group>"; };
 		CD6F746B22518A2C0081ED74 /* GoogleMock.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = GoogleMock.framework; path = "../../../gmock-xcode-master/build/Release/GoogleMock.framework"; sourceTree = "<group>"; };
+		CD760CB822621776008A62DE /* pattern_layout_test.cxx */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = pattern_layout_test.cxx; sourceTree = "<group>"; };
 		CD88E9552252BDFC00927F40 /* log_manager.cxx */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = log_manager.cxx; sourceTree = "<group>"; };
 		CD88E95D2252D3EF00927F40 /* c_logger.cxx */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = c_logger.cxx; sourceTree = "<group>"; };
 		CD88E9612252D67A00927F40 /* common.cxx */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = common.cxx; sourceTree = "<group>"; };
@@ -172,6 +174,7 @@
 			children = (
 				CD6F73FC225187E10081ED74 /* logger_test.cxx */,
 				CD1CDEB22256B04600E5B6B2 /* format_test.cxx */,
+				CD760CB822621776008A62DE /* pattern_layout_test.cxx */,
 				CD1CDE8C22540D9B00E5B6B2 /* c_logger_test.cxx */,
 				CD1CDE8F22542CC500E5B6B2 /* log_manager_test.cxx */,
 				CD1CDE9122543E7E00E5B6B2 /* test_properties.cxx */,
@@ -367,6 +370,7 @@
 			files = (
 				CD1CDE9022542CC500E5B6B2 /* log_manager_test.cxx in Sources */,
 				CD6F740C225187FD0081ED74 /* logger_test.cxx in Sources */,
+				CD760CB922621776008A62DE /* pattern_layout_test.cxx in Sources */,
 				CD1CDE9222543E7E00E5B6B2 /* test_properties.cxx in Sources */,
 				CD1CDEB32256B04600E5B6B2 /* format_test.cxx in Sources */,
 				CD1CDE8D22540D9B00E5B6B2 /* c_logger_test.cxx in Sources */,

test/format_test.cxx

@@ -53,7 +53,9 @@ TEST(FormatTest, CatchesRawContentAfterFmt) {
 }
 
 // Thursday, April 4, 2019 6:17:20 PM GMT
-constexpr const int NOW = 1554401840;
+namespace {
+  constexpr const int NOW = 1554401840;
+}
 
 TEST(FormatTest, HandlesDateFormatter) {
   using testing::Eq;

test/pattern_layout_test.cxx

@@ -0,0 +1,37 @@
+//
+//  pattern_layout_test.cxx
+//  logger_test
+//
+//  Created by Sam Jaffe on 4/13/19.
+//
+
+#include <gmock/gmock.h>
+
+#include "resource_factory/prototype_factory.hpp"
+
+#include "logger/detail/layout.h"
+#include "logger/log_manager.h"
+#include "logger/logpacket.h"
+#include "logger/properties.h"
+
+// Thursday, April 4, 2019 6:17:20 PM GMT
+namespace {
+  constexpr const int NOW = 1554401840;
+}
+
+TEST(PatternLayoutTest, TestInvokesFormatter) {
+  using namespace logging;
+  using namespace logging::property;
+  properties props{_obj({
+    {"pattern", _v("%d{%I:%M:%S.%_ms} [%%] %-5.5p %.36c - %m")}
+  })};
+  auto playout = layouts::instance().get("PatternLayout", props);
+  
+  std::stringstream ss;
+  playout->format(ss, {{NOW, 0}, level::warning, {}, "UnitTest",
+    "This is a test message"});
+  
+  using testing::Eq;
+  EXPECT_THAT(ss.str(), Eq("06:17:20.000 [%] WARNI UnitTest -"
+                           " This is a test message"));
+}