add test for readlink

test-src/integration/test_readlink.cpp

@@ -0,0 +1,71 @@
+#include "webfuse/webfuse.hpp"
+#include "webfuse/test/fixture.hpp"
+#include "webfuse/test/filesystem_mock.hpp"
+
+using testing::_;
+using testing::Return;
+using testing::Invoke;
+using testing::AnyNumber;
+
+namespace
+{
+
+int fs_getattr(std::string const & path, struct stat * attr){
+        memset(reinterpret_cast<void*>(attr),0, sizeof(struct stat));
+
+        if (path == "/")
+        {
+            attr->st_nlink = 1;
+            attr->st_mode = S_IFDIR | 0755;
+            return 0;
+        }
+        else if (path == "/some_link")
+        {
+            attr->st_nlink = 1;
+            attr->st_mode = S_IFLNK | 0755;
+            return 0;            
+        }
+        else
+        {
+            return -ENOENT;
+        }        
+    }
+
+}
+
+TEST(readlink, existing_link)
+{
+    webfuse::filesystem_mock fs;
+    EXPECT_CALL(fs, access("/",_)).Times(AnyNumber()).WillRepeatedly(Return(0));
+    EXPECT_CALL(fs, getattr(_,_)).WillRepeatedly(Invoke(fs_getattr));
+    EXPECT_CALL(fs, readlink("/some_link",_)).WillOnce(Invoke([](auto const & path, auto & out) {
+        out = "link-target";
+        return 0;
+    }));
+
+    webfuse::fixture fixture(fs);
+    auto const path = fixture.get_path() + "/some_link";
+
+    char buffer[100];
+    auto const length = ::readlink(path.c_str(), buffer, 99);
+    ASSERT_LT(0, length);
+    buffer[length] = '\0';
+    ASSERT_STREQ("link-target", buffer);
+}
+
+TEST(readlink, non_existing_link)
+{
+    webfuse::filesystem_mock fs;
+    EXPECT_CALL(fs, access("/",_)).Times(AnyNumber()).WillRepeatedly(Return(0));
+    EXPECT_CALL(fs, getattr(_,_)).WillRepeatedly(Invoke(fs_getattr));
+    EXPECT_CALL(fs, readlink("/some_link",_)).WillOnce(Invoke([](auto const & path, auto & out) {
+        return -ENOENT;
+    }));
+
+    webfuse::fixture fixture(fs);
+    auto const path = fixture.get_path() + "/some_link";
+
+    char buffer[100];
+    ASSERT_GT(0, ::readlink(path.c_str(), buffer, 100));
+    ASSERT_EQ(ENOENT, errno);
+}