add test for readlink

CMakeLists.txt

@@ -73,6 +73,7 @@ if(NOT(WITHOUT_TEST))
         test-src/integration/webfuse/test/daemon.cpp
         test-src/integration/test_access.cpp
         test-src/integration/test_readdir.cpp
+        test-src/integration/test_readlink.cpp
     )
 
     target_include_directories(integration_tests PRIVATE test-src/integration ${GTEST_INCLUDE_DIRS} ${GMOCK_INCLUDE_DIRS})

src/webfuse/provider.cpp

@@ -61,6 +61,9 @@ public:
             case request_type::getattr:
                 fs_getattr(reader, writer);
                 break;
+            case request_type::readlink:
+                fs_readlink(reader, writer);
+                break;
             case request_type::readdir:
                 fs_readdir(reader, writer);
                 break;
@@ -107,6 +110,19 @@ private:
         }
     }
 
+    void fs_readlink(messagereader & reader, messagewriter & writer)
+    {
+        auto const path = reader.read_str();
+        std::string out;
+
+        auto const result = fs_.readlink(path, out);
+        writer.write_i32(result);
+        if (0 == result)
+        {
+            writer.write_str(out);
+        }
+    }
+
     filesystem_i & fs_;
     ws_client client;
 };

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);
+}