From e7181c3c8b7680b58ae1020b3c1d243ef28fdb6f Mon Sep 17 00:00:00 2001
From: Sebastian Messmer <mail@smessmer.de>
Date: Thu, 20 Nov 2014 20:04:39 +0100
Subject: [PATCH] Comments

---
 .../fuse/{FuseTest.cpp => BasicFuseTest.cpp}  |  2 +-
 .../fspp/fuse/lstat/FuseLstatErrorTest.cpp    |  2 ++
 .../lstat/testutils/FuseLstatReturnTest.h     |  6 ++++++
 .../fspp/fuse/lstat/testutils/FuseLstatTest.h | 19 ++++++++++++++++---
 4 files changed, 25 insertions(+), 4 deletions(-)
 rename src/test/fspp/fuse/{FuseTest.cpp => BasicFuseTest.cpp} (74%)

diff --git a/src/test/fspp/fuse/FuseTest.cpp b/src/test/fspp/fuse/BasicFuseTest.cpp
similarity index 74%
rename from src/test/fspp/fuse/FuseTest.cpp
rename to src/test/fspp/fuse/BasicFuseTest.cpp
index a5550bed..2615a6c4 100644
--- a/src/test/fspp/fuse/FuseTest.cpp
+++ b/src/test/fspp/fuse/BasicFuseTest.cpp
@@ -11,7 +11,7 @@ using ::testing::StrEq;
 
 typedef FuseTest BasicFuseTest;
 
+//This test case simply checks whether a filesystem can be setup and teardown without crashing.
 TEST_F(BasicFuseTest, setupAndTearDown) {
-  //This test case simply checks whether a filesystem can be setup and teardown without crashing.
   auto fs = TestFS();
 }
diff --git a/src/test/fspp/fuse/lstat/FuseLstatErrorTest.cpp b/src/test/fspp/fuse/lstat/FuseLstatErrorTest.cpp
index da7a9294..f87ca39e 100644
--- a/src/test/fspp/fuse/lstat/FuseLstatErrorTest.cpp
+++ b/src/test/fspp/fuse/lstat/FuseLstatErrorTest.cpp
@@ -17,7 +17,9 @@ INSTANTIATE_TEST_CASE_P(LstatErrorCodes, FuseLstatErrorTest, Values(EACCES, EBAD
 
 TEST_F(FuseLstatErrorTest, ReturnNoError) {
   EXPECT_CALL(fsimpl, lstat(StrEq(FILENAME), _)).Times(1).WillOnce(ReturnIsFile);
+  errno = 0;
   int retval = LstatPathAllowErrors(FILENAME);
+  EXPECT_EQ(errno, 0);
   EXPECT_EQ(retval, 0);
 }
 
diff --git a/src/test/fspp/fuse/lstat/testutils/FuseLstatReturnTest.h b/src/test/fspp/fuse/lstat/testutils/FuseLstatReturnTest.h
index 8dae044c..7f62c285 100644
--- a/src/test/fspp/fuse/lstat/testutils/FuseLstatReturnTest.h
+++ b/src/test/fspp/fuse/lstat/testutils/FuseLstatReturnTest.h
@@ -4,15 +4,21 @@
 
 #include "FuseLstatTest.h"
 
+// This class offers test helpers for testing (struct stat) entries. We return them from
+// our mock filesystem, set up a temporary filesystem, call lstat syscall on it, and
+// then check the return value.
 template<typename Property>
 class FuseLstatReturnTest: public FuseLstatTest {
 public:
+  // Set the specified (struct stat) entry to the given value, and test whether it is correctly returned from the syscall.
+  // The CallFile[...] version tests it on a file node of the filesystem, the CallDir[...] version on a dir node.
   struct stat CallFileLstatWithValue(Property value);
   struct stat CallDirLstatWithValue(Property value);
 
 private:
   std::function<void(struct stat*)> SetPropertyImpl(Property value);
 
+  // Override this function to specify, how to set the specified (struct stat) entry on the passed (struct stat *) object.
   virtual void set(struct stat *stat, Property value) = 0;
 };
 
diff --git a/src/test/fspp/fuse/lstat/testutils/FuseLstatTest.h b/src/test/fspp/fuse/lstat/testutils/FuseLstatTest.h
index 5ad68549..961d56fb 100644
--- a/src/test/fspp/fuse/lstat/testutils/FuseLstatTest.h
+++ b/src/test/fspp/fuse/lstat/testutils/FuseLstatTest.h
@@ -10,19 +10,32 @@
 
 #include "test/testutils/FuseTest.h"
 
+// This class offers some utility functions for testing lstat().
 class FuseLstatTest: public FuseTest {
-public:
+protected:
   const char *FILENAME = "/myfile";
 
+  // Set up a temporary filesystem (using the fsimpl mock in FuseTest as filesystem implementation)
+  // and call the lstat syscall on the given (filesystem-relative) path.
   void LstatPath(const std::string &path);
+  // Same as LstatPath above, but also return the result of the lstat syscall.
   void LstatPath(const std::string &path, struct stat *result);
+
+  // These two functions are the same as LstatPath above, but they don't fail the test when the lstat syscall
+  // crashes. Instead, they return the result value of the lstat syscall.
   int LstatPathAllowErrors(const std::string &path);
   int LstatPathAllowErrors(const std::string &path, struct stat *result);
 
-protected:
+  // You can specify an implementation, which can modify the (struct stat *) result,
+  // our fuse mock filesystem implementation will then return this to fuse on an lstat call.
+  // This functions then set up a temporary filesystem with this mock, call lstat on a filesystem node
+  // and return the (struct stat) returned from an lstat syscall to this filesystem.
+  struct stat CallLstatWithImpl(std::function<void(struct stat*)> implementation);
+
+  // These two functions are like CallLstatWithImpl, but they also modify the (struct stat).st_mode
+  // field, so the node accessed is specified to be a file/directory.
   struct stat CallFileLstatWithImpl(std::function<void(struct stat*)> implementation);
   struct stat CallDirLstatWithImpl(std::function<void(struct stat*)> implementation);
-  struct stat CallLstatWithImpl(std::function<void(struct stat*)> implementation);
 
 private: