Issue 6477 - separate done and error callbacks in IFileSystem::Read

test/DefaultFileSystem.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 112 matching lines @@
     EXPECT_EQ(SLASH_STRING "foo" SLASH_STRING "bar" SLASH_STRING "baz.txt",
               fullPath);
   }
 }
 
 TEST_F(DefaultFileSystemTest, WriteReadRemove)
 {
   WriteString("foo");
 
   bool hasReadRun = false;
+  bool hasErrorRun = false;
   fileSystem->Read(testFileName,
-    [this, &hasReadRun](IFileSystem::IOBuffer&& content, const std::string& error)
-  {
-    EXPECT_TRUE(error.empty());
-    EXPECT_EQ("foo", std::string(content.cbegin(), content.cend()));
-    hasReadRun = true;
-  });
+    [this, &hasReadRun](IFileSystem::IOBuffer&& content)
+    {
+      EXPECT_EQ("foo", std::string(content.cbegin(), content.cend()));
+      hasReadRun = true;
+    }, [&hasErrorRun](const std::string& error)
+    {
+      hasErrorRun = true;
+    });
   EXPECT_FALSE(hasReadRun);
+  EXPECT_FALSE(hasErrorRun);
   PumpTask();
   EXPECT_TRUE(hasReadRun);
+  EXPECT_FALSE(hasErrorRun);
 
   bool hasRemoveRun = false;
   fileSystem->Remove(testFileName, [&hasRemoveRun](const std::string& error)
   {
     EXPECT_TRUE(error.empty());
     hasRemoveRun = true;
   });
   EXPECT_FALSE(hasRemoveRun);
   PumpTask();
   EXPECT_TRUE(hasRemoveRun);
@@ skipping 79 matching lines @@
   fileSystem->Stat(newTestFileName, [&hasStatRemovedFileRun](const IFileSystem::StatResult& result, const std::string& error)
   {
     EXPECT_TRUE(error.empty());
     ASSERT_FALSE(result.exists);
     hasStatRemovedFileRun = true;
   });
   EXPECT_FALSE(hasStatRemovedFileRun);
   PumpTask();
   EXPECT_TRUE(hasStatRemovedFileRun);
 }