1 files changed, 57 insertions, 0 deletions
diff --git a/clang-tools-extra/unittests/clangd/TestFS.h b/clang-tools-extra/unittests/clangd/TestFS.h
new file mode 100644
index 00000000000..31433162fa3
--- /dev/null
+++ b/clang-tools-extra/unittests/clangd/TestFS.h
@@ -0,0 +1,57 @@
+//===-- TestFS.h ------------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Allows setting up fake filesystem environments for tests.
+//
+//===----------------------------------------------------------------------===//
+#include "ClangdServer.h"
+#include "clang/Basic/VirtualFileSystem.h"
+#include "llvm/ADT/IntrusiveRefCntPtr.h"
+#include "llvm/Support/Path.h"
+
+namespace clang {
+namespace clangd {
+
+// Builds a VFS that provides access to the provided files, plus temporary
+// directories.
+llvm::IntrusiveRefCntPtr<vfs::FileSystem>
+buildTestFS(llvm::StringMap<std::string> const &Files);
+
+// A VFS provider that returns TestFSes containing a provided set of files.
+class MockFSProvider : public FileSystemProvider {
+public:
+  Tagged<IntrusiveRefCntPtr<vfs::FileSystem>>
+  getTaggedFileSystem(PathRef File) override;
+
+  llvm::Optional<SmallString<32>> ExpectedFile;
+  llvm::StringMap<std::string> Files;
+  VFSTag Tag = VFSTag();
+};
+
+// A Compilation database that returns a fixed set of compile flags.
+class MockCompilationDatabase : public GlobalCompilationDatabase {
+public:
+  MockCompilationDatabase(bool AddFreestandingFlag) {
+    // We have to add -ffreestanding to VFS-specific tests to avoid errors on
+    // implicit includes of stdc-predef.h.
+    if (AddFreestandingFlag)
+      ExtraClangFlags.push_back("-ffreestanding");
+  }
+
+  llvm::Optional<tooling::CompileCommand>
+  getCompileCommand(PathRef File) const override;
+
+  std::vector<std::string> ExtraClangFlags;
+};
+
+// Returns a suitable absolute path for this OS.
+llvm::SmallString<32> getVirtualTestFilePath(PathRef File);
+
+} // namespace clangd
+} // namespace clang