From e312278b64fcc76272e2ca45d970892026823de7 Mon Sep 17 00:00:00 2001
From: John Bytheway <jbytheway@gmail.com>
Date: Sat, 11 Jan 2020 11:06:49 -0500
Subject: [PATCH] Add clang-tidy check for test filenames

Enforce the rule that test files should be named *_test.cpp.
---
 tools/clang-tidy-plugin/CMakeLists.txt        |  1 +
 tools/clang-tidy-plugin/CataTidyModule.cpp    |  2 +
 tools/clang-tidy-plugin/TestFilenameCheck.cpp | 56 +++++++++++++++++++
 tools/clang-tidy-plugin/TestFilenameCheck.h   | 26 +++++++++
 .../clang-tidy-plugin/test/test-filename.cpp  |  6 ++
 5 files changed, 91 insertions(+)
 create mode 100644 tools/clang-tidy-plugin/TestFilenameCheck.cpp
 create mode 100644 tools/clang-tidy-plugin/TestFilenameCheck.h
 create mode 100644 tools/clang-tidy-plugin/test/test-filename.cpp

diff --git a/tools/clang-tidy-plugin/CMakeLists.txt b/tools/clang-tidy-plugin/CMakeLists.txt
index 553ef0ebe015c..a78f9f1d50f6e 100644
--- a/tools/clang-tidy-plugin/CMakeLists.txt
+++ b/tools/clang-tidy-plugin/CMakeLists.txt
@@ -12,6 +12,7 @@ add_library(
     PointInitializationCheck.cpp
     SimplifyPointConstructorsCheck.cpp
     StringLiteralIterator.cpp
+    TestFilenameCheck.cpp
     TextStyleCheck.cpp
     TranslatorCommentsCheck.cpp
     UseNamedPointConstantsCheck.cpp
diff --git a/tools/clang-tidy-plugin/CataTidyModule.cpp b/tools/clang-tidy-plugin/CataTidyModule.cpp
index 47da679700dbe..441c31a4dadb5 100644
--- a/tools/clang-tidy-plugin/CataTidyModule.cpp
+++ b/tools/clang-tidy-plugin/CataTidyModule.cpp
@@ -7,6 +7,7 @@
 #include "NoStaticGettextCheck.h"
 #include "PointInitializationCheck.h"
 #include "SimplifyPointConstructorsCheck.h"
+#include "TestFilenameCheck.h"
 #include "TextStyleCheck.h"
 #include "TranslatorCommentsCheck.h"
 #include "UseNamedPointConstantsCheck.h"
@@ -31,6 +32,7 @@ class CataModule : public ClangTidyModule
             CheckFactories.registerCheck<PointInitializationCheck>( "cata-point-initialization" );
             CheckFactories.registerCheck<SimplifyPointConstructorsCheck>(
                 "cata-simplify-point-constructors" );
+            CheckFactories.registerCheck<TestFilenameCheck>( "cata-test-filename" );
             CheckFactories.registerCheck<TextStyleCheck>( "cata-text-style" );
             CheckFactories.registerCheck<TranslatorCommentsCheck>( "cata-translator-comments" );
             CheckFactories.registerCheck<UseNamedPointConstantsCheck>(
diff --git a/tools/clang-tidy-plugin/TestFilenameCheck.cpp b/tools/clang-tidy-plugin/TestFilenameCheck.cpp
new file mode 100644
index 0000000000000..9d1f94dea3c0b
--- /dev/null
+++ b/tools/clang-tidy-plugin/TestFilenameCheck.cpp
@@ -0,0 +1,56 @@
+#include "TestFilenameCheck.h"
+
+#include <clang/Lex/PPCallbacks.h>
+#include <clang/Lex/Preprocessor.h>
+#include <clang/Lex/Token.h>
+#include <string>
+
+#include "clang/Frontend/CompilerInstance.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang
+{
+namespace tidy
+{
+namespace cata
+{
+
+class TestFilenameCallbacks : public PPCallbacks
+{
+    public:
+        TestFilenameCallbacks( TestFilenameCheck *Check, CompilerInstance *Compiler ) :
+            Check( Check ), Compiler( Compiler ) {}
+
+        void MacroExpands( const Token &MacroNameTok,
+                           const MacroDefinition &,
+                           SourceRange Range,
+                           const MacroArgs * ) override {
+            StringRef MacroName = MacroNameTok.getIdentifierInfo()->getName();
+
+            if( MacroName == "TEST_CASE" ) {
+                SourceManager &SM = Compiler->getSourceManager();
+                StringRef Filename = SM.getBufferName( Range.getBegin() );
+                bool IsTestFilename = Filename.endswith( "_test.cpp" );
+
+                if( !IsTestFilename ) {
+                    Check->diag( Range.getBegin(),
+                                 "Files containing a test definition should have a filename "
+                                 "ending in '_test.cpp'." );
+                }
+            }
+        }
+    private:
+        TestFilenameCheck *Check;
+        CompilerInstance *Compiler;
+};
+
+void TestFilenameCheck::registerPPCallbacks( CompilerInstance &Compiler )
+{
+    Compiler.getPreprocessor().addPPCallbacks(
+        llvm::make_unique<TestFilenameCallbacks>( this, &Compiler ) );
+}
+
+} // namespace cata
+} // namespace tidy
+} // namespace clang
diff --git a/tools/clang-tidy-plugin/TestFilenameCheck.h b/tools/clang-tidy-plugin/TestFilenameCheck.h
new file mode 100644
index 0000000000000..2c6a8832279ea
--- /dev/null
+++ b/tools/clang-tidy-plugin/TestFilenameCheck.h
@@ -0,0 +1,26 @@
+#ifndef CATA_TOOLS_CLANG_TIDY_TESTFILENAMECHECK_H
+#define CATA_TOOLS_CLANG_TIDY_TESTFILENAMECHECK_H
+
+#include "ClangTidy.h"
+
+namespace clang
+{
+namespace tidy
+{
+namespace cata
+{
+
+class TestFilenameCheck : public ClangTidyCheck
+{
+    public:
+        TestFilenameCheck( StringRef Name, ClangTidyContext *Context )
+            : ClangTidyCheck( Name, Context ) {}
+
+        void registerPPCallbacks( CompilerInstance &Compiler ) override;
+};
+
+} // namespace cata
+} // namespace tidy
+} // namespace clang
+
+#endif // CATA_TOOLS_CLANG_TIDY_TESTFILENAMECHECK_H
diff --git a/tools/clang-tidy-plugin/test/test-filename.cpp b/tools/clang-tidy-plugin/test/test-filename.cpp
new file mode 100644
index 0000000000000..605583e12d0f8
--- /dev/null
+++ b/tools/clang-tidy-plugin/test/test-filename.cpp
@@ -0,0 +1,6 @@
+// RUN: %check_clang_tidy %s cata-test-filename %t -- -plugins=%cata_plugin -- -isystem %cata_include
+
+#define TEST_CASE(name)
+
+TEST_CASE( "test_name" )
+// CHECK-MESSAGES: warning: Files containing a test definition should have a filename ending in '_test.cpp'. [cata-test-filename]