[include-fixer] Correct an incorrecst judgement about prefix scoped qualifiers.

[hokein]

Summary

The judgement that checks whether the fully-qualified name has scoped qualifiers
prefix is incorrect. Should always check whether the first matched postion is the
beginning position.

[bkramer]

include-fixer/IncludeFixerContext.cpp

46

StringRef(FullyQualifiedName).startswith

[hokein]

Use StringRef::startwith.

include-fixer/IncludeFixerContext.cpp

46

+1, more clear than std::string methods.

include-fixer/IncludeFixerContext.cpp

std::string createQualifiedNameForReplacement(
   std::string StrippedQualifiers;
   while (!SymbolQualifiers.empty() &&
          !llvm::StringRef(QualifiedName).endswith(SymbolQualifiers.back())) {
     StrippedQualifiers = "::" + SymbolQualifiers.back().str();
     SymbolQualifiers.pop_back();
   }
   // Append the missing stripped qualifiers.
   std::string FullyQualifiedName = QualifiedName + StrippedQualifiers;
-  auto pos = FullyQualifiedName.find(SymbolScopedQualifiers);
-  return FullyQualifiedName.substr(
-      pos == std::string::npos ? 0 : SymbolScopedQualifiers.size());
+
+  // Skips symbol scoped qualifiers prefix.
+  if (llvm::StringRef(FullyQualifiedName).startswith(SymbolScopedQualifiers))
+    return FullyQualifiedName.substr(SymbolScopedQualifiers.size());
+
+  return FullyQualifiedName;
 }
 
 } // anonymous namespace
 
 IncludeFixerContext::IncludeFixerContext(
     llvm::StringRef Name, llvm::StringRef ScopeQualifiers,
     std::vector<find_all_symbols::SymbolInfo> Symbols,
     tooling::Range Range)

unittests/include-fixer/IncludeFixerTest.cpp

std::vector<SymbolInfo> Symbols = {
       SymbolInfo("sting", SymbolInfo::SymbolKind::Class, "\"sting\"", 1,
                  {{SymbolInfo::ContextType::Namespace, "std"}}),
       SymbolInfo("foo", SymbolInfo::SymbolKind::Class, "\"dir/otherdir/qux.h\"",
                  1, {{SymbolInfo::ContextType::Namespace, "b"},
                      {SymbolInfo::ContextType::Namespace, "a"}}),
       SymbolInfo("bar", SymbolInfo::SymbolKind::Class, "\"bar.h\"", 1,
                  {{SymbolInfo::ContextType::Namespace, "b"},
                   {SymbolInfo::ContextType::Namespace, "a"}}),
+      SymbolInfo("bar", SymbolInfo::SymbolKind::Class, "\"bar2.h\"", 1,
+                 {{SymbolInfo::ContextType::Namespace, "c"},
+                  {SymbolInfo::ContextType::Namespace, "a"}}),
       SymbolInfo("Green", SymbolInfo::SymbolKind::Class, "\"color.h\"", 1,
                  {{SymbolInfo::ContextType::EnumDecl, "Color"},
                   {SymbolInfo::ContextType::Namespace, "b"},
                   {SymbolInfo::ContextType::Namespace, "a"}}),
       SymbolInfo("Vector", SymbolInfo::SymbolKind::Class, "\"Vector.h\"", 1,
                  {{SymbolInfo::ContextType::Namespace, "__a"},
                   {SymbolInfo::ContextType::Namespace, "a"}},
                  /*num_occurrences=*/2),
TEST(IncludeFixer, FixNamespaceQualifiers) {
   EXPECT_EQ("#include \"bar.h\"\nnamespace a {\nb::bar b;\n}\n",
             runIncludeFixer("namespace a {\nb::bar b;\n}\n"));
   EXPECT_EQ("#include \"bar.h\"\nnamespace a {\nb::bar b;\n}\n",
             runIncludeFixer("namespace a {\nbar b;\n}\n"));
   EXPECT_EQ("#include \"bar.h\"\nnamespace a {\nnamespace b{\nbar b;\n}\n}\n",
             runIncludeFixer("namespace a {\nnamespace b{\nbar b;\n}\n}\n"));
   EXPECT_EQ("c::b::bar b;\n",
             runIncludeFixer("c::b::bar b;\n"));
-  EXPECT_EQ("#include \"bar.h\"\nnamespace c {\na::b::bar b;\n}\n",
+  EXPECT_EQ("#include \"bar.h\"\nnamespace d {\na::b::bar b;\n}\n",
+            runIncludeFixer("namespace d {\nbar b;\n}\n"));
+  EXPECT_EQ("#include \"bar2.h\"\nnamespace c {\na::c::bar b;\n}\n",
             runIncludeFixer("namespace c {\nbar b;\n}\n"));
 
   // Test nested classes.
-  EXPECT_EQ("#include \"bar.h\"\nnamespace c {\na::b::bar::t b;\n}\n",
+  EXPECT_EQ("#include \"bar.h\"\nnamespace d {\na::b::bar::t b;\n}\n",
+            runIncludeFixer("namespace d {\nbar::t b;\n}\n"));
+  EXPECT_EQ("#include \"bar2.h\"\nnamespace c {\na::c::bar::t b;\n}\n",
             runIncludeFixer("namespace c {\nbar::t b;\n}\n"));
   EXPECT_EQ("#include \"bar.h\"\nnamespace a {\nb::bar::t b;\n}\n",
             runIncludeFixer("namespace a {\nbar::t b;\n}\n"));
 
   EXPECT_EQ("#include \"color.h\"\nint test = a::b::Green;\n",
             runIncludeFixer("int test = Green;\n"));
   EXPECT_EQ("#include \"color.h\"\nnamespace d {\nint test = a::b::Green;\n}\n",
             runIncludeFixer("namespace d {\nint test = Green;\n}\n"));