CSV reporter: escape counter names and keep skipped rows full width

Two ways the CSV output could stop being well-formed:

The header wrote each user counter name as "\"" << name << "\"", so a
counter whose name contains a double quote produced a broken header
field. Write it with CsvEscape, like every other string field. Names
without quotes come out exactly as before.

A skipped benchmark's row stopped after error_message, without the
empty fields for the user counters that every other row and the header
have. Readers then see a row with fewer columns than the header (the
test helper's own ResultsChecker asserts that the widths match). Append
one empty field per user counter.

user_counters_test gains a skipped benchmark; its CSV row now ends with
the two empty "bar" and "foo" fields, and the test fails with "End of
output reached before match" without this change.

Author: devtejasx

src/csv_reporter.cc

@@ -78,9 +78,8 @@ void CSVReporter::ReportRuns(const std::vector<Run>& reports) {
         Out << ",";
       }
     }
-    for (auto B = user_counter_names_.begin();
-         B != user_counter_names_.end();) {
-      Out << ",\"" << *B++ << "\"";
+    for (const auto& name : user_counter_names_) {
+      Out << "," << CsvEscape(name);
     }
     Out << "\n";
 
@@ -115,7 +114,9 @@ void CSVReporter::PrintRunData(const Run& run) {
   if (run.skipped != 0u) {
     Out << std::string(elements.size() - 3, ',');
     Out << std::boolalpha << (internal::SkippedWithError == run.skipped) << ",";
-    Out << CsvEscape(run.skip_message) << "\n";
+    Out << CsvEscape(run.skip_message);
+    // Keep the row as wide as the header: one empty field per user counter.
+    Out << std::string(user_counter_names_.size(), ',') << "\n";
     return;
   }
 

test/user_counters_test.cc

@@ -587,6 +587,20 @@ CHECK_BENCHMARK_RESULTS("BM_Counters_kAvgIterationsRate",
                         &CheckAvgIterationsRate);
 }  // end namespace
 
+// ========================================================================= //
+// ------------------------- Skipped Benchmark Output ---------------------- //
+// ========================================================================= //
+
+void BM_Counters_Skipped(benchmark::State& state) {
+  state.SkipWithError("skipped");
+  for (auto _ : state) {
+  }
+}
+BENCHMARK(BM_Counters_Skipped);
+// The row for a skipped benchmark has one empty field per user counter in the
+// header ("bar" and "foo"), like every other row.
+ADD_CASES(TC_CSVOut, {{"^\"BM_Counters_Skipped\",,,,,,,,true,\"skipped\",,$"}});
+
 // ========================================================================= //
 // --------------------------- TEST CASES END ------------------------------ //
 // ========================================================================= //