1 files changed, 101 insertions, 0 deletions
diff --git a/cpp/043scenario_trace b/cpp/043scenario_trace
new file mode 100644
index 00000000..90dab204
--- /dev/null
+++ b/cpp/043scenario_trace
@@ -0,0 +1,101 @@
+:(before "End scenario Fields")
+vector<pair<string, string> > trace_checks;
+vector<pair<string, string> > trace_negative_checks;
+
+:(before "End Scenario Command Handlers")
+else if (scenario_command == "trace") {
+  handle_scenario_trace_directive(inner, x);
+}
+
+:(before "End Scenario Checks")
+check_trace_contents(Scenarios[i]);
+check_trace_negative_contents(Scenarios[i]);
+
+:(code)
+void handle_scenario_trace_directive(istream& in, scenario& out) {
+  if (next_word(in) != "should") {
+    raise << "'trace' directive inside scenario must continue 'trace should'\n";
+  }
+  string s = next_word(in);
+  if (s == "not") {
+    handle_scenario_trace_negative_directive(in, out);
+    return;
+  }
+  if (s != "contain") {
+    raise << "'trace' directive inside scenario must continue 'trace should [not] contain'\n";
+  }
+  skip_bracket(in, "'trace' directive inside scenario must begin with 'trace should contain ['\n");
+  while (true) {
+    skip_whitespace_and_comments(in);
+    if (in.eof()) break;
+    if (in.peek() == ']') break;
+    string curr_line;
+    getline(in, curr_line);
+    istringstream tmp(curr_line);
+    tmp >> std::noskipws;
+    string label = slurp_until(tmp, ':');
+    if (tmp.get() != ' ') {
+      raise << "'trace' directive inside scenario should contain lines of the form 'label: message', instead got " << curr_line;
+      continue;
+    }
+    string message = slurp_rest(tmp);
+    out.trace_checks.push_back(pair<string, string>(label, message));
+    trace("scenario") << "trace: " << label << ": " << message << '\n';
+  }
+  skip_whitespace(in);
+  assert(in.get() == ']');
+}
+
+void handle_scenario_trace_negative_directive(istream& in, scenario& out) {
+  // 'not' already slurped
+  if (next_word(in) != "contain") {
+    raise << "'trace' directive inside scenario must continue 'trace should not contain'\n";
+  }
+  skip_bracket(in, "'trace' directive inside scenario must begin with 'trace should not contain ['\n");
+  while (true) {
+    skip_whitespace_and_comments(in);
+    if (in.eof()) break;
+    if (in.peek() == ']') break;
+    string curr_line;
+    getline(in, curr_line);
+    istringstream tmp(curr_line);
+    tmp >> std::noskipws;
+    string label = slurp_until(tmp, ':');
+    if (tmp.get() != ' ') {
+      raise << "'trace' directive inside scenario should contain lines of the form 'label: message', instead got " << curr_line;
+      continue;
+    }
+    string message = slurp_rest(tmp);
+    out.trace_negative_checks.push_back(pair<string, string>(label, message));
+    trace("scenario") << "trace: " << label << ": " << message << '\n';
+  }
+  skip_whitespace(in);
+  assert(in.get() == ']');
+}
+
+string slurp_rest(istream& in) {
+  ostringstream out;
+  char c;
+  while (in >> c) {
+    out << c;
+  }
+  return out.str();
+}
+
+void check_trace_contents(const scenario& s) {
+  if (s.trace_checks.empty()) return;
+  ostringstream contents;
+  for (size_t i = 0; i < s.trace_checks.size(); ++i) {
+    contents << s.trace_checks[i].first << ": " << s.trace_checks[i].second << "";
+  }
+  CHECK_TRACE_CONTENTS(contents.str());
+}
+
+void check_trace_negative_contents(const scenario& s) {
+  for (size_t i = 0; i < s.trace_negative_checks.size(); ++i) {
+    if (trace_count(s.trace_negative_checks[i].first, s.trace_negative_checks[i].second) > 0) {
+      raise << "trace shouldn't contain " << s.trace_negative_checks[i].first << ": " << s.trace_negative_checks[i].second << '\n';
+      Passed = false;
+    }
+  }
+}