From b54098a9abade957ab3c4e94ae5e5225ef0015a4 Mon Sep 17 00:00:00 2001 From: kosak Date: Mon, 28 Jul 2014 21:54:50 +0000 Subject: Expand equality failure messages with a by-line diff. --- src/gtest.cc | 285 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 285 insertions(+) (limited to 'src') diff --git a/src/gtest.cc b/src/gtest.cc index ca3596eb..e4f3df3e 100644 --- a/src/gtest.cc +++ b/src/gtest.cc @@ -46,6 +46,8 @@ #include #include #include +#include +#include #include // NOLINT #include #include @@ -80,6 +82,7 @@ #elif GTEST_OS_WINDOWS_MOBILE // We are on Windows CE. # include // NOLINT +# undef min #elif GTEST_OS_WINDOWS // We are on Windows proper. @@ -102,6 +105,7 @@ // cpplint thinks that the header is already included, so we want to // silence it. # include // NOLINT +# undef min #else @@ -981,6 +985,276 @@ AssertionResult AssertionFailure(const Message& message) { namespace internal { +namespace edit_distance { +std::vector CalculateOptimalEdits(const std::vector& left, + const std::vector& right) { + std::vector > costs( + left.size() + 1, std::vector(right.size() + 1)); + std::vector > best_move( + left.size() + 1, std::vector(right.size() + 1)); + + // Populate for empty right. + for (size_t l_i = 0; l_i < costs.size(); ++l_i) { + costs[l_i][0] = static_cast(l_i); + best_move[l_i][0] = kRemove; + } + // Populate for empty left. + for (size_t r_i = 1; r_i < costs[0].size(); ++r_i) { + costs[0][r_i] = static_cast(r_i); + best_move[0][r_i] = kAdd; + } + + for (size_t l_i = 0; l_i < left.size(); ++l_i) { + for (size_t r_i = 0; r_i < right.size(); ++r_i) { + if (left[l_i] == right[r_i]) { + // Found a match. Consume it. + costs[l_i + 1][r_i + 1] = costs[l_i][r_i]; + best_move[l_i + 1][r_i + 1] = kMatch; + continue; + } + + const double add = costs[l_i + 1][r_i]; + const double remove = costs[l_i][r_i + 1]; + const double replace = costs[l_i][r_i]; + if (add < remove && add < replace) { + costs[l_i + 1][r_i + 1] = add + 1; + best_move[l_i + 1][r_i + 1] = kAdd; + } else if (remove < add && remove < replace) { + costs[l_i + 1][r_i + 1] = remove + 1; + best_move[l_i + 1][r_i + 1] = kRemove; + } else { + // We make replace a little more expensive than add/remove to lower + // their priority. + costs[l_i + 1][r_i + 1] = replace + 1.00001; + best_move[l_i + 1][r_i + 1] = kReplace; + } + } + } + + // Reconstruct the best path. We do it in reverse order. + std::vector best_path; + for (size_t l_i = left.size(), r_i = right.size(); l_i > 0 || r_i > 0;) { + EditType move = best_move[l_i][r_i]; + best_path.push_back(move); + l_i -= move != kAdd; + r_i -= move != kRemove; + } + std::reverse(best_path.begin(), best_path.end()); + return best_path; +} + +namespace { + +// Helper class to convert string into ids with deduplication. +class InternalStrings { + public: + size_t GetId(const std::string& str) { + IdMap::iterator it = ids_.find(str); + if (it != ids_.end()) return it->second; + size_t id = ids_.size(); + return ids_[str] = id; + } + + private: + typedef std::map IdMap; + IdMap ids_; +}; + +} // namespace + +std::vector CalculateOptimalEdits( + const std::vector& left, + const std::vector& right) { + std::vector left_ids, right_ids; + { + InternalStrings intern_table; + for (size_t i = 0; i < left.size(); ++i) { + left_ids.push_back(intern_table.GetId(left[i])); + } + for (size_t i = 0; i < right.size(); ++i) { + right_ids.push_back(intern_table.GetId(right[i])); + } + } + return CalculateOptimalEdits(left_ids, right_ids); +} + +namespace { + +// Helper class that holds the state for one hunk and prints it out to the +// stream. +// It reorders adds/removes when possible to group all removes before all +// adds. It also adds the hunk header before printint into the stream. +class Hunk { + public: + Hunk(size_t left_start, size_t right_start) + : left_start_(left_start), + right_start_(right_start), + adds_(), + removes_(), + common_() {} + + void PushLine(char edit, const char* line) { + switch (edit) { + case ' ': + ++common_; + FlushEdits(); + hunk_.push_back(std::make_pair(' ', line)); + break; + case '-': + ++removes_; + hunk_removes_.push_back(std::make_pair('-', line)); + break; + case '+': + ++adds_; + hunk_adds_.push_back(std::make_pair('+', line)); + break; + } + } + + void PrintTo(std::ostream* os) { + PrintHeader(os); + FlushEdits(); + for (std::list >::const_iterator it = + hunk_.begin(); + it != hunk_.end(); ++it) { + *os << it->first << it->second << "\n"; + } + } + + bool has_edits() const { return adds_ || removes_; } + + private: + void FlushEdits() { + hunk_.splice(hunk_.end(), hunk_removes_); + hunk_.splice(hunk_.end(), hunk_adds_); + } + + // Print a unified diff header for one hunk. + // The format is + // "@@ -, +, @@" + // where the left/right parts are ommitted if unnecessary. + void PrintHeader(std::ostream* ss) const { + *ss << "@@ "; + if (removes_) { + *ss << "-" << left_start_ << "," << (removes_ + common_); + } + if (removes_ && adds_) { + *ss << " "; + } + if (adds_) { + *ss << "+" << right_start_ << "," << (adds_ + common_); + } + *ss << " @@\n"; + } + + size_t left_start_, right_start_; + size_t adds_, removes_, common_; + std::list > hunk_, hunk_adds_, hunk_removes_; +}; + +} // namespace + +// Create a list of diff hunks in Unified diff format. +// Each hunk has a header generated by PrintHeader above plus a body with +// lines prefixed with ' ' for no change, '-' for deletion and '+' for +// addition. +// 'context' represents the desired unchanged prefix/suffix around the diff. +// If two hunks are close enough that their contexts overlap, then they are +// joined into one hunk. +std::string CreateUnifiedDiff(const std::vector& left, + const std::vector& right, + size_t context) { + const std::vector edits = CalculateOptimalEdits(left, right); + + size_t l_i = 0, r_i = 0, edit_i = 0; + std::stringstream ss; + while (edit_i < edits.size()) { + // Find first edit. + while (edit_i < edits.size() && edits[edit_i] == kMatch) { + ++l_i; + ++r_i; + ++edit_i; + } + + // Find the first line to include in the hunk. + const size_t prefix_context = std::min(l_i, context); + Hunk hunk(l_i - prefix_context + 1, r_i - prefix_context + 1); + for (size_t i = prefix_context; i > 0; --i) { + hunk.PushLine(' ', left[l_i - i].c_str()); + } + + // Iterate the edits until we found enough suffix for the hunk or the input + // is over. + size_t n_suffix = 0; + for (; edit_i < edits.size(); ++edit_i) { + if (n_suffix >= context) { + // Continue only if the next hunk is very close. + std::vector::const_iterator it = edits.begin() + edit_i; + while (it != edits.end() && *it == kMatch) ++it; + if (it == edits.end() || (it - edits.begin()) - edit_i >= context) { + // There is no next edit or it is too far away. + break; + } + } + + EditType edit = edits[edit_i]; + // Reset count when a non match is found. + n_suffix = edit == kMatch ? n_suffix + 1 : 0; + + if (edit == kMatch || edit == kRemove || edit == kReplace) { + hunk.PushLine(edit == kMatch ? ' ' : '-', left[l_i].c_str()); + } + if (edit == kAdd || edit == kReplace) { + hunk.PushLine('+', right[r_i].c_str()); + } + + // Advance indices, depending on edit type. + l_i += edit != kAdd; + r_i += edit != kRemove; + } + + if (!hunk.has_edits()) { + // We are done. We don't want this hunk. + break; + } + + hunk.PrintTo(&ss); + } + return ss.str(); +} + +} // namespace edit_distance + +namespace { + +// The string representation of the values received in EqFailure() are already +// escaped. Split them on escaped '\n' boundaries. Leave all other escaped +// characters the same. +std::vector SplitEscapedString(const std::string& str) { + std::vector lines; + size_t start = 0, end = str.size(); + if (end > 2 && str[0] == '"' && str[end - 1] == '"') { + ++start; + --end; + } + bool escaped = false; + for (size_t i = start; i + 1 < end; ++i) { + if (escaped) { + escaped = false; + if (str[i] == 'n') { + lines.push_back(str.substr(start, i - start - 1)); + start = i + 1; + } + } else { + escaped = str[i] == '\\'; + } + } + lines.push_back(str.substr(start, end - start)); + return lines; +} + +} // namespace + // Constructs and returns the message for an equality assertion // (e.g. ASSERT_EQ, EXPECT_STREQ, etc) failure. // @@ -1015,6 +1289,17 @@ AssertionResult EqFailure(const char* expected_expression, msg << "\nWhich is: " << expected_value; } + if (!expected_value.empty() && !actual_value.empty()) { + const std::vector expected_lines = + SplitEscapedString(expected_value); + const std::vector actual_lines = + SplitEscapedString(actual_value); + if (expected_lines.size() > 1 || actual_lines.size() > 1) { + msg << "\nWith diff:\n" + << edit_distance::CreateUnifiedDiff(expected_lines, actual_lines); + } + } + return AssertionFailure() << msg; } -- cgit v1.2.3