Replace Catch2's runner with the Catch3 runner

Catch3 keeps Catch2's API for writing tests (test cases, sections,
assertions, matchers, generators, listeners, benchmarks) and replaces its
session, command line and reporters with a runner of its own.

The runner starts the test binary again as worker processes that take the
next test when they are free. A crash, an exit or a hang ends one test, not
the run. On top of that it adds:

- retries that tell deterministic, flaky and order-dependent failures
  apart, and a bisection that names the test leaving state behind;
- a history of verdicts and durations, kept under a file lock, that drives
  automatic quarantine, adaptive time limits, predictive ordering,
  incremental runs, failure replay and analytics;
- selection by change, past failure or prediction, dependency closure,
  and sharding by a stable hash or by recorded durations;
- tags for serial and isolated tests, shared resources, dependencies,
  time limits and retries;
- a failure category, a signature, an analysis and a replay command for
  every failure;
- console, JUnit XML (with flakyFailure and rerunFailure), JSON and Chrome
  trace reports, and a versioned discovery listing (--list=json);
- a temporary directory per test (TMPDIR, TMP, TEMP and
  TestTemporaryDirectory());
- Bazel's test environment: XML output file, test filter, sharding, seed,
  premature exit file and undeclared outputs.

The command line is parsed by a hand-written, typed parser. Catch::Session
remains as a thin facade over the runner for custom main functions.

The result model in Progmasoft/Catch3/Results.hpp was rewritten around
tests and attempts, and the JUnit writer now writes it. The property
engine's example database is updated under a file lock with an atomic
rename, so parallel workers can write it at the same time.

Removed: Clara, the command-line and reporter-spec parsers, every reporter
and CATCH_REGISTER_REPORTER, listing, text flow, console colour and width,
the JSON and XML writers, sharding in the test registry, approval tests and
their baselines, Conan packaging, and the unused third_party/clara.hpp.
Listeners keep working; reporters' list and skip events are gone.

The Catch2 library is now compiled as C++20; code that includes only
Catch2's headers still needs C++14. Duplicate test cases are still refused
at start-up. Version 0.3.0.

ExtraTests now turn exceptions off for clang-cl with MSVC-style options,
which -fno-exceptions did not do.

1 files changed, 311 insertions, 48 deletions

diff --git a/src/Progmasoft/Results.cpp b/src/Progmasoft/Results.cpp
index 69a819a7..41698cd4 100644
--- a/src/Progmasoft/Results.cpp
+++ b/src/Progmasoft/Results.cpp
@@ -2,72 +2,335 @@
 // SPDX-License-Identifier: MPL-2.0 WITH AdditionRef-Progmasoft-Exception-1.1
 #include <Progmasoft/Catch3/Results.hpp>
 
-#include <cmath>
-#include <limits>
-#include <stdexcept>
+#include <array>
+#include <string_view>
+#include <utility>
 
-namespace Progmasoft::Catch3 {
+namespace Progmasoft::Catch3
+{
+    namespace
+    {
+        constexpr std::array<std::pair<Outcome, std::string_view>, 9>
+            kOutcomeNames = {{
+                {Outcome::kPassed, "passed"},
+                {Outcome::kFailed, "failed"},
+                {Outcome::kFailedAsExpected, "failed-as-expected"},
+                {Outcome::kSkipped, "skipped"},
+                {Outcome::kCrashed, "crashed"},
+                {Outcome::kTimedOut, "timed-out"},
+                {Outcome::kBlocked, "blocked"},
+                {Outcome::kNotRun, "not-run"},
+                {Outcome::kUpToDate, "up-to-date"},
+            }};
 
-    namespace {
+        constexpr std::array<std::pair<FailureCategory, std::string_view>, 9>
+            kCategoryNames = {{
+                {FailureCategory::kNone, "none"},
+                {FailureCategory::kAssertion, "assertion"},
+                {FailureCategory::kUnexpectedException, "unexpected-exception"},
+                {FailureCategory::kMissingException, "missing-exception"},
+                {FailureCategory::kExplicitFailure, "explicit-failure"},
+                {FailureCategory::kCrash, "crash"},
+                {FailureCategory::kTimeout, "timeout"},
+                {FailureCategory::kInfrastructure, "infrastructure"},
+                {FailureCategory::kDependency, "dependency"},
+            }};
+    } // namespace
 
-        void AccumulateCases( TestRunSummary& summary,
-                              const std::vector<TestCaseResult>& testCases ) {
-            for ( const TestCaseResult& testCase : testCases ) {
-                if ( !std::isfinite( testCase.DurationSeconds ) ||
-                     testCase.DurationSeconds < 0.0 ) {
-                    throw std::invalid_argument(
-                        "test duration must be finite and non-negative" );
-                }
-                if ( summary.Tests ==
-                     std::numeric_limits<std::size_t>::max() ) {
-                    throw std::overflow_error( "test count overflow" );
-                }
+    std::int64_t
+    TestResult::DurationMicroseconds() const noexcept
+    {
+        std::int64_t total = 0;
+        for (const auto &attempt : attempts)
+        {
+            total += attempt.durationMicroseconds;
+        }
+        return total;
+    }
 
-                ++summary.Tests;
-                summary.DurationSeconds += testCase.DurationSeconds;
-                if ( !std::isfinite( summary.DurationSeconds ) ) {
-                    throw std::overflow_error( "test duration total overflow" );
-                }
+    bool
+    TestResult::FailsRun() const noexcept
+    {
+        if (quarantined)
+        {
+            return false;
+        }
+        switch (outcome)
+        {
+            case Outcome::kFailed:
+            case Outcome::kCrashed:
+            case Outcome::kTimedOut:
+            case Outcome::kBlocked:
+                return true;
+            default:
+                return false;
+        }
+    }
 
-                switch ( testCase.Status ) {
-                case TestCaseStatus::kPassed:
+    RunSummary
+    Summarize(const RunResult &run)
+    {
+        RunSummary summary;
+        summary.tests = run.tests.size();
+        summary.wallMicroseconds = run.wallMicroseconds;
+        for (const auto &test : run.tests)
+        {
+            switch (test.outcome)
+            {
+                case Outcome::kPassed:
+                    ++summary.passed;
                     break;
-                case TestCaseStatus::kFailed:
-                    ++summary.Failures;
+                case Outcome::kFailed:
+                    ++summary.failed;
                     break;
-                case TestCaseStatus::kErrored:
-                    ++summary.Errors;
+                case Outcome::kFailedAsExpected:
+                    ++summary.failedAsExpected;
                     break;
-                case TestCaseStatus::kSkipped:
-                    ++summary.Skipped;
+                case Outcome::kSkipped:
+                    ++summary.skipped;
                     break;
-                default:
-                    throw std::invalid_argument( "unknown test case status" );
-                }
+                case Outcome::kCrashed:
+                    ++summary.crashed;
+                    break;
+                case Outcome::kTimedOut:
+                    ++summary.timedOut;
+                    break;
+                case Outcome::kBlocked:
+                    ++summary.blocked;
+                    break;
+                case Outcome::kNotRun:
+                    ++summary.notRun;
+                    break;
+                case Outcome::kUpToDate:
+                    ++summary.upToDate;
+                    break;
+            }
+            summary.flaky += test.flaky ? 1 : 0;
+            summary.quarantined += test.quarantined ? 1 : 0;
+            summary.attempts += test.attempts.size();
+            for (const auto &attempt : test.attempts)
+            {
+                summary.assertionsPassed += attempt.assertionsPassed;
+                summary.assertionsFailed += attempt.assertionsFailed;
+                summary.testMicroseconds += attempt.durationMicroseconds;
             }
         }
+        return summary;
+    }
 
-    } // namespace
+    const char *
+    OutcomeName(Outcome outcome) noexcept
+    {
+        for (const auto &[value, name] : kOutcomeNames)
+        {
+            if (value == outcome)
+            {
+                return name.data();
+            }
+        }
+        return "unknown";
+    }
+
+    std::optional<Outcome>
+    OutcomeFromName(const std::string &name) noexcept
+    {
+        for (const auto &[value, text] : kOutcomeNames)
+        {
+            if (text == name)
+            {
+                return value;
+            }
+        }
+        return std::nullopt;
+    }
 
-    std::size_t TestRunSummary::Passed() const noexcept {
-        if ( Failures > Tests || Errors > Tests - Failures ) { return 0; }
-        const std::size_t failuresAndErrors = Failures + Errors;
-        if ( Skipped > Tests - failuresAndErrors ) { return 0; }
-        return Tests - failuresAndErrors - Skipped;
+    const char *
+    CategoryName(FailureCategory category) noexcept
+    {
+        for (const auto &[value, name] : kCategoryNames)
+        {
+            if (value == category)
+            {
+                return name.data();
+            }
+        }
+        return "unknown";
     }
 
-    TestRunSummary SummarizeTestSuite( const TestSuiteResult& result ) {
-        TestRunSummary summary;
-        AccumulateCases( summary, result.TestCases );
-        return summary;
+    std::optional<FailureCategory>
+    CategoryFromName(const std::string &name) noexcept
+    {
+        for (const auto &[value, text] : kCategoryNames)
+        {
+            if (text == name)
+            {
+                return value;
+            }
+        }
+        return std::nullopt;
     }
 
-    TestRunSummary SummarizeTestRun( const TestRunResult& result ) {
-        TestRunSummary summary;
-        for ( const TestSuiteResult& suite : result.TestSuites ) {
-            AccumulateCases( summary, suite.TestCases );
+    const char *
+    HistoryName(FailureHistory history) noexcept
+    {
+        switch (history)
+        {
+            case FailureHistory::kUnknown:
+                return "unknown";
+            case FailureHistory::kNew:
+                return "new";
+            case FailureHistory::kPersistent:
+                return "persistent";
+            case FailureHistory::kIntermittent:
+                return "intermittent";
         }
-        return summary;
+        return "unknown";
     }
 
+    namespace
+    {
+        void
+        AppendIndented(std::string &text, const std::string &block)
+        {
+            std::size_t start = 0;
+            while (start <= block.size())
+            {
+                const auto end = block.find('\n', start);
+                text += "  ";
+                text += block.substr(start,
+                                     end == std::string::npos ? std::string::npos
+                                                              : end - start);
+                text += '\n';
+                if (end == std::string::npos)
+                {
+                    break;
+                }
+                start = end + 1;
+            }
+        }
+
+        std::string
+        JoinSections(const std::vector<std::string> &sections)
+        {
+            std::string text;
+            for (const auto &section : sections)
+            {
+                text += text.empty() ? "" : " / ";
+                text += section;
+            }
+            return text;
+        }
+
+        std::string
+        Seconds(std::int64_t microseconds)
+        {
+            const auto tenths = (microseconds + 50000) / 100000;
+            return std::to_string(tenths / 10) + "." +
+                   std::to_string(tenths % 10) + " s";
+        }
+    } // namespace
+
+    std::string
+    DescribeFailure(const Attempt &attempt)
+    {
+        std::string text;
+        if (attempt.outcome == Outcome::kTimedOut)
+        {
+            text += "timed out after " + Seconds(attempt.durationMicroseconds);
+            text += "\n";
+        }
+        else if (attempt.outcome == Outcome::kCrashed)
+        {
+            text += "crashed";
+            if (!attempt.exitDescription.empty())
+            {
+                text += " with " + attempt.exitDescription;
+            }
+            text += "\n";
+            if (!attempt.fatalMessage.empty())
+            {
+                AppendIndented(text, attempt.fatalMessage);
+            }
+        }
+        if ((attempt.outcome == Outcome::kTimedOut ||
+             attempt.outcome == Outcome::kCrashed) &&
+            !attempt.lastLocation.empty())
+        {
+            text += "last assertion started at " + attempt.lastLocation + "\n";
+        }
+        if ((attempt.outcome == Outcome::kTimedOut ||
+             attempt.outcome == Outcome::kCrashed))
+        {
+            // The innermost section that had not ended is where it stopped.
+            std::vector<std::string> open;
+            for (const auto &section : attempt.sections)
+            {
+                if (section.durationMicroseconds < 0)
+                {
+                    open.resize(section.depth);
+                    open.push_back(section.name);
+                }
+            }
+            if (!open.empty())
+            {
+                text += "in section " + JoinSections(open) + "\n";
+            }
+        }
+        for (const auto &assertion : attempt.assertions)
+        {
+            if (assertion.passed)
+            {
+                continue;
+            }
+            text += assertion.file + ":" + std::to_string(assertion.line) +
+                    ": " + (assertion.allowed ? "FAILED (allowed)" : "FAILED") +
+                    ":\n";
+            if (!assertion.expression.empty())
+            {
+                AppendIndented(text,
+                               assertion.macro.empty()
+                                   ? assertion.expression
+                                   : assertion.macro + "( " +
+                                         assertion.expression + " )");
+            }
+            if (!assertion.expansion.empty() &&
+                assertion.expansion != assertion.expression)
+            {
+                text += "with expansion:\n";
+                AppendIndented(text, assertion.expansion);
+            }
+            if (!assertion.message.empty())
+            {
+                text += assertion.category ==
+                                FailureCategory::kUnexpectedException
+                            ? "due to unexpected exception with message:\n"
+                            : "with message:\n";
+                AppendIndented(text, assertion.message);
+            }
+            for (const auto &context : assertion.context)
+            {
+                text += "with context:\n";
+                AppendIndented(text, context);
+            }
+            if (!assertion.sections.empty())
+            {
+                text += "in section " + JoinSections(assertion.sections) + "\n";
+            }
+        }
+        return text;
+    }
+
+    std::string
+    SummarizeFailure(const Attempt &attempt)
+    {
+        const std::string text = DescribeFailure(attempt);
+        return text.substr(0, text.find('\n'));
+    }
+
+    bool
+    IsFailure(Outcome outcome) noexcept
+    {
+        return outcome == Outcome::kFailed || outcome == Outcome::kCrashed ||
+               outcome == Outcome::kTimedOut;
+    }
 } // namespace Progmasoft::Catch3