Provide round-tripping serialization for TestSpec

4 files changed, 112 insertions, 10 deletions

diff --git a/src/catch2/catch_test_spec.cpp b/src/catch2/catch_test_spec.cpp
index a3235d43..0a64de0d 100644
--- a/src/catch2/catch_test_spec.cpp
+++ b/src/catch2/catch_test_spec.cpp
@@ -6,12 +6,14 @@
 
 // SPDX-License-Identifier: BSL-1.0
 #include <catch2/catch_test_spec.hpp>
+#include <catch2/internal/catch_reusable_string_stream.hpp>
 #include <catch2/internal/catch_string_manip.hpp>
 #include <catch2/catch_test_case_info.hpp>
 
 #include <algorithm>
 #include <string>
 #include <vector>
+#include <ostream>
 
 namespace Catch {
 
@@ -35,6 +37,10 @@ namespace Catch {
         return m_wildcardPattern.matches( testCase.name );
     }
 
+    void TestSpec::NamePattern::serializeTo( std::ostream& out ) const {
+        out << '"' << name() << '"';
+    }
+
 
     TestSpec::TagPattern::TagPattern( std::string const& tag, std::string const& filterString )
     : Pattern( filterString )
@@ -47,6 +53,10 @@ namespace Catch {
                           Tag( m_tag ) ) != end( testCase.tags );
     }
 
+    void TestSpec::TagPattern::serializeTo( std::ostream& out ) const {
+        out << name();
+    }
+
     bool TestSpec::Filter::matches( TestCaseInfo const& testCase ) const {
         bool should_use = !testCase.isHidden();
         for (auto const& pattern : m_required) {
@@ -63,18 +73,31 @@ namespace Catch {
         return should_use;
     }
 
-    std::string TestSpec::Filter::name() const {
-        std::string name;
-        for (auto const& p : m_required) {
-            name += p->name();
+    void TestSpec::Filter::serializeTo( std::ostream& out ) const {
+        bool first = true;
+        for ( auto const& pattern : m_required ) {
+            if ( !first ) {
+                out << ' ';
+            }
+            out << *pattern;
+            first = false;
         }
-        for (auto const& p : m_forbidden) {
-            name += p->name();
+        for ( auto const& pattern : m_forbidden ) {
+            if ( !first ) {
+                out << ' ';
+            }
+            out << *pattern;
+            first = false;
         }
-        return name;
     }
 
 
+    std::string TestSpec::extractFilterName( Filter const& filter ) {
+        Catch::ReusableStringStream sstr;
+        sstr << filter;
+        return sstr.str();
+    }
+
     bool TestSpec::hasFilters() const {
         return !m_filters.empty();
     }
@@ -91,7 +114,7 @@ namespace Catch {
             for( auto const& test : testCases )
                 if( isThrowSafe( test, config ) && filter.matches( test.getTestCaseInfo() ) )
                     currentMatches.emplace_back( &test );
-            return FilterMatch{ filter.name(), currentMatches };
+            return FilterMatch{ extractFilterName(filter), currentMatches };
         } );
         return matches;
     }
@@ -100,4 +123,15 @@ namespace Catch {
         return m_invalidSpecs;
     }
 
+    void TestSpec::serializeTo( std::ostream& out ) const {
+        bool first = true;
+        for ( auto const& filter : m_filters ) {
+            if ( !first ) {
+                out << ',';
+            }
+            out << filter;
+            first = false;
+        }
+    }
+
 }
diff --git a/src/catch2/catch_test_spec.hpp b/src/catch2/catch_test_spec.hpp
index 499bfaa5..98881f8b 100644
--- a/src/catch2/catch_test_spec.hpp
+++ b/src/catch2/catch_test_spec.hpp
@@ -16,6 +16,7 @@
 #include <catch2/internal/catch_unique_ptr.hpp>
 #include <catch2/internal/catch_wildcard_pattern.hpp>
 
+#include <iosfwd>
 #include <string>
 #include <vector>
 
@@ -34,6 +35,14 @@ namespace Catch {
             virtual bool matches( TestCaseInfo const& testCase ) const = 0;
             std::string const& name() const;
         private:
+            virtual void serializeTo( std::ostream& out ) const = 0;
+            // Writes string that would be reparsed into the pattern
+            friend std::ostream& operator<<(std::ostream& out,
+                                            Pattern const& pattern) {
+                pattern.serializeTo( out );
+                return out;
+            }
+
             std::string const m_name;
         };
 
@@ -42,6 +51,8 @@ namespace Catch {
             explicit NamePattern( std::string const& name, std::string const& filterString );
             bool matches( TestCaseInfo const& testCase ) const override;
         private:
+            void serializeTo( std::ostream& out ) const override;
+
             WildcardPattern m_wildcardPattern;
         };
 
@@ -50,6 +61,8 @@ namespace Catch {
             explicit TagPattern( std::string const& tag, std::string const& filterString );
             bool matches( TestCaseInfo const& testCase ) const override;
         private:
+            void serializeTo( std::ostream& out ) const override;
+
             std::string m_tag;
         };
 
@@ -57,10 +70,19 @@ namespace Catch {
             std::vector<Detail::unique_ptr<Pattern>> m_required;
             std::vector<Detail::unique_ptr<Pattern>> m_forbidden;
 
+            //! Serializes this filter into a string that would be parsed into
+            //! an equivalent filter
+            void serializeTo( std::ostream& out ) const;
+            friend std::ostream& operator<<(std::ostream& out, Filter const& f) {
+                f.serializeTo( out );
+                return out;
+            }
+
             bool matches( TestCaseInfo const& testCase ) const;
-            std::string name() const;
         };
 
+        static std::string extractFilterName( Filter const& filter );
+
     public:
         struct FilterMatch {
             std::string name;
@@ -77,7 +99,16 @@ namespace Catch {
     private:
         std::vector<Filter> m_filters;
         std::vector<std::string> m_invalidSpecs;
+
         friend class TestSpecParser;
+        //! Serializes this test spec into a string that would be parsed into
+        //! equivalent test spec
+        void serializeTo( std::ostream& out ) const;
+        friend std::ostream& operator<<(std::ostream& out,
+                                        TestSpec const& spec) {
+            spec.serializeTo( out );
+            return out;
+        }
     };
 }
 
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 1fec3914..ff941cef 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -249,7 +249,7 @@ add_test(NAME TestSpecs::CombiningMatchingAndNonMatchingIsOk-1 COMMAND $<TARGET_
 
 add_test(NAME TestSpecs::CombiningMatchingAndNonMatchingIsOk-2 COMMAND $<TARGET_FILE:SelfTest> Tracker, "___nonexistent_test___")
 set_tests_properties(TestSpecs::CombiningMatchingAndNonMatchingIsOk-2 PROPERTIES
-    PASS_REGULAR_EXPRESSION "No test cases matched '___nonexistent_test___'"
+    PASS_REGULAR_EXPRESSION "No test cases matched '\"___nonexistent_test___\"'"
     FAIL_REGULAR_EXPRESSION "No tests ran"
 )
 
diff --git a/tests/SelfTest/IntrospectiveTests/TestSpec.tests.cpp b/tests/SelfTest/IntrospectiveTests/TestSpec.tests.cpp
index 99ad6073..f692ae61 100644
--- a/tests/SelfTest/IntrospectiveTests/TestSpec.tests.cpp
+++ b/tests/SelfTest/IntrospectiveTests/TestSpec.tests.cpp
@@ -325,3 +325,40 @@ TEST_CASE("#1912 -- test spec parser handles escaping", "[command-line][test-spe
         REQUIRE(spec.matches(*fakeTestCase(R"(spec \ char)")));
     }
 }
+
+TEST_CASE("Test spec serialization is round-trippable", "[test-spec][serialization][approvals]") {
+    using Catch::parseTestSpec;
+    using Catch::TestSpec;
+
+    auto serializedTestSpec = []( std::string const& spec ) {
+        Catch::ReusableStringStream sstr;
+        sstr << parseTestSpec( spec );
+        return sstr.str();
+    };
+
+    SECTION("Spaces are normalized") {
+        CHECK( serializedTestSpec( "[abc][def]" ) == "[abc] [def]" );
+        CHECK( serializedTestSpec( "[def]    [abc]" ) == "[def] [abc]" );
+        CHECK( serializedTestSpec( "[def] [abc]" ) == "[def] [abc]" );
+    }
+    SECTION("Output is order dependent") {
+        CHECK( serializedTestSpec( "[abc][def]" ) == "[abc] [def]" );
+        CHECK( serializedTestSpec( "[def][abc]" ) == "[def] [abc]" );
+    }
+    SECTION("Multiple disjunct filters") {
+        CHECK( serializedTestSpec( "[abc],[def]" ) == "[abc],[def]" );
+        CHECK( serializedTestSpec( "[def],[abc],[idkfa]" ) == "[def],[abc],[idkfa]" );
+    }
+    SECTION("Test names are enclosed in string") {
+        CHECK( serializedTestSpec( "Some test" ) == "\"Some test\"" );
+        CHECK( serializedTestSpec( "*Some test" ) == "\"*Some test\"" );
+        CHECK( serializedTestSpec( "* Some test" ) == "\"* Some test\"" );
+        CHECK( serializedTestSpec( "* Some test *" ) == "\"* Some test *\"" );
+    }
+    SECTION( "Mixing test names and tags" ) {
+        CHECK( serializedTestSpec( "some test[abcd]" ) ==
+               "\"some test\" [abcd]" );
+        CHECK( serializedTestSpec( "[ab]some test[cd]" ) ==
+               "[ab] \"some test\" [cd]" );
+    }
+}