Print the active section/generator selection

When a section/generator selection (`-c`, `-g`, or `-p`) is in effect,
the console and compact reporters now print the active path filters next
to the existing `Filters:` line, as a labelled list, e.g.

    Filters: "foo"
    Path filters:
      - Section: "A"
      - Generator: "0"

The filters are listed one per line, in the order they were specified.
This makes it obvious what has actually been selected, which is especially
helpful when a filter combination ends up running no assertions.

Related to #3099

Author: ShivaPriyanShanmuga

docs/filtering-execution-path.md

@@ -19,6 +19,22 @@ behaviour, which does not affect generators at all. If you also use either
 `-g`/`--generator-index`, or `-p`/`--path-filter`, you will get the new
 behaviour, which can also filter generator elements.
 
+When path filters are in effect, the console and compact reporters print
+the active selection at the start of the run, next to the `Filters:` line,
+e.g.
+
+```text
+Filters: "foo"
+Path filters:
+  - Section: "A"
+  - Generator: "0"
+```
+
+The filters are listed one per line, labelled as `Section` or `Generator`,
+in the order in which they were specified. This makes it easy to see exactly
+what has been selected when a filter combination ends up running no
+assertions.
+
 Both the new and old filter behaviours include some potentially surprising
 things:
   * Code outside of sections being skipped will still be executed. E.g.

src/catch2/reporters/catch_reporter_compact.cpp

@@ -215,6 +215,12 @@ class AssertionPrinter {
                          << m_config->testSpec()
                          << '\n';
             }
+            if ( !m_config->getPathFilters().empty() ) {
+                m_stream << m_colour->guardColour( Colour::BrightYellow )
+                         << "Path filters:\n"
+                         << serializePathFilters( m_config->getPathFilters() )
+                         << '\n';
+            }
             m_stream << "RNG seed: " << getSeed() << '\n'
                      << std::flush;
         }

src/catch2/reporters/catch_reporter_console.cpp

@@ -530,6 +530,11 @@ void ConsoleReporter::testRunStarting(TestRunInfo const& _testRunInfo) {
         m_stream << m_colour->guardColour( Colour::BrightYellow ) << "Filters: "
                  << m_config->testSpec() << '\n';
     }
+    if ( !m_config->getPathFilters().empty() ) {
+        m_stream << m_colour->guardColour( Colour::BrightYellow )
+                 << "Path filters:\n"
+                 << serializePathFilters( m_config->getPathFilters() ) << '\n';
+    }
     m_stream << "Randomness seeded to: " << getSeed() << '\n'
              << std::flush;
 }

src/catch2/reporters/catch_reporter_helpers.cpp

@@ -9,6 +9,7 @@
 #include <catch2/reporters/catch_reporter_helpers.hpp>
 #include <catch2/interfaces/catch_interfaces_config.hpp>
 #include <catch2/internal/catch_console_width.hpp>
+#include <catch2/internal/catch_path_filter.hpp>
 #include <catch2/internal/catch_errno_guard.hpp>
 #include <catch2/internal/catch_textflow.hpp>
 #include <catch2/internal/catch_reusable_string_stream.hpp>
@@ -101,6 +102,28 @@ namespace Catch {
         return serialized;
     }
 
+    std::string serializePathFilters( std::vector<PathFilter> const& filters ) {
+        ReusableStringStream rss;
+        bool first = true;
+        for ( auto const& filter : filters ) {
+            if ( !first ) {
+                rss << '\n';
+            }
+            first = false;
+            rss << "  - ";
+            switch ( filter.type ) {
+            case PathFilter::For::Section:
+                rss << "Section: ";
+                break;
+            case PathFilter::For::Generator:
+                rss << "Generator: ";
+                break;
+            }
+            rss << '"' << filter.filter << '"';
+        }
+        return rss.str();
+    }
+
     std::ostream& operator<<( std::ostream& out, lineOfChars value ) {
         for ( size_t idx = 0; idx < CATCH_CONFIG_CONSOLE_WIDTH - 1; ++idx ) {
             out.put( value.c );

src/catch2/reporters/catch_reporter_helpers.hpp

@@ -21,6 +21,7 @@ namespace Catch {
     class IConfig;
     class TestCaseHandle;
     class ColourImpl;
+    struct PathFilter;
 
     // Returns double formatted as %.3f (format expected on output)
     std::string getFormattedDuration( double duration );
@@ -30,6 +31,18 @@ namespace Catch {
 
     std::string serializeFilters( std::vector<std::string> const& filters );
 
+    /**
+     * Serializes the active section/generator path filters into a
+     * human-readable, indented list, one filter per line and in the order
+     * in which they were specified, e.g.
+     *
+     *     - Section: "A"
+     *     - Generator: "0"
+     *
+     * The returned string has no trailing newline.
+     */
+    std::string serializePathFilters( std::vector<PathFilter> const& filters );
+
     struct lineOfChars {
         char c;
         constexpr lineOfChars( char c_ ): c( c_ ) {}

tests/CMakeLists.txt

@@ -666,6 +666,33 @@ foreach(reporterName # "Automake" - the simple .trs format does not support any
   )
 endforeach()
 
+# The console and compact reporters print the active section/generator
+# selection (path filters), so that it is obvious what has been selected.
+# The exact serialization is unit-tested in `serializePathFilters ...`, so
+# here we only check that both reporters actually emit the line, using a
+# section filter for one and a generator filter for the other.
+add_test(NAME "Reporters:PathFilters:Section:compact"
+  COMMAND
+    $<TARGET_FILE:SelfTest> "Tracker"
+      --reporter compact
+      --section "section name"
+)
+set_tests_properties("Reporters:PathFilters:Section:compact"
+  PROPERTIES
+    PASS_REGULAR_EXPRESSION "- Section: \"section name\""
+)
+
+add_test(NAME "Reporters:PathFilters:Generator:console"
+  COMMAND
+    $<TARGET_FILE:SelfTest> "Generators internals"
+      --reporter console
+      --generator-index 0
+)
+set_tests_properties("Reporters:PathFilters:Generator:console"
+  PROPERTIES
+    PASS_REGULAR_EXPRESSION "- Generator: \"0\""
+)
+
 add_test(NAME "Bazel::RngSeedEnvVar::JustEnv"
   COMMAND
     $<TARGET_FILE:SelfTest> "Factorials are computed"

tests/SelfTest/Baselines/automake.sw.approved.txt

@@ -409,6 +409,7 @@ b1!
 :test-result: SKIP sections can be skipped dynamically at runtime
 :test-result: FAIL send a single char to INFO
 :test-result: FAIL sends information to INFO
+:test-result: PASS serializePathFilters serializes the section/generator selection
 :test-result: PASS shortened hide tags are split apart
 :test-result: SKIP skipped tests can optionally provide a reason
 :test-result: PASS splitString

tests/SelfTest/Baselines/automake.sw.multi.approved.txt

@@ -398,6 +398,7 @@
 :test-result: SKIP sections can be skipped dynamically at runtime
 :test-result: FAIL send a single char to INFO
 :test-result: FAIL sends information to INFO
+:test-result: PASS serializePathFilters serializes the section/generator selection
 :test-result: PASS shortened hide tags are split apart
 :test-result: SKIP skipped tests can optionally provide a reason
 :test-result: PASS splitString

tests/SelfTest/Baselines/compact.sw.approved.txt

@@ -2831,6 +2831,20 @@ Skip.tests.cpp:<line number>: skipped:
 Skip.tests.cpp:<line number>: passed:
 Misc.tests.cpp:<line number>: failed: false with 1 message: '3'
 Message.tests.cpp:<line number>: failed: false with 2 messages: 'hi' and 'i := 7'
+Reporters.tests.cpp:<line number>: passed: serializePathFilters( {} ).empty() for: true
+Reporters.tests.cpp:<line number>: passed: serializePathFilters( filters ) == "  - Section: \"a section\"" for: "  - Section: "a section""
+==
+"  - Section: "a section""
+Reporters.tests.cpp:<line number>: passed: serializePathFilters( filters ) == "  - Generator: \"0\"" for: "  - Generator: "0""
+==
+"  - Generator: "0""
+Reporters.tests.cpp:<line number>: passed: serializePathFilters( filters ) == "  - Section: \"A\"\n" "  - Generator: \"1\"\n" "  - Section: \"B\"" for: "  - Section: "A"
+  - Generator: "1"
+  - Section: "B""
+==
+"  - Section: "A"
+  - Generator: "1"
+  - Section: "B""
 Tag.tests.cpp:<line number>: passed: testcase.tags, VectorContains( Tag( "magic-tag" ) ) && VectorContains( Tag( "."_catch_sr ) ) for: { {?}, {?} } ( Contains: {?} and Contains: {?} )
 Skip.tests.cpp:<line number>: skipped: 'skipping because answer = 43'
 StringManip.tests.cpp:<line number>: passed: splitStringRef("", ','), Equals(std::vector<StringRef>()) for: {  } Equals: {  }
@@ -3000,7 +3014,7 @@ InternalBenchmark.tests.cpp:<line number>: passed: med == 18. for: 18.0 == 18.0
 InternalBenchmark.tests.cpp:<line number>: passed: q3 == 23. for: 23.0 == 23.0
 Misc.tests.cpp:<line number>: passed:
 Misc.tests.cpp:<line number>: passed:
-test cases:  451 |  331 passed |  96 failed | 6 skipped | 18 failed as expected
-assertions: 2416 | 2215 passed | 158 failed | 43 failed as expected
+test cases:  452 |  332 passed |  96 failed | 6 skipped | 18 failed as expected
+assertions: 2420 | 2219 passed | 158 failed | 43 failed as expected
 
 

tests/SelfTest/Baselines/compact.sw.multi.approved.txt

@@ -2820,6 +2820,20 @@ Skip.tests.cpp:<line number>: skipped:
 Skip.tests.cpp:<line number>: passed:
 Misc.tests.cpp:<line number>: failed: false with 1 message: '3'
 Message.tests.cpp:<line number>: failed: false with 2 messages: 'hi' and 'i := 7'
+Reporters.tests.cpp:<line number>: passed: serializePathFilters( {} ).empty() for: true
+Reporters.tests.cpp:<line number>: passed: serializePathFilters( filters ) == "  - Section: \"a section\"" for: "  - Section: "a section""
+==
+"  - Section: "a section""
+Reporters.tests.cpp:<line number>: passed: serializePathFilters( filters ) == "  - Generator: \"0\"" for: "  - Generator: "0""
+==
+"  - Generator: "0""
+Reporters.tests.cpp:<line number>: passed: serializePathFilters( filters ) == "  - Section: \"A\"\n" "  - Generator: \"1\"\n" "  - Section: \"B\"" for: "  - Section: "A"
+  - Generator: "1"
+  - Section: "B""
+==
+"  - Section: "A"
+  - Generator: "1"
+  - Section: "B""
 Tag.tests.cpp:<line number>: passed: testcase.tags, VectorContains( Tag( "magic-tag" ) ) && VectorContains( Tag( "."_catch_sr ) ) for: { {?}, {?} } ( Contains: {?} and Contains: {?} )
 Skip.tests.cpp:<line number>: skipped: 'skipping because answer = 43'
 StringManip.tests.cpp:<line number>: passed: splitStringRef("", ','), Equals(std::vector<StringRef>()) for: {  } Equals: {  }
@@ -2989,7 +3003,7 @@ InternalBenchmark.tests.cpp:<line number>: passed: med == 18. for: 18.0 == 18.0
 InternalBenchmark.tests.cpp:<line number>: passed: q3 == 23. for: 23.0 == 23.0
 Misc.tests.cpp:<line number>: passed:
 Misc.tests.cpp:<line number>: passed:
-test cases:  451 |  331 passed |  96 failed | 6 skipped | 18 failed as expected
-assertions: 2416 | 2215 passed | 158 failed | 43 failed as expected
+test cases:  452 |  332 passed |  96 failed | 6 skipped | 18 failed as expected
+assertions: 2420 | 2219 passed | 158 failed | 43 failed as expected