Add %stderr and %stdout as recognized magic stream names

src/catch2/internal/catch_stream.cpp

@@ -102,6 +102,20 @@ namespace Detail {
             bool isStdout() const override { return true; }
         };
 
+        class CerrStream : public IStream {
+            mutable std::ostream m_os;
+
+        public:
+            // Store the streambuf from cerr up-front because
+            // cout may get redirected when running tests
+            CerrStream(): m_os( Catch::cerr().rdbuf() ) {}
+            ~CerrStream() override = default;
+
+        public: // IStream
+            std::ostream& stream() const override { return m_os; }
+            bool isStdout() const override { return true; }
+        };
+
         ///////////////////////////////////////////////////////////////////////////
 
         class DebugOutStream : public IStream {
@@ -128,13 +142,17 @@ namespace Detail {
         if ( filename.empty() || filename == "-" ) {
             return Detail::make_unique<Detail::CoutStream>();
         }
-        else if( filename[0] == '%' ) {
-            if( filename == "%debug" )
+        if( filename[0] == '%' ) {
+            if ( filename == "%debug" ) {
                 return Detail::make_unique<Detail::DebugOutStream>();
-            else
+            } else if ( filename == "%stderr" ) {
+                return Detail::make_unique<Detail::CerrStream>();
+            } else if ( filename == "%stdout" ) {
+                return Detail::make_unique<Detail::CoutStream>();
+            } else {
                 CATCH_ERROR( "Unrecognised stream: '" << filename << '\'' );
             }
-        else
+        }
         return Detail::make_unique<Detail::FileStream>( filename );
     }
 

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

@@ -337,6 +337,7 @@ loose text artifact
 :test-result: FAIL prints unscoped info only for the first assertion
 :test-result: PASS random SECTION tests
 :test-result: PASS replaceInPlace
+:test-result: PASS request an unknown %-starting stream fails
 :test-result: PASS resolution
 :test-result: PASS run_for_at_least, chronometer
 :test-result: PASS run_for_at_least, int
@@ -352,6 +353,7 @@ loose text artifact
 :test-result: PASS std::pair<int,std::string> -> toString
 :test-result: PASS std::set is convertible string
 :test-result: PASS std::vector<std::pair<std::string,int> > -> toString
+:test-result: PASS stdout and stderr streams have %-starting name
 :test-result: PASS stringify ranges
 :test-result: PASS stringify( has_maker )
 :test-result: PASS stringify( has_maker_and_operator )

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

@@ -329,6 +329,7 @@
 :test-result: FAIL prints unscoped info only for the first assertion
 :test-result: PASS random SECTION tests
 :test-result: PASS replaceInPlace
+:test-result: PASS request an unknown %-starting stream fails
 :test-result: PASS resolution
 :test-result: PASS run_for_at_least, chronometer
 :test-result: PASS run_for_at_least, int
@@ -344,6 +345,7 @@
 :test-result: PASS std::pair<int,std::string> -> toString
 :test-result: PASS std::set is convertible string
 :test-result: PASS std::vector<std::pair<std::string,int> > -> toString
+:test-result: PASS stdout and stderr streams have %-starting name
 :test-result: PASS stringify ranges
 :test-result: PASS stringify( has_maker )
 :test-result: PASS stringify( has_maker_and_operator )

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

@@ -2309,6 +2309,7 @@ StringManip.tests.cpp:<line number>: passed: !(Catch::replaceInPlace(letters, "x
 StringManip.tests.cpp:<line number>: passed: letters == letters for: "abcdefcg" == "abcdefcg"
 StringManip.tests.cpp:<line number>: passed: Catch::replaceInPlace(s, "'", "|'") for: true
 StringManip.tests.cpp:<line number>: passed: s == "didn|'t" for: "didn|'t" == "didn|'t"
+Stream.tests.cpp:<line number>: passed: Catch::makeStream( "%somestream" )
 InternalBenchmark.tests.cpp:<line number>: passed: res.size() == count for: 10 == 10
 InternalBenchmark.tests.cpp:<line number>: passed: res[i] == rate for: 1000.0 == 1000 (0x<hex digits>)
 InternalBenchmark.tests.cpp:<line number>: passed: res[i] == rate for: 1000.0 == 1000 (0x<hex digits>)
@@ -2367,6 +2368,8 @@ ToStringGeneral.tests.cpp:<line number>: passed: Catch::Detail::stringify( set )
 ToStringPair.tests.cpp:<line number>: passed: ::Catch::Detail::stringify( pr ) == "{ { \"green\", 55 } }" for: "{ { "green", 55 } }"
 ==
 "{ { "green", 55 } }"
+Stream.tests.cpp:<line number>: passed: Catch::makeStream( "%stderr" )->isStdout() for: true
+Stream.tests.cpp:<line number>: passed: Catch::makeStream( "%stdout" )->isStdout() for: true
 ToStringWhich.tests.cpp:<line number>: passed: ::Catch::Detail::stringify(streamable_range{}) == "op<<(streamable_range)" for: "op<<(streamable_range)"
 ==
 "op<<(streamable_range)"

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

@@ -2301,6 +2301,7 @@ StringManip.tests.cpp:<line number>: passed: !(Catch::replaceInPlace(letters, "x
 StringManip.tests.cpp:<line number>: passed: letters == letters for: "abcdefcg" == "abcdefcg"
 StringManip.tests.cpp:<line number>: passed: Catch::replaceInPlace(s, "'", "|'") for: true
 StringManip.tests.cpp:<line number>: passed: s == "didn|'t" for: "didn|'t" == "didn|'t"
+Stream.tests.cpp:<line number>: passed: Catch::makeStream( "%somestream" )
 InternalBenchmark.tests.cpp:<line number>: passed: res.size() == count for: 10 == 10
 InternalBenchmark.tests.cpp:<line number>: passed: res[i] == rate for: 1000.0 == 1000 (0x<hex digits>)
 InternalBenchmark.tests.cpp:<line number>: passed: res[i] == rate for: 1000.0 == 1000 (0x<hex digits>)
@@ -2359,6 +2360,8 @@ ToStringGeneral.tests.cpp:<line number>: passed: Catch::Detail::stringify( set )
 ToStringPair.tests.cpp:<line number>: passed: ::Catch::Detail::stringify( pr ) == "{ { \"green\", 55 } }" for: "{ { "green", 55 } }"
 ==
 "{ { "green", 55 } }"
+Stream.tests.cpp:<line number>: passed: Catch::makeStream( "%stderr" )->isStdout() for: true
+Stream.tests.cpp:<line number>: passed: Catch::makeStream( "%stdout" )->isStdout() for: true
 ToStringWhich.tests.cpp:<line number>: passed: ::Catch::Detail::stringify(streamable_range{}) == "op<<(streamable_range)" for: "op<<(streamable_range)"
 ==
 "op<<(streamable_range)"

tests/SelfTest/Baselines/console.std.approved.txt

@@ -1395,6 +1395,6 @@ due to unexpected exception with message:
   Why would you throw a std::string?
 
 ===============================================================================
-test cases:  383 |  307 passed |  69 failed |  7 failed as expected
-assertions: 2213 | 2058 passed | 128 failed | 27 failed as expected
+test cases:  385 |  309 passed |  69 failed |  7 failed as expected
+assertions: 2216 | 2061 passed | 128 failed | 27 failed as expected
 

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

@@ -16447,6 +16447,15 @@ StringManip.tests.cpp:<line number>: PASSED:
 with expansion:
   "didn|'t" == "didn|'t"
 
+-------------------------------------------------------------------------------
+request an unknown %-starting stream fails
+-------------------------------------------------------------------------------
+Stream.tests.cpp:<line number>
+...............................................................................
+
+Stream.tests.cpp:<line number>: PASSED:
+  REQUIRE_THROWS( Catch::makeStream( "%somestream" ) )
+
 -------------------------------------------------------------------------------
 resolution
 -------------------------------------------------------------------------------
@@ -16843,6 +16852,22 @@ with expansion:
   ==
   "{ { "green", 55 } }"
 
+-------------------------------------------------------------------------------
+stdout and stderr streams have %-starting name
+-------------------------------------------------------------------------------
+Stream.tests.cpp:<line number>
+...............................................................................
+
+Stream.tests.cpp:<line number>: PASSED:
+  REQUIRE( Catch::makeStream( "%stderr" )->isStdout() )
+with expansion:
+  true
+
+Stream.tests.cpp:<line number>: PASSED:
+  REQUIRE( Catch::makeStream( "%stdout" )->isStdout() )
+with expansion:
+  true
+
 -------------------------------------------------------------------------------
 stringify ranges
 -------------------------------------------------------------------------------
@@ -17786,6 +17811,6 @@ Misc.tests.cpp:<line number>
 Misc.tests.cpp:<line number>: PASSED:
 
 ===============================================================================
-test cases:  383 |  293 passed |  83 failed |  7 failed as expected
-assertions: 2228 | 2058 passed | 143 failed | 27 failed as expected
+test cases:  385 |  295 passed |  83 failed |  7 failed as expected
+assertions: 2231 | 2061 passed | 143 failed | 27 failed as expected
 

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

@@ -16439,6 +16439,15 @@ StringManip.tests.cpp:<line number>: PASSED:
 with expansion:
   "didn|'t" == "didn|'t"
 
+-------------------------------------------------------------------------------
+request an unknown %-starting stream fails
+-------------------------------------------------------------------------------
+Stream.tests.cpp:<line number>
+...............................................................................
+
+Stream.tests.cpp:<line number>: PASSED:
+  REQUIRE_THROWS( Catch::makeStream( "%somestream" ) )
+
 -------------------------------------------------------------------------------
 resolution
 -------------------------------------------------------------------------------
@@ -16835,6 +16844,22 @@ with expansion:
   ==
   "{ { "green", 55 } }"
 
+-------------------------------------------------------------------------------
+stdout and stderr streams have %-starting name
+-------------------------------------------------------------------------------
+Stream.tests.cpp:<line number>
+...............................................................................
+
+Stream.tests.cpp:<line number>: PASSED:
+  REQUIRE( Catch::makeStream( "%stderr" )->isStdout() )
+with expansion:
+  true
+
+Stream.tests.cpp:<line number>: PASSED:
+  REQUIRE( Catch::makeStream( "%stdout" )->isStdout() )
+with expansion:
+  true
+
 -------------------------------------------------------------------------------
 stringify ranges
 -------------------------------------------------------------------------------
@@ -17778,6 +17803,6 @@ Misc.tests.cpp:<line number>
 Misc.tests.cpp:<line number>: PASSED:
 
 ===============================================================================
-test cases:  383 |  293 passed |  83 failed |  7 failed as expected
-assertions: 2228 | 2058 passed | 143 failed | 27 failed as expected
+test cases:  385 |  295 passed |  83 failed |  7 failed as expected
+assertions: 2231 | 2061 passed | 143 failed | 27 failed as expected
 

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

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <testsuitesloose text artifact
 >
-  <testsuite name="<exe-name>" errors="17" failures="126" tests="2228" hostname="tbd" time="{duration}" timestamp="{iso8601-timestamp}">
+  <testsuite name="<exe-name>" errors="17" failures="126" tests="2231" hostname="tbd" time="{duration}" timestamp="{iso8601-timestamp}">
     <properties>
       <property name="random-seed" value="1"/>
       <property name="filters" value="~[!nonportable]~[!benchmark]~[approvals] *"/>
@@ -1785,6 +1785,7 @@ Message.tests.cpp:<line number>
     <testcase classname="<exe-name>.global" name="replaceInPlace/replace all chars" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="replaceInPlace/replace no chars" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="replaceInPlace/escape '" time="{duration}" status="run"/>
+    <testcase classname="<exe-name>.global" name="request an unknown %-starting stream fails" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="resolution" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="run_for_at_least, chronometer" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="run_for_at_least, int" time="{duration}" status="run"/>
@@ -1837,6 +1838,7 @@ Message.tests.cpp:<line number>
     <testcase classname="<exe-name>.global" name="std::set is convertible string/single item" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="std::set is convertible string/several items" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="std::vector&lt;std::pair&lt;std::string,int> > -> toString" time="{duration}" status="run"/>
+    <testcase classname="<exe-name>.global" name="stdout and stderr streams have %-starting name" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="stringify ranges" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="stringify( has_maker )" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="stringify( has_maker_and_operator )" time="{duration}" status="run"/>

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

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <testsuites>
-  <testsuite name="<exe-name>" errors="17" failures="126" tests="2228" hostname="tbd" time="{duration}" timestamp="{iso8601-timestamp}">
+  <testsuite name="<exe-name>" errors="17" failures="126" tests="2231" hostname="tbd" time="{duration}" timestamp="{iso8601-timestamp}">
     <properties>
       <property name="random-seed" value="1"/>
       <property name="filters" value="~[!nonportable]~[!benchmark]~[approvals] *"/>
@@ -1784,6 +1784,7 @@ Message.tests.cpp:<line number>
     <testcase classname="<exe-name>.global" name="replaceInPlace/replace all chars" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="replaceInPlace/replace no chars" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="replaceInPlace/escape '" time="{duration}" status="run"/>
+    <testcase classname="<exe-name>.global" name="request an unknown %-starting stream fails" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="resolution" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="run_for_at_least, chronometer" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="run_for_at_least, int" time="{duration}" status="run"/>
@@ -1836,6 +1837,7 @@ Message.tests.cpp:<line number>
     <testcase classname="<exe-name>.global" name="std::set is convertible string/single item" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="std::set is convertible string/several items" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="std::vector&lt;std::pair&lt;std::string,int> > -> toString" time="{duration}" status="run"/>
+    <testcase classname="<exe-name>.global" name="stdout and stderr streams have %-starting name" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="stringify ranges" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="stringify( has_maker )" time="{duration}" status="run"/>
     <testcase classname="<exe-name>.global" name="stringify( has_maker_and_operator )" time="{duration}" status="run"/>

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

@@ -219,6 +219,8 @@
   <file path="tests/<exe-name>/IntrospectiveTests/Stream.tests.cpp">
     <testCase name="Cout stream properly declares it writes to stdout" duration="{duration}"/>
     <testCase name="Empty stream name opens cout stream" duration="{duration}"/>
+    <testCase name="request an unknown %-starting stream fails" duration="{duration}"/>
+    <testCase name="stdout and stderr streams have %-starting name" duration="{duration}"/>
   </file>
   <file path="tests/<exe-name>/IntrospectiveTests/String.tests.cpp">
     <testCase name="StringRef/Empty string" duration="{duration}"/>

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

@@ -218,6 +218,8 @@
   <file path="tests/<exe-name>/IntrospectiveTests/Stream.tests.cpp">
     <testCase name="Cout stream properly declares it writes to stdout" duration="{duration}"/>
     <testCase name="Empty stream name opens cout stream" duration="{duration}"/>
+    <testCase name="request an unknown %-starting stream fails" duration="{duration}"/>
+    <testCase name="stdout and stderr streams have %-starting name" duration="{duration}"/>
   </file>
   <file path="tests/<exe-name>/IntrospectiveTests/String.tests.cpp">
     <testCase name="StringRef/Empty string" duration="{duration}"/>

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

@@ -4138,6 +4138,8 @@ ok {test-number} - letters == letters for: "abcdefcg" == "abcdefcg"
 ok {test-number} - Catch::replaceInPlace(s, "'", "|'") for: true
 # replaceInPlace
 ok {test-number} - s == "didn|'t" for: "didn|'t" == "didn|'t"
+# request an unknown %-starting stream fails
+ok {test-number} - Catch::makeStream( "%somestream" )
 # resolution
 ok {test-number} - res.size() == count for: 10 == 10
 # resolution
@@ -4242,6 +4244,10 @@ ok {test-number} - Catch::Detail::stringify( set ) == "{ \"one\" }" for: "{ "one
 ok {test-number} - Catch::Detail::stringify( set ) == "{ \"abc\", \"def\", \"ghi\" }" for: "{ "abc", "def", "ghi" }" == "{ "abc", "def", "ghi" }"
 # std::vector<std::pair<std::string,int> > -> toString
 ok {test-number} - ::Catch::Detail::stringify( pr ) == "{ { \"green\", 55 } }" for: "{ { "green", 55 } }" == "{ { "green", 55 } }"
+# stdout and stderr streams have %-starting name
+ok {test-number} - Catch::makeStream( "%stderr" )->isStdout() for: true
+# stdout and stderr streams have %-starting name
+ok {test-number} - Catch::makeStream( "%stdout" )->isStdout() for: true
 # stringify ranges
 ok {test-number} - ::Catch::Detail::stringify(streamable_range{}) == "op<<(streamable_range)" for: "op<<(streamable_range)" == "op<<(streamable_range)"
 # stringify ranges
@@ -4458,5 +4464,5 @@ ok {test-number} - q3 == 23. for: 23.0 == 23.0
 ok {test-number} -
 # xmlentitycheck
 ok {test-number} -
-1..2228
+1..2231
 

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

@@ -4130,6 +4130,8 @@ ok {test-number} - letters == letters for: "abcdefcg" == "abcdefcg"
 ok {test-number} - Catch::replaceInPlace(s, "'", "|'") for: true
 # replaceInPlace
 ok {test-number} - s == "didn|'t" for: "didn|'t" == "didn|'t"
+# request an unknown %-starting stream fails
+ok {test-number} - Catch::makeStream( "%somestream" )
 # resolution
 ok {test-number} - res.size() == count for: 10 == 10
 # resolution
@@ -4234,6 +4236,10 @@ ok {test-number} - Catch::Detail::stringify( set ) == "{ \"one\" }" for: "{ "one
 ok {test-number} - Catch::Detail::stringify( set ) == "{ \"abc\", \"def\", \"ghi\" }" for: "{ "abc", "def", "ghi" }" == "{ "abc", "def", "ghi" }"
 # std::vector<std::pair<std::string,int> > -> toString
 ok {test-number} - ::Catch::Detail::stringify( pr ) == "{ { \"green\", 55 } }" for: "{ { "green", 55 } }" == "{ { "green", 55 } }"
+# stdout and stderr streams have %-starting name
+ok {test-number} - Catch::makeStream( "%stderr" )->isStdout() for: true
+# stdout and stderr streams have %-starting name
+ok {test-number} - Catch::makeStream( "%stdout" )->isStdout() for: true
 # stringify ranges
 ok {test-number} - ::Catch::Detail::stringify(streamable_range{}) == "op<<(streamable_range)" for: "op<<(streamable_range)" == "op<<(streamable_range)"
 # stringify ranges
@@ -4450,5 +4456,5 @@ ok {test-number} - q3 == 23. for: 23.0 == 23.0
 ok {test-number} -
 # xmlentitycheck
 ok {test-number} -
-1..2228
+1..2231
 

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

@@ -817,6 +817,8 @@ Message.tests.cpp:<line number>|nexpression failed with message:|n  "this SHOULD
 ##teamcity[testFinished name='random SECTION tests' duration="{duration}"]
 ##teamcity[testStarted name='replaceInPlace']
 ##teamcity[testFinished name='replaceInPlace' duration="{duration}"]
+##teamcity[testStarted name='request an unknown %-starting stream fails']
+##teamcity[testFinished name='request an unknown %-starting stream fails' duration="{duration}"]
 ##teamcity[testStarted name='resolution']
 ##teamcity[testFinished name='resolution' duration="{duration}"]
 ##teamcity[testStarted name='run_for_at_least, chronometer']
@@ -851,6 +853,8 @@ Message.tests.cpp:<line number>|nexpression failed with messages:|n  "Count 4 to
 ##teamcity[testFinished name='std::set is convertible string' duration="{duration}"]
 ##teamcity[testStarted name='std::vector<std::pair<std::string,int> > -> toString']
 ##teamcity[testFinished name='std::vector<std::pair<std::string,int> > -> toString' duration="{duration}"]
+##teamcity[testStarted name='stdout and stderr streams have %-starting name']
+##teamcity[testFinished name='stdout and stderr streams have %-starting name' duration="{duration}"]
 ##teamcity[testStarted name='stringify ranges']
 ##teamcity[testFinished name='stringify ranges' duration="{duration}"]
 ##teamcity[testStarted name='stringify( has_maker )']

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

@@ -816,6 +816,8 @@ Message.tests.cpp:<line number>|nexpression failed with message:|n  "this SHOULD
 ##teamcity[testFinished name='random SECTION tests' duration="{duration}"]
 ##teamcity[testStarted name='replaceInPlace']
 ##teamcity[testFinished name='replaceInPlace' duration="{duration}"]
+##teamcity[testStarted name='request an unknown %-starting stream fails']
+##teamcity[testFinished name='request an unknown %-starting stream fails' duration="{duration}"]
 ##teamcity[testStarted name='resolution']
 ##teamcity[testFinished name='resolution' duration="{duration}"]
 ##teamcity[testStarted name='run_for_at_least, chronometer']
@@ -850,6 +852,8 @@ Message.tests.cpp:<line number>|nexpression failed with messages:|n  "Count 4 to
 ##teamcity[testFinished name='std::set is convertible string' duration="{duration}"]
 ##teamcity[testStarted name='std::vector<std::pair<std::string,int> > -> toString']
 ##teamcity[testFinished name='std::vector<std::pair<std::string,int> > -> toString' duration="{duration}"]
+##teamcity[testStarted name='stdout and stderr streams have %-starting name']
+##teamcity[testFinished name='stdout and stderr streams have %-starting name' duration="{duration}"]
 ##teamcity[testStarted name='stringify ranges']
 ##teamcity[testFinished name='stringify ranges' duration="{duration}"]
 ##teamcity[testStarted name='stringify( has_maker )']

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

@@ -19353,6 +19353,17 @@ loose text artifact
     </Section>
     <OverallResult success="true"/>
   </TestCase>
+  <TestCase name="request an unknown %-starting stream fails" tags="[streams]" filename="tests/<exe-name>/IntrospectiveTests/Stream.tests.cpp" >
+    <Expression success="true" type="REQUIRE_THROWS" filename="tests/<exe-name>/IntrospectiveTests/Stream.tests.cpp" >
+      <Original>
+        Catch::makeStream( "%somestream" )
+      </Original>
+      <Expanded>
+        Catch::makeStream( "%somestream" )
+      </Expanded>
+    </Expression>
+    <OverallResult success="true"/>
+  </TestCase>
   <TestCase name="resolution" tags="[benchmark]" filename="tests/<exe-name>/IntrospectiveTests/InternalBenchmark.tests.cpp" >
     <Expression success="true" type="REQUIRE" filename="tests/<exe-name>/IntrospectiveTests/InternalBenchmark.tests.cpp" >
       <Original>
@@ -19871,6 +19882,25 @@ loose text artifact
     </Expression>
     <OverallResult success="true"/>
   </TestCase>
+  <TestCase name="stdout and stderr streams have %-starting name" tags="[streams]" filename="tests/<exe-name>/IntrospectiveTests/Stream.tests.cpp" >
+    <Expression success="true" type="REQUIRE" filename="tests/<exe-name>/IntrospectiveTests/Stream.tests.cpp" >
+      <Original>
+        Catch::makeStream( "%stderr" )->isStdout()
+      </Original>
+      <Expanded>
+        true
+      </Expanded>
+    </Expression>
+    <Expression success="true" type="REQUIRE" filename="tests/<exe-name>/IntrospectiveTests/Stream.tests.cpp" >
+      <Original>
+        Catch::makeStream( "%stdout" )->isStdout()
+      </Original>
+      <Expanded>
+        true
+      </Expanded>
+    </Expression>
+    <OverallResult success="true"/>
+  </TestCase>
   <TestCase name="stringify ranges" tags="[toString]" filename="tests/<exe-name>/UsageTests/ToStringWhich.tests.cpp" >
     <Expression success="true" type="REQUIRE" filename="tests/<exe-name>/UsageTests/ToStringWhich.tests.cpp" >
       <Original>
@@ -20901,6 +20931,6 @@ loose text artifact
     </Section>
     <OverallResult success="true"/>
   </TestCase>
-  <OverallResults successes="2058" failures="143" expectedFailures="27"/>
-  <OverallResultsCases successes="293" failures="83" expectedFailures="7"/>
+  <OverallResults successes="2061" failures="143" expectedFailures="27"/>
+  <OverallResultsCases successes="295" failures="83" expectedFailures="7"/>
 </Catch2TestRun>

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

@@ -19352,6 +19352,17 @@ There is no extra whitespace here
     </Section>
     <OverallResult success="true"/>
   </TestCase>
+  <TestCase name="request an unknown %-starting stream fails" tags="[streams]" filename="tests/<exe-name>/IntrospectiveTests/Stream.tests.cpp" >
+    <Expression success="true" type="REQUIRE_THROWS" filename="tests/<exe-name>/IntrospectiveTests/Stream.tests.cpp" >
+      <Original>
+        Catch::makeStream( "%somestream" )
+      </Original>
+      <Expanded>
+        Catch::makeStream( "%somestream" )
+      </Expanded>
+    </Expression>
+    <OverallResult success="true"/>
+  </TestCase>
   <TestCase name="resolution" tags="[benchmark]" filename="tests/<exe-name>/IntrospectiveTests/InternalBenchmark.tests.cpp" >
     <Expression success="true" type="REQUIRE" filename="tests/<exe-name>/IntrospectiveTests/InternalBenchmark.tests.cpp" >
       <Original>
@@ -19870,6 +19881,25 @@ There is no extra whitespace here
     </Expression>
     <OverallResult success="true"/>
   </TestCase>
+  <TestCase name="stdout and stderr streams have %-starting name" tags="[streams]" filename="tests/<exe-name>/IntrospectiveTests/Stream.tests.cpp" >
+    <Expression success="true" type="REQUIRE" filename="tests/<exe-name>/IntrospectiveTests/Stream.tests.cpp" >
+      <Original>
+        Catch::makeStream( "%stderr" )->isStdout()
+      </Original>
+      <Expanded>
+        true
+      </Expanded>
+    </Expression>
+    <Expression success="true" type="REQUIRE" filename="tests/<exe-name>/IntrospectiveTests/Stream.tests.cpp" >
+      <Original>
+        Catch::makeStream( "%stdout" )->isStdout()
+      </Original>
+      <Expanded>
+        true
+      </Expanded>
+    </Expression>
+    <OverallResult success="true"/>
+  </TestCase>
   <TestCase name="stringify ranges" tags="[toString]" filename="tests/<exe-name>/UsageTests/ToStringWhich.tests.cpp" >
     <Expression success="true" type="REQUIRE" filename="tests/<exe-name>/UsageTests/ToStringWhich.tests.cpp" >
       <Original>
@@ -20900,6 +20930,6 @@ There is no extra whitespace here
     </Section>
     <OverallResult success="true"/>
   </TestCase>
-  <OverallResults successes="2058" failures="143" expectedFailures="27"/>
-  <OverallResultsCases successes="293" failures="83" expectedFailures="7"/>
+  <OverallResults successes="2061" failures="143" expectedFailures="27"/>
+  <OverallResultsCases successes="295" failures="83" expectedFailures="7"/>
 </Catch2TestRun>

tests/SelfTest/IntrospectiveTests/Stream.tests.cpp

@@ -17,3 +17,12 @@ TEST_CASE( "Cout stream properly declares it writes to stdout", "[streams]" ) {
 TEST_CASE( "Empty stream name opens cout stream", "[streams]" ) {
     REQUIRE( Catch::makeStream( "" )->isStdout() );
 }
+
+TEST_CASE( "stdout and stderr streams have %-starting name", "[streams]" ) {
+    REQUIRE( Catch::makeStream( "%stderr" )->isStdout() );
+    REQUIRE( Catch::makeStream( "%stdout" )->isStdout() );
+}
+
+TEST_CASE( "request an unknown %-starting stream fails", "[streams]" ) {
+    REQUIRE_THROWS( Catch::makeStream( "%somestream" ) );
+}