test: Document non-parity between tinyformat and ConstevalFormatstring

- for "%n" (which is supposed write to the arg for printf). - for string/integer mismatches of width/precision specifiers. Co-Authored-By: Ryan Ofsky <[email protected]>
hodlinator · Dec 5, 2024 · f71933c · f71933c
1 parent 4352596
commit f71933c
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Showing 2 changed files with 13 additions and 0 deletions.
diff --git a/src/test/util_string_tests.cpp b/src/test/util_string_tests.cpp
@@ -123,6 +123,17 @@ BOOST_AUTO_TEST_CASE(ConstevalFormatString_NumSpec)
     FailFmtWithError<2>("%1$.*2$", err_term);
     FailFmtWithError<2>("%1$9.*2$", err_term);
 
+    // Non-parity between tinyformat and ConstevalFormatString
+    BOOST_CHECK_NO_THROW(util::detail::CheckNumFormatSpecifiers<1>("%n"));
+    BOOST_CHECK_EXCEPTION(tfm::format(std::string{"%n"}, 0), tfm::format_error,
+        HasReason{"tinyformat: %n conversion spec not supported"});
+    BOOST_CHECK_NO_THROW(util::detail::CheckNumFormatSpecifiers<2>("%*s"));
+    BOOST_CHECK_EXCEPTION(tfm::format(std::string{"%*s"}, "hi", "hi"), tfm::format_error,
+        HasReason{"tinyformat: Cannot convert from argument type to integer for use as variable width or precision"});
+    BOOST_CHECK_NO_THROW(util::detail::CheckNumFormatSpecifiers<2>("%.*s"));
+    BOOST_CHECK_EXCEPTION(tfm::format(std::string{"%.*s"}, "hi", "hi"), tfm::format_error,
+        HasReason{"tinyformat: Cannot convert from argument type to integer for use as variable width or precision"});
+
     // Belt & suspenders for tinyformat behavior
     BOOST_CHECK_EXCEPTION(TfmFormatZeroes<2>("%s"), tfm::format_error,
         HasReason{"tinyformat: Not enough conversion specifiers in format string"});

diff --git a/test/lint/run-lint-format-strings.py b/test/lint/run-lint-format-strings.py
@@ -15,6 +15,8 @@
 FALSE_POSITIVES = [
     ("src/clientversion.cpp", "strprintf(_(COPYRIGHT_HOLDERS), COPYRIGHT_HOLDERS_SUBSTITUTION)"),
     ("src/test/translation_tests.cpp", "strprintf(format, arg)"),
+    ("src/test/util_string_tests.cpp", 'tfm::format(std::string{"%*s"}, "hi", "hi")'),
+    ("src/test/util_string_tests.cpp", 'tfm::format(std::string{"%.*s"}, "hi", "hi")'),
 ]