Store was reading Parser's error taxonomy directly to tell a broken
assumption from ordinary bad input. The reporting stays in Store: a
parse runs on every read — the admin index parses every contact on
every page load — so a parser that reported would alert once per page
view rather than once per arrival.

Assisted-by: Claude Opus 5 via Claude Code

diff --git a/lib/pro_tacts/store.rb b/lib/pro_tacts/store.rb
index 8872724..b9ebd11 100644
--- a/lib/pro_tacts/store.rb
+++ b/lib/pro_tacts/store.rb
@@ -428,7 +428,7 @@ module ProTacts
         # A line that broke a parser assumption is not an unrecognized
         # BDAY, it is a line this server declined to read at all —
         # report_broken_assumptions says so, and more precisely.
-        next false if line.error.is_a?(VCard::Parser::BrokenAssumption)
+        next false if line.broke_assumption?
 
         property = bday_of(line)
         property.nil? || (!Birthday.rendered?(property) && !Birthday.unrendered_value?(property.value))
@@ -455,16 +455,22 @@ module ProTacts
     end
 
     # The assumption report, louder than the two above it: a submitted
-    # card that breaks one of the parser's assumptions
-    # (VCard::Parser::BrokenAssumption) is not bad input, it is news
-    # that the assumption is wrong and every simplification resting on
-    # it is now suspect. Nothing else would say so — the card is stored
-    # and served either way, and only its index entry is lost. The
-    # message carries no card content (ProTacts::SentryScrubber's
-    # line); the admin view shows the card raw.
+    # card that breaks one of the parser's assumptions is not bad
+    # input, it is news that the assumption is wrong and every
+    # simplification resting on it is now suspect. Nothing else would
+    # say so — the card is stored and served either way, and only its
+    # index entry is lost.
+    #
+    # Here rather than in the parser, which is where the break is
+    # found: a parse happens on every read of a card — the admin index
+    # parses every contact on every page load — and one bad card must
+    # not alert once per page view. An arrival is the event worth a
+    # message. The message carries no card content
+    # (ProTacts::SentryScrubber's line); the admin view shows the card
+    # raw.
     #: (VCard card) -> void
     def report_broken_assumptions(card)
-      broken = card.lines.count { it.error.is_a?(VCard::Parser::BrokenAssumption) }
+      broken = card.broken_assumptions.length
       return if broken.zero?
 
       Sentry.capture_message(
diff --git a/lib/pro_tacts/vcard.rb b/lib/pro_tacts/vcard.rb
index 58fb859..d39817c 100644
--- a/lib/pro_tacts/vcard.rb
+++ b/lib/pro_tacts/vcard.rb
@@ -79,6 +79,14 @@ module ProTacts
       def names?(name)
         verbatim.match?(/\A(?:[A-Za-z0-9-]+\.)?#{Regexp.escape(name)}[;:]/i)
       end
+
+      # Whether this line broke one of the parser's assumptions rather
+      # than merely failing to read. Asked here so no caller has to
+      # know the error taxonomy to tell the two apart.
+      #: () -> bool
+      def broke_assumption?
+        error.is_a?(Parser::BrokenAssumption)
+      end
     end
 
     # Text values escape backslash, the component separator, and the
@@ -180,6 +188,21 @@ module ProTacts
       parsed && parsed.find { it.name.casecmp?("UID") }&.value
     end
 
+    # The parser assumptions this card broke — the errors themselves,
+    # so a caller reporting them can say what was assumed and where.
+    # Empty for a card that reads, and for one that merely will not:
+    # a broken assumption is news about this server, ordinary bad
+    # input is not (Parser::BrokenAssumption). Deciding what to do
+    # about it is the caller's — reporting on every parse would fire
+    # on every read of the card, not once on its arrival.
+    #: () -> Array[Parser::BrokenAssumption]
+    def broken_assumptions
+      lines.filter_map { |line|
+        error = line.error
+        error if error.is_a?(Parser::BrokenAssumption)
+      }
+    end
+
     # The card's logical lines, each parsed beside its verbatim bytes —
     # the enumeration the questions that move bytes are asked over. A
     # continuation travels with its line, terminators attached, so no
diff --git a/test/pro_tacts/vcard/test_lines.rb b/test/pro_tacts/vcard/test_lines.rb
index 1d4bd55..9683640 100644
--- a/test/pro_tacts/vcard/test_lines.rb
+++ b/test/pro_tacts/vcard/test_lines.rb
@@ -98,6 +98,29 @@ class VCardLinesTest < Minitest::Test
     assert_equal "BDAY;=;:\r\n", unparsed.verbatim
   end
 
+  # A broken assumption and an ordinary unreadable line are both
+  # errors on a line, and telling them apart belongs here rather than
+  # in whoever reports it: news about this server and ordinary bad
+  # input want different handling, and neither caller should have to
+  # know the parser's error taxonomy to pick.
+  def test_a_card_separates_broken_assumptions_from_bad_input
+    packed = VCARD.new("BEGIN:VCARD\r\nFN:A\rNOTE:n\r\nEND:VCARD\r\n")
+
+    assert_equal 1, packed.broken_assumptions.length
+    assert_match "bare CR", packed.broken_assumptions.fetch(0).message
+    assert_equal [false, true, false], packed.lines.map { it.broke_assumption? }
+
+    unreadable = VCARD.new("BEGIN:VCARD\r\nBDAY;=;:\r\nEND:VCARD\r\n")
+
+    assert_kind_of VCARD::ParseError, unreadable.lines.fetch(1).error
+    assert_empty unreadable.broken_assumptions
+    refute unreadable.lines.fetch(1).broke_assumption?
+  end
+
+  def test_a_card_that_reads_broke_no_assumption
+    assert_empty VCARD.new(CARD).broken_assumptions
+  end
+
   ## insert
 
   def test_insert_takes_the_end_lines_terminator_for_a_bare_line