From a0885c03bcdf0e239ac37db3afb8eed305d0ccd6 Mon Sep 17 00:00:00 2001
From: Drew Ritter <drew@primeradiant.com>
Date: Thu, 6 Aug 2026 16:35:34 -0700
Subject: [PATCH] fix(e2e): respect fenced code marker width

---
 .../scripts/check-cards-against-spec          | 21 +++--
 .../test-check-cards-against-spec.sh          | 79 +++++++++++++++++++
 2 files changed, 93 insertions(+), 7 deletions(-)

diff --git a/skills/agentic-end-to-end-testing/scripts/check-cards-against-spec b/skills/agentic-end-to-end-testing/scripts/check-cards-against-spec
index 149cdc4b..de32f558 100755
--- a/skills/agentic-end-to-end-testing/scripts/check-cards-against-spec
+++ b/skills/agentic-end-to-end-testing/scripts/check-cards-against-spec
@@ -38,24 +38,31 @@ normalize() { tr -s '[:space:]' ' ' | sed -e 's/^ //' -e 's/ $//'; }
 # only backtick/tilde fences; it is not a general Markdown parser.
 without_fenced_code() {
   awk '
-    function fence_family(line, first, count) {
+    function read_fence(line, first, count) {
+      marker_family = ""
+      marker_width = 0
       sub(/^[[:space:]]*/, "", line)
       first = substr(line, 1, 1)
-      if (first != "`" && first != "~") return ""
+      if (first != "`" && first != "~") return
       count = 0
       while (substr(line, count + 1, 1) == first) count++
-      return count >= 3 ? first : ""
+      if (count >= 3) {
+        marker_family = first
+        marker_width = count
+      }
     }
     {
-      marker = fence_family($0)
-      if (!in_fence && marker != "") {
+      read_fence($0)
+      if (!in_fence && marker_family != "") {
         in_fence = 1
-        family = marker
+        family = marker_family
+        opening_width = marker_width
         next
       }
-      if (in_fence && marker == family) {
+      if (in_fence && marker_family == family && marker_width >= opening_width) {
         in_fence = 0
         family = ""
+        opening_width = 0
         next
       }
       if (!in_fence) print
diff --git a/tests/agentic-e2e-checker/test-check-cards-against-spec.sh b/tests/agentic-e2e-checker/test-check-cards-against-spec.sh
index d672005c..95e09933 100755
--- a/tests/agentic-e2e-checker/test-check-cards-against-spec.sh
+++ b/tests/agentic-e2e-checker/test-check-cards-against-spec.sh
@@ -327,6 +327,85 @@ assert_exit 2 "pipe-less table remains unsupported -> exit 2" \
 assert_out_contains "scenario table rows must use leading and trailing outer pipes" \
   "diagnostic names the canonical outer-pipe contract"
 
+echo "a shorter backtick run does not close a longer spec fence"
+mkdir -p "$TEST_ROOT/t21/cards"
+make_cards "$TEST_ROOT/t21/cards"
+cat > "$TEST_ROOT/t21/spec.md" <<'EOF'
+# Widget Design
+
+## E2E scenario cards
+
+````markdown
+```text
+| Card | Covers | Falsification |
+| --- | --- | --- |
+| widget-show-table | Example only | If stdout's last line is not `TOTAL` followed by the two-decimal sum (20.85 for the seed fixture), or the TOTAL row is absent entirely, the scenario FAILS. |
+````
+EOF
+assert_exit 2 "shorter backtick run stays inside four-backtick fence -> exit 2" \
+  "$CHECKER" "$TEST_ROOT/t21/spec.md" "$TEST_ROOT/t21/cards"
+
+echo "a shorter tilde run does not expose card structure"
+make_spec "$TEST_ROOT/t22"; make_cards "$TEST_ROOT/t22/cards"
+cat > "$TEST_ROOT/t22/cards/widget-show-table.md" <<'EOF'
+# widget-show-table: fenced example only
+
+~~~~markdown
+~~~text
+**What this covers**: the rendered table.
+
+## Pre-state
+A built widget binary.
+
+## Steps
+1. Run `widget show`.
+
+## Expected
+If stdout's last line is not `TOTAL` followed by the two-decimal sum (20.85 for the seed fixture), or the TOTAL row is absent entirely, the scenario FAILS.
+
+## Cleanup
+Nothing to clean.
+~~~~
+EOF
+assert_exit 1 "shorter tilde run stays inside four-tilde fence -> exit 1" \
+  "$CHECKER" "$TEST_ROOT/t22/spec.md" "$TEST_ROOT/t22/cards"
+
+echo "a longer same-family run closes the fence"
+mkdir -p "$TEST_ROOT/t23/cards"
+make_cards "$TEST_ROOT/t23/cards"
+cat > "$TEST_ROOT/t23/spec.md" <<'EOF'
+# Widget Design
+
+## E2E scenario cards
+
+````markdown
+example only
+``````
+
+| Card | Covers | Falsification |
+| --- | --- | --- |
+| widget-show-table | Rendered table | If stdout's last line is not `TOTAL` followed by the two-decimal sum (20.85 for the seed fixture), or the TOTAL row is absent entirely, the scenario FAILS. |
+EOF
+assert_exit 0 "longer backtick run closes four-backtick fence -> exit 0" \
+  "$CHECKER" "$TEST_ROOT/t23/spec.md" "$TEST_ROOT/t23/cards"
+
+echo "the other marker family does not close the fence"
+mkdir -p "$TEST_ROOT/t24/cards"
+make_cards "$TEST_ROOT/t24/cards"
+cat > "$TEST_ROOT/t24/spec.md" <<'EOF'
+# Widget Design
+
+## E2E scenario cards
+
+````markdown
+~~~~
+| Card | Covers | Falsification |
+| --- | --- | --- |
+| widget-show-table | Example only | If stdout's last line is not `TOTAL` followed by the two-decimal sum (20.85 for the seed fixture), or the TOTAL row is absent entirely, the scenario FAILS. |
+EOF
+assert_exit 2 "tilde run does not close backtick fence -> exit 2" \
+  "$CHECKER" "$TEST_ROOT/t24/spec.md" "$TEST_ROOT/t24/cards"
+
 echo "no scenario table"
 mkdir -p "$TEST_ROOT/t7/cards"
 printf '# Widget Design\n\nNo table here.\n' > "$TEST_ROOT/t7/spec.md"