diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5896edab..e97e0ff8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -218,10 +218,17 @@ jobs:
       - uses: actions/setup-node@v4
         with:
           node-version: 22
-      # The glob is the SHELL's, not node's: `web/tests/bundle/` needs a built
+      # The glob is the SCRIPT's, not the shell's and not node's. Under bash an
+      # unmatched glob survives as a literal, node globs it, matches nothing and
+      # exits 0 having run no test -- so this step gated nothing the moment
+      # `web/tests/` moved (improvise-vz54). `web/tests/bundle/` needs a built
       # wasm bundle and runs in the browser job instead.
       - name: What the page decides between its boundaries
-        run: node --test web/tests/*.test.js
+        run: ./scripts/node-test.sh 'web/tests/*.test.js'
+      # The guard above is only worth its line if its refusals are themselves
+      # checked -- the step it replaces was green while asserting nothing.
+      - name: The node test runner refuses what it claims to
+        run: ./scripts/node-test-test.sh
 
   kb:
     name: Knowledge base consistency
@@ -349,7 +356,7 @@ jobs:
       # runs here rather than in the `js` job, and before Playwright — a
       # renamed export is cheaper to read here than as a blank page.
       - name: The page's calls match the bundle it calls
-        run: node --test web/tests/bundle/*.test.js
+        run: ./scripts/node-test.sh 'web/tests/bundle/*.test.js'
       - name: Run the harness
         working-directory: harness
         run: npx playwright test
diff --git a/scripts/node-test-test.sh b/scripts/node-test-test.sh
new file mode 100755
index 00000000..c8e69c9f
--- /dev/null
+++ b/scripts/node-test-test.sh
@@ -0,0 +1,86 @@
+#!/usr/bin/env bash
+# check_the_checker for scripts/node-test.sh. Every case is a way a node test
+# step can exit 0 having asserted nothing -- which is what the step it replaces
+# did, on both CI jobs, for the whole life of web/tests/ (improvise-vz54).
+set -uo pipefail
+
+here="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+RUN="$here/node-test.sh"
+work="$(mktemp -d)"
+trap 'rm -rf "$work"' EXIT
+
+pass=0; fail=0
+ok()  { printf '  ok   %s\n' "$1"; pass=$((pass+1)); }
+bad() { printf '  FAIL %s (exit %s, wanted %s)\n' "$1" "$2" "$3"; fail=$((fail+1)); }
+
+# $1 name, $2 expected exit, rest: patterns
+run_case() {
+  local name="$1" want="$2"; shift 2
+  "$RUN" "$@" >/dev/null 2>&1
+  local got=$?
+  if [ "$want" = "nonzero" ]; then
+    [ "$got" -ne 0 ] && ok "$name" || bad "$name" "$got" "$want"
+  else
+    [ "$got" = "$want" ] && ok "$name" || bad "$name" "$got" "$want"
+  fi
+}
+
+mkdir -p "$work/tests" "$work/empty"
+
+cat > "$work/tests/green.test.js" <<'EOF'
+const { test } = require("node:test");
+test("a test that passes", () => {});
+EOF
+
+cat > "$work/tests/red.test.js" <<'EOF'
+const { test } = require("node:test");
+const assert = require("node:assert");
+test("a test that fails", () => { assert.equal(1, 2); });
+EOF
+
+# A file that matches the glob and declares no test -- a helper left in the
+# directory, or a suite emptied by a refactor. node reports it as ONE
+# PASSING TEST named after the file, so its own count cannot see it and a
+# minimum-count assertion over `# tests` is satisfied by the offender.
+cat > "$work/empty/nothing.test.js" <<'EOF'
+module.exports = { helper: () => 1 };
+EOF
+
+# The lexical check must not call a real suite barren. Both spellings the
+# repo uses, and the indented form, live here.
+mkdir -p "$work/shapes"
+cat > "$work/shapes/shapes.test.js" <<'EOF'
+const { test } = require("node:test");
+test.describe("a group", () => {
+  test("an indented test", () => {});
+});
+EOF
+
+# The bug itself. Under bash the literal survives, node globs it, matches
+# nothing, and the step goes green. Demonstrated at improvise-vz54.
+run_case "a pattern that matches nothing is refused" 1 "$work/gone/*.test.js"
+
+run_case "a matching file with a passing test is accepted" 0 "$work/tests/green.test.js"
+
+# The refusal must not be bought by swallowing real failures.
+run_case "a failing test still fails" nonzero "$work/tests/red.test.js"
+
+run_case "a file that declares no test is refused" 1 "$work/empty/*.test.js"
+
+run_case "a suite using describe and an indented test is not called barren" 0 \
+  "$work/shapes/*.test.js"
+
+# Two globs where the SECOND dies is the shape a directory move makes: the
+# first still matches, so a check over the union would pass.
+run_case "one dead pattern among several is refused" 1 \
+  "$work/tests/green.test.js" "$work/gone/*.test.js"
+
+run_case "no argument at all is a usage error, not a pass" 2
+
+# The literal the caller would pass if they forgot to quote AND the glob
+# matched: ordinary filenames, which expand to themselves.
+run_case "already-expanded filenames still run" 0 \
+  "$work/tests/green.test.js"
+
+printf '\nnode-test-test: %d passed, %d failed\n' "$pass" "$fail"
+[ "$fail" -eq 0 ]
diff --git a/scripts/node-test.sh b/scripts/node-test.sh
new file mode 100755
index 00000000..058dca88
--- /dev/null
+++ b/scripts/node-test.sh
@@ -0,0 +1,56 @@
+#!/usr/bin/env bash
+# `node --test web/tests/*.test.js` is a gate that stops gating the moment the
+# directory moves: bash leaves an unmatched glob as a literal, node 22+ treats
+# the literal as a glob of its own, matches nothing, reports 0 tests and exits
+# 0 (improvise-vz54). zsh aborts on an unmatched glob, so the failure is
+# invisible from a developer's shell and visible only under CI's.
+#
+# So the glob is the SCRIPT's, not the shell's -- quote it at the call site.
+# Two things are refused, and both are "the gate asserted nothing" wearing an
+# exit 0: a pattern that matches no file, and a matched file that declares no
+# test.
+#
+# The second is checked LEXICALLY, and that is not laziness. node's own count
+# cannot see it: a file registering no test is reported as one passing test
+# named after the file, so `# tests N` reads as the FILE count and a
+# minimum-count assertion over it is satisfied by the very file it should
+# reject. Measured on node 24.20.
+#
+# scripts/node-test-test.sh proves each refusal by injecting its fault.
+set -uo pipefail
+
+usage() {
+  echo "usage: ${0##*/} '<glob>' ['<glob>'...]" >&2
+  echo "  quote each glob: this script expands it, not the calling shell" >&2
+  exit 2
+}
+
+[ "$#" -gt 0 ] || usage
+
+shopt -s nullglob
+
+files=()
+for pattern in "$@"; do
+  matched=($pattern)
+  if [ "${#matched[@]}" -eq 0 ]; then
+    echo "node-test: no file matches '$pattern'" >&2
+    echo "node-test: refusing to run, because node would report success here" >&2
+    exit 1
+  fi
+  files+=("${matched[@]}")
+done
+
+barren=()
+for f in "${files[@]}"; do
+  grep -Eq '(^|[^A-Za-z0-9_.])(test|it)(\.[A-Za-z]+)?[[:space:]]*\(' "$f" || barren+=("$f")
+done
+if [ "${#barren[@]}" -gt 0 ]; then
+  echo "node-test: these files declare no test, so running them asserts nothing:" >&2
+  printf '  %s\n' "${barren[@]}" >&2
+  exit 1
+fi
+
+node --test "${files[@]}"
+status=$?
+[ "$status" -eq 0 ] && echo "node-test: ${#files[@]} file(s) ran"
+exit "$status"