kind-isolation :testkit: a battery that invokes the published conformance suite is a live battery

xtask/src/gates/kind_isolation.rs

@@ -873,6 +873,18 @@ const BATTERY_MARKER: &str = "testkit";
 /// A per-crate battery file matches this, under the crate's own `tests/`.
 const CONFORMANCE_MARKER: &str = "conformance";
 
+/// THE PUBLISHED CONFORMANCE SUITE'S INVOCATION. A plugin runs busbar's published suite (OWNER
+/// 2026-10-03: plugins test themselves against busbar's published suite) by invoking
+/// `busbar_plugin_loader::conformance_suite!` in its `tests/conformance.rs`, and the macro expands
+/// to the suite's `#[test]` entries (`crates/plugin-loader/src/conformance/mod.rs`). The file
+/// itself spells no `#[test]`, so a counter that reads only attributes scored a running battery as
+/// one with no entry.
+const PUBLISHED_SUITE_MACRO: &str = "conformance_suite!";
+
+/// The key an invocation of [`PUBLISHED_SUITE_MACRO`] names its subject with. An invocation that
+/// names no `door:` expands to no entry against any subject, so it is not counted.
+const PUBLISHED_SUITE_SUBJECT: &str = "door:";
+
 // ------------------------------------------------------------------------------------------------
 // the vocabulary bans
 // ------------------------------------------------------------------------------------------------
@@ -4020,9 +4032,68 @@ fn live_battery_entries(text: &str) -> (usize, usize) {
             live += 1;
         }
     }
+    live += published_suite_invocations(&lines);
     (live, ignored)
 }
 
+/// How many invocations of the published suite ([`PUBLISHED_SUITE_MACRO`]) a battery file makes
+/// that name a subject — each one is the suite's entries run against that subject.
+///
+/// Read off the BLANKED lines, so the macro's name in prose or in a string is not an invocation.
+/// The invocation runs from the macro's name to the delimiter that closes the one it opened, and it
+/// counts only if that span names [`PUBLISHED_SUITE_SUBJECT`]: `conformance_suite! {}` expands to
+/// nothing and stays a file with no entry. A file that DEFINES its own `macro_rules!
+/// conformance_suite` is not invoking the published suite, whatever its invocation looks like, so
+/// none of its invocations count.
+fn published_suite_invocations(lines: &[String]) -> usize {
+    let shadowed = lines.iter().any(|l| {
+        l.contains("macro_rules!") && l.contains(PUBLISHED_SUITE_MACRO.trim_end_matches('!'))
+    });
+    if shadowed {
+        return 0;
+    }
+    let mut count = 0usize;
+    for (i, l) in lines.iter().enumerate() {
+        let Some(at) = l.find(PUBLISHED_SUITE_MACRO) else {
+            continue;
+        };
+        // The macro's name must be a path's last segment, not the tail of a longer identifier.
+        let before = l[..at].chars().next_back();
+        if before.is_some_and(|c| c.is_ascii_alphanumeric() || c == '_') {
+            continue;
+        }
+        let mut span = String::new();
+        let mut depth = 0i32;
+        let mut opened = false;
+        'walk: for (j, line) in lines[i..].iter().enumerate() {
+            let text = if j == 0 {
+                &line[at + PUBLISHED_SUITE_MACRO.len()..]
+            } else {
+                line.as_str()
+            };
+            for ch in text.chars() {
+                match ch {
+                    '{' | '(' | '[' => {
+                        depth += 1;
+                        opened = true;
+                    }
+                    '}' | ')' | ']' => depth -= 1,
+                    _ => {}
+                }
+                span.push(ch);
+                if opened && depth <= 0 {
+                    break 'walk;
+                }
+            }
+            span.push('\n');
+        }
+        if span.contains(PUBLISHED_SUITE_SUBJECT) {
+            count += 1;
+        }
+    }
+    count
+}
+
 /// The `<…>` immediately after `impl`, skipped as a BALANCED group: `impl<S: CellStore>` and
 /// `impl<'a, T: Into<Vec<u8>>>` both end at the `>` that closes the one this opened, not at the
 /// first `>` in the line.
@@ -9686,6 +9757,81 @@ impl Gate for KindIsolationGate {
             &["battery-ignored", "busbar-store-ignored"],
         ));
 
+        // THE PUBLISHED SUITE IS A BATTERY. A plugin's `tests/conformance.rs` that invokes
+        // `busbar_plugin_loader::conformance_suite!` over its door runs the suite's entries — the
+        // macro expands to them — and spells no `#[test]` of its own. It is a live battery, and the
+        // row must not call it ignored.
+        let mut ov = manifest_plant(
+            "crates/busbar-store-suite",
+            "busbar-store-suite",
+            &["busbar-contract"],
+        );
+        ov.set(
+            "crates/busbar-store-suite/src/lib.rs",
+            "pub struct P;\nimpl Store for P {}\n",
+        );
+        ov.set(
+            "crates/busbar-store-suite/tests/conformance.rs",
+            "busbar_plugin_loader::conformance_suite! {\n    door: busbar_store_suite::door,\n    \
+             cdylib: \"store_suite_door\",\n    inputs: include_str!(\"conformance.json\"),\n}\n",
+        );
+        report.push(prove_rows_green(
+            cx,
+            subject,
+            "a battery that invokes the published suite over its door is a live battery",
+            &[ROW_TESTKIT],
+            ov,
+        ));
+
+        // AN INVOCATION THAT EXPANDS TO NOTHING IS NOT A BATTERY. The same file with the subject
+        // taken out names the published macro and runs no entry against anything.
+        let mut ov = manifest_plant(
+            "crates/busbar-store-emptysuite",
+            "busbar-store-emptysuite",
+            &["busbar-contract"],
+        );
+        ov.set(
+            "crates/busbar-store-emptysuite/src/lib.rs",
+            "pub struct P;\nimpl Store for P {}\n",
+        );
+        ov.set(
+            "crates/busbar-store-emptysuite/tests/conformance.rs",
+            "busbar_plugin_loader::conformance_suite! {}\n",
+        );
+        report.push(prove_rows_red(
+            cx,
+            subject,
+            "a published-suite invocation that names no subject is a file with no entry",
+            &[ROW_TESTKIT],
+            ov,
+            &["battery-ignored", "busbar-store-emptysuite"],
+        ));
+
+        // A LOCAL MACRO BY THE SAME NAME IS NOT THE PUBLISHED SUITE. A file that defines its own
+        // `conformance_suite` to expand to nothing, then invokes it with a subject, runs nothing.
+        let mut ov = manifest_plant(
+            "crates/busbar-store-shadowsuite",
+            "busbar-store-shadowsuite",
+            &["busbar-contract"],
+        );
+        ov.set(
+            "crates/busbar-store-shadowsuite/src/lib.rs",
+            "pub struct P;\nimpl Store for P {}\n",
+        );
+        ov.set(
+            "crates/busbar-store-shadowsuite/tests/conformance.rs",
+            "macro_rules! conformance_suite {\n    ($($t:tt)*) => {};\n}\n\
+             conformance_suite! {\n    door: busbar_store_shadowsuite::door,\n}\n",
+        );
+        report.push(prove_rows_red(
+            cx,
+            subject,
+            "a file-local conformance_suite macro is not the published suite",
+            &[ROW_TESTKIT],
+            ov,
+            &["battery-ignored", "busbar-store-shadowsuite"],
+        ));
+
         // A BATTERY WITH NO SUBJECT. The same crate, with a live battery and no implementor of its
         // kind's trait anywhere in shipped source: the file compiles, the battery passes, and it is
         // evidence about nothing this crate ships.