mesh-catalog: narrow the placing by a string, which the check's non-strict compile can follow

modules/mesh-catalog/heard.ts

@@ -59,19 +59,19 @@ export const BUILD_EVENTS = [
  * version the catalogue calls current.
  */
 export function placeable(body: Built):
-  | { place: true; module: string; commit: string }
-  | { place: false; why: string; fault: boolean } {
+  | { placed: "yes"; module: string; commit: string }
+  | { placed: "no"; why: string; fault: boolean } {
   if (body["check-outcome"] != null || body.check != null) {
-    return { place: false, why: "a merge check or a try: nothing of it merged", fault: false };
+    return { placed: "no", why: "a merge check or a try: nothing of it merged", fault: false };
   }
   if (body["dry-run"]) {
-    return { place: false, why: "a dry run is looked at, never taken in", fault: false };
+    return { placed: "no", why: "a dry run is looked at, never taken in", fault: false };
   }
   if (body.failed) {
-    return { place: false, why: "a failed build made no module-version", fault: false };
+    return { placed: "no", why: "a failed build made no module-version", fault: false };
   }
   if (!body.module || !body.commit) {
-    return { place: false, why: "it named no module or no commit", fault: true };
+    return { placed: "no", why: "it named no module or no commit", fault: true };
   }
-  return { place: true, module: body.module, commit: body.commit };
+  return { placed: "yes", module: body.module, commit: body.commit };
 }

modules/mesh-catalog/index.ts

@@ -33,7 +33,7 @@ const graph = Graph.fromEnv();
 const placeTheBuild = async (event: { body: unknown }): Promise<void> => {
   const body = (event.body ?? {}) as Built;
   const placing = placeable(body);
-  if (!placing.place) {
+  if (placing.placed === "no") {
     // A check, a try, a dry run and a failure are the build seat's ordinary outcomes: passed over. One
     // that names no module or commit is a fault in the builder, said rather than dropped, so it does
     // not look like a missing event.

modules/mesh-catalog/test/heard.test.ts

@@ -26,9 +26,9 @@ test("the catalogue hears the build seat that builds now, not only the retired o
 });
 
 test("a walk's build is placed, under its module and commit", () => {
-  assert.deepEqual(placeable(walkBuild), { place: true, module: "mailu", commit: walkBuild.commit });
+  assert.deepEqual(placeable(walkBuild), { placed: "yes", module: "mailu", commit: walkBuild.commit });
   // A walk that took the check's build of the same key says so, and is placed all the same (ADR 0350 §2).
-  assert.equal(placeable({ ...walkBuild, reused: "the check's build" } as never).place, true);
+  assert.equal(placeable({ ...walkBuild, reused: "the check's build" } as never).placed, "yes");
 });
 
 test("a merge check, a try, a dry run and a failure are passed over without a fault", () => {
@@ -39,8 +39,8 @@ test("a merge check, a try, a dry run and a failure are passed over without a fa
     [{ ...walkBuild, failed: "exit status 1" }, "failed"],
   ] as const) {
     const placing = placeable(body);
-    assert.equal(placing.place, false);
-    if (!placing.place) {
+    assert.equal(placing.placed, "no");
+    if (placing.placed === "no") {
       assert.match(placing.why, new RegExp(why));
       assert.equal(placing.fault, false);
     }
@@ -49,6 +49,6 @@ test("a merge check, a try, a dry run and a failure are passed over without a fa
 
 test("an outcome that names no module or commit is said as the builder's fault", () => {
   const placing = placeable({ repository: walkBuild.repository, commit: walkBuild.commit });
-  assert.equal(placing.place, false);
-  if (!placing.place) assert.equal(placing.fault, true);
+  assert.equal(placing.placed, "no");
+  if (placing.placed === "no") assert.equal(placing.fault, true);
 });