Defend entity type lookups against nullish IDs

Make the generated getEntityTypeById() helper return undefined for
unexpected nullish inputs instead of crashing on href access. Also add
a regression test for nullish calls and refresh the generator
snapshots.

#681

Assisted-by: OpenCode:gpt-5.4

Author: dahlia

packages/vocab-tools/src/__snapshots__/class.test.ts.deno.snap

@@ -95871,7 +95871,7 @@ export function isEntityType(value: unknown): value is \$EntityType {
  * Gets the generated vocabulary entity class for the given type URI.
  */
 export function getEntityTypeById(id: string | URL): \$EntityType | undefined {
-  return entityTypeIds.get(typeof id === \\"string\\" ? id : id.href);
+  return entityTypeIds.get(typeof id === \\"string\\" ? id : id?.href);
 }
 
 "

packages/vocab-tools/src/__snapshots__/class.test.ts.node.snap

@@ -95869,7 +95869,7 @@ export function isEntityType(value: unknown): value is $EntityType {
  * Gets the generated vocabulary entity class for the given type URI.
  */
 export function getEntityTypeById(id: string | URL): $EntityType | undefined {
-  return entityTypeIds.get(typeof id === \\"string\\" ? id : id.href);
+  return entityTypeIds.get(typeof id === \\"string\\" ? id : id?.href);
 }
 
 "

packages/vocab-tools/src/__snapshots__/class.test.ts.snap

@@ -95871,7 +95871,7 @@ export function isEntityType(value: unknown): value is $EntityType {
  * Gets the generated vocabulary entity class for the given type URI.
  */
 export function getEntityTypeById(id: string | URL): $EntityType | undefined {
-  return entityTypeIds.get(typeof id === "string" ? id : id.href);
+  return entityTypeIds.get(typeof id === "string" ? id : id?.href);
 }
 
 "

packages/vocab-tools/src/class.test.ts

@@ -109,7 +109,7 @@ test("generateClasses() emits $EntityType helpers for fedify:vocabEntityType", a
   );
   match(
     entireCode,
-    /return entityTypeIds\.get\(typeof id === "string" \? id : id\.href\);/,
+    /return entityTypeIds\.get\(typeof id === "string" \? id : id\?\.href\);/,
   );
 });
 

packages/vocab-tools/src/class.ts

@@ -153,7 +153,7 @@ export function isEntityType(value: unknown): value is $EntityType {
  * Gets the generated vocabulary entity class for the given type URI.
  */
 export function getEntityTypeById(id: string | URL): $EntityType | undefined {
-  return entityTypeIds.get(typeof id === "string" ? id : id.href);
+  return entityTypeIds.get(typeof id === "string" ? id : id?.href);
 }
 
 `;

packages/vocab/src/type.test.ts

@@ -25,4 +25,12 @@ test("entity type helpers", () => {
   deepStrictEqual(getEntityTypeById(Person.typeId), Person);
   deepStrictEqual(getEntityTypeById(Person.typeId.href), Person);
   deepStrictEqual(getEntityTypeById(Link.typeId), undefined);
+  deepStrictEqual(
+    getEntityTypeById(null as unknown as string | URL),
+    undefined,
+  );
+  deepStrictEqual(
+    getEntityTypeById(undefined as unknown as string | URL),
+    undefined,
+  );
 });