refactor(daemon): Standardize on 'name change' instead of 'diff'

Replaces all references to "diff" in pubsub type names to "name change"
to match the names of the pubsub APIs (e.g. `followNameChanges`). Also
removes an extraneous `if` condition.

packages/daemon/src/directory.js

@@ -108,16 +108,16 @@ export const makeDirectoryMaker = ({
       locator,
     ) {
       const id = idFromLocator(locator);
-      for await (const idDiff of petStore.followIdNameChanges(id)) {
+      for await (const idNameChange of petStore.followIdNameChanges(id)) {
         /** @type {any} */
-        const locatorDiff = {
-          ...idDiff,
-          ...(Object.hasOwn(idDiff, 'add')
+        const locatorNameChange = {
+          ...idNameChange,
+          ...(Object.hasOwn(idNameChange, 'add')
             ? { add: locator }
             : { remove: locator }),
         };
 
-        yield /** @type {import('./types.js').LocatorDiff} */ locatorDiff;
+        yield /** @type {import('./types.js').LocatorNameChange} */ locatorNameChange;
       }
     };
 

packages/daemon/src/pet-sitter.js

@@ -63,17 +63,17 @@ export const makePetSitter = (petStore, specialNames) => {
   const followIdNameChanges = async function* currentAndSubsequentIds(id) {
     const subscription = petStore.followIdNameChanges(id);
 
-    const [idSpecialName] = Object.entries(specialNames)
+    const idSpecialNames = Object.entries(specialNames)
       .filter(([_, specialId]) => specialId === id)
       .map(([specialName, _]) => specialName);
 
-    if (typeof idSpecialName === 'string') {
-      // The first published event contains the existing names for the id, if any.
-      const { value: existingNames } = await subscription.next();
-      existingNames?.names?.unshift(idSpecialName);
-      existingNames?.names?.sort();
-      yield /** @type {import('./types.js').PetStoreIdDiff} */ (existingNames);
-    }
+    // The first published event contains the existing names for the id, if any.
+    const { value: existingNames } = await subscription.next();
+    existingNames?.names?.unshift(...idSpecialNames);
+    existingNames?.names?.sort();
+    yield /** @type {import('./types.js').PetStoreIdNameChange} */ (
+      existingNames
+    );
 
     yield* subscription;
   };

packages/daemon/src/pet-store.js

@@ -31,7 +31,7 @@ export const makePetStoreMaker = (filePowers, config) => {
      * Publishes an id change to its subscribers, if any.
      *
      * @param {string} id - The id to publish a change for.
-     * @param {import('./types.js').PetStoreIdDiff} payload - The payload to publish.
+     * @param {import('./types.js').PetStoreIdNameChange} payload - The payload to publish.
      */
     const publishIdChangeToSubscribers = (id, payload) => {
       const idTopic = idsToTopics.get(id);
@@ -133,7 +133,7 @@ export const makePetStoreMaker = (filePowers, config) => {
           /** @type {string} */ (idsToPetNames.getKey(name)),
         );
 
-        yield /** @type {import('./types.js').PetStoreNameDiff} */ ({
+        yield /** @type {import('./types.js').PetStoreNameChange} */ ({
           add: name,
           value: idRecord,
         });
@@ -152,7 +152,7 @@ export const makePetStoreMaker = (filePowers, config) => {
       const subscription = idTopic.subscribe();
 
       const existingNames = idsToPetNames.getAllFor(id).sort();
-      yield /** @type {import('./types.js').PetStoreIdDiff} */ ({
+      yield /** @type {import('./types.js').PetStoreIdNameChange} */ ({
         add: parseId(id),
         names: existingNames,
       });

packages/daemon/src/types.d.ts

@@ -360,17 +360,17 @@ export interface Handle {
 
 export type MakeSha512 = () => Sha512;
 
-export type PetStoreNameDiff =
+export type PetStoreNameChange =
   | { add: string; value: IdRecord }
   | { remove: string };
 
-export type PetStoreIdDiff =
+export type PetStoreIdNameChange =
   | { add: IdRecord; names: string[] }
   | { remove: IdRecord; names?: string[] };
 
-export type NameChangesTopic = Topic<PetStoreNameDiff>;
+export type NameChangesTopic = Topic<PetStoreNameChange>;
 
-export type IdChangesTopic = Topic<PetStoreIdDiff>;
+export type IdChangesTopic = Topic<PetStoreIdNameChange>;
 
 export interface PetStore {
   has(petName: string): boolean;
@@ -380,15 +380,15 @@ export interface PetStore {
    * Subscribe to all name changes. First publishes all existing names in alphabetical order.
    * Then publishes diffs as names are added and removed.
    */
-  followNameChanges(): AsyncGenerator<PetStoreNameDiff, undefined, undefined>;
+  followNameChanges(): AsyncGenerator<PetStoreNameChange, undefined, undefined>;
   /**
    * Subscribe to name changes for the specified id. First publishes the existing names for the id.
    * Then publishes diffs as names are added and removed, or if the id is itself removed.
    * @throws If attempting to follow an id with no names.
    */
   followIdNameChanges(
     id: string,
-  ): AsyncGenerator<PetStoreIdDiff, undefined, undefined>;
+  ): AsyncGenerator<PetStoreIdNameChange, undefined, undefined>;
   write(petName: string, id: string): Promise<void>;
   remove(petName: string): Promise<void>;
   rename(fromPetName: string, toPetName: string): Promise<void>;
@@ -402,7 +402,7 @@ export interface PetStore {
 /**
  * `add` and `remove` are locators.
  */
-export type LocatorDiff =
+export type LocatorNameChange =
   | { add: string; names: string[] }
   | { remove: string; names?: string[] };
 
@@ -413,12 +413,12 @@ export interface NameHub {
   reverseLocate(locator: string): Promise<string[]>;
   followLocatorNameChanges(
     locator: string,
-  ): AsyncGenerator<LocatorDiff, undefined, undefined>;
+  ): AsyncGenerator<LocatorNameChange, undefined, undefined>;
   list(...petNamePath: string[]): Promise<Array<string>>;
   listIdentifiers(...petNamePath: string[]): Promise<Array<string>>;
   followNameChanges(
     ...petNamePath: string[]
-  ): AsyncGenerator<PetStoreNameDiff, undefined, undefined>;
+  ): AsyncGenerator<PetStoreNameChange, undefined, undefined>;
   lookup(...petNamePath: string[]): Promise<unknown>;
   reverseLookup(value: unknown): Array<string>;
   write(petNamePath: string[], id: string): Promise<void>;