add watch() API

lib/index.js

@@ -1,3 +1,5 @@
+// @ts-ignore
+const Obz = require('obz')
 const MsgV3 = require('ppppp-db/msg-v3')
 
 const PREFIX = 'set_v1__'
@@ -23,6 +25,9 @@ const PREFIX = 'set_v1__'
  *   supersedes: Array<MsgID>,
  * }} SetMsgData
  * @typedef {{
+ *   set: (ev: { event: 'add' | 'del', subdomain: string, value: string }) => void
+ * }} ObzType
+ * @typedef {{
  *   set?: {
  *     ghostSpan?: number
  *   }
@@ -92,6 +97,7 @@ function initSet(peer, config) {
   let accountID = /** @type {string | null} */ (null)
   let loadPromise = /** @type {Promise<void> | null} */ (null)
   let cancelOnRecordAdded = /** @type {CallableFunction | null} */ (null)
+  const watch = /**@type {ObzType}*/ (Obz())
   const tangles = /** @type {Map<Subdomain, MsgV3.Tangle>} */ (new Map())
 
   const itemRoots = {
@@ -374,6 +380,7 @@ function initSet(peer, config) {
         }
         // @ts-ignore
         cb(null, true)
+        watch.set({ event: 'add', subdomain, value })
       })
     })
   }
@@ -410,6 +417,7 @@ function initSet(peer, config) {
         if (err) return cb(new Error(`Failed to create msg when deleting from Set "${subdomain}"`, { cause: err }))
         // @ts-ignore
         cb(null, true)
+        watch.set({ event: 'del', subdomain, value })
       })
     })
   }
@@ -570,6 +578,7 @@ function initSet(peer, config) {
     del,
     has,
     values,
+    watch,
     getDomain: fromSubdomain,
     getFeedID,
     isGhostable,

package.json

@@ -29,6 +29,7 @@
   "devDependencies": {
     "bs58": "^5.0.0",
     "c8": "7",
+    "obz": "~1.1.0",
     "ppppp-db": "github:staltz/ppppp-db",
     "ppppp-caps": "github:staltz/ppppp-caps",
     "ppppp-keypair": "github:staltz/ppppp-keypair",

test/index.test.js

@@ -42,13 +42,17 @@ function lastMsgID() {
 }
 
 let add1, add2, del1, add3, del2
-test('Set add(), del(), has()', async (t) => {
+test('Set add(), del(), has(), watch()', async (t) => {
+  const expectedWatch = [
+    { event: 'add', subdomain: 'follows', value: '1st' },
+    { event: 'add', subdomain: 'follows', value: '2nd' },
+    { event: 'del', subdomain: 'follows', value: '1st' },
+  ]
+  const actualWatch = []
+  const stopWatch = peer.set.watch((ev) => actualWatch.push(ev))
+
   // Add 1st
-  assert.equal(
-    peer.set.has('follows', '1st'),
-    false,
-    'doesnt have 1st'
-  )
+  assert.equal(peer.set.has('follows', '1st'), false, 'doesnt have 1st')
   assert(await p(peer.set.add)('follows', '1st'), 'add 1st')
   assert.equal(peer.set.has('follows', '1st'), true, 'has 1st')
   add1 = lastMsgID()
@@ -59,11 +63,7 @@ test('Set add(), del(), has()', async (t) => {
   )
 
   // Add 2nd
-  assert.equal(
-    peer.set.has('follows', '2nd'),
-    false,
-    'doesnt have 2nd'
-  )
+  assert.equal(peer.set.has('follows', '2nd'), false, 'doesnt have 2nd')
   assert(await p(peer.set.add)('follows', '2nd'), 'add 2nd')
   assert.equal(peer.set.has('follows', '2nd'), true, 'has 2nd')
   add2 = lastMsgID()
@@ -76,11 +76,7 @@ test('Set add(), del(), has()', async (t) => {
   // Del 1st
   assert.equal(peer.set.has('follows', '1st'), true, 'has 1st')
   assert(await p(peer.set.del)('follows', '1st'), 'del 1st')
-  assert.equal(
-    peer.set.has( 'follows', '1st'),
-    false,
-    'doesnt have 1st'
-  )
+  assert.equal(peer.set.has('follows', '1st'), false, 'doesnt have 1st')
   del1 = lastMsgID()
   assert.deepEqual(
     peer.set._getItemRoots('follows'),
@@ -88,12 +84,12 @@ test('Set add(), del(), has()', async (t) => {
     'itemRoots'
   )
 
+  // Check `watch()` results
+  stopWatch()
+  assert.deepEqual(actualWatch, expectedWatch, 'watch() events')
+
   // Add 3rd
-  assert.equal(
-    peer.set.has( 'follows', '3rd'),
-    false,
-    'doesnt have 3rd'
-  )
+  assert.equal(peer.set.has('follows', '3rd'), false, 'doesnt have 3rd')
   assert(await p(peer.set.add)('follows', '3rd'), 'add 3rd')
   assert.equal(peer.set.has('follows', '3rd'), true, 'has 3rd')
   add3 = lastMsgID()
@@ -106,11 +102,7 @@ test('Set add(), del(), has()', async (t) => {
   // Del 2nd
   assert.equal(peer.set.has('follows', '2nd'), true, 'has 2nd')
   assert(await p(peer.set.del)('follows', '2nd'), 'del 2nd') // msg seq 4
-  assert.equal(
-    peer.set.has( 'follows', '2nd'),
-    false,
-    'doesnt have 2nd'
-  )
+  assert.equal(peer.set.has('follows', '2nd'), false, 'doesnt have 2nd')
   del2 = lastMsgID()
   assert.deepEqual(
     peer.set._getItemRoots('follows'),
@@ -124,11 +116,7 @@ test('Set add(), del(), has()', async (t) => {
     false,
     'del 2nd idempotent'
   )
-  assert.equal(
-    peer.set.has( 'follows', '2nd'),
-    false,
-    'doesnt have 2nd'
-  )
+  assert.equal(peer.set.has('follows', '2nd'), false, 'doesnt have 2nd')
   assert.deepEqual(
     peer.set._getItemRoots('follows'),
     { '3rd': [add3], '2nd': [del2] },