Emit clear when a range of blocks is cleared from local storage

README.md

@@ -755,6 +755,10 @@ Emitted when the core has been appended to (i.e. has a new length / byteLength),
 
 Emitted when the core has been truncated, either locally or remotely.
 
+#### `core.on('clear', start, end)`
+
+Emitted when a range of blocks has been cleared from local storage with `core.clear()`.
+
 #### `core.on('peer-add')`
 
 Emitted when a new connection has been established with a peer.

lib/session-state.js

@@ -605,6 +605,10 @@ class SessionState {
         this.core.replicator.onhave(start, length, true)
 
         if (this.core.hintsChanged) await this.core.flushHints()
+
+        for (let i = this.sessions.length - 1; i >= 0; i--) {
+          this.sessions[i].emit('clear', start, end)
+        }
       }
     } finally {
       this._unlock()

test/clear.js

@@ -22,6 +22,19 @@ test('clear', async function (t) {
   await a.close()
 })
 
+test('clear emits a clear event with the cleared range', async function (t) {
+  const a = await create(t)
+  await a.append(['a', 'b', 'c'])
+
+  const cleared = new Promise((resolve) => a.once('clear', (start, end) => resolve({ start, end })))
+
+  await a.clear(1, 3)
+
+  t.alike(await cleared, { start: 1, end: 3 }, 'clear event fired with the cleared range')
+
+  await a.close()
+})
+
 test('clear + replication', async function (t) {
   const a = await create(t)
   const b = await create(t, a.key)