feat: add getOperation([seq]) API

README.md

@@ -270,3 +270,14 @@ Current version.
 #### `await db.ready()`
 
 Makes sure internal state is loaded. Call this once before checking the version if you haven't called any of the other APIs.
+
+#### `await db.getOperation(seq)`
+
+Similar to [createHistoryStream](#stream--dbcreatehistorystreamoptions) but returns a single operation at a given sequence.
+
+If the sequence is `0` it will return null, as the first entry is a header and not a part of the tree operations.
+
+```js
+await db.getOperation(db.feed.length - 1)
+// { seq: 1, key: 'a', value: 'hello', type: 'put' }
+```

index.js

@@ -248,6 +248,13 @@ class BlockEntry {
     }
   }
 
+  operation () {
+    return {
+      type: this.isDeletion() ? 'del' : 'put',
+      ...this.final()
+    }
+  }
+
   getTreeNode (offset) {
     if (this.index === null) {
       this.index = inflate(this.indexBuffer)
@@ -308,6 +315,14 @@ class Hyperbee {
     return iteratorPeek(this.createRangeIterator({ ...opts, limit: 1 }))
   }
 
+  async getOperation (seq, opts) {
+    if (seq === 0) return null
+
+    const b = new Batch(this, this.feed.snapshot(), null, false, opts)
+    const block = await b.getBlock(seq)
+    return block.operation()
+  }
+
   createRangeIterator (opts = {}) {
     const extension = (opts.extension === false && opts.limit !== 0) ? null : this.extension
 

iterators/history.js

@@ -26,22 +26,17 @@ module.exports = class HistoryIterator {
 
     if (this.reverse) {
       if (this.lt <= 1) return null
-      return final(await this.batch.getBlock(--this.lt, this.options))
+      return (await this.batch.getBlock(--this.lt, this.options)).operation()
     }
 
-    return final(await this.batch.getBlock(this.gte++, this.options))
+    return (await this.batch.getBlock(this.gte++, this.options)).operation()
   }
 
   close () {
     return this.batch._closeSnapshot()
   }
 }
 
-function final (node) {
-  const type = node.isDeletion() ? 'del' : 'put'
-  return { type, ...node.final() }
-}
-
 function gte (opts, version) {
   if (opts.gt) return (opts.gt < 0 ? (opts.gt + version) : opts.gt) + 1
   const gte = opts.gte || opts.since || 1