feat(json-pack): 🎸 add verbatim string extension

Author: streamich

src/json-pack/resp/RespEncoder.ts

@@ -1,7 +1,8 @@
 import {Writer} from '../../util/buffers/Writer';
 import {RESP} from './constants';
 import {utf8Size} from '../../util/strings/utf8';
-import {RespAttributes, RespPush} from './extensions';
+import {RespAttributes, RespPush, RespVerbatimString} from './extensions';
+import {JsonPackExtension} from '../JsonPackExtension';
 import type {IWriter, IWriterGrowable} from '../../util/buffers';
 import type {BinaryJsonEncoder, StreamingBinaryJsonEncoder, TlvBinaryJsonEncoder} from '../types';
 import type {Slice} from '../../util/buffers/Slice';
@@ -38,8 +39,11 @@ export class RespEncoder<W extends IWriter & IWriterGrowable = IWriter & IWriter
         if (value instanceof Uint8Array) return this.writeBin(value);
         if (value instanceof Error) return this.writeErr(value.message);
         if (value instanceof Set) return this.writeSet(value);
-        if (value instanceof RespPush) return this.writePush(value.val);
-        if (value instanceof RespAttributes) return this.writeAttr(value.val);
+        if (value instanceof JsonPackExtension) {
+          if (value instanceof RespPush) return this.writePush(value.val);
+          if (value instanceof RespVerbatimString) return this.writeVerbatimStr('txt', value.val);
+          if (value instanceof RespAttributes) return this.writeAttr(value.val);
+        }
         return this.writeObj(value as Record<string, unknown>);
       }
       case 'undefined':

src/json-pack/resp/__tests__/RespEncoder.spec.ts

@@ -1,5 +1,6 @@
 import {bufferToUint8Array} from '../../../util/buffers/bufferToUint8Array';
 import {RespEncoder} from '../RespEncoder';
+import {RespVerbatimString} from '../extensions';
 const Parser = require('redis-parser');
 
 const parse = (uint8: Uint8Array): unknown => {
@@ -76,6 +77,12 @@ describe('strings', () => {
       const encoded = encoder.writer.flush();
       expect(toStr(encoded)).toBe('=8\r\ntxt:asdf\r\n');
     });
+
+    test('can encode verbatim string using RespVerbatimString', () => {
+      const encoder = new RespEncoder();
+      const encoded = encoder.encode(new RespVerbatimString('asdf'));
+      expect(toStr(encoded)).toBe('=8\r\ntxt:asdf\r\n');
+    });
   });
 });
 

src/json-pack/resp/extensions.ts

@@ -11,3 +11,9 @@ export class RespAttributes extends JsonPackExtension<Record<string, unknown>> {
     super(2, val);
   }
 }
+
+export class RespVerbatimString extends JsonPackExtension<string> {
+  constructor(public readonly val: string) {
+    super(3, val);
+  }
+}