feat(json-pack): 🎸 add Bencode Map encoding support

Author: streamich

src/json-pack/bencode/BencodeEncoder.ts

@@ -40,6 +40,8 @@ export class BencodeEncoder implements BinaryJsonEncoder {
             return this.writeArr(value as unknown[]);
           case Uint8Array:
             return this.writeBin(value as Uint8Array);
+          case Map:
+            return this.writeMap(value as Map<unknown, unknown>);
           default:
             return this.writeUnknown(value);
         }
@@ -140,4 +142,17 @@ export class BencodeEncoder implements BinaryJsonEncoder {
     }
     writer.u8(0x65); // 'e'
   }
+
+  public writeMap(obj: Map<unknown, unknown>): void {
+    const writer = this.writer;
+    writer.u8(0x64); // 'd'
+    const keys = sort([...obj.keys()]);
+    const length = keys.length;
+    for (let i = 0; i < length; i++) {
+      const key = keys[i];
+      this.writeStr(key + '');
+      this.writeAny(obj.get(key));
+    }
+    writer.u8(0x65); // 'e'
+  }
 }

src/json-pack/bencode/__tests__/BencodeEncoder.spec.ts

@@ -6,7 +6,7 @@ import {BencodeEncoder} from '../BencodeEncoder';
 const writer = new Writer(32);
 const encoder = new BencodeEncoder(writer);
 
-const assertEncoder = (value: PackValue, expected: Uint8Array) => {
+const assertEncoder = (value: unknown, expected: Uint8Array) => {
   const encoded = encoder.encode(value);
   expect(encoded).toEqual(expected);
 };
@@ -156,3 +156,29 @@ describe('object', () => {
     }, utf8`d3:arrli1ei2ei3ee3:numi123e3:objd3:foo3:bare3:str6:qwertye`);
   });
 });
+
+describe('map', () => {
+  test('empty object', () => {
+    assertEncoder(new Map(), utf8`de`);
+  });
+
+  test('object with one key', () => {
+    assertEncoder(new Map([['foo', 'bar']]), utf8`d3:foo3:bare`);
+  });
+
+  test('object with two keys (sorted)', () => {
+    assertEncoder(new Map<unknown, unknown>([
+      ['foo', 'bar'],
+      ['baz', 123],
+    ]), utf8`d3:bazi123e3:foo3:bare`);
+  });
+
+  test('object with various nested types', () => {
+    assertEncoder(new Map<unknown, unknown>([
+      ['str', 'qwerty'],
+      ['num', 123],
+      ['arr', [1, 2, 3]],
+      ['obj', {foo: 'bar'}],
+    ]), utf8`d3:arrli1ei2ei3ee3:numi123e3:objd3:foo3:bare3:str6:qwertye`);
+  });
+});