fix: use variable map size for map encoding (#85)

Signed-off-by: Timo Glastra <[email protected]>

Author: TimoGlastra

.changeset/seven-pears-relate.md

@@ -0,0 +1,5 @@
+---
+"@animo-id/mdoc": minor
+---
+
+fix: use variable map size for map encoding

src/cbor/parser.ts

@@ -10,6 +10,7 @@ const encoderDefaults: CborOptions = {
   useRecords: false,
   mapsAsObjects: false,
   unwrapTopLevelDataItem: true,
+  variableMapSize: true,
 }
 
 export const cborDecode = <T>(input: Uint8Array, options: CborOptions = encoderDefaults): T => {

tests/cbor.tests.ts

@@ -13,6 +13,27 @@ describe('cbor', () => {
     expect(decoded.get('foo')?.data.get('bar')).toBe('baz')
   })
 
+  it('should properly encoded and decoded maps (length <= 23)', () => {
+    const length = 23
+    const obj = Object.fromEntries(Array.from({ length }, (_, i) => [`key${i}`, i]))
+    const encoded = cborEncode(DataItem.fromData(obj))
+    const decoded = cborDecode(encoded, { unwrapTopLevelDataItem: false })
+    const reEncode = cborEncode(decoded)
+    expect(compareBytes(reEncode, encoded)).toBeTruthy()
+    expect(encoded[4].toString(16)).toBe((0xa0 + length).toString(16))
+  })
+
+  it('should properly encoded and decoded maps (length >= 23)', () => {
+    const length = 24
+    const obj = Object.fromEntries(Array.from({ length }, (_, i) => [`key${i}`, i]))
+    const encoded = cborEncode(DataItem.fromData(obj))
+    const decoded = cborDecode(encoded, { unwrapTopLevelDataItem: false })
+    const reEncode = cborEncode(decoded)
+    expect(compareBytes(reEncode, encoded)).toBeTruthy()
+    expect(encoded[4].toString(16)).toBe('b8')
+    expect(encoded[5].toString(16)).toBe(length.toString(16))
+  })
+
   it('should properly encoded and decoded maps', () => {
     const encoded = cborEncode(DataItem.fromData({ foo: 'baz' }))
     const decoded = cborDecode(encoded, { unwrapTopLevelDataItem: false })

tests/models/validity-info.test.ts

@@ -3,7 +3,7 @@ import { ValidityInfo } from '../../src/mdoc/models/validity-info'
 import { hex } from '../../src/utils'
 
 const cbor =
-  'b90003667369676e6564c074323032302d31302d30315431333a33303a30325a6976616c696446726f6dc074323032302d31302d30315431333a33303a30325a6a76616c6964556e74696cc074323032312d31302d30315431333a33303a30325a'
+  'a3667369676e6564c074323032302d31302d30315431333a33303a30325a6976616c696446726f6dc074323032302d31302d30315431333a33303a30325a6a76616c6964556e74696cc074323032312d31302d30315431333a33303a30325a'
 
 describe('validity info', () => {
   test('parse', () => {