feat(core): functions to (de-)serialize TL JSON

packages/core/src/index.ts

@@ -5,6 +5,7 @@ export * from './types'
 
 export * from './utils/crypto'
 export * from './utils/peer-utils'
+export * from './utils/tl-json'
 
 export { BinaryReader } from './utils/binary/binary-reader'
 export { BinaryWriter } from './utils/binary/binary-writer'

packages/core/src/utils/tl-json.ts

@@ -0,0 +1,57 @@
+import { tl } from '@mtcute/tl'
+
+/**
+ * Convert a JS object to TL JSON
+ *
+ * @param obj  Object to be converted
+ */
+export function jsonToTlJson(obj: any): tl.TypeJSONValue {
+    if (obj === null || obj === undefined) return { _: 'jsonNull' }
+    if (typeof obj === 'boolean') return { _: 'jsonBool', value: obj }
+    if (typeof obj === 'number') return { _: 'jsonNumber', value: obj }
+    if (typeof obj === 'string') return { _: 'jsonString', value: obj }
+    if (Array.isArray(obj))
+        return { _: 'jsonArray', value: obj.map(jsonToTlJson) }
+
+    if (typeof obj !== 'object')
+        throw new Error(`Unsupported type: ${typeof obj}`)
+
+    const items: tl.TypeJSONObjectValue[] = []
+
+    Object.entries(obj).forEach(([key, value]) => {
+        items.push({
+            _: 'jsonObjectValue',
+            key,
+            value: jsonToTlJson(value),
+        })
+    })
+
+    return {
+        _: 'jsonObject',
+        value: items,
+    }
+}
+
+/**
+ * Convert TL JSON object to plain JS object
+ *
+ * @param obj  TL JSON object to convert
+ */
+export function tlJsonToJson(obj: tl.TypeJSONValue): any {
+    if (obj._ === 'jsonNull') return null
+    if (
+        obj._ === 'jsonBool' ||
+        obj._ === 'jsonNumber' ||
+        obj._ === 'jsonString'
+    )
+        return obj.value
+    if (obj._ === 'jsonArray') return obj.value.map(tlJsonToJson)
+
+    const ret: any = {}
+
+    obj.value.forEach((item) => {
+        ret[item.key] = tlJsonToJson(item.value)
+    })
+
+    return ret
+}