fix: switch delegations

Author: hugomrdias

src/commands/delegations/switch.js

@@ -1,6 +1,7 @@
 // @ts-ignore
 import { Delegation } from '@ucanto/server'
 import inquirer from 'inquirer'
+import { stringToDelegation } from '../../encoding.js'
 
 import { getClient } from '../../client.js'
 import { hasID } from '../../validation.js'
@@ -27,7 +28,7 @@ const handler = async ({ did, alias, profile }) => {
   let choices = []
 
   for (const del of Object.values(delegations)) {
-    const imported = Delegation.import([del.ucan.root])
+    const imported = await stringToDelegation(del.ucan) // Delegation.import([del.ucan.root])
     choices.push({
       name: del.alias + '\t' + imported.issuer.did(),
       alias: del.alias,

src/encoding.js

@@ -0,0 +1,111 @@
+// @ts-nocheck
+/* eslint-disable unicorn/prefer-spread */
+import { CarReader } from '@ipld/car/reader'
+import { CarWriter } from '@ipld/car/writer'
+import { Delegation } from '@ucanto/core/delegation'
+// eslint-disable-next-line no-unused-vars
+import * as Types from '@ucanto/interface'
+import * as u8 from 'uint8arrays'
+
+/**
+ * @param {AsyncIterable<Uint8Array>} iterable
+ */
+function collector(iterable) {
+  const chunks = []
+  const cfn = (async () => {
+    for await (const chunk of iterable) {
+      chunks.push(chunk)
+    }
+    return u8.concat(chunks)
+  })()
+  return cfn
+}
+
+/**
+ * @param {Types.Delegation[]} delegations
+ * @param {import('uint8arrays/to-string').SupportedEncodings} encoding
+ */
+export async function encodeDelegations(delegations, encoding = 'base64url') {
+  if (delegations.length === 0) {
+    return ''
+  }
+
+  const roots = delegations.map((d) => d.root.cid)
+
+  // @ts-ignore
+  const { writer, out } = CarWriter.create(roots)
+  const collection = collector(out)
+
+  for (const delegation of delegations) {
+    for (const block of delegation.export()) {
+      // @ts-ignore
+      await writer.put(block)
+    }
+  }
+  await writer.close()
+
+  const bytes = await collection
+
+  return u8.toString(bytes, encoding)
+}
+
+/**
+ * Encode one {@link Types.Delegation Delegation} into a string
+ *
+ * @param {Types.Delegation<Types.Capabilities>} delegation
+ * @param {import('uint8arrays/to-string').SupportedEncodings} [encoding]
+ */
+export function delegationToString(delegation, encoding) {
+  return encodeDelegations([delegation], encoding)
+}
+
+/**
+ * Decode string into {@link Types.Delegation Delegation}
+ *
+ * @template {Types.Capabilities} [T=Types.Capabilities]
+ * @param {import('./types.js').EncodedDelegation<T>} raw
+ * @param {import('uint8arrays/to-string').SupportedEncodings} [encoding]
+ */
+export async function decodeDelegations(raw, encoding = 'base64url') {
+  if (!raw) {
+    return []
+  }
+  const bytes = u8.fromString(raw, encoding)
+  const reader = await CarReader.fromBytes(bytes)
+  const roots = await reader.getRoots()
+
+  /** @type {Types.Delegation<T>[]} */
+  const delegations = []
+
+  for (const root of roots) {
+    const rootBlock = await reader.get(root)
+
+    if (rootBlock) {
+      const blocks = new Map()
+      for (const block of reader._blocks) {
+        if (block.cid.toString() !== root.toString())
+          blocks.set(block.cid.toString(), block)
+      }
+
+      // @ts-ignore
+      delegations.push(new Delegation(rootBlock, blocks))
+    } else {
+      throw new Error('Failed to find root from raw delegation.')
+    }
+  }
+
+  return delegations
+}
+
+/**
+ * Decode string into a {@link Types.Delegation Delegation}
+ *
+ * @template {Types.Capabilities} [T=Types.Capabilities]
+ * @param {import('./types.js').EncodedDelegation<T>} raw
+ * @param {import('uint8arrays/to-string').SupportedEncodings} [encoding]
+ */
+export async function stringToDelegation(raw, encoding) {
+  const delegations = await decodeDelegations(raw, encoding)
+
+  return /** @type {Types.Delegation<T>} */ (delegations[0])
+}

src/types.ts

@@ -0,0 +1,4 @@
+import type { Capabilities, Phantom } from '@ucanto/interface'
+
+export type EncodedDelegation<C extends Capabilities = Capabilities> = string &
+  Phantom<C>