fix: add expiration parameter (#21)

If you don't set this the UCANs expire immediately 🙈.

bin.js

@@ -63,6 +63,7 @@ cli.command('delegation create <audience-did>')
   .option('-c, --can', 'One or more abilities to delegate.', '*')
   .option('-n, --name', 'Human readable name for the audience receiving the delegation.')
   .option('-t, --type', 'Type of the audience receiving the delegation, one of: device, app, service.')
+  .option('-e, --expiration', 'Unix timestamp when the delegation is no longer valid. Zero indicates no expiration.', 0)
   .option('-o, --output', 'Path of file to write the exported delegation data to.')
   .action(createDelegation)
 

index.js

@@ -186,6 +186,7 @@ export async function useSpace (did) {
  * @param {string[]|string} opts.can
  * @param {string} [opts.name]
  * @param {string} [opts.type]
+ * @param {number} [opts.expiration]
  * @param {string} [opts.output]
  */
 export async function createDelegation (audienceDID, opts) {
@@ -198,9 +199,13 @@ export async function createDelegation (audienceDID, opts) {
   const audienceMeta = {}
   if (opts.name) audienceMeta.name = opts.name
   if (opts.type) audienceMeta.type = opts.type
+  const expiration = opts.expiration || Infinity
 
   // @ts-expect-error createDelegation should validate abilities
-  const delegation = await client.createDelegation(audience, abilities, { audienceMeta })
+  const delegation = await client.createDelegation(audience, abilities, {
+    expiration,
+    audienceMeta
+  })
   delegation.export()
 
   const { writer, out } = CarWriter.create()