Merge pull request #181 from iov-one/wait

[iov-cli] Add wait() function to repl

packages/iov-cli/README.md

@@ -14,13 +14,7 @@ How to use the web4 cli
 > profile.getIdentities(0)
 []
 
-> profile.createIdentity(0)
-
-> profile.getIdentities(0)
-[ { pubkey: { algo: 'ed25519', data: [Object] },
-    label: undefined } ]
-
-> const mainIdentity = profile.getIdentities(0)[0]
+> const mainIdentity = wait(profile.createIdentity(0))
 
 > mainIdentity.pubkey
 { algo: 'ed25519',
@@ -92,7 +86,7 @@ const sendTx: SendTx = {
 7. and restore
 
 ```
-> var profileFromDb; UserProfile.loadFrom(db, "secret passwd").then(p => { profileFromDb = p })
+> const profileFromDb = wait(UserProfile.loadFrom(db, "secret passwd"));
 > profileFromDb
 UserProfile {
   createdAt: 2018-07-04T16:07:14.583Z,

packages/iov-cli/init

@@ -6,6 +6,7 @@ import { bnsCodec } from "@iov/bns";
 import { Encoding } from '@iov/encoding';
 import { Ed25519SimpleAddressKeyringEntry, UserProfile } from '@iov/keycontrol';
 import { AddressBytes, ChainId, Nonce, SendTx, TokenTicker, TransactionKind } from "@iov/types";
+function wait<T>(promise: Promise<T>): T { return require('deasync2').await(promise); }
 console.log(colors.green('Done initializing session for you. Have fun!'));
 console.log(colors.yellow('Available imports:'));
 console.log(colors.yellow('  * leveldown'));
@@ -26,3 +27,5 @@ console.log(colors.yellow('    - Nonce'));
 console.log(colors.yellow('    - SendTx'));
 console.log(colors.yellow('    - TokenTicker'));
 console.log(colors.yellow('    - TransactionKind'));
+console.log(colors.yellow('  * helper functions'));
+console.log(colors.yellow('    - wait'));

packages/iov-cli/package.json

@@ -9,10 +9,11 @@
     "url": "https://github.com/iov-one/web4/tree/master/packages/iov-cli"
   },
   "scripts": {
-    "web4": "echo '\\nTo get started type: .load init\\n' && ts-node"
+    "web4": "echo '\\nTo get started type: .load init\\n' && NODE_NO_WARNINGS=1 ts-node"
   },
   "dependencies": {
     "colors": "^1.3.0",
+    "deasync2": "https://github.com/bluelovers/deasync.git#43ace7b11",
     "ts-node": "^7.0.0"
   }
 }

packages/iov-cli/wait-demo.ts

@@ -0,0 +1,20 @@
+// This is an example of the non-trivial art of converting an asynchonous
+// method into a synchonous one. This should only be used in the REPL where
+// await is not available since the user is working in a top level scope.
+//
+// yarn run ts-node wait-demo.ts
+
+function wait<T>(promise: Promise<T>): T {
+  return require('deasync2').await(promise);
+}
+
+const somePromise = new Promise((resolve, _) => {
+  setTimeout(() => {
+    console.log("done! Will resolve now");
+    resolve("abc");
+  }, 2000);
+})
+
+console.log("Let's wait until we get what we need …");
+const value = wait(somePromise)
+console.log(value)

yarn.lock

@@ -654,6 +654,10 @@ bindings@^1.3.0, bindings@~1.3.0:
   version "1.3.0"
   resolved "https://registry.yarnpkg.com/bindings/-/bindings-1.3.0.tgz#b346f6ecf6a95f5a815c5839fc7cdb22502f1ed7"
 
+bindings@~1.2.1:
+  version "1.2.1"
+  resolved "https://registry.yarnpkg.com/bindings/-/bindings-1.2.1.tgz#14ad6113812d2d37d72e67b4cacb4bb726505f11"
+
 bip39@^2.5.0:
   version "2.5.0"
   resolved "https://registry.yarnpkg.com/bip39/-/bip39-2.5.0.tgz#51cbd5179460504a63ea3c000db3f787ca051235"
@@ -1557,6 +1561,13 @@ dateformat@^3.0.0:
   version "3.0.3"
   resolved "https://registry.yarnpkg.com/dateformat/-/dateformat-3.0.3.tgz#a6e37499a4d9a9cf85ef5872044d62901c9889ae"
 
+"deasync2@https://github.com/bluelovers/deasync.git#43ace7b11":
+  version "0.1.15"
+  resolved "https://github.com/bluelovers/deasync.git#43ace7b11b96f86a59255c398a48cb53d3f7c0dd"
+  dependencies:
+    bindings "~1.2.1"
+    nan "^2.0.7"
+
 debug@2, debug@2.6.9, debug@^2.1.2, debug@^2.2.0, debug@^2.3.3, debug@~2.6.4, debug@~2.6.6:
   version "2.6.9"
   resolved "https://registry.yarnpkg.com/debug/-/debug-2.6.9.tgz#5d128515df134ff327e90a4c93f4e077a536341f"
@@ -3928,7 +3939,7 @@ mute-stream@0.0.7:
   version "0.0.7"
   resolved "https://registry.yarnpkg.com/mute-stream/-/mute-stream-0.0.7.tgz#3075ce93bc21b8fab43e1bc4da7e8115ed1e7bab"
 
-nan@^2.10.0, nan@^2.9.2, nan@~2.10.0:
+nan@^2.0.7, nan@^2.10.0, nan@^2.9.2, nan@~2.10.0:
   version "2.10.0"
   resolved "https://registry.yarnpkg.com/nan/-/nan-2.10.0.tgz#96d0cd610ebd58d4b4de9cc0c6828cda99c7548f"