Add flow type checking

src/api/transaction/order.js

@@ -1,3 +1,4 @@
+/* @flow */
 'use strict';
 const _ = require('lodash');
 const utils = require('./utils');
@@ -34,9 +35,9 @@ function createOrderTransaction(account, order) {
   const _order = renameCounterpartyToIssuerInOrder(order);
   const transaction = new ripple.Transaction();
   const takerPays = _order.taker_pays.currency !== 'XRP'
-    ? _order.taker_pays : utils.xrpToDrops(_order.taker_pays.value);
+    ? _order.taker_pays : utils.common.xrpToDrops(_order.taker_pays.value);
   const takerGets = _order.taker_gets.currency !== 'XRP'
-    ? _order.taker_gets : utils.xrpToDrops(_order.taker_gets.value);
+    ? _order.taker_gets : utils.common.xrpToDrops(_order.taker_gets.value);
 
   transaction.offerCreate(account, ripple.Amount.from_json(takerPays),
     ripple.Amount.from_json(takerGets));

src/api/transaction/ordercancellation.js

@@ -1,3 +1,4 @@
+/* @flow */
 'use strict';
 const utils = require('./utils');
 const validate = utils.common.validate;

src/api/transaction/payment.js

@@ -1,3 +1,4 @@
+/* @flow */
 /* eslint-disable valid-jsdoc */
 'use strict';
 const BigNumber = require('bignumber.js');
@@ -77,7 +78,7 @@ function createPaymentTransaction(account, payment) {
       .plus(payment.source.slippage || 0).toString();
 
     if (payment.source_amount.currency === 'XRP') {
-      transaction.sendMax(utils.xrpToDrops(maxValue));
+      transaction.sendMax(utils.common.utils.xrpToDrops(maxValue));
     } else {
       transaction.sendMax({
         value: maxValue,

src/api/transaction/settings.js

@@ -1,3 +1,4 @@
+/* @flow */
 /* eslint-disable valid-jsdoc */
 'use strict';
 const _ = require('lodash');

src/api/transaction/sign.js

@@ -1,3 +1,4 @@
+/* @flow */
 'use strict';
 const utils = require('./utils');
 const ripple = utils.common.core;
@@ -37,7 +38,7 @@ function hashJSON(txJSON, prefix) {
   return hashSerialization(serialize(txJSON), prefix);
 }
 
-function signingHash(txJSON, isTestNet) {
+function signingHash(txJSON, isTestNet=false) {
   return hashJSON(txJSON, isTestNet ? HASH_TX_SIGN_TESTNET : HASH_TX_SIGN);
 }
 
@@ -46,11 +47,14 @@ function computeSignature(txJSON, keypair) {
   return ripple.sjcl.codec.hex.fromBits(signature).toUpperCase();
 }
 
-function sign(txJSON, secret) {
+/*:: type TxJSON = {Account: string; SigningPubKey: string,
+                    TxnSignature: string};
+     type Signed = {tx_blob: string; hash: string}; */
+function sign(txJSON: TxJSON, secret: string): Signed {
   validate.txJSON(txJSON);
   validate.addressAndSecret({address: txJSON.Account, secret: secret});
 
-  const keypair = getKeyPair(txJSON.Acccount, secret);
+  const keypair = getKeyPair(txJSON.Account, secret);
   if (txJSON.SigningPubKey === undefined) {
     txJSON.SigningPubKey = getPublicKeyHex(keypair);
   }

src/api/transaction/submit.js

@@ -1,9 +1,11 @@
+/* @flow */
 'use strict';
 const utils = require('./utils');
 const ripple = utils.common.core;
 const validate = utils.common.validate;
 
-function submit(tx_blob, callback) {
+/*:: type Callback = (err: any, data: any) => void */
+function submit(tx_blob: string, callback: Callback): void {
   validate.blob(tx_blob);
   const request = new ripple.Request(this.remote, 'submit');
   request.message.tx_blob = tx_blob;

src/api/transaction/trustline.js

@@ -1,3 +1,4 @@
+/* @flow */
 'use strict';
 const utils = require('./utils');
 const ripple = utils.common.core;

src/api/transaction/utils.js

@@ -1,3 +1,4 @@
+/* @flow */
 /* eslint-disable valid-jsdoc */
 'use strict';
 const BigNumber = require('bignumber.js');
@@ -18,7 +19,8 @@ const common = require('../common');
  *
  * @returns undefined
  */
-function setTransactionBitFlags(transaction, options) {
+/*:: type FlagOptions = {flags: any; input: any; clear_setting?: string} */
+function setTransactionBitFlags(transaction: any, options: FlagOptions): void {
   for (let flagName in options.flags) {
     const flag = options.flags[flagName];
 
@@ -46,7 +48,9 @@ function getFeeDrops(remote) {
   return remote.feeTx(feeUnits).to_text();
 }
 
-function createTxJSON(transaction, remote, instructions, callback) {
+/*:: type Callback = (err: typeof Error, data: {tx_json: any}) => void */
+function createTxJSON(transaction: any, remote: any,
+    instructions: any, callback: Callback): void {
   common.validate.instructions(instructions);
 
   transaction.complete();
@@ -85,12 +89,12 @@ function createTxJSON(transaction, remote, instructions, callback) {
   }
 }
 
-function wrapCatch(asyncFunction) {
+function wrapCatch(asyncFunction: any): any {
   return function() {
-    const callback = arguments[arguments.length - 1];
     try {
       asyncFunction.apply(this, arguments);
     } catch (error) {
+      const callback = arguments[arguments.length - 1];
       callback(error);
     }
   };