Documentation for various controllers and libs

9 files changed, 387 insertions, 19 deletions

diff --git a/app/scripts/controllers/address-book.js b/app/scripts/controllers/address-book.js
index 6fb4ee114..cd6756e03 100644
--- a/app/scripts/controllers/address-book.js
+++ b/app/scripts/controllers/address-book.js
@@ -4,9 +4,22 @@ const extend = require('xtend')
 class AddressBookController {
 
 
-  // Controller in charge of managing the address book functionality from the
-  // recipients field on the send screen. Manages a history of all saved
-  // addresses and all currently owned addresses.
+  /**
+   * Controller in charge of managing the address book functionality from the
+   * recipients field on the send screen. Manages a history of all saved
+   * addresses and all currently owned addresses.
+   *
+   * @typedef {Object} AddressBookController
+   * @param {object} opts Overides the defaults for the initial state of this.store
+   * @property {array} opts.initState  initializes the the state of the AddressBookController. Can contain an
+   * addressBook property to initialize the addressBook array
+   * @param {KeyringController} keyringController (Soon to be depracated) The keyringController used in the current
+   * MetamaskController. Contains the identities used in this AddressBookController.
+   * @property {object} store The the store of the current users address book
+   * @property {array} store.addressBook An array of addresses and nicknames. These are set by the user when sending
+   * to a new address.
+   *
+   */
   constructor (opts = {}, keyringController) {
     const initState = extend({
       addressBook: [],
@@ -19,7 +32,14 @@ class AddressBookController {
   // PUBLIC METHODS
   //
 
-  // Sets a new address book in store by accepting a new address and nickname.
+  /**
+   * Sets a new address book in store by accepting a new address and nickname.
+   *
+   * @param {string} address A hex address of a new account that the user is sending to.
+   * @param {string} name The name the user wishes to associate with the new account
+   * @returns {Promise<undefined>} Promises an undefined
+   *
+   */
   setAddressBook (address, name) {
     return this._addToAddressBook(address, name)
     .then((addressBook) => {
@@ -30,14 +50,16 @@ class AddressBookController {
     })
   }
 
-  //
-  // PRIVATE METHODS
-  //
-
-
-  // Performs the logic to add the address and name into the address book. The
-  // pushed object is an object of two fields. Current behavior does not set an
-  // upper limit to the number of addresses.
+  /**
+   * Performs the logic to add the address and name into the address book. The pushed object is an object of two
+   * fields. Current behavior does not set an upper limit to the number of addresses.
+   *
+   * @private
+   * @param {string} address A hex address of a new account that the user is sending to.
+   * @param {string} name The name the user wishes to associate with the new account
+   * @returns {Promise<array>} Promises the updated addressBook array
+   *
+   */
   _addToAddressBook (address, name) {
     const addressBook = this._getAddressBook()
     const identities = this._getIdentities()
@@ -62,14 +84,26 @@ class AddressBookController {
     return Promise.resolve(addressBook)
   }
 
-  // Internal method to get the address book. Current persistence behavior
-  // should not require that this method be called from the UI directly.
+  /**
+   * Internal method to get the address book. Current persistence behavior should not require that this method be
+   * called from the UI directly.
+   *
+   * @private
+   * @returns {array} The addressBook array from the store.
+   *
+   */
   _getAddressBook () {
     return this.store.getState().addressBook
   }
 
-  // Retrieves identities from the keyring controller in order to avoid
-  // duplication
+  /**
+   * Retrieves identities from the keyring controller in order to avoid
+   * duplication
+   *
+   * @depricated
+   * @returns {array} Returns the identies array from the keyringContoller's state
+   *
+   */
   _getIdentities () {
     return this.keyringController.memStore.getState().identities
   }
diff --git a/app/scripts/controllers/currency.js b/app/scripts/controllers/currency.js
index 36b8808aa..275219ce4 100644
--- a/app/scripts/controllers/currency.js
+++ b/app/scripts/controllers/currency.js
@@ -6,6 +6,22 @@ const POLLING_INTERVAL = 600000
 
 class CurrencyController {
 
+	/**
+	 * Controller responsible for managing data associated with the currently selected currency.
+	 *
+   * @typedef {Object} CurrencyController
+	 * @param {object} opts Overides the defaults for the initial state of this.store
+	 * @property {array} opts.initState  initializes the the state of the CurrencyController. Can contain an
+   * currentCurrency, conversionRate and conversionDate properties
+   * @property {string} currentCurrency A 2-4 character shorthand that describes a specific currency, currently
+   * selected by the user
+   * @property {number} conversionRate The conversion rate from ETH to the selected currency. 
+   * @property {string} conversionDate The date at which the conversion rate was set. Expressed in in milliseconds
+   * since midnight of January 1, 1970 
+   * @property {number} conversionInterval The id of the interval created by the scheduleConversionInterval method.
+   * Used to clear an existing interval on subsequent calls of that method.
+	 *
+	 */
   constructor (opts = {}) {
     const initState = extend({
       currentCurrency: 'usd',
@@ -19,30 +35,73 @@ class CurrencyController {
   // PUBLIC METHODS
   //
 
+	/**
+	 * A getter for the currentCurrency property
+	 *
+	 * @returns {string} A 2-4 character shorthand that describes a specific currency, currently selected by the user
+	 *
+	 */
   getCurrentCurrency () {
     return this.store.getState().currentCurrency
   }
 
+	/**
+	 * A setter for the currentCurrency property
+	 *
+	 * @params {string} currentCurrency The new currency to set as the currentCurrency in the store
+	 *
+	 */
   setCurrentCurrency (currentCurrency) {
     this.store.updateState({ currentCurrency })
   }
 
+  /**
+   * A getter for the conversionRate property
+   *
+   * @returns {string} The conversion rate from ETH to the selected currency. 
+   *
+   */
   getConversionRate () {
     return this.store.getState().conversionRate
   }
 
+  /**
+   * A setter for the conversionRate property
+   *
+   * @params {number} conversionRate The new rate to set as the conversionRate in the store
+   *
+   */
   setConversionRate (conversionRate) {
     this.store.updateState({ conversionRate })
   }
 
+  /**
+   * A getter for the conversionDate property
+   *
+   * @returns {string} The date at which the conversion rate was set. Expressed in milliseconds since midnight of
+   * January 1, 1970 
+   *
+   */
   getConversionDate () {
     return this.store.getState().conversionDate
   }
 
+  /**
+   * A setter for the conversionDate property
+   *
+   * @params {number} conversionDate The date, expressed in milliseconds since midnight of January 1, 1970, that the
+   * conversionRate was set
+   *
+   */
   setConversionDate (conversionDate) {
     this.store.updateState({ conversionDate })
   }
 
+  /**
+   * Updates the conversionRate and conversionDate properties associated with the currentCurrency. Updated info is
+   * fetched from an external API
+   *
+   */
   async updateConversionRate () {
     let currentCurrency
     try {
@@ -58,6 +117,12 @@ class CurrencyController {
     }
   }
 
+	/**
+	 * Creates a new poll, using setInterval, to periodically call updateConversionRate. The id of the interval is
+   * stored at the controller's conversionInterval property. If it is called and such an id already exists, the
+   * previous interval is clear and a new one is created.
+	 *
+	 */
   scheduleConversionInterval () {
     if (this.conversionInterval) {
       clearInterval(this.conversionInterval)
diff --git a/app/scripts/controllers/preferences.js b/app/scripts/controllers/preferences.js
index b4819d951..92c016309 100644
--- a/app/scripts/controllers/preferences.js
+++ b/app/scripts/controllers/preferences.js
@@ -4,6 +4,21 @@ const extend = require('xtend')
 
 class PreferencesController {
 
+	/**
+	 *
+   * @typedef {Object} PreferencesController
+	 * @param {object} opts Overides the defaults for the initial state of this.store
+   * @property {object} store The an object containing a users preferences, stored in local storage
+	 * @property {array} store.frequentRpcList A list of custom rpcs to provide the user
+   * @property {string} store.currentAccountTab Indicates the selected tab in the ui
+   * @property {array} store.tokens The tokens the user wants display in their token lists
+   * @property {boolean} store.useBlockie The users preference for blockie identicons within the UI
+   * @property {object} store.featureFlags A key-boolean map, where keys refer to features and booleans to whether the
+   * user wishes to see that feature
+   * @property {string} store.currentLocale The preferred language locale key
+   * @property {string} store.selectedAddress A hex string that matches the currently selected address in the app
+   *
+	 */
   constructor (opts = {}) {
     const initState = extend({
       frequentRpcList: [],
@@ -17,18 +32,43 @@ class PreferencesController {
   }
 // PUBLIC METHODS
 
+	/**
+	 * Setter for the `useBlockie` property
+	 *
+	 * @param {boolean} val Whether or not the user prefers blockie indicators
+	 *
+	 */
   setUseBlockie (val) {
     this.store.updateState({ useBlockie: val })
   }
 
+	/**
+	 * Getter for the `useBlockie` property
+	 *
+	 * @returns {boolean} this.store.useBlockie
+	 *
+	 */
   getUseBlockie () {
     return this.store.getState().useBlockie
   }
 
+	/**
+	 * Setter for the `currentLocale` property
+   *
+   * @param {string} key he preferred language locale key
+	 *
+	 */
   setCurrentLocale (key) {
     this.store.updateState({ currentLocale: key })
   }
 
+	/**
+	 * Setter for the `selectedAddress` property
+	 *
+	 * @param {string} _address A new hex address for an account
+	 * @returns {Promise<undefined>} Promises an undefined return value
+	 *
+	 */
   setSelectedAddress (_address) {
     return new Promise((resolve, reject) => {
       const address = normalizeAddress(_address)
@@ -37,10 +77,37 @@ class PreferencesController {
     })
   }
 
+  /**
+   * Getter for the `selectedAddress` property
+   *
+   * @returns {string} The hex address for the currently selected account
+   *
+   */
   getSelectedAddress () {
     return this.store.getState().selectedAddress
   }
 
+  /**
+   * Contains data about tokens users add to their account.
+   * @typedef {Object} AddedToken
+   * @property {string} address - The hex address for the token contract. Will be all lower cased and hex-prefixed.
+   * @property {string} symbol - The symbol of the token, usually 3 or 4 capitalized letters
+   *  {@link https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md#symbol}
+   * @property {boolean} decimals - The number of decimals the token uses.
+   *  {@link https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md#decimals}
+   */
+
+  /**
+   * Adds a new token to the token array, or updates the token if passed an address that already exists.
+   * Modifies the existing tokens array from the store. All objects in the tokens array array AddedToken objects.
+   * @see AddedToken {@link AddedToken} 
+   *
+   * @param {string} rawAddress Hex address of the token contract. May or may not be a checksum address.
+   * @param {string} symbol The symbol of the token
+   * @param {number} decimals  The number of decimals the token uses.
+   * @returns {Promise<array>} Promises the new array of AddedToken objects.
+   *
+   */
   async addToken (rawAddress, symbol, decimals) {
     const address = normalizeAddress(rawAddress)
     const newEntry = { address, symbol, decimals }
@@ -62,6 +129,13 @@ class PreferencesController {
     return Promise.resolve(tokens)
   }
 
+	/**
+	 * Removes a specified token from the tokens array.
+	 *
+	 * @param {string} rawAddress Hex address of the token contract to remove.
+	 * @returns {Promise<array> The new array of AddedToken objects
+	 *
+	 */
   removeToken (rawAddress) {
     const tokens = this.store.getState().tokens
 
@@ -71,10 +145,23 @@ class PreferencesController {
     return Promise.resolve(updatedTokens)
   }
 
+	/**
+	 * A getter for the `tokens` property
+	 *
+	 * @returns {array} The current array of AddedToken objects
+	 *
+	 */
   getTokens () {
     return this.store.getState().tokens
   }
 
+	/**
+	 * Gets an updated rpc list from this.addToFrequentRpcList() and sets the `frequentRpcList` to this update list.
+	 *
+	 * @param {string} _url The the new rpc url to add to the updated list
+	 * @returns {Promise<undefined>} Promises an undefined value.
+	 *
+	 */
   updateFrequentRpcList (_url) {
     return this.addToFrequentRpcList(_url)
       .then((rpcList) => {
@@ -83,6 +170,13 @@ class PreferencesController {
       })
   }
 
+	/**
+	 * Setter for the `currentAccountTab` property 
+	 *
+	 * @param {string} currentAccountTab Specifies the new tab to be marked as current
+	 * @returns {Promise<undefined>} Promises an undefined value.
+	 *
+	 */
   setCurrentAccountTab (currentAccountTab) {
     return new Promise((resolve, reject) => {
       this.store.updateState({ currentAccountTab })
@@ -90,6 +184,15 @@ class PreferencesController {
     })
   }
 
+	/**
+	 * Returns an updated rpcList based on the passed url and the current list.
+   * The returned list will have a max length of 2. If the _url currently exists it the list, it will be moved to the
+   * end of the list. The current list is modified and returned as a promise.
+	 *
+	 * @param {string} _url The rpc url to add to the frequentRpcList.
+	 * @returns {Promise<array>} The updated frequentRpcList. 
+	 *
+	 */
   addToFrequentRpcList (_url) {
     const rpcList = this.getFrequentRpcList()
     const index = rpcList.findIndex((element) => { return element === _url })
@@ -105,10 +208,24 @@ class PreferencesController {
     return Promise.resolve(rpcList)
   }
 
+	/**
+	 * Getter for the `frequentRpcList` property.
+	 *
+	 * @returns {array<string>} An array of one or two rpc urls.
+	 *
+	 */
   getFrequentRpcList () {
     return this.store.getState().frequentRpcList
   }
 
+	/**
+	 * Updates the `featureFlags` property, which is an object. One property within that object will be set to a boolean.
+	 *
+	 * @param {string} feature A key that corresponds to a UI feature.
+   * @param {boolean} activated Indicates whether or not the UI feature should be displayed
+	 * @returns {Promise<object>} Promises a new object; the updated featureFlags object.
+	 *
+	 */
   setFeatureFlag (feature, activated) {
     const currentFeatureFlags = this.store.getState().featureFlags
     const updatedFeatureFlags = {
@@ -121,6 +238,13 @@ class PreferencesController {
     return Promise.resolve(updatedFeatureFlags)
   }
 
+	/**
+	 * A getter for the `featureFlags` property
+	 *
+	 * @returns {object} A key-boolean map, where keys refer to features and booleans to whether the
+   * user wishes to see that feature
+	 *
+	 */
   getFeatureFlags () {
     return this.store.getState().featureFlags
   }
diff --git a/app/scripts/controllers/shapeshift.js b/app/scripts/controllers/shapeshift.js
index 3bbfaa1c5..b24b010ea 100644
--- a/app/scripts/controllers/shapeshift.js
+++ b/app/scripts/controllers/shapeshift.js
@@ -6,6 +6,17 @@ const POLLING_INTERVAL = 3000
 
 class ShapeshiftController {
 
+    /**
+     * Controller responsible for managing the list of shapeshift transactions. On construction, it initiates a poll
+     * that queries a shapeshift.io API for updates to any pending shapeshift transactions
+     *
+     * @typedef {Object} ShapeshiftController
+     * @param {object} opts Overides the defaults for the initial state of this.store
+     * @property {array} opts.initState  initializes the the state of the ShapeshiftController. Can contain an
+     * shapeShiftTxList array.
+     * @property {array} shapeShiftTxList An array of ShapeShiftTx objects
+     *
+     */
   constructor (opts = {}) {
     const initState = extend({
       shapeShiftTxList: [],
@@ -14,21 +25,54 @@ class ShapeshiftController {
     this.pollForUpdates()
   }
 
+  /**
+   * Represents, and contains data about, a single shapeshift transaction.
+   * @typedef {Object} ShapeShiftTx
+   * @property {string} depositAddress - An address at which to send a crypto deposit, so that eth can be sent to the
+   * user's Metamask account
+   * @property {string} depositType - An abbreviation of the type of crypto currency to be deposited.
+   * @constant {string} key - The 'shapeshift' key differentiates this from other types of txs in Metamask
+   * @property {number} time - The time at which the tx was created
+   * @property {object} response - Initiated as an empty object, which will be replaced by a Response object. @see {@link
+   * https://developer.mozilla.org/en-US/docs/Web/API/Response}
+   */
+
   //
   // PUBLIC METHODS
   //
 
+	/**
+	 * A getter for the shapeShiftTxList property
+	 *
+	 * @returns {array<ShapeShiftTx>}
+	 *
+	 */
   getShapeShiftTxList () {
     const shapeShiftTxList = this.store.getState().shapeShiftTxList
     return shapeShiftTxList
   }
 
+	/**
+	 * A getter for all ShapeShiftTx in the shapeShiftTxList that have not successfully completed a deposit.
+	 *
+	 * @returns {array<ShapeShiftTx>} Only includes ShapeShiftTx which has a response property with a status !== complete
+	 *
+	 */
   getPendingTxs () {
     const txs = this.getShapeShiftTxList()
     const pending = txs.filter(tx => tx.response && tx.response.status !== 'complete')
     return pending
   }
 
+	/**
+	 * A poll that exists as long as there are pending transactions. Each call attempts to update the data of any
+   * pendingTxs, and then calls itself again. If there are no pending txs, the recursive call is not made and
+   * the polling stops.
+   *
+   * this.updateTx is used to attempt the update to the pendingTxs in the ShapeShiftTxList, and that updated data
+   * is saved with saveTx.
+	 *
+	 */
   pollForUpdates () {
     const pendingTxs = this.getPendingTxs()
 
@@ -45,6 +89,15 @@ class ShapeshiftController {
     })
   }
 
+    /**
+     * Attempts to update a ShapeShiftTx with data from a shapeshift.io API. Both the response and time properties
+     * can be updated. The response property is updated with every call, but the time property is only updated when
+     * the response status updates to 'complete'. This will occur once the user makes a deposit as the ShapeShiftTx
+     * depositAddress
+     *
+     * @param {ShapeShiftTx} tx The tx to update
+     *
+     */
   async updateTx (tx) {
     try {
       const url = `https://shapeshift.io/txStat/${tx.depositAddress}`
@@ -60,6 +113,13 @@ class ShapeshiftController {
     }
   }
 
+	/**
+	 * Saves an updated to a ShapeShiftTx in the shapeShiftTxList. If the passed ShapeShiftTx is not in the
+   * shapeShiftTxList, nothing happens.
+	 *
+	 * @params {ShapeShiftTx} tx The updated tx to save, if it exists in the current shapeShiftTxList
+	 *
+	 */
   saveTx (tx) {
     const { shapeShiftTxList } = this.store.getState()
     const index = shapeShiftTxList.indexOf(tx)
@@ -69,6 +129,12 @@ class ShapeshiftController {
     }
   }
 
+	/**
+	 * Removes a ShapeShiftTx from the shapeShiftTxList
+	 *
+	 * @params {ShapeShiftTx} tx The tx to remove
+	 *
+	 */
   removeShapeShiftTx (tx) {
     const { shapeShiftTxList } = this.store.getState()
     const index = shapeShiftTxList.indexOf(index)
@@ -78,6 +144,14 @@ class ShapeshiftController {
     this.updateState({ shapeShiftTxList })
   }
 
+	/**
+	 * Creates a new ShapeShiftTx, adds it to the shapeShiftTxList, and initiates a new poll for updates of pending txs
+	 *
+   * @param {string} depositAddress - An address at which to send a crypto deposit, so that eth can be sent to the
+   * user's Metamask account
+   * @param {string} depositType - An abbreviation of the type of crypto currency to be deposited.
+	 *
+	 */
   createShapeShiftTx (depositAddress, depositType) {
     const state = this.store.getState()
     let { shapeShiftTxList } = state
diff --git a/app/scripts/lib/buy-eth-url.js b/app/scripts/lib/buy-eth-url.js
index b9dde3c28..c7c7bc33c 100644
--- a/app/scripts/lib/buy-eth-url.js
+++ b/app/scripts/lib/buy-eth-url.js
@@ -1,5 +1,15 @@
 module.exports = getBuyEthUrl
 
+/**
+ * Gives the caller a url at which the user can acquire eth, depending on the network they are in
+ *
+ * @param {object} opts Options required to determine the correct url
+ * @param {string} opts.network The network for which to return a url
+ * @param {string} opts.amount The amount of ETH to buy on coinbase. Only relevant if network === '1'.
+ * @param {string} opts.address The adderss the bought ETH should be sent to.  Only relevant if network === '1'.
+ * @returns {string} The url at which the user can access ETH, while in the given network
+ *
+ */
 function getBuyEthUrl ({ network, amount, address }) {
   let url
   switch (network) {
diff --git a/app/scripts/lib/get-first-preferred-lang-code.js b/app/scripts/lib/get-first-preferred-lang-code.js
index e3635434e..78448ad43 100644
--- a/app/scripts/lib/get-first-preferred-lang-code.js
+++ b/app/scripts/lib/get-first-preferred-lang-code.js
@@ -4,6 +4,13 @@ const allLocales = require('../../_locales/index.json')
 
 const existingLocaleCodes = allLocales.map(locale => locale.code.toLowerCase().replace('_', '-'))
 
+/**
+ * Returns a preferred language code, based on settings within the user's browser. If we have no translations for the
+ * users preferred locales, 'en' is returned.
+ *
+ * @returns {string} A locale code, either one from the user's preferred list that we have a translation for, or 'en'
+ *
+ */
 async function getFirstPreferredLangCode () {
   const userPreferredLocaleCodes = await promisify(
     extension.i18n.getAcceptLanguages,
diff --git a/app/scripts/lib/is-popup-or-notification.js b/app/scripts/lib/is-popup-or-notification.js
index ad3e825c0..894564def 100644
--- a/app/scripts/lib/is-popup-or-notification.js
+++ b/app/scripts/lib/is-popup-or-notification.js
@@ -1,8 +1,14 @@
+/**
+ * Indicates whether the user is viewing the app through an extension like window or through a notification.
+ * Used to make some style decisions on the frontend, and when deciding whether to close the popup in the backend.
+ *
+ * @returns {string} Returns 'popup' if the user is viewing through the browser ('home.html') or popup extension
+ * ('popup.html'). Otherwise it returns 'notification'.
+ *
+ */
 module.exports = function isPopupOrNotification () {
   const url = window.location.href
-  // if (url.match(/popup.html$/) || url.match(/home.html$/)) {
-  // Below regexes needed for feature toggles (e.g. see line ~340 in ui/app/app.js)
-  // Revert below regexes to above commented out regexes before merge to master
+
   if (url.match(/popup.html(?:\?.+)*$/) ||
     url.match(/home.html(?:\?.+)*$/) || url.match(/home.html(?:#.*)*$/)) {
     return 'popup'
diff --git a/app/scripts/lib/nodeify.js b/app/scripts/lib/nodeify.js
index 9b595d93c..d568035c0 100644
--- a/app/scripts/lib/nodeify.js
+++ b/app/scripts/lib/nodeify.js
@@ -1,6 +1,14 @@
 const promiseToCallback = require('promise-to-callback')
 const noop = function () {}
 
+/**
+ * A generator that returns a function which, when passed a promise, can treat that promise as a node style callback.
+ * The primse advantage being that callbacks are better for error handling.
+ *
+ * @params {Function} fn The function to handle as a callback
+ * @params {Object} context The context in which the fn is to be called, most often a this reference
+ *
+ */
 module.exports = function nodeify (fn, context) {
   return function () {
     const args = [].slice.call(arguments)
diff --git a/app/scripts/lib/util.js b/app/scripts/lib/util.js
index 6dee9edf0..11565790f 100644
--- a/app/scripts/lib/util.js
+++ b/app/scripts/lib/util.js
@@ -10,11 +10,28 @@ module.exports = {
   BnMultiplyByFraction,
 }
 
+/**
+ * Generates an example stack trace
+ *
+ * @returns {string} A stack trace
+ *
+ */
 function getStack () {
   const stack = new Error('Stack trace generator - not an error').stack
   return stack
 }
 
+/**
+ * Checks whether a given balance of ETH, represented as a hex string, is sufficient to pay a value plus a gas fee
+ *
+ * @param {object} txParams Contains data about a transaction
+ * @param {string} txParams.gas The gas for a transaction
+ * @param {string} txParams.gasPrice The price per gas for the transaction
+ * @param {string} txParams.value The value of ETH to send
+ * @param {string} hexBalance A balance of ETH represented as a hex string
+ * @returns {boolean} Whether the balance is greater than or equal to the value plus the value of gas times gasPrice
+ *
+ */
 function sufficientBalance (txParams, hexBalance) {
   // validate hexBalance is a hex string
   assert.equal(typeof hexBalance, 'string', 'sufficientBalance - hexBalance is not a hex string')
@@ -29,14 +46,37 @@ function sufficientBalance (txParams, hexBalance) {
   return balance.gte(maxCost)
 }
 
+/**
+ * Converts a BN object to a hex string with a '0x' prefix
+ *
+ * @param {BN} inputBn Description
+ * @returns {string} A hex string
+ *
+ */
 function bnToHex (inputBn) {
   return ethUtil.addHexPrefix(inputBn.toString(16))
 }
 
+/**
+ * Converts a hex string to a BN object
+ *
+ * @param {string} inputHex A number represented as a hex string
+ * @returns {Object} A BN object
+ *
+ */
 function hexToBn (inputHex) {
   return new BN(ethUtil.stripHexPrefix(inputHex), 16)
 }
 
+/**
+ * Used to multiply a BN by a fraction
+ *
+ * @param {BN} targetBN The number to multiply by a fraction
+ * @param {number|string} numerator
+ * @param {number|string} denominator
+ * @returns {BN} The product of the multiplication
+ *
+ */
 function BnMultiplyByFraction (targetBN, numerator, denominator) {
   const numBN = new BN(numerator)
   const denomBN = new BN(denominator)