Declare variables before use (#6806)

While working on #6805, I noticed that many variables were being used
before they were declared. Technically this worked fine in practice
because we were using the `transform-es2015-block-scoping` Babel plugin,
which transforms `let` and `const` to `var`, which is hoisted. However,
after removing that Babel transformation, many things broke.

All instances of variables or classes being used before declared have
been fixed.

The `no-use-before-define` eslint rule has been added to catch these
cases going forward. The rule is disabled for function declarations for
the moment, because those are always hoisted. We could disable that too
if we want to, but it's purely stylistic and would require a lot more
changes.

.eslintrc

@@ -134,6 +134,7 @@
     "no-unreachable": 2,
     "no-unsafe-finally": 2,
     "no-unused-vars": [2, { "vars": "all", "args": "all", "argsIgnorePattern": "[_]+" }],
+    "no-use-before-define": [2, { "functions": false }],
     "no-useless-call": 2,
     "no-useless-computed-key": 2,
     "no-useless-constructor": 2,

app/scripts/inpage.js

@@ -1,4 +1,36 @@
 /*global Web3*/
+
+
+// need to make sure we aren't affected by overlapping namespaces
+// and that we dont affect the app with our namespace
+// mostly a fix for web3's BigNumber if AMD's "define" is defined...
+let __define
+
+/**
+ * Caches reference to global define object and deletes it to
+ * avoid conflicts with other global define objects, such as
+ * AMD's define function
+ */
+const cleanContextForImports = () => {
+  __define = global.define
+  try {
+    global.define = undefined
+  } catch (_) {
+    console.warn('MetaMask - global.define could not be deleted.')
+  }
+}
+
+/**
+ * Restores global define object from cached reference
+ */
+const restoreContextAfterImports = () => {
+  try {
+    global.define = __define
+  } catch (_) {
+    console.warn('MetaMask - global.define could not be overwritten.')
+  }
+}
+
 cleanContextForImports()
 require('web3/dist/web3.min.js')
 const log = require('loglevel')
@@ -46,6 +78,20 @@ inpageProvider.enable = function ({ force } = {}) {
 // this will be default true so it does not break any old apps.
 inpageProvider.autoRefreshOnNetworkChange = true
 
+
+// publicConfig isn't populated until we get a message from background.
+// Using this getter will ensure the state is available
+const getPublicConfigWhenReady = async () => {
+  const store = inpageProvider.publicConfigStore
+  let state = store.getState()
+  // if state is missing, wait for first update
+  if (!state.networkVersion) {
+    state = await new Promise(resolve => store.once('update', resolve))
+    console.log('new state', state)
+  }
+  return state
+}
+
 // add metamask-specific convenience methods
 inpageProvider._metamask = new Proxy({
   /**
@@ -87,19 +133,6 @@ inpageProvider._metamask = new Proxy({
   },
 })
 
-// publicConfig isn't populated until we get a message from background.
-// Using this getter will ensure the state is available
-async function getPublicConfigWhenReady () {
-  const store = inpageProvider.publicConfigStore
-  let state = store.getState()
-  // if state is missing, wait for first update
-  if (!state.networkVersion) {
-    state = await new Promise(resolve => store.once('update', resolve))
-    console.log('new state', state)
-  }
-  return state
-}
-
 // Work around for [email protected] deleting the bound `sendAsync` but not the unbound
 // `sendAsync` method on the prototype, causing `this` reference issues with drizzle
 const proxiedInpageProvider = new Proxy(inpageProvider, {
@@ -161,33 +194,3 @@ inpageProvider.publicConfigStore.subscribe(function (state) {
     window.postMessage('onboardingcomplete', '*')
   }
 })
-
-// need to make sure we aren't affected by overlapping namespaces
-// and that we dont affect the app with our namespace
-// mostly a fix for web3's BigNumber if AMD's "define" is defined...
-let __define
-
-/**
- * Caches reference to global define object and deletes it to
- * avoid conflicts with other global define objects, such as
- * AMD's define function
- */
-function cleanContextForImports () {
-  __define = global.define
-  try {
-    global.define = undefined
-  } catch (_) {
-    console.warn('MetaMask - global.define could not be deleted.')
-  }
-}
-
-/**
- * Restores global define object from cached reference
- */
-function restoreContextAfterImports () {
-  try {
-    global.define = __define
-  } catch (_) {
-    console.warn('MetaMask - global.define could not be overwritten.')
-  }
-}

app/scripts/lib/createStreamSink.js

@@ -1,13 +1,6 @@
 const WritableStream = require('readable-stream').Writable
 const promiseToCallback = require('promise-to-callback')
 
-module.exports = createStreamSink
-
-
-function createStreamSink (asyncWriteFn, _opts) {
-  return new AsyncWritableStream(asyncWriteFn, _opts)
-}
-
 class AsyncWritableStream extends WritableStream {
 
   constructor (asyncWriteFn, _opts) {
@@ -22,3 +15,9 @@ class AsyncWritableStream extends WritableStream {
   }
 
 }
+
+function createStreamSink (asyncWriteFn, _opts) {
+  return new AsyncWritableStream(asyncWriteFn, _opts)
+}
+
+module.exports = createStreamSink

test/unit/app/controllers/metamask-controller-test.js

@@ -679,19 +679,6 @@ describe('MetaMaskController', function () {
   })
 
   describe('#newUnsignedPersonalMessage', function () {
-
-    it('errors with no from in msgParams', async () => {
-      const msgParams = {
-        'data': data,
-      }
-      try {
-        await metamaskController.newUnsignedPersonalMessage(msgParams)
-        assert.fail('should have thrown')
-      } catch (error) {
-        assert.equal(error.message, 'MetaMask Message Signature: from field is required.')
-      }
-    })
-
     let msgParams, metamaskPersonalMsgs, personalMessages, msgId
 
     const address = '0xc42edfcc21ed14dda456aa0756c153f7985d8813'
@@ -718,6 +705,18 @@ describe('MetaMaskController', function () {
       personalMessages[0].msgParams.metamaskId = parseInt(msgId)
     })
 
+    it('errors with no from in msgParams', async () => {
+      const msgParams = {
+        'data': data,
+      }
+      try {
+        await metamaskController.newUnsignedPersonalMessage(msgParams)
+        assert.fail('should have thrown')
+      } catch (error) {
+        assert.equal(error.message, 'MetaMask Message Signature: from field is required.')
+      }
+    })
+
     it('persists address from msg params', function () {
       assert.equal(metamaskPersonalMsgs[msgId].msgParams.from, address)
     })

test/unit/ui/app/reducers/app.spec.js

@@ -700,7 +700,7 @@ describe('App State', () => {
   })
 
   it('hides sub loading indicator', () => {
-    const oldState = {...metamaskState, ...oldState}
+    const oldState = {...metamaskState, isSubLoading: true }
     const state = reduceApp(oldState, {
       type: actions.HIDE_SUB_LOADING_INDICATION,
     })

ui/app/helpers/utils/conversion-util.js

@@ -37,13 +37,6 @@ const BIG_NUMBER_WEI_MULTIPLIER = new BigNumber('1000000000000000000')
 const BIG_NUMBER_GWEI_MULTIPLIER = new BigNumber('1000000000')
 const BIG_NUMBER_ETH_MULTIPLIER = new BigNumber('1')
 
-// Individual Setters
-const convert = R.invoker(1, 'times')
-const round = R.invoker(2, 'round')(R.__, BigNumber.ROUND_HALF_DOWN)
-const roundDown = R.invoker(2, 'round')(R.__, BigNumber.ROUND_DOWN)
-const invertConversionRate = conversionRate => () => new BigNumber(1.0).div(conversionRate)
-const decToBigNumberViaString = () => R.pipe(String, toBigNumber['dec'])
-
 // Setter Maps
 const toBigNumber = {
   hex: n => new BigNumber(stripHexPrefix(n), 16),
@@ -66,6 +59,13 @@ const baseChange = {
   BN: n => new BN(n.toString(16)),
 }
 
+// Individual Setters
+const convert = R.invoker(1, 'times')
+const round = R.invoker(2, 'round')(R.__, BigNumber.ROUND_HALF_DOWN)
+const roundDown = R.invoker(2, 'round')(R.__, BigNumber.ROUND_DOWN)
+const invertConversionRate = conversionRate => () => new BigNumber(1.0).div(conversionRate)
+const decToBigNumberViaString = () => R.pipe(String, toBigNumber['dec'])
+
 // Predicates
 const fromAndToCurrencyPropsNotEqual = R.compose(
   R.not,

ui/app/pages/routes/index.js

@@ -183,18 +183,6 @@ class Routes extends Component {
       this.getConnectingLabel(loadingMessage) : null
     log.debug('Main ui render function')
 
-    const sidebarOnOverlayClose = sidebarType === WALLET_VIEW_SIDEBAR
-      ? () => {
-        this.context.metricsEvent({
-          eventOpts: {
-            category: 'Navigation',
-            action: 'Wallet Sidebar',
-            name: 'Closed Sidebare Via Overlay',
-          },
-        })
-      }
-      : null
-
     const {
       isOpen: sidebarIsOpen,
       transitionName: sidebarTransitionName,
@@ -203,6 +191,18 @@ class Routes extends Component {
     } = sidebar
     const { transaction: sidebarTransaction } = props || {}
 
+    const sidebarOnOverlayClose = sidebarType === WALLET_VIEW_SIDEBAR
+    ? () => {
+      this.context.metricsEvent({
+        eventOpts: {
+          category: 'Navigation',
+          action: 'Wallet Sidebar',
+          name: 'Closed Sidebare Via Overlay',
+        },
+      })
+    }
+    : null
+
     return (
       <div
         className="app"

ui/app/store/actions.js

@@ -1210,6 +1210,20 @@ function signTokenTx (tokenAddress, toAddress, amount, txData) {
   }
 }
 
+const updateMetamaskStateFromBackground = () => {
+  log.debug(`background.getState`)
+
+  return new Promise((resolve, reject) => {
+    background.getState((error, newState) => {
+      if (error) {
+        return reject(error)
+      }
+
+      resolve(newState)
+    })
+  })
+}
+
 function updateTransaction (txData) {
   log.info('actions: updateTx: ' + JSON.stringify(txData))
   return dispatch => {
@@ -1618,20 +1632,6 @@ const backgroundSetLocked = () => {
   })
 }
 
-const updateMetamaskStateFromBackground = () => {
-  log.debug(`background.getState`)
-
-  return new Promise((resolve, reject) => {
-    background.getState((error, newState) => {
-      if (error) {
-        return reject(error)
-      }
-
-      resolve(newState)
-    })
-  })
-}
-
 function lockMetamask () {
   log.debug(`background.setLocked`)