Fix no-plusplus issues (#9206)

See [`no-plusplus`](https://eslint.org/docs/rules/no-plusplus) for more information.

This change enables `no-plusplus` and fixes the issues raised by the rule.

.eslintrc.js

@@ -51,6 +51,7 @@ module.exports = {
     'no-empty': 'error',
     'no-eq-null': 'error',
     'no-loop-func': 'error',
+    'no-plusplus': ['error', { 'allowForLoopAfterthoughts': true }],
     'no-useless-catch': 'error',
     'no-useless-concat': 'error',
     /* End v2 rules */

app/scripts/controllers/transactions/index.js

@@ -684,7 +684,7 @@ export default class TransactionController extends EventEmitter {
       if (!('retryCount' in txMeta)) {
         txMeta.retryCount = 0
       }
-      txMeta.retryCount++
+      txMeta.retryCount += 1
       this.txStateManager.updateTx(txMeta, 'transactions/pending-tx-tracker#event: tx:retry')
     })
   }

app/scripts/lib/random-id.js

@@ -3,5 +3,6 @@ const MAX = Number.MAX_SAFE_INTEGER
 let idCounter = Math.round(Math.random() * MAX)
 export default function createRandomId () {
   idCounter = idCounter % MAX
+  // eslint-disable-next-line no-plusplus
   return idCounter++
 }

app/scripts/metamask-controller.js

@@ -1519,7 +1519,7 @@ export default class MetamaskController extends EventEmitter {
     const api = this.getApi()
     const dnode = Dnode(api)
     // report new active controller connection
-    this.activeControllerConnections++
+    this.activeControllerConnections += 1
     this.emit('controllerConnectionChanged', this.activeControllerConnections)
     // connect dnode api to remote connection
     pump(
@@ -1528,7 +1528,7 @@ export default class MetamaskController extends EventEmitter {
       outStream,
       (err) => {
         // report new active controller connection
-        this.activeControllerConnections--
+        this.activeControllerConnections -= 1
         this.emit('controllerConnectionChanged', this.activeControllerConnections)
         // report any error
         if (err) {

app/scripts/migrations/019.js

@@ -72,7 +72,7 @@ function getHighestContinuousFrom (txList, startPoint) {
 
   let highest = startPoint
   while (nonces.includes(highest)) {
-    highest++
+    highest += 1
   }
 
   return highest

development/sourcemap-validator.js

@@ -91,7 +91,7 @@ async function validateSourcemapForFile ({ buildName }) {
   const matchesPerLine = buildLines.map((line) => indicesOf(targetString, line))
   matchesPerLine.forEach((matchIndices, lineIndex) => {
     matchIndices.forEach((matchColumn) => {
-      sampleCount++
+      sampleCount += 1
       const position = { line: lineIndex + 1, column: matchColumn }
       const result = consumer.originalPositionFor(position)
       // warn if source content is missing

test/unit/migrations/023-test.js

@@ -41,7 +41,7 @@ while (transactions.length <= 100) {
   // This is an old migration, let's allow it
   // eslint-disable-next-line no-loop-func
   if (!deletableTxStates.find((s) => s === status)) {
-    nonDeletableCount++
+    nonDeletableCount += 1
   }
   transactions.push({ status })
 }
@@ -67,7 +67,7 @@ describe('storage is migrated successfully and the proper transactions are remov
         const migratedTransactions = migratedData.data.TransactionController.transactions
         migratedTransactions.forEach((tx) => {
           if (!deletableTxStates.find((s) => s === tx.status)) {
-            leftoverNonDeletableTxCount++
+            leftoverNonDeletableTxCount += 1
           }
         })
         assert.equal(leftoverNonDeletableTxCount, nonDeletableCount, "migration shouldn't delete transactions we want to keep")

ui/app/components/app/gas-customization/gas-price-chart/gas-price-chart.utils.js

@@ -163,7 +163,7 @@ export function setSelectedCircle ({
     while (lowerX === higherX) {
       higherX = getCoordinateData(`.c3-circle-${count}`).x
       higherY = getCoordinateData(`.c3-circle-${count}`).y
-      count++
+      count += 1
     }
   }
 

ui/app/components/app/modals/fade-modal.js

@@ -22,6 +22,7 @@ const insertRule = (css) => {
 
 const insertKeyframesRule = (keyframes) => {
   // random name
+  // eslint-disable-next-line no-plusplus
   const name = 'anim_' + (++index) + (+new Date())
   let css = `@keyframes ${name} {`
 

ui/app/pages/mobile-sync/mobile-sync.component.js

@@ -173,8 +173,10 @@ export default class MobileSyncPage extends Component {
   chunkString (str, size) {
     const numChunks = Math.ceil(str.length / size)
     const chunks = new Array(numChunks)
-    for (let i = 0, o = 0; i < numChunks; ++i, o += size) {
+    for (let i = 0, o = 0; i < numChunks;) {
       chunks[i] = str.substr(o, size)
+      i += 1
+      o += size
     }
     return chunks
   }