service2.js: Unify equal/same comparisons

service2.js

@@ -382,7 +382,7 @@ class BesDOMService extends BesService {
           // Block elements are grammar-checked independently.
           this.onProofing()
           let result = this.getProofing(node)
-          if (result != null) {
+          if (result) {
             this.onProofingProgress(result.matches.length)
             return [{ text: `<${node.tagName}/>`, node: node, markup: true }]
           }
@@ -663,14 +663,14 @@ class BesDOMService extends BesService {
     // Walk parent nodes from start to common ancestor.
     for (node = start.parentNode; node; node = node.parentNode) {
       nodes.push(node)
-      if (node == commonAncestor) break
+      if (node === commonAncestor) break
     }
     nodes.reverse()
 
     // Walk children and siblings from start until end node is found.
     for (node = start; node; node = BesDOMService.getNextNode(node)) {
       nodes.push(node)
-      if (node == end) break
+      if (node === end) break
     }
 
     return nodes
@@ -904,7 +904,7 @@ class BesPlainTextService extends BesService {
     ) {
       this.reEOP.lastIndex = start
       let match = this.reEOP.exec(text)
-      if (match !== null) {
+      if (match) {
         eop = match.index
         end = this.reEOP.lastIndex
       } else {
@@ -924,7 +924,7 @@ class BesPlainTextService extends BesService {
 
       this.onProofing()
       let result = this.getProofing(paragraphRange)
-      if (result != null) {
+      if (result) {
         this.onProofingProgress(result.matches.length)
         continue
       }
@@ -1550,7 +1550,7 @@ window.addEventListener('load', () => {
     if (hostElement.tagName === 'TEXTAREA') {
       BesTAService.register(hostElement)
     } else if (
-      hostElement.getAttribute('contenteditable').toLowerCase() ==
+      hostElement.getAttribute('contenteditable').toLowerCase() ===
       'plaintext-only'
     ) {
       BesPlainTextService.register(hostElement)