perf: Use strict equals

packages/babel-parser/src/parser/expression.js

@@ -525,7 +525,7 @@ export default class ExpressionParser extends LValParser {
     } else if (this.match(tt.questionDot)) {
       this.expectPlugin("optionalChaining");
       state.optionalChainMember = true;
-      if (noCalls && this.lookahead().type == tt.parenL) {
+      if (noCalls && this.lookahead().type === tt.parenL) {
         state.stop = true;
         return base;
       }

packages/babel-parser/src/parser/statement.js

@@ -161,7 +161,7 @@ export default class StatementParser extends ExpressionParser {
         this.next();
 
         let result;
-        if (starttype == tt._import) {
+        if (starttype === tt._import) {
           result = this.parseImport(node);
 
           if (
@@ -693,9 +693,9 @@ export default class StatementParser extends ExpressionParser {
     node.body = this.parseStatement(declaration);
 
     if (
-      node.body.type == "ClassDeclaration" ||
-      (node.body.type == "VariableDeclaration" && node.body.kind !== "var") ||
-      (node.body.type == "FunctionDeclaration" &&
+      node.body.type === "ClassDeclaration" ||
+      (node.body.type === "VariableDeclaration" && node.body.kind !== "var") ||
+      (node.body.type === "FunctionDeclaration" &&
         (this.state.strict || node.body.generator || node.body.async))
     ) {
       this.raise(node.body.start, "Invalid labeled declaration");

packages/babel-parser/src/parser/util.js

@@ -25,7 +25,7 @@ export default class UtilParser extends Tokenizer {
 
   isLookaheadRelational(op: "<" | ">"): boolean {
     const l = this.lookahead();
-    return l.type == tt.relational && l.value == op;
+    return l.type === tt.relational && l.value === op;
   }
 
   // TODO

packages/babel-parser/src/plugins/flow.js

@@ -1630,7 +1630,7 @@ export default (superClass: Class<Parser>): Class<Parser> =>
         this.match(tt.name) &&
         (this.state.value === "type" ||
           this.state.value === "interface" ||
-          this.state.value == "opaque")
+          this.state.value === "opaque")
       ) {
         return false;
       }