change the internal var name for clarity (from PR review)

Author: trentm

plugins/node/opentelemetry-instrumentation-express/src/instrumentation.ts

@@ -62,11 +62,11 @@ export class ExpressInstrumentation extends InstrumentationBase<ExpressInstrumen
         'express',
         ['>=4.0.0 <6'],
         moduleExports => {
-          const isExpressV5 =
+          const isExpressWithRouterPrototype =
             typeof moduleExports?.Router?.prototype?.route === 'function';
-          const routerProto = isExpressV5
-            ? moduleExports.Router.prototype
-            : moduleExports.Router;
+          const routerProto = isExpressWithRouterPrototype
+            ? moduleExports.Router.prototype // Express v5
+            : moduleExports.Router; // Express v4
           // patch express.Router.route
           if (isWrapped(routerProto.route)) {
             this._unwrap(routerProto, 'route');
@@ -86,15 +86,15 @@ export class ExpressInstrumentation extends InstrumentationBase<ExpressInstrumen
             moduleExports.application,
             'use',
             // eslint-disable-next-line @typescript-eslint/no-explicit-any
-            this._getAppUsePatch(isExpressV5) as any
+            this._getAppUsePatch(isExpressWithRouterPrototype) as any
           );
           return moduleExports;
         },
         moduleExports => {
           if (moduleExports === undefined) return;
-          const isExpressV5 =
+          const isExpressWithRouterPrototype =
             typeof moduleExports?.Router?.prototype?.route === 'function';
-          const routerProto = isExpressV5
+          const routerProto = isExpressWithRouterPrototype
             ? moduleExports.Router.prototype
             : moduleExports.Router;
           this._unwrap(routerProto, 'route');
@@ -144,7 +144,7 @@ export class ExpressInstrumentation extends InstrumentationBase<ExpressInstrumen
   /**
    * Get the patch for Application.use function
    */
-  private _getAppUsePatch(isExpressV5: boolean) {
+  private _getAppUsePatch(isExpressWithRouterPrototype: boolean) {
     const instrumentation = this;
     return function (original: express.Application['use']) {
       return function use(
@@ -154,7 +154,9 @@ export class ExpressInstrumentation extends InstrumentationBase<ExpressInstrumen
       ) {
         // If we access app.router in express 4.x we trigger an assertion error.
         // This property existed in v3, was removed in v4 and then re-added in v5.
-        const router = isExpressV5 ? this.router : this._router;
+        const router = isExpressWithRouterPrototype
+          ? this.router
+          : this._router;
         const route = original.apply(this, args);
         if (router) {
           const layer = router.stack[router.stack.length - 1];