test: lint fixes for ESLint update

This commit introduces changes required for the ESLint 5 update.

PR-URL: #20855
Reviewed-By: Rich Trott <rtrott@gmail.com>

Author: cjihrig

test/es-module/test-esm-forbidden-globals.mjs

@@ -1,6 +1,7 @@
 // Flags: --experimental-modules
 import '../common';
 
+// eslint-disable-next-line no-undef
 if (typeof arguments !== 'undefined') {
   throw new Error('not an ESM');
 }

test/parallel/test-console-is-a-namespace.js

@@ -5,7 +5,8 @@ require('../common');
 const { test, assert_equals, assert_true, assert_false } =
   require('../common/wpt');
 
-global.console = global.console; // Should not throw.
+// Assigning to itself should not throw.
+global.console = global.console; // eslint-disable-line no-self-assign
 
 const self = global;
 

test/parallel/test-http2-socket-proxy.js

@@ -52,8 +52,8 @@ server.on('stream', common.mustCall(function(stream, headers) {
   common.expectsError(() => (socket.write = undefined), errMsg);
 
   // Resetting the socket listeners to their own value should not throw.
-  socket.on = socket.on;
-  socket.once = socket.once;
+  socket.on = socket.on;  // eslint-disable-line no-self-assign
+  socket.once = socket.once;  // eslint-disable-line no-self-assign
 
   stream.respond();