From cd58695674679bdf070fea3390b86d51dddf0996 Mon Sep 17 00:00:00 2001
From: Michael Lumish <mlumish@google.com>
Date: Thu, 21 Apr 2022 16:09:24 -0700
Subject: [PATCH] grpc-js: Add regression tests for repeated DNS requests

---
 packages/grpc-js/test/test-resolver.ts | 64 ++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/packages/grpc-js/test/test-resolver.ts b/packages/grpc-js/test/test-resolver.ts
index 354413ea..512740ca 100644
--- a/packages/grpc-js/test/test-resolver.ts
+++ b/packages/grpc-js/test/test-resolver.ts
@@ -356,6 +356,70 @@ describe('Name Resolver', () => {
       const resolver2 = resolverManager.createResolver(target2, listener, {});
       resolver2.updateResolution();
     });
+    it('should not keep repeating successful resolutions', done => {
+      const target = resolverManager.mapUriDefaultScheme(parseUri('localhost')!)!;
+      let resultCount = 0;
+      const resolver = resolverManager.createResolver(target, {
+        onSuccessfulResolution: (
+          addressList: SubchannelAddress[],
+          serviceConfig: ServiceConfig | null,
+          serviceConfigError: StatusObject | null
+        ) => {
+          assert(
+            addressList.some(
+              addr =>
+                isTcpSubchannelAddress(addr) &&
+                addr.host === '127.0.0.1' &&
+                addr.port === 443
+            )
+          );
+          assert(
+            addressList.some(
+              addr =>
+                isTcpSubchannelAddress(addr) &&
+                addr.host === '::1' &&
+                addr.port === 443
+            )
+          );
+          resultCount += 1;
+          if (resultCount === 1) {
+            process.nextTick(() => resolver.updateResolution());
+          }
+        },
+        onError: (error: StatusObject) => {
+          assert.ifError(error);
+        },
+      }, {'grpc.dns_min_time_between_resolutions_ms': 2000});
+      resolver.updateResolution();
+      setTimeout(() => {
+        assert.strictEqual(resultCount, 2, `resultCount ${resultCount} !== 2`);
+        done();
+      }, 10_000);
+    }).timeout(15_000);
+    it('should not keep repeating failed resolutions', done => {
+      const target = resolverManager.mapUriDefaultScheme(parseUri('host.invalid')!)!;
+      let resultCount = 0;
+      const resolver = resolverManager.createResolver(target, {
+        onSuccessfulResolution: (
+          addressList: SubchannelAddress[],
+          serviceConfig: ServiceConfig | null,
+          serviceConfigError: StatusObject | null
+        ) => {
+          assert.fail('Resolution succeeded unexpectedly');
+        },
+        onError: (error: StatusObject) => {
+          resultCount += 1;
+          if (resultCount === 1) {
+            process.nextTick(() => resolver.updateResolution());
+          }
+        },
+      }, {});
+      resolver.updateResolution();
+      setTimeout(() => {
+        assert.strictEqual(resultCount, 2, `resultCount ${resultCount} !== 2`);
+        done();
+      }, 10_000);
+    }).timeout(15_000);
   });
   describe('UDS Names', () => {
     it('Should handle a relative Unix Domain Socket name', done => {