gRPC testing doc updates (#24644)

Co-authored-by: Luke Latham <1622880+guardrex@users.noreply.github.com>

aspnetcore/grpc/test-services.md

@@ -15,10 +15,11 @@ By: [James Newton-King](https://twitter.com/jamesnk)
 
 Testing is an important aspect of building stable and maintainable software. This article discusses how to test ASP.NET Core gRPC services.
 
-There are two common approaches for testing gRPC services:
+There are three common approaches for testing gRPC services:
 
 * **Unit testing**: Test gRPC services directly from a unit testing library.
-* **Integration testing**: The gRPC app is hosted in <xref:Microsoft.AspNetCore.TestHost.TestServer> from the [`Microsoft.AspNetCore.TestHost`](https://www.nuget.org/packages/Microsoft.AspNetCore.TestHost) package. gRPC services are tested by calling them using a gRPC client from a unit testing library.
+* **Integration testing**: The gRPC app is hosted in <xref:Microsoft.AspNetCore.TestHost.TestServer>, an in-memory test server from the [`Microsoft.AspNetCore.TestHost`](https://www.nuget.org/packages/Microsoft.AspNetCore.TestHost) package. gRPC services are tested by calling them using a gRPC client from a unit testing library.
+* **Manual testing**: Test gRPC servers with ad hoc calls. For information about how to use command-line and UI tooling with gRPC services, see <xref:grpc/test-tools>.
 
 In unit testing, only the gRPC service is involved. Dependencies injected into the service must be mocked. In integration testing, the gRPC service and its auxiliary infrastructure are part of the test. This includes app startup, dependency injection, routing and authentication, and authorization.
 

aspnetcore/grpc/test-tools.md

@@ -19,32 +19,22 @@ Tooling is available for gRPC that allows developers to test services without bu
 
 This article discusses how to:
 
-* Download and install gRPCurl and gRPCui.
 * Set up gRPC reflection with a gRPC ASP.NET Core app.
+* Download and install gRPCurl and gRPCui.
 * Discover and test gRPC services with `grpcurl`.
 * Interact with gRPC services via a browser using `grpcui`.
 
-## About gRPCurl
-
-gRPCurl is a command-line tool created by the gRPC community. Its features include:
-
-* Calling gRPC services, including streaming services.
-* Service discovery using [gRPC reflection](https://github.com/grpc/grpc/blob/master/doc/server-reflection.md).
-* Listing and describing gRPC services.
-* Works with secure (TLS) and insecure (plain-text) servers.
-
-For information about downloading and installing `grpcurl`, see the [gRPCurl GitHub homepage](https://github.com/fullstorydev/grpcurl#installation).
-
-![gRPCurl command line](~/grpc/test-tools/static/grpcurl.png)
+> [!NOTE]
+> To learn how to unit test gRPC services, see <xref:grpc/test-services>.
 
 ## Set up gRPC reflection
 
-`grpcurl` must know the Protobuf contract of services before it can call them. There are two ways to do this:
+Tooling must know the Protobuf contract of services before it can call them. There are two ways to do this:
 
-* Set up [gRPC reflection](https://github.com/grpc/grpc/blob/master/doc/server-reflection.md) on the server. gRPCurl automatically discovers service contracts.
+* Set up [gRPC reflection](https://github.com/grpc/grpc/blob/master/doc/server-reflection.md) on the server. Tools, such as gRPCurl and Postman, automatically discover service contracts.
 * Specify `.proto` files in command-line arguments to gRPCurl.
 
-It's easier to use gRPCurl with gRPC reflection. gRPC reflection adds a new gRPC service to the app that clients can call to discover services.
+It's easier to use gRPC reflection. gRPC reflection adds a new gRPC service to the app that clients can call to discover services.
 
 gRPC ASP.NET Core has built-in support for gRPC reflection with the [`Grpc.AspNetCore.Server.Reflection`](https://www.nuget.org/packages/Grpc.AspNetCore.Server.Reflection) package. To configure reflection in an app:
 
@@ -61,7 +51,20 @@ When gRPC reflection is set up:
 * Client apps that support gRPC reflection can call the reflection service to discover services hosted by the server.
 * gRPC services are still called from the client. Reflection only enables service discovery and doesn't bypass server-side security. Endpoints protected by [authentication and authorization](xref:grpc/authn-and-authz) require the caller to pass credentials for the endpoint to be called successfully.
 
-## Use `grpcurl`
+## gRPCurl
+
+gRPCurl is a command-line tool created by the gRPC community. Its features include:
+
+* Calling gRPC services, including streaming services.
+* Service discovery using [gRPC reflection](https://github.com/grpc/grpc/blob/master/doc/server-reflection.md).
+* Listing and describing gRPC services.
+* Works with secure (TLS) and insecure (plain-text) servers.
+
+For information about downloading and installing `grpcurl`, see the [gRPCurl GitHub homepage](https://github.com/fullstorydev/grpcurl#installation).
+
+![gRPCurl command line](~/grpc/test-tools/static/grpcurl.png)
+
+### Use `grpcurl`
 
 The `-help` argument explains `grpcurl` command-line options:
 
@@ -129,13 +132,13 @@ $ grpcurl -d '{ "name": "World" }' localhost:5001 greet.Greeter/SayHello
 }
 ```
 
-## About gRPCui
+## gRPCui
 
 gRPCui is an interactive web UI for gRPC. It builds on top of gRPCurl and offers a GUI for discovering and testing gRPC services, similar to HTTP tools such as Postman or Swagger UI.
 
 For information about downloading and installing `grpcui`, see the [gRPCui GitHub homepage](https://github.com/fullstorydev/grpcui#installation).
 
-## Using `grpcui`
+### Using `grpcui`
 
 Run `grpcui` with the server address to interact with as an argument: