java.lang.Object
- io.grpc.stub.CallStreamObserver<V>
- - io.grpc.stub.ServerCallStreamObserver<ResponseT>
  - - pl.morgwai.base.grpc.utils.FakeResponseObserver<ResponseT>

All Implemented Interfaces:

StreamObserver<ResponseT>
```
public class FakeResponseObserver<ResponseT>
extends ServerCallStreamObserver<ResponseT>
```
A fake ServerCallStreamObserver testing helper class. Helps to emulate behavior of a client and the gRPC system in server-side infrastructure code tests.
Note: in most cases it is better to use io.grpc.inprocess.InProcessChannelBuilder for testing gRPC methods. This class is mainly intended for testing infrastructure parts.

Usage:
1. Configure observer's readiness by adjusting outputBufferSize and unreadyDurationMillis variables.
2. Depending on client type (unary/streaming) of your gRPC method pass it to one of callWithinListenerLock(Consumer), callWithinListenerLock(Function, Consumer) methods.
3. awaitFinalization(long) can be used to wait until onCompleted() or onError(Throwable) is called.
4. Client canceling can be simulated using cancel() method.
5. Results can be verified with getOutputData(), getFinalizedCount(), getReportedError() methods and by shutting down and inspecting FakeResponseObserver.LoggingExecutor supplied to the constructor.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class FakeResponseObserver.LoggingExecutor
Logs task scheduling and executions and scheduling rejections.

Field Summary

Fields
Modifier and Type	Field	Description
`boolean`	`failOnMultipleFinalizations`	Should an IllegalStateException be thrown immediately upon second finalization.
`int`	`outputBufferSize`	Response observer becomes unready after each `outputBufferSize` messages are submitted to it.
`long`	`unreadyDurationMillis`	Duration for which observer will be unready.

Constructor Summary

Constructors
Constructor Description

FakeResponseObserver(FakeResponseObserver.LoggingExecutor grpcInternalExecutor)

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`awaitFinalization(long timeoutMillis)`	Awaits until finalization (call to either `onCompleted()` or `onError(Throwable)`) occurs or `timoutMillis` passes.
`void`	`callWithinListenerLock(Consumer<StreamObserver<ResponseT>> unaryClientMethod)`	Calls `unaryClientMethod` within listener's lock.
`<RequestT> void`	`callWithinListenerLock(Function<StreamObserver<ResponseT>,StreamObserver<RequestT>> streamingClientMethod, Consumer<StreamObserver<RequestT>> requestProducer)`	Calls `streamingClientMethod` within listener's lock and delivers request messages to returned request observer from `requestProducer`.
`void`	`cancel()`	Simulates client canceling a call by a client.
`void`	`disableAutoInboundFlowControl()`
`void`	`disableAutoRequest()`
`int`	`getFinalizedCount()`	Count of calls to `onCompleted()` and `onError(Throwable)`.
`static Logger`	`getLogger()`
`List<ResponseT>`	`getOutputData()`	List of arguments of calls to `onNext(Object)`.
`static long`	`getRemainingMillis(long startMillis, long timeoutMillis)`
`Throwable`	`getReportedError()`	Stored argument of `onError(Throwable)`.
`boolean`	`isCancelled()`
`boolean`	`isReady()`
`void`	`onCompleted()`
`void`	`onError(Throwable t)`
`void`	`onNext(ResponseT message)`
`void`	`request(int count)`
`void`	`runWithinListenerLock(Runnable handler)`	For low level testing of onReady and onCancel handlers.
`void`	`setCompression(String compression)`
`void`	`setMessageCompression(boolean enable)`
`void`	`setOnCancelHandler(Runnable onCancelHandler)`
`void`	`setOnReadyHandler(Runnable onReadyHandler)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - outputBufferSize
```
public volatile int outputBufferSize
```
    Response observer becomes unready after each outputBufferSize messages are submitted to it. Default is 0 which means always ready.
  - unreadyDurationMillis
```
public volatile long unreadyDurationMillis
```
    Duration for which observer will be unready. By default 1ms.
  - failOnMultipleFinalizations
```
public boolean failOnMultipleFinalizations
```
    Should an IllegalStateException be thrown immediately upon second finalization. By default true.
- Constructor Detail
  - FakeResponseObserver
```
public FakeResponseObserver(FakeResponseObserver.LoggingExecutor grpcInternalExecutor)
```
    Parameters:
    
    grpcInternalExecutor - executor for gRPC internal tasks, such as marking response observer as ready, delivering requested messages etc. Its pool size should be not smaller than the number of requests concurrently processed by the code under test (usually determined by the argument of the initial call to ServerCallStreamObserver.request(int).
- Method Detail
  - getOutputData
```
public List<ResponseT> getOutputData()
```
    List of arguments of calls to onNext(Object).
  - callWithinListenerLock
```
public void callWithinListenerLock(Consumer<StreamObserver<ResponseT>> unaryClientMethod)
```
    Calls unaryClientMethod within listener's lock.
  - callWithinListenerLock
```
public <RequestT> void callWithinListenerLock(Function<StreamObserver<ResponseT>,StreamObserver<RequestT>> streamingClientMethod,
                                              Consumer<StreamObserver<RequestT>> requestProducer)
```
    Calls streamingClientMethod within listener's lock and delivers request messages to returned request observer from requestProducer.
    
    Parameters:
    
    requestProducer - dispatched to grpcInternalExecutor whenever request(int) method is called. It should usually call its argument's StreamObserver.onNext(Object) possibly followed by StreamObserver.onCompleted() or StreamObserver.onError(Throwable) to simulate client's behavior. It may sleep arbitrarily long to simulate before the above calls to simulate client's or network delay.
  - runWithinListenerLock
```
public void runWithinListenerLock(Runnable handler)
```
    For low level testing of onReady and onCancel handlers.
  - onNext
```
public void onNext(ResponseT message)
```
  - isReady
```
public boolean isReady()
```
    Specified by:
    
    isReady in class ServerCallStreamObserver<ResponseT>
  - setOnReadyHandler
```
public void setOnReadyHandler(Runnable onReadyHandler)
```
    Specified by:
    
    setOnReadyHandler in class ServerCallStreamObserver<ResponseT>
  - getFinalizedCount
```
public int getFinalizedCount()
```
    Count of calls to onCompleted() and onError(Throwable). Should be 1 at the end of positive test methods.
  - onCompleted
```
public void onCompleted()
```
  - onError
```
public void onError(Throwable t)
```
  - getReportedError
```
public Throwable getReportedError()
```
    Stored argument of onError(Throwable).
  - awaitFinalization
```
public void awaitFinalization(long timeoutMillis)
                       throws InterruptedException
```
    Awaits until finalization (call to either onCompleted() or onError(Throwable)) occurs or timoutMillis passes.
    
    Throws:
    
    RuntimeException - if timoutMillis is exceeded.
    
    InterruptedException
  - getRemainingMillis
```
public static long getRemainingMillis(long startMillis,
                                      long timeoutMillis)
```
  - disableAutoRequest
```
public void disableAutoRequest()
```
    Overrides:
    
    disableAutoRequest in class ServerCallStreamObserver<ResponseT>
  - disableAutoInboundFlowControl
```
public void disableAutoInboundFlowControl()
```
    Specified by:
    
    disableAutoInboundFlowControl in class CallStreamObserver<ResponseT>
  - request
```
public void request(int count)
```
    Specified by:
    
    request in class ServerCallStreamObserver<ResponseT>
  - cancel
```
public void cancel()
```
    Simulates client canceling a call by a client.
  - isCancelled
```
public boolean isCancelled()
```
    Specified by:
    
    isCancelled in class ServerCallStreamObserver<ResponseT>
  - setOnCancelHandler
```
public void setOnCancelHandler(Runnable onCancelHandler)
```
    Specified by:
    
    setOnCancelHandler in class ServerCallStreamObserver<ResponseT>
  - setCompression
```
public void setCompression(String compression)
```
    Specified by:
    
    setCompression in class ServerCallStreamObserver<ResponseT>
  - setMessageCompression
```
public void setMessageCompression(boolean enable)
```
    Specified by:
    
    setMessageCompression in class ServerCallStreamObserver<ResponseT>
  - getLogger
```
public static Logger getLogger()
```

Class FakeResponseObserver<ResponseT>

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

outputBufferSize

unreadyDurationMillis

failOnMultipleFinalizations

Constructor Detail

FakeResponseObserver

Method Detail

getOutputData

callWithinListenerLock

callWithinListenerLock

runWithinListenerLock

onNext

isReady

setOnReadyHandler

getFinalizedCount

onCompleted

onError

getReportedError

awaitFinalization

getRemainingMillis

disableAutoRequest

disableAutoInboundFlowControl

request

cancel

isCancelled

setOnCancelHandler

setCompression

setMessageCompression

getLogger