ronantakizawa/codereview-bench huggingface dataset:
Repository: grpc/grpc-go
File: internal/grpctest/tlogger.go (Go)

Code before:
	return "UNKNOWN"
}

const (
	infoLog logType = iota
	warningLog
	errorLog
	fatalLog
)

type tLogger struct {
	v           int
	initialized bool

	mu     sync.Mutex // guards t, start, and errors
	t      *testing.T
	start  time.Time
	errors map[*regexp.Regexp]int
}

func init() {
	tLogr = &tLogger{errors: map[*regexp.Regexp]int{}}
	vLevel := os.Getenv("GRPC_GO_LOG_VERBOSITY_LEVEL")
	if vl, err := strconv.Atoi(vLevel); err == nil {
		tLogr.v = vl
	}
}

func getLogger() *tLogger {
	return tLogr
}

// getCallingPrefix returns the <file:line> at the given depth from the stack.
func getCallingPrefix(depth int) (string, error) {
	_, file, line, ok := runtime.Caller(depth)
	if !ok {
		return "", errors.New("frame request out-of-bounds")
	}
	return fmt.Sprintf("%s:%d", path.Base(file), line), nil
}

// log logs the message with the specified parameters to the tLogger.
func (tl *tLogger) log(ltype logType, depth int, format string, args ...any) {
	tl.mu.Lock()
	defer tl.mu.Unlock()
	prefix, err := getCallingPrefix(callingFrame + depth)
	if err != nil {
		tl.t.Error(err)
		return
	}
	args = append([]any{ltype.String() + " " + prefix}, args...)

Review comment (suggestion):
While you are here, you could reorder this such that we read the env var first, and then initialize the `tLogger`. That way, you could directly set the `v` field using the literal struct initialization syntax.

Also, you could use `os.LookupEnv` instead of `os.GetEnv` to distinguish between an empty value and an unset value.

Code after:
	return "UNKNOWN"
}

const (
	infoLog logType = iota
	warningLog
	errorLog
	fatalLog
)

type tLogger struct {
	v           int
	initialized bool

	mu     sync.Mutex // guards t, start, and errors
	t      *testing.T
	start  time.Time
	errors map[*regexp.Regexp]int
}

func init() {
	vLevel := 0 // Default verbosity level

	if vLevelEnv, found := os.LookupEnv("GRPC_GO_LOG_VERBOSITY_LEVEL"); found {
		// If found, attempt to convert. If conversion is successful, update vLevel.
		// If conversion fails, log a warning, but vLevel remains its default of 0.
		if val, err := strconv.Atoi(vLevelEnv); err == nil {
			vLevel = val
		} else {
			// Log the error if the environment variable is not a valid integer.
			fmt.Printf("Warning: GRPC_GO_LOG_VERBOSITY_LEVEL environment variable '%s' is not a valid integer. "+
				"Using default verbosity level 0. Error: %v\n", vLevelEnv, err)
		}
	}
	// Initialize tLogr with the determined verbosity level.
	tLogr = &tLogger{errors: make(map[*regexp.Regexp]int), v: vLevel}
}

// getCallingPrefix returns the <file:line> at the given depth from the stack.
func getCallingPrefix(depth int) (string, error) {
	_, file, line, ok := runtime.Caller(depth)
	if !ok {
		return "", errors.New("frame request out-of-bounds")
	}
	return fmt.Sprintf("%s:%d", path.Base(file), line), nil
}

// log logs the message with the specified parameters to the tLogger.
func (tl *tLogger) log(ltype logType, depth int, format string, args ...any) {
	tl.mu.Lock()
	defer tl.mu.Unlock()
Repository: grpc/grpc-go
File: internal/balancergroup/balancergroup_test.go (Go)

Code before:
	case <-exitIdleCh:
	}
}

func (s) TestBalancerGroup_ExitIdleOne_AfterClose(t *testing.T) {
	balancerName := "stub-balancer-test-exit-idle-one-after-close"
	called := false

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			called = true
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()
	bg.ExitIdleOne(testBalancerIDs[0])

	if called {
		t.Fatalf("ExitIdleOne called ExitIdle on sub-balancer after BalancerGroup was closed")
	}
}

func (s) TestBalancerGroup_ExitIdleOne_NonExistentID(t *testing.T) {
	balancerName := "stub-balancer-test-exit-idle-one-missing-id"
	called := false

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			called = true
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})
	defer bg.Close()

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.ExitIdleOne("non-existent-id")


Review comment (suggestion):
This should be changed to waiting for a channel similar to the test above and wait for `defaultTestShortTimeout` to make sure it that `ExitIdleOne` is not called. Something like :

```
select {
    case <-exitIdleCh:
        t.Fatalf("ExitIdleOne called on sub-balancer after BalancerGroup was closed")
	case <-time.After(defaultTestShortTimeout):
	}
    ```

Code after:
	bg.ExitIdleOne(testBalancerIDs[0])
	select {
	case <-time.After(time.Second):
		t.Fatal("Timeout when waiting for ExitIdle to be invoked on child policy")
	case <-exitIdleCh:
	}
}

func (s) TestBalancerGroup_ExitIdleOne_AfterClose(t *testing.T) {
	balancerName := t.Name()
	exitIdleCh := make(chan struct{})

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			close(exitIdleCh)
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()
	bg.ExitIdleOne(testBalancerIDs[0])

	select {
	case <-time.After(defaultTestShortTimeout):
	case <-exitIdleCh:
		t.Fatalf("ExitIdleOne called ExitIdle on sub-balancer after BalancerGroup was closed")
	}
}

func (s) TestBalancerGroup_ExitIdleOne_NonExistentID(t *testing.T) {
	balancerName := t.Name()
	exitIdleCh := make(chan struct{}, 1)

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			exitIdleCh <- struct{}{}
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
Repository: grpc/grpc-go
File: internal/balancergroup/balancergroup_test.go (Go)

Code before:
		StateAggregator: nil,
		Logger:          nil,
	})
	defer bg.Close()

	bg.Add(testIDs[0], balancer.Get(balancerOne))
	bg.Add(testIDs[1], balancer.Get(balancerTwo))
	bg.Add(testIDs[2], balancer.Get(balancerThree))

	bg.ExitIdle()

	called := make(map[string]bool)
	for i := 0; i < len(balancerNames); i++ {
		select {
		case name := <-exitIdleCh:
			called[name] = true
		case <-time.After(time.Second):
			t.Fatalf("Timeout: ExitIdle not called for all sub-balancers, got %d/%d", len(called), len(balancerNames))
		}
	}

	for _, expected := range balancerNames {
		if !called[expected] {
			t.Errorf("ExitIdle was not called for sub-balancer registered as %q", expected)
		}
	}
}

func (s) TestBalancerGroup_ExitIdle_AfterClose(t *testing.T) {
	balancerName := "stub-balancer-test-balancer-group-exit-idle-after-close"
	called := false

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			called = true
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()
	bg.ExitIdle()

	if called {
		t.Fatalf("ExitIdle was called on sub-balancer even after BalancerGroup was closed")

Review comment (bug):
This block makes sense only in the case where one or more of the balancer's `ExitIdle` method is called twice and one of the balancer's method is not called. We could combine this check with the above block itself by checking if `called[name]` is already true and fail if it is.

Code after:
		ExitIdle: func(_ *stub.BalancerData) {
			exitIdleCh2 <- struct{}{}
		},
	})

	cc := testutils.NewBalancerClientConn(t)
	bg := New(Options{
		CC:              cc,
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})
	defer bg.Close()

	bg.Add(testID1, balancer.Get(balancer1))
	bg.Add(testID2, balancer.Get(balancer2))

	bg.ExitIdle()

	errCh := make(chan error, 2)

	go func() {
		select {
		case <-exitIdleCh1:
			errCh <- nil
		case <-time.After(defaultTestTimeout):
			errCh <- fmt.Errorf("timeout waiting for ExitIdle on balancer1")
		}
	}()

	go func() {
		select {
		case <-exitIdleCh2:
			errCh <- nil
		case <-time.After(defaultTestTimeout):
			errCh <- fmt.Errorf("timeout waiting for ExitIdle on balancer2")
		}
	}()

	for i := 0; i < 2; i++ {
		if err := <-errCh; err != nil {
			t.Fatal(err)
		}
	}
}

func (s) TestBalancerGroup_ExitIdle_AfterClose(t *testing.T) {
	balancerName := t.Name()
	exitIdleCh := make(chan struct{}, 1)

	stub.Register(balancerName, stub.BalancerFuncs{
Repository: grpc/grpc-go
File: internal/balancergroup/balancergroup_test.go (Go)

Code before:
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})
	defer bg.Close()

	// Add the stub balancer build above as a child policy.
	builder := balancer.Get(balancerName)
	bg.Add(testBalancerIDs[0], builder)

	// Call ExitIdleOne on the child policy.
	bg.ExitIdleOne(testBalancerIDs[0])
	select {
	case <-time.After(time.Second):
		t.Fatal("Timeout when waiting for ExitIdle to be invoked on child policy")
	case <-exitIdleCh:
	}
}

func (s) TestBalancerGroup_ExitIdleOne_AfterClose(t *testing.T) {
	balancerName := "stub-balancer-test-exit-idle-one-after-close"
	called := false

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			called = true
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()
	bg.ExitIdleOne(testBalancerIDs[0])

	if called {
		t.Fatalf("ExitIdleOne called ExitIdle on sub-balancer after BalancerGroup was closed")
	}
}

func (s) TestBalancerGroup_ExitIdleOne_NonExistentID(t *testing.T) {
	balancerName := "stub-balancer-test-exit-idle-one-missing-id"
	called := false

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {

Review comment (suggestion):
```suggestion
			close(exitIdleCh)
```
Here instead of a variable , a channel can be closed and waited for in a select block since this operation is done only once.

Code after:
	})
	cc := testutils.NewBalancerClientConn(t)
	bg := New(Options{
		CC:              cc,
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})
	defer bg.Close()

	// Add the stub balancer build above as a child policy.
	builder := balancer.Get(balancerName)
	bg.Add(testBalancerIDs[0], builder)

	// Call ExitIdleOne on the child policy.
	bg.ExitIdleOne(testBalancerIDs[0])
	select {
	case <-time.After(time.Second):
		t.Fatal("Timeout when waiting for ExitIdle to be invoked on child policy")
	case <-exitIdleCh:
	}
}

func (s) TestBalancerGroup_ExitIdleOne_AfterClose(t *testing.T) {
	balancerName := t.Name()
	exitIdleCh := make(chan struct{})

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			close(exitIdleCh)
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()
	bg.ExitIdleOne(testBalancerIDs[0])

	select {
	case <-time.After(defaultTestShortTimeout):
	case <-exitIdleCh:
		t.Fatalf("ExitIdleOne called ExitIdle on sub-balancer after BalancerGroup was closed")
	}
}
Repository: grpc/grpc-go
File: internal/balancergroup/balancergroup_test.go (Go)

Code before:
	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()

	err := bg.UpdateClientConnState(testBalancerIDs[0], balancer.ClientConnState{})
	if err != nil {
		t.Fatalf("Expected nil error, got %v", err)
	}
	if called {
		t.Fatalf("UpdateClientConnState was called after BalancerGroup was closed")
	}
}

func (s) TestBalancerGroup_ResolverError_AfterClose(t *testing.T) {
	balancerName := "stub-balancer-test-resolver-error-after-close"
	called := false

	stub.Register(balancerName, stub.BalancerFuncs{
		ResolverError: func(_ *stub.BalancerData, _ error) {
			called = true
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()

	bg.ResolverError(errors.New("test error"))

	if called {
		t.Fatalf("ResolverError was called on sub-balancer after BalancerGroup was closed")
	}
}

func (s) TestBalancerExitIdleOne(t *testing.T) {
	const balancerName = "stub-balancer-test-balancergroup-exit-idle-one"
	exitIdleCh := make(chan struct{}, 1)
	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(*stub.BalancerData) {

Review comment (suggestion):
Change to use channel here too. In the check add a `defaultShortTestTimeout` case along with wait for channel in select block.

Code after:
	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()

	if err := bg.UpdateClientConnState(testBalancerIDs[0], balancer.ClientConnState{}); err != nil {
		t.Fatalf("Expected nil error, got %v", err)
	}

	select {
	case <-clientConnStateCh:
		t.Fatalf("UpdateClientConnState was called after BalancerGroup was closed")
	case <-time.After(defaultTestShortTimeout):
	}
}

func (s) TestBalancerGroup_ResolverError_AfterClose(t *testing.T) {
	balancerName := t.Name()
	resolveErrorCh := make(chan struct{}, 1)

	stub.Register(balancerName, stub.BalancerFuncs{
		ResolverError: func(_ *stub.BalancerData, _ error) {
			resolveErrorCh <- struct{}{}
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()

	bg.ResolverError(errors.New("test error"))

	select {
	case <-resolveErrorCh:
		t.Fatalf("ResolverError was called on sub-balancer after BalancerGroup was closed")
	case <-time.After(defaultTestShortTimeout):
	}
}

func (s) TestBalancerExitIdleOne(t *testing.T) {
Repository: grpc/grpc-go
File: internal/balancergroup/balancergroup_test.go (Go)

Code before:

func (s) TestBalancerGroup_ExitIdle_AfterClose(t *testing.T) {
	balancerName := "stub-balancer-test-balancer-group-exit-idle-after-close"
	exitIdleCh := make(chan struct{})

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			close(exitIdleCh)
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()
	bg.ExitIdle()

	select {
	case <-exitIdleCh:
		t.Fatalf("ExitIdle was called on sub-balancer even after BalancerGroup was closed")
	case <-time.After(defaultTestTimeout):
	}
}


Review comment (suggestion):
```suggestion
	case <-time.After(defaultShortTestTimeout):
```
We use `defaultShortTestTimeout` to wait for some time for cases that are *not* expected to happen , and use `defaultTestTimeout` for cases that are expected to happen.


Code after:
			errCh <- fmt.Errorf("timeout waiting for ExitIdle on balancer1")
		}
	}()

	go func() {
		select {
		case <-exitIdleCh2:
			errCh <- nil
		case <-time.After(defaultTestTimeout):
			errCh <- fmt.Errorf("timeout waiting for ExitIdle on balancer2")
		}
	}()

	for i := 0; i < 2; i++ {
		if err := <-errCh; err != nil {
			t.Fatal(err)
		}
	}
}

func (s) TestBalancerGroup_ExitIdle_AfterClose(t *testing.T) {
	balancerName := t.Name()
	exitIdleCh := make(chan struct{}, 1)

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			exitIdleCh <- struct{}{}
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()
	bg.ExitIdle()

	select {
	case <-exitIdleCh:
		t.Fatalf("ExitIdle was called on sub-balancer even after BalancerGroup was closed")
	case <-time.After(defaultTestShortTimeout):
	}
}
Repository: grpc/grpc-go
File: internal/balancergroup/balancergroup_test.go (Go)

Code before:
	}
}

func (s) TestBalancerGroup_ExitIdleOne_AfterClose(t *testing.T) {
	balancerName := "stub-balancer-test-exit-idle-one-after-close"
	exitIdleCh := make(chan struct{})

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			close(exitIdleCh)
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()
	bg.ExitIdleOne(testBalancerIDs[0])

	select {
	case <-time.After(time.Second):
	case <-exitIdleCh:
		t.Fatalf("ExitIdleOne called ExitIdle on sub-balancer after BalancerGroup was closed")
	}
}

func (s) TestBalancerGroup_ExitIdleOne_NonExistentID(t *testing.T) {
	balancerName := "stub-balancer-test-exit-idle-one-missing-id"
	called := false

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			called = true
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})
	defer bg.Close()

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.ExitIdleOne("non-existent-id")

Review comment (suggestion):
```suggestion
	case <-time.After(defaultTestTImeout):
```

Code after:
	select {
	case <-time.After(time.Second):
		t.Fatal("Timeout when waiting for ExitIdle to be invoked on child policy")
	case <-exitIdleCh:
	}
}

func (s) TestBalancerGroup_ExitIdleOne_AfterClose(t *testing.T) {
	balancerName := t.Name()
	exitIdleCh := make(chan struct{})

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			close(exitIdleCh)
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()
	bg.ExitIdleOne(testBalancerIDs[0])

	select {
	case <-time.After(defaultTestShortTimeout):
	case <-exitIdleCh:
		t.Fatalf("ExitIdleOne called ExitIdle on sub-balancer after BalancerGroup was closed")
	}
}

func (s) TestBalancerGroup_ExitIdleOne_NonExistentID(t *testing.T) {
	balancerName := t.Name()
	exitIdleCh := make(chan struct{}, 1)

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			exitIdleCh <- struct{}{}
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})
Repository: grpc/grpc-go
File: internal/balancergroup/balancergroup_test.go (Go)

Code before:
	}
}

func (s) TestBalancerGroup_ExitIdleOne_AfterClose(t *testing.T) {
	balancerName := "stub-balancer-test-exit-idle-one-after-close"
	exitIdleCh := make(chan struct{})

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			close(exitIdleCh)
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()
	bg.ExitIdleOne(testBalancerIDs[0])

	select {
	case <-time.After(defaultTestTimeout):
	case <-exitIdleCh:
		t.Fatalf("ExitIdleOne called ExitIdle on sub-balancer after BalancerGroup was closed")
	}
}

func (s) TestBalancerGroup_ExitIdleOne_NonExistentID(t *testing.T) {
	balancerName := "stub-balancer-test-exit-idle-one-missing-id"
	called := false

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			called = true
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})
	defer bg.Close()

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.ExitIdleOne("non-existent-id")

Review comment (suggestion):
```suggestion
	case <-time.After(defaultTestShortTimeout):
```

Code after:

func (s) TestBalancerGroup_ExitIdleOne_AfterClose(t *testing.T) {
	balancerName := t.Name()
	exitIdleCh := make(chan struct{})

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			close(exitIdleCh)
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.Close()
	bg.ExitIdleOne(testBalancerIDs[0])

	select {
	case <-time.After(defaultTestShortTimeout):
	case <-exitIdleCh:
		t.Fatalf("ExitIdleOne called ExitIdle on sub-balancer after BalancerGroup was closed")
	}
}

func (s) TestBalancerGroup_ExitIdleOne_NonExistentID(t *testing.T) {
	balancerName := t.Name()
	exitIdleCh := make(chan struct{}, 1)

	stub.Register(balancerName, stub.BalancerFuncs{
		ExitIdle: func(_ *stub.BalancerData) {
			exitIdleCh <- struct{}{}
		},
	})

	bg := New(Options{
		CC:              testutils.NewBalancerClientConn(t),
		BuildOpts:       balancer.BuildOptions{},
		StateAggregator: nil,
		Logger:          nil,
	})
	defer bg.Close()

	bg.Add(testBalancerIDs[0], balancer.Get(balancerName))
	bg.ExitIdleOne("non-existent-id")

	select {