text: // Copyright 2014 The Go Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style
  // license that can be found in the LICENSE file.
  
  package http2
  
  import "testing"
  
  func TestFlow(t *testing.T) {
  	var st flow
  	var conn flow
  	st.add(3)
  	conn.add(2)
  
  	if got, want := st.available(), int32(3); got != want {
  		t.Errorf("available = %d; want %d", got, want)
  	}
  	st.setConnFlow(&conn)
  	if got, want := st.available(), int32(2); got != want {
  		t.Errorf("after parent setup, available = %d; want %d", got, want)
  	}
  
  	st.take(2)
  	if got, want := conn.available(), int32(0); got != want {
  		t.Errorf("after taking 2, conn = %d; want %d", got, want)
  	}
  	if got, want := st.available(), int32(0); got != want {
  		t.Errorf("after taking 2, stream = %d; want %d", got, want)
  	}
  }
  
  func TestFlowAdd(t *testing.T) {
  	var f flow
  	if !f.add(1) {
  		t.Fatal("failed to add 1")
  	}
  	if !f.add(-1) {
  		t.Fatal("failed to add -1")
  	}
  	if got, want := f.available(), int32(0); got != want {
  		t.Fatalf("size = %d; want %d", got, want)
  	}
  	if !f.add(1<<31 - 1) {
  		t.Fatal("failed to add 2^31-1")
  	}
  	if got, want := f.available(), int32(1<<31-1); got != want {
  		t.Fatalf("size = %d; want %d", got, want)
  	}
  	if f.add(1) {
  		t.Fatal("adding 1 to max shouldn't be allowed")
  	}
  
  }
  