QuantumKatas/SuperdenseCoding/Tests.qs

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT license.

//////////////////////////////////////////////////////////////////////
// This file contains testing harness for all tasks.
// You should not modify anything in this file.
// The tasks themselves can be found in Tasks.qs file.
//////////////////////////////////////////////////////////////////////

namespace Quantum.Kata.SuperdenseCoding {
    
    open Microsoft.Quantum.Intrinsic;
    open Microsoft.Quantum.Diagnostics;
    
    
    // ------------------------------------------------------
    @Test("QuantumSimulator")    
    operation T1_CreateEntangledPair () : Unit {
        use (q1, q2) = (Qubit(), Qubit());

        // apply operation that needs to be tested
        CreateEntangledPair(q1, q2);

        // apply adjoint reference operation and check that the result is |0^N⟩
        Adjoint CreateEntangledPair_Reference(q1, q2);

        // assert that all qubits end up in |0⟩ state
        AssertAllZero([q1, q2]);
    }
    
    
    // ------------------------------------------------------
    // Helper operation that runs superdense coding protocol using two building blocks
    // specified as first two parameters.
    operation ComposeProtocol (
		encodeOp : ((Qubit, ProtocolMessage) => Unit), 
		decodeOp : ((Qubit, Qubit) => ProtocolMessage), 
		message : ProtocolMessage
	) : ProtocolMessage {
        
        use qs = Qubit[2];
        CreateEntangledPair_Reference(qs[0], qs[1]);
        encodeOp(qs[0], message);
        return decodeOp(qs[0], qs[1]);
    }
    
    
    // ------------------------------------------------------
    // Helper operation that runs superdense coding protocol (specified by protocolOp)
    // on all possible input values and verifies that decoding result matches the inputs
    operation TestProtocol (protocolOp : (ProtocolMessage => ProtocolMessage)) : Unit {
        
        // Loop over the 4 possible combinations of two bits
        for n in 0 .. 3 {
            let data = ProtocolMessage(1 == n / 2, 1 == n % 2);
            
            for iter in 1 .. 100 {
                let result = protocolOp(data);
                
                // Now test if the bits were transfered correctly.
                Fact(result::Bit1 == data::Bit1 and result::Bit2 == data::Bit2, 
                    $"{data} was transfered incorrectly as {result}");
            }
        }
    }
    
    @Test("QuantumSimulator")
    operation T2_EncodeMessageInQubit () : Unit {
        TestProtocol(ComposeProtocol(EncodeMessageInQubit, DecodeMessageFromQubits_Reference, _));
    }
    
    @Test("QuantumSimulator")
    operation T3_DecodeMessageFromQubits () : Unit {
        TestProtocol(ComposeProtocol(EncodeMessageInQubit_Reference, DecodeMessageFromQubits, _));
    }
    
    @Test("QuantumSimulator")
    operation T4_SuperdenseCodingProtocol () : Unit {
        TestProtocol(SuperdenseCodingProtocol);
    }
    
}