project_tests.py

'''
You should not edit project_tests.py as part of your submission.

This file is used for unit testing your work within main.py.
'''

import sys
import os
from copy import deepcopy
from glob import glob
from unittest import mock

import numpy as np
import tensorflow as tf


def test_safe(func):
    """
    Isolate tests
    """
    def func_wrapper(*args):
        with tf.Graph().as_default():
            result = func(*args)
        print('Tests Passed')
        return result

    return func_wrapper


def _prevent_print(function, params):
    """
    Prevent print statements for a given function
    :param function: The function in which to repress any prints to the terminal
    :param params: Parameters to feed into function
    """
    sys.stdout = open(os.devnull, "w")
    function(**params)
    sys.stdout = sys.__stdout__


def _assert_tensor_shape(tensor, shape, display_name):
    """
    Check whether the tensor and another shape match in shape
    :param tensor: TF Tensor
    :param shape: Some array
    :param display_name: Name of tensor to print if assertions fail
    """
    assert tf.assert_rank(tensor, len(shape), message='{} has wrong rank'.format(display_name))

    tensor_shape = tensor.get_shape().as_list() if len(shape) else []

    wrong_dimension = [ten_dim for ten_dim, cor_dim in zip(tensor_shape, shape)
                       if cor_dim is not None and ten_dim != cor_dim]
    assert not wrong_dimension, \
        '{} has wrong shape.  Found {}'.format(display_name, tensor_shape)


class TmpMock(object):
    """
    Mock a attribute.  Restore attribute when exiting scope.
    """
    def __init__(self, module, attrib_name):
        self.original_attrib = deepcopy(getattr(module, attrib_name))
        setattr(module, attrib_name, mock.MagicMock())
        self.module = module
        self.attrib_name = attrib_name

    def __enter__(self):
        return getattr(self.module, self.attrib_name)

    def __exit__(self, type, value, traceback):
        setattr(self.module, self.attrib_name, self.original_attrib)


@test_safe
def test_load_vgg(load_vgg, tf_module):
    """
    Test whether `load_vgg()` is correctly implemented, based on layers 3, 4 and 7.
    :param load_vgg: A function to load vgg layers 3, 4 and 7.
    :param tf_module: The tensorflow module import
    """
    with TmpMock(tf_module.saved_model.loader, 'load') as mock_load_model:
        vgg_path = ''
        sess = tf.Session()
        test_input_image = tf.placeholder(tf.float32, name='image_input')
        test_keep_prob = tf.placeholder(tf.float32, name='keep_prob')
        test_vgg_layer3_out = tf.placeholder(tf.float32, name='layer3_out')
        test_vgg_layer4_out = tf.placeholder(tf.float32, name='layer4_out')
        test_vgg_layer7_out = tf.placeholder(tf.float32, name='layer7_out')

        input_image, keep_prob, vgg_layer3_out, vgg_layer4_out, vgg_layer7_out = load_vgg(sess, vgg_path)

        assert mock_load_model.called, \
            'tf.saved_model.loader.load() not called'
        assert mock_load_model.call_args == mock.call(sess, ['vgg16'], vgg_path), \
            'tf.saved_model.loader.load() called with wrong arguments.'

        assert input_image == test_input_image, 'input_image is the wrong object'
        assert keep_prob == test_keep_prob, 'keep_prob is the wrong object'
        assert vgg_layer3_out == test_vgg_layer3_out, 'layer3_out is the wrong object'
        assert vgg_layer4_out == test_vgg_layer4_out, 'layer4_out is the wrong object'
        assert vgg_layer7_out == test_vgg_layer7_out, 'layer7_out is the wrong object'


@test_safe
def test_layers(layers):
    """
    Test whether `layers()` function is correctly implemented.
    param: layers: An implemented `layers()` function with deconvolutional layers in a FCN.
    """
    num_classes = 2
    vgg_layer3_out = tf.placeholder(tf.float32, [None, None, None, 256])
    vgg_layer4_out = tf.placeholder(tf.float32, [None, None, None, 512])
    vgg_layer7_out = tf.placeholder(tf.float32, [None, None, None, 4096])
    layers_output = layers(vgg_layer3_out, vgg_layer4_out, vgg_layer7_out, num_classes)

    _assert_tensor_shape(layers_output, [None, None, None, num_classes], 'Layers Output')


@test_safe
def test_optimize(optimize):
    """
    Test whether the `optimize()` function correctly creates logits and the training optimizer.
    If the optimize is not set correctly, training will fail to update weights.
    :param optimize: An implemented `optimize()` function.
    """
    num_classes = 2
    shape = [2, 3, 4, num_classes]
    layers_output = tf.Variable(tf.zeros(shape))
    correct_label = tf.placeholder(tf.float32, [None, None, None, num_classes])
    learning_rate = tf.placeholder(tf.float32)
    logits, train_op, cross_entropy_loss = optimize(layers_output, correct_label, learning_rate, num_classes)

    _assert_tensor_shape(logits, [2*3*4, num_classes], 'Logits')

    with tf.Session() as sess:
        sess.run(tf.global_variables_initializer())
        sess.run([train_op], {correct_label: np.arange(np.prod(shape)).reshape(shape), learning_rate: 10})
        test, loss = sess.run([layers_output, cross_entropy_loss], {correct_label: np.arange(np.prod(shape)).reshape(shape)})

    assert test.min() != 0 or test.max() != 0, 'Training operation not changing weights.'


@test_safe
def test_train_nn(train_nn):
    """
    Test whether the `train_nn()` function correctly begins training a neural network on simple data.
    :param train_nn: An implemented `train_nn()` function.
    """
    epochs = 1
    batch_size = 2

    def get_batches_fn(batch_size_param):
        shape = [batch_size_param, 2, 3, 3]
        return np.arange(np.prod(shape)).reshape(shape)

    train_op = tf.constant(0)
    cross_entropy_loss = tf.constant(10.11)
    input_image = tf.placeholder(tf.float32, name='input_image')
    correct_label = tf.placeholder(tf.float32, name='correct_label')
    keep_prob = tf.placeholder(tf.float32, name='keep_prob')
    learning_rate = tf.placeholder(tf.float32, name='learning_rate')
    with tf.Session() as sess:
        parameters = {
            'sess': sess,
            'epochs': epochs,
            'batch_size': batch_size,
            'get_batches_fn': get_batches_fn,
            'train_op': train_op,
            'cross_entropy_loss': cross_entropy_loss,
            'input_image': input_image,
            'correct_label': correct_label,
            'keep_prob': keep_prob,
            'learning_rate': learning_rate}
        _prevent_print(train_nn, parameters)


@test_safe
def test_for_kitti_dataset(data_dir):
    """
    Test whether the KITTI dataset has been downloaded, and whether the full, correct dataset is present.
    :param data_dir: Directory where the KITTI dataset was downloaded into.
    """
    kitti_dataset_path = os.path.join(data_dir, 'data_road')
    training_labels_count = len(glob(os.path.join(kitti_dataset_path, 'training/gt_image_2/*_road_*.png')))
    training_images_count = len(glob(os.path.join(kitti_dataset_path, 'training/image_2/*.png')))
    testing_images_count = len(glob(os.path.join(kitti_dataset_path, 'testing/image_2/*.png')))

    assert not (training_images_count == training_labels_count == testing_images_count == 0),\
        'Kitti dataset not found. Extract Kitti dataset in {}'.format(kitti_dataset_path)
    assert training_images_count == 289, 'Expected 289 training images, found {} images.'.format(training_images_count)
    assert training_labels_count == 289, 'Expected 289 training labels, found {} labels.'.format(training_labels_count)
    assert testing_images_count == 290, 'Expected 290 testing images, found {} images.'.format(testing_images_count)