TDD for trees comparison in C++

tdd-trees-comp-c++

Build with: `g++ test.cpp && ./a.out`

For editing two files in `vim` run command `:vsplit tree.h`.

http://www.cs.swarthmore.edu/help/vim/windows.html

test.cpp

#include <iostream>
#include <string>
#include "tree.h"

using namespace std;

void assert(bool test, string message) {
	string res = test ? "   pass" : "failure";
	cout << res << " - " << message << endl;
}

int main() {
	node n;
	n.data = 42; n.left = 0; n.right = 0;
	assert(n.data == 42, "node defines data");

	node * a = 0; node * b = 0;
	assert(
		compare(a, b),
		"compares two null trees"
	);

	a = new node;
	assert(
		compare(a, b) == false,
		"compares null and non-null trees"
	);

	b = new node; a->data = 42; b->data = 13;

	assert(
		compare(a, b) == false,
		"compares non-null trees diff data"
	);

	b->data = 42;
	a->left = 0; a->right = 0;
	b->left = 0; b->right = 0;

	assert(
		compare(a, b) == true,
		"compares non-null trees same data"
	);

	a->left = new node;

	assert(
		compare(a, b) == false,
		"non-null trees same data diff subtree"
	);

	return 0;
}

tree.h

// This file will define a tree data structure
// and a function that compares two trees

class node {
public:
	int data;
	node * left;
	node * right;
};

bool compare(node * a, node * b) {
	if( a == 0 && b == 0 ) {
		return true;
	}
	if( a == 0 || b == 0 ) {
		return false;
	}
	if( a->data != b->data ) {
		return false;
	}

	return compare(a->left, b->left) &&
	       compare(a->right, b->right);
};