mathjs/test/expression/node/RangeNode.test.js

// test RangeNode
var assert = require('assert'),
    approx = require('../../../tools/approx'),
    math = require('../../../index'),
    Node = require('../../../lib/expression/node/Node'),
    ConstantNode = require('../../../lib/expression/node/ConstantNode'),
    SymbolNode = require('../../../lib/expression/node/SymbolNode'),
    RangeNode = require('../../../lib/expression/node/RangeNode'),
  OperatorNode = require('../../../lib/expression/node/OperatorNode');

describe('RangeNode', function() {

  it ('should create a RangeNode', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var n = new RangeNode(start, end);
    assert(n instanceof RangeNode);
    assert(n instanceof Node);
    assert.equal(n.type, 'RangeNode');
  });

  it ('should throw an error when calling without new operator', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    assert.throws(function () {RangeNode([start, end])}, SyntaxError);
  });

  it ('should throw an error creating a RangeNode with wrong number or type of arguments', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);

    assert.throws(function () { new RangeNode(); }, TypeError);
    assert.throws(function () { new RangeNode(start); }, TypeError);
    assert.throws(function () { new RangeNode([]); }, TypeError);
    assert.throws(function () { new RangeNode(start, end, start, end); }, Error);
    assert.throws(function () { new RangeNode(0, 10); }, TypeError);
  });

  it ('should compile a RangeNode', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var step = new ConstantNode(2);
    var n = new RangeNode(start, end, step);

    var expr = n.compile(math);
    assert.deepEqual(expr.eval(), math.matrix([0, 2, 4, 6, 8, 10]));
  });

  it ('should filter a RangeNode', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var step = new ConstantNode(2);
    var n = new RangeNode(start, end, step);

    assert.deepEqual(n.filter(function (node) {return node instanceof RangeNode}),  [n]);
    assert.deepEqual(n.filter(function (node) {return node instanceof SymbolNode}),  []);
    assert.deepEqual(n.filter(function (node) {return node instanceof ConstantNode}),  [start, end, step]);
    assert.deepEqual(n.filter(function (node) {return node instanceof ConstantNode && node.value == '2'}),  [step]);
    assert.deepEqual(n.filter(function (node) {return node instanceof ConstantNode && node.value == '4'}),  []);
  });

  it ('should run forEach on a RangeNode', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var step = new ConstantNode(2);
    var n = new RangeNode(start, end, step);

    var nodes = [];
    var paths = [];
    n.forEach(function (node, path, parent) {
      nodes.push(node);
      paths.push(path);
      assert.strictEqual(parent, n);
    });

    assert.equal(nodes.length, 3);
    assert.strictEqual(nodes[0], start);
    assert.strictEqual(nodes[1], end);
    assert.strictEqual(nodes[2], step);
    assert.deepEqual(paths, ['start', 'end', 'step']);
  });

  it ('should map a RangeNode', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var step = new ConstantNode(2);
    var n = new RangeNode(start, end, step);

    var nodes = [];
    var paths = [];
    var e = new ConstantNode(3);
    var f = n.map(function (node, path, parent) {
      nodes.push(node);
      paths.push(path);
      assert.strictEqual(parent, n);

      return node instanceof ConstantNode && node.value == '0' ? e : node;
    });

    assert.equal(nodes.length, 3);
    assert.strictEqual(nodes[0], start);
    assert.strictEqual(nodes[1], end);
    assert.strictEqual(nodes[2], step);
    assert.deepEqual(paths, ['start', 'end', 'step']);

    assert.notStrictEqual(f, n);
    assert.deepEqual(f.start,  e);
    assert.deepEqual(f.end,  end);
    assert.deepEqual(f.step,  step);
  });

  it ('should throw an error when the map callback does not return a node', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var step = new ConstantNode(2);
    var n = new RangeNode(start, end, step);

    assert.throws(function () {
      n.map(function () {});
    }, /Callback function must return a Node/)
  });

  it ('should transform a RangeNodes start', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var step = new ConstantNode(2);
    var n = new RangeNode(start, end, step);

    var e = new ConstantNode(3);
    var f = n.transform(function (node) {
      return node instanceof ConstantNode && node.value == '0' ? e : node;
    });

    assert.notStrictEqual(f, n);
    assert.deepEqual(f.start,  e);
    assert.deepEqual(f.end,  end);
    assert.deepEqual(f.step,  step);
  });

  it ('should transform a RangeNodes end', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var step = new ConstantNode(2);
    var n = new RangeNode(start, end, step);

    var e = new ConstantNode(3);
    var f = n.transform(function (node) {
      return node instanceof ConstantNode && node.value == '10' ? e : node;
    });

    assert.notStrictEqual(f, n);
    assert.deepEqual(f.start,  start);
    assert.deepEqual(f.end,  e);
    assert.deepEqual(f.step,  step);
  });

  it ('should transform a RangeNodes step', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var step = new ConstantNode(2);
    var n = new RangeNode(start, end, step);

    var e = new ConstantNode(3);
    var f = n.transform(function (node) {
      return node instanceof ConstantNode && node.value == '2' ? e : node;
    });

    assert.notStrictEqual(f, n);
    assert.deepEqual(f.start, start);
    assert.deepEqual(f.end, end);
    assert.deepEqual(f.step, e);
  });

  it ('should transform a RangeNodes without step', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var n = new RangeNode(start, end);

    var e = new ConstantNode(3);
    var f = n.transform(function (node) {
      return node instanceof ConstantNode && node.value == '10' ? e : node;
    });

    assert.notStrictEqual(f, n);
    assert.deepEqual(f.start, start);
    assert.deepEqual(f.end, e);
  });

  it ('should transform a RangeNode itself', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var step = new ConstantNode(2);
    var n = new RangeNode(start, end, step);

    var e = new ConstantNode(5);
    var f = n.transform(function (node) {
      return node instanceof RangeNode ? e : node;
    });

    assert.deepEqual(f, e);
  });

  it ('should clone a RangeNode', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var step = new ConstantNode(2);
    var c = new RangeNode(start, end, step);

    var d = c.clone();

    assert.deepEqual(d, c);
    assert.notStrictEqual(d, c);
    assert.strictEqual(d.start, c.start);
    assert.strictEqual(d.end, c.end);
    assert.strictEqual(d.step, c.step);
  });

  it ('should clone a RangeNode without step', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var c = new RangeNode(start, end);

    var d = c.clone();

    assert(d instanceof RangeNode);
    assert.deepEqual(d, c);
    assert.notStrictEqual(d, c);
    assert.strictEqual(d.start, c.start);
    assert.strictEqual(d.end, c.end);
    assert.strictEqual(d.step, c.step);
    assert.strictEqual(d.step, null);
  });

  it ('should stringify a RangeNode without step', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var n = new RangeNode(start, end);

    assert.equal(n.toString(), '0:10');
  });

  it ('should stringify a RangeNode with step', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var step = new ConstantNode(2);
    var n = new RangeNode(start, end, step);

    assert.equal(n.toString(), '0:2:10');
  });
  
  it ('should stringify a RangeNode with an OperatorNode', function () {
    var a = new ConstantNode(1);
    var b = new ConstantNode(2);

    var o1 = new OperatorNode('+', 'add', [a, b]);
    var o2 = new OperatorNode('<', 'smaller', [a, b]);

    var n = new RangeNode(o1, o1, o2);

    assert.equal(n.toString(), '1 + 2:(1 < 2):1 + 2');
  });

  it ('should stringify a RangeNode with a RangeNode', function () {
    var start1 = new ConstantNode(0);
    var end1 = new ConstantNode(10);
    var step2 = new ConstantNode(2);
    var end2 = new ConstantNode(100);

    var start2 = new RangeNode(start1, end1);
    var n = new RangeNode(start2, end2, step2);

    assert.equal(n.toString(), '(0:10):2:100');
  });

  it ('should LaTeX a RangeNode without step', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var n = new RangeNode(start, end);

    assert.equal(n.toTex(), '0:10');
  });

  it ('should LaTeX a RangeNode with step', function () {
    var start = new ConstantNode(0);
    var end = new ConstantNode(10);
    var step = new ConstantNode(2);
    var n = new RangeNode(start, end, step);

    assert.equal(n.toTex(), '0:2:10');
  });

  it ('should LaTeX a RangeNode with custom toTex', function () {
    //Also checks if the custom functions get passed on to the children
    var customFunction = function (node, callback) {
      if (node.type === 'RangeNode') {
        return 'from ' + node.start.toTex(callback)
          + ' to ' + node.end.toTex(callback)
          + ' with steps of ' + node.step.toTex(callback);
      }
      else if (node.type === 'ConstantNode') {
        return 'const\\left(' + node.value + ', ' + node.valueType + '\\right)'
      }
    };

    var a = new ConstantNode(1);
    var b = new ConstantNode(2);
    var c = new ConstantNode(3);

    var n = new RangeNode(a, b, c);

    assert.equal(n.toTex(customFunction), 'from const\\left(1, number\\right) to const\\left(2, number\\right) with steps of const\\left(3, number\\right)');
  });

});