mathjs/test/expression/node/ConstantNode.test.js

// test ConstantNode
var assert = require('assert'),
    approx = require('../../../tools/approx'),
    math = require('../../../index'),
    bigmath = require('../../../index').create({number: 'bignumber'}),
    Node = require('../../../lib/expression/node/Node'),
    ConstantNode = require('../../../lib/expression/node/ConstantNode'),
    SymbolNode = require('../../../lib/expression/node/SymbolNode');

describe('ConstantNode', function() {

  it ('should create a ConstantNode with value type', function () {
    var a = new ConstantNode('3', 'number');
    assert(a instanceof Node);
    assert.equal(a.type, 'ConstantNode');
  });

  it ('should create a ConstantNode without value type', function () {
    var a = new ConstantNode(3);
    assert(a instanceof Node);
    assert.equal(a.type, 'ConstantNode');
    // TODO: extensively test each of the supported types

    assert.deepEqual(new ConstantNode(3), new ConstantNode('3', 'number'));
    assert.deepEqual(new ConstantNode('hello'), new ConstantNode('hello', 'string'));
    assert.deepEqual(new ConstantNode(true), new ConstantNode('true', 'boolean'));
    assert.deepEqual(new ConstantNode(false), new ConstantNode('false', 'boolean'));
    assert.deepEqual(new ConstantNode(null), new ConstantNode('null', 'null'));
    assert.deepEqual(new ConstantNode(undefined), new ConstantNode('undefined', 'undefined'));
  });

  it ('should throw an error when calling without new operator', function () {
    assert.throws(function () {ConstantNode('3', 'number')}, SyntaxError);
  });

  it ('should throw an error in case of wrong construction arguments', function () {
    assert.throws(function () {new ConstantNode(3, 'number');}, TypeError);
    assert.throws(function () {new ConstantNode(new Date());}, TypeError);
    assert.throws(function () {new ConstantNode('3', Number);}, TypeError);
  });

  it ('should throw an error in case of unknown type of constant', function () {
    assert.throws(function () {new ConstantNode('3', 'bla').compile(math);}, TypeError);
  });

  it ('should compile a ConstantNode', function () {
    var expr = new ConstantNode('2.3', 'number').compile(math);
    assert.strictEqual(expr.eval(), 2.3);

    expr = new ConstantNode('002.3', 'number').compile(math);
    assert.strictEqual(expr.eval(), 2.3);

    expr = new ConstantNode('hello', 'string').compile(math);
    assert.strictEqual(expr.eval(), 'hello');

    expr = new ConstantNode('true', 'boolean').compile(math);
    assert.strictEqual(expr.eval(), true);

    expr = new ConstantNode('undefined', 'undefined').compile(math);
    assert.strictEqual(expr.eval(), undefined);

    expr = new ConstantNode('null', 'null').compile(math);
    assert.strictEqual(expr.eval(), null);

  });

  it ('should compile a ConstantNode with bigmath', function () {
    var expr = new ConstantNode('2.3', 'number').compile(bigmath);
    assert.deepEqual(expr.eval(), new bigmath.type.BigNumber(2.3));
  });

  it ('should find a ConstantNode', function () {
    var a = new ConstantNode('2', 'number');
    assert.deepEqual(a.find({type: ConstantNode}),  [a]);
    assert.deepEqual(a.find({type: SymbolNode}), []);
  });

  it ('should match a ConstantNode', function () {
    var a = new ConstantNode('2', 'number');
    assert.equal(a.match({type: ConstantNode}),  true);
    assert.equal(a.match({properties: {value: '2'}}), true);
    assert.equal(a.match({properties: {value: '4'}}), false);
    assert.equal(a.match({type: SymbolNode}), false);
  });

  it ('should stringify a ConstantNode', function () {
    assert.equal(new ConstantNode('3', 'number').toString(), '3');
    assert.deepEqual(new ConstantNode('3', 'number').toString(), '3');
    assert.equal(new ConstantNode('hi', 'string').toString(), '"hi"');
    assert.equal(new ConstantNode('true', 'boolean').toString(), 'true');
    assert.equal(new ConstantNode('false', 'boolean').toString(), 'false');
    assert.equal(new ConstantNode('undefined', 'undefined').toString(), 'undefined');
    assert.equal(new ConstantNode('null', 'null').toString(), 'null');
  });

  it ('should LaTeX a ConstantNode', function () {
    assert.equal(new ConstantNode('3', 'number').toTex(), '3');
    assert.deepEqual(new ConstantNode('3', 'number').toTex(), '3');
    assert.equal(new ConstantNode('hi', 'string').toTex(), '\\text{hi}');
    assert.equal(new ConstantNode('true', 'boolean').toTex(), 'true');
    assert.equal(new ConstantNode('false', 'boolean').toTex(), 'false');
    assert.equal(new ConstantNode('undefined', 'undefined').toTex(), 'undefined');
    assert.equal(new ConstantNode('null', 'null').toTex(), 'null');
  });

});