jamiebuilds_the-super-tiny-compiler/test.js

var tokenizer     = require('./1-tokenizer');
var parser        = require('./2-parser');
// Note: The traverser is only used inside of the transformer...
var transformer   = require('./4-transformer');
var codeGenerator = require('./5-code-generator');
var compiler      = require('./6-compiler');


// assert is a Node.js utility for asserting values and throwing and error if
// they aren't what you expect
var assert = require('assert');

/**
 * Setting up all of the expected values through out our compiler phases:
 */ 
var input  = '(add 2 (subtract 4 2))';
var output = 'add(2, subtract(4, 2));';

var tokens = [
  { type: 'paren',  value: '('        },
  { type: 'name',   value: 'add'      },
  { type: 'number', value: '2'        },
  { type: 'paren',  value: '('        },
  { type: 'name',   value: 'subtract' },
  { type: 'number', value: '4'        },
  { type: 'number', value: '2'        },
  { type: 'paren',  value: ')'        },
  { type: 'paren',  value: ')'        }
];

var ast = {
  type: 'Program',
  body: [{
    type: 'CallExpression',
    name: 'add',
    params: [{
      type: 'NumberLiteral',
      value: '2'
    }, {
      type: 'CallExpression',
      name: 'subtract',
      params: [{
        type: 'NumberLiteral',
        value: '4'
      }, {
        type: 'NumberLiteral',
        value: '2'
      }]
    }]
  }]
};

var newAst = {
  type: 'Program',
  body: [{
    type: 'ExpressionStatement',
    expression: {
      type: 'CallExpression',
      callee: {
        type: 'Identifier',
        name: 'add'
      },
      arguments: [{
        type: 'NumberLiteral',
        value: '2'
      }, {
        type: 'CallExpression',
        callee: {
          type: 'Identifier',
          name: 'subtract'
        },
        arguments: [{
          type: 'NumberLiteral',
          value: '4'
        }, {
          type: 'NumberLiteral',
          value: '2'
        }]
      }]
    }
  }]
};

/**
 * Now let's write some assertions to make sure our compiler does everything we
 * want it to...
 */

assert.deepStrictEqual(     tokenizer(input),  tokens, 'Tokenizer should turn `input` string into `tokens` array');
assert.deepStrictEqual(        parser(tokens), ast,    'Parser should turn `tokens` array into `ast`');
assert.deepStrictEqual(   transformer(ast),    newAst, 'Transformer should turn `ast` into a `newAst`');
assert.deepStrictEqual( codeGenerator(newAst), output, 'Code Generator should turn `newAst` into `output` string');
assert.deepStrictEqual(      compiler(input),  output, 'Compiler should turn `input` into `output`');

// If none of the above asserts threw an error...
console.log('All Passed!');