| 'use strict'; |
| |
| var esprima; |
| |
| // Browserified version does not have esprima |
| // |
| // 1. For node.js just require module as deps |
| // 2. For browser try to require mudule via external AMD system. |
| // If not found - try to fallback to window.esprima. If not |
| // found too - then fail to parse. |
| // |
| try { |
| // workaround to exclude package from browserify list. |
| var _require = require; |
| esprima = _require('esprima'); |
| } catch (_) { |
| /*global window */ |
| if (typeof window !== 'undefined') esprima = window.esprima; |
| } |
| |
| var Type = require('../../type'); |
| |
| function resolveJavascriptFunction(data) { |
| if (data === null) return false; |
| |
| try { |
| var source = '(' + data + ')', |
| ast = esprima.parse(source, { range: true }); |
| |
| if (ast.type !== 'Program' || |
| ast.body.length !== 1 || |
| ast.body[0].type !== 'ExpressionStatement' || |
| (ast.body[0].expression.type !== 'ArrowFunctionExpression' && |
| ast.body[0].expression.type !== 'FunctionExpression')) { |
| return false; |
| } |
| |
| return true; |
| } catch (err) { |
| return false; |
| } |
| } |
| |
| function constructJavascriptFunction(data) { |
| /*jslint evil:true*/ |
| |
| var source = '(' + data + ')', |
| ast = esprima.parse(source, { range: true }), |
| params = [], |
| body; |
| |
| if (ast.type !== 'Program' || |
| ast.body.length !== 1 || |
| ast.body[0].type !== 'ExpressionStatement' || |
| (ast.body[0].expression.type !== 'ArrowFunctionExpression' && |
| ast.body[0].expression.type !== 'FunctionExpression')) { |
| throw new Error('Failed to resolve function'); |
| } |
| |
| ast.body[0].expression.params.forEach(function (param) { |
| params.push(param.name); |
| }); |
| |
| body = ast.body[0].expression.body.range; |
| |
| // Esprima's ranges include the first '{' and the last '}' characters on |
| // function expressions. So cut them out. |
| if (ast.body[0].expression.body.type === 'BlockStatement') { |
| /*eslint-disable no-new-func*/ |
| return new Function(params, source.slice(body[0] + 1, body[1] - 1)); |
| } |
| // ES6 arrow functions can omit the BlockStatement. In that case, just return |
| // the body. |
| /*eslint-disable no-new-func*/ |
| return new Function(params, 'return ' + source.slice(body[0], body[1])); |
| } |
| |
| function representJavascriptFunction(object /*, style*/) { |
| return object.toString(); |
| } |
| |
| function isFunction(object) { |
| return Object.prototype.toString.call(object) === '[object Function]'; |
| } |
| |
| module.exports = new Type('tag:yaml.org,2002:js/function', { |
| kind: 'scalar', |
| resolve: resolveJavascriptFunction, |
| construct: constructJavascriptFunction, |
| predicate: isFunction, |
| represent: representJavascriptFunction |
| }); |