es-feature-detection/lib/filterFeatures.js

'use strict';

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) {
  return typeof obj;
} : function (obj) {
  return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj;
};

var es5 = require('../caniuse/es5');
var es6 = require('../caniuse/es6');

var browserVersions = require('./browserVersions');
var getVersions = browserVersions.getVersions;
var pid = browserVersions.parseId;

function polyfillNeeded(browsers, versions, testCase) {
  var _iteratorNormalCompletion = true;
  var _didIteratorError = false;
  var _iteratorError = undefined;

  try {
    var _loop = function _loop() {
      var entry = _step.value;

      var browser = entry[0];
      var target = entry[1];
      var versionList = versions.get(browser);

      // If the version demanded version is greater than the highest one in the list, just skip it
      if (!versionList || target.version > versionList[0].version) {
        return 'continue';
      }

      var test = testCase.res[target.id];

      // If there is no result for the current test, look if there should be one
      // for lower versions
      if (typeof test === 'undefined') {
        var closestVersion = 0;
        var closestId = Object.keys(testCase.res).reduce(function (closest, id) {
          if (id.indexOf(browser) !== 0) {
            return closest;
          }

          var v = pid(id).version;
          if (v < target.version && v > closestVersion) {
            closestVersion = v;
            return id;
          }
        });

        if (!closestId || testCase.res[closestId] !== true) {
          return {
            v: true
          };
        }

        // if the test is not really passed
        // Just return true as the browser needs a polyfill for the feature
      } else if (test !== true) {
        return {
          v: true
        };
      }
    };

    for (var _iterator = browsers.entries()[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
      var _ret = _loop();

      switch (_ret) {
        case 'continue':
          continue;

        default:
          if ((typeof _ret === 'undefined' ? 'undefined' : _typeof(_ret)) === "object") return _ret.v;
      }
    }

    // If none of the tests already returned true, it means no polyfill is needed, so return false
  } catch (err) {
    _didIteratorError = true;
    _iteratorError = err;
  } finally {
    try {
      if (!_iteratorNormalCompletion && _iterator.return) {
        _iterator.return();
      }
    } finally {
      if (_didIteratorError) {
        throw _iteratorError;
      }
    }
  }

  return false;
}

module.exports = function filterFeatures(features, versions) {
  var dbBrowsers = getVersions(versions);

  return features.filter(function (feature) {
    var split = feature.split('.');
    var obj = split[0];
    var method = split[1] || '';

    // Start by checking ES 5
    var test = null;
    es5.tests.some(function (t) {
      if (!new RegExp('^' + obj).test(t.name)) {
        return false;
      }

      if (t.subtests) {
        // Otherwise search for a matching sub test
        var _iteratorNormalCompletion2 = true;
        var _didIteratorError2 = false;
        var _iteratorError2 = undefined;

        try {
          for (var _iterator2 = t.subtests[Symbol.iterator](), _step2; !(_iteratorNormalCompletion2 = (_step2 = _iterator2.next()).done); _iteratorNormalCompletion2 = true) {
            var sub = _step2.value;

            if (sub.name.replace('.prototype.', '.') === feature) {
              test = sub;
              return true;
            }
          }
        } catch (err) {
          _didIteratorError2 = true;
          _iteratorError2 = err;
        } finally {
          try {
            if (!_iteratorNormalCompletion2 && _iterator2.return) {
              _iterator2.return();
            }
          } finally {
            if (_didIteratorError2) {
              throw _iteratorError2;
            }
          }
        }
      } else if (t.name.replace('.prototype.', '.') === feature) {
        test = t;
        return true;
      }
    });

    if (test) {
      return polyfillNeeded(dbBrowsers.parsed, dbBrowsers.es5, test);
    }

    // If feature was not a es5 feature then test es6
    es6.tests.some(function (t) {
      // We only look at 'built-ins' or 'built-in extensions' and only if it is
      // concerning the current Object
      if (['built-ins', 'built-in extensions'].indexOf(t.category) < 0 || !new RegExp('^' + obj).test(t.name) || t.category === 'built-in extensions' && !method) {
        return false;
      }

      if (!method) {
        // If there is a 'basic functionality' sub category, just examine that test
        if (t.subtests['basic functionality']) {
          test = t.subtests['basic functionality'];
          return true;
        }

        // Examine all tests if there is no 'basic functionality' sub category
        test = Object.keys(t.subtests).map(function (sub) {
          return t.subtests[sub];
        });
        return true;
      }

      // Otherwise search for a matching sub test
      var _iteratorNormalCompletion3 = true;
      var _didIteratorError3 = false;
      var _iteratorError3 = undefined;

      try {
        for (var _iterator3 = t.subtests[Symbol.iterator](), _step3; !(_iteratorNormalCompletion3 = (_step3 = _iterator3.next()).done); _iteratorNormalCompletion3 = true) {
          var sub = _step3.value;

          if (sub.name.replace('.prototype.', '.') === feature) {
            test = sub;
            return true;
          }
        }
      } catch (err) {
        _didIteratorError3 = true;
        _iteratorError3 = err;
      } finally {
        try {
          if (!_iteratorNormalCompletion3 && _iterator3.return) {
            _iterator3.return();
          }
        } finally {
          if (_didIteratorError3) {
            throw _iteratorError3;
          }
        }
      }
    });

    // If it is an array of tests see if polyfill would be needed for one of them
    if (Array.isArray(test)) {
      return test.some(function (t) {
        return polyfillNeeded(dbBrowsers.parsed, dbBrowsers.es6, t);
      });
    }

    // If it is just one, then see if the polyfill would be needed for the feature
    if (test) {
      return polyfillNeeded(dbBrowsers.parsed, dbBrowsers.es6, test);
    }

    // If no test was found in the caniuse db then leave it in the list, so the
    // browser can perform the test
    return true;
  });
};