jsExecutionTransformer.js 8.4 KB

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  1. var debug = require('debug')('ylt:jsExecutionTransformer');
  2. var offendersHelpers = require('../offendersHelpers');
  3. var Collection = require('./phantomas/custom_modules/util/collection');
  4. var jsExecutionTransformer = function() {
  5. this.transform = function(data) {
  6. var javascriptExecutionTree = {};
  7. var jQueryFunctionsCollection = new Collection();
  8. var metrics = {
  9. DOMaccesses: 0,
  10. DOMaccessesOnScroll: 0,
  11. queriesWithoutResults: 0
  12. };
  13. var offenders = {};
  14. var hasjQuery = (data.toolsResults.phantomas.metrics.jQueryVersionsLoaded > 0);
  15. if (hasjQuery) {
  16. metrics.jQueryCalls = 0;
  17. metrics.jQueryFunctionsUsed = 0;
  18. metrics.jQueryCallsOnEmptyObject = 0;
  19. metrics.jQueryNotDelegatedEvents = 0;
  20. offenders.jQueryFunctionsUsed = [];
  21. }
  22. try {
  23. debug('Starting JS execution transformation');
  24. javascriptExecutionTree = JSON.parse(data.toolsResults.phantomas.offenders.javascriptExecutionTree[0]);
  25. if (javascriptExecutionTree.children) {
  26. javascriptExecutionTree.children.forEach(function(node) {
  27. var contextLength = (node.data.callDetails && node.data.callDetails.context) ? node.data.callDetails.context.length : null;
  28. if (isABindWithoutEventDelegation(node, contextLength)) {
  29. metrics.jQueryNotDelegatedEvents += contextLength;
  30. node.warning = true;
  31. node.eventNotDelegated = true;
  32. }
  33. if (node.data.resultsNumber === 0) {
  34. metrics.queriesWithoutResults ++;
  35. node.queryWithoutResults = true;
  36. node.warning = true;
  37. }
  38. if (contextLength === 0) {
  39. metrics.jQueryCallsOnEmptyObject ++;
  40. node.jQueryCallOnEmptyObject = true;
  41. node.warning = true;
  42. }
  43. if (node.data.type.indexOf('jQuery - ') === 0) {
  44. metrics.jQueryCalls ++;
  45. jQueryFunctionsCollection.push(node.data.type);
  46. }
  47. // Mark errors with an error flag
  48. if (node.data.type === 'error' || node.data.type === 'jQuery version change') {
  49. node.error = true;
  50. }
  51. // Mark a performance flag
  52. if (['domInteractive', 'domContentLoaded', 'domContentLoadedEnd', 'domComplete'].indexOf(node.data.type) >= 0) {
  53. node.windowPerformance = true;
  54. }
  55. // Read the execution tree and adjust the navigation timings (cause their not very well synchronised)
  56. switch(node.data.type) {
  57. case 'domInteractive':
  58. data.toolsResults.phantomas.metrics.domInteractive = node.data.timestamp;
  59. break;
  60. case 'domContentLoaded':
  61. data.toolsResults.phantomas.metrics.domContentLoaded = node.data.timestamp;
  62. break;
  63. case 'domContentLoadedEnd':
  64. data.toolsResults.phantomas.metrics.domContentLoadedEnd = node.data.timestamp;
  65. break;
  66. case 'domComplete':
  67. data.toolsResults.phantomas.metrics.domComplete = node.data.timestamp;
  68. break;
  69. }
  70. // Transform domPaths into objects
  71. changeListOfDomPaths(node);
  72. // Count the number of DOM accesses, by counting the tree leafs
  73. metrics.DOMaccesses += countTreeLeafs(node);
  74. });
  75. // Count the number of different jQuery functions called
  76. if (hasjQuery) {
  77. jQueryFunctionsCollection.sort().forEach(function(fnName, cnt) {
  78. if (fnName === 'jQuery - find') {
  79. fnName = 'jQuery - $';
  80. }
  81. metrics.jQueryFunctionsUsed ++;
  82. offenders.jQueryFunctionsUsed.push({
  83. functionName: fnName.substring(9),
  84. count: cnt
  85. });
  86. });
  87. }
  88. }
  89. debug('JS execution transformation complete');
  90. debug('Starting scroll execution transformation');
  91. offenders.DOMaccessesOnScroll = JSON.parse(data.toolsResults.phantomas.offenders.scrollExecutionTree[0]);
  92. if (offenders.DOMaccessesOnScroll.children) {
  93. offenders.DOMaccessesOnScroll.children.forEach(function(node) {
  94. // Mark a event flag
  95. if (['documentScroll', 'windowScroll', 'window.onscroll'].indexOf(node.data.type) >= 0) {
  96. node.windowPerformance = true;
  97. }
  98. // Transform domPaths into objects
  99. changeListOfDomPaths(node);
  100. // Count the number of DOM accesses, by counting the tree leafs
  101. metrics.DOMaccessesOnScroll += countTreeLeafs(node);
  102. });
  103. }
  104. debug('Scroll execution transformation complete');
  105. } catch(err) {
  106. throw err;
  107. }
  108. data.javascriptExecutionTree = javascriptExecutionTree;
  109. data.toolsResults.jsExecutionTransformer = {
  110. metrics: metrics,
  111. offenders: offenders
  112. };
  113. return data;
  114. };
  115. function treeRecursiveParser(node, fn) {
  116. if (node.children) {
  117. node.children.forEach(function(child) {
  118. treeRecursiveParser(child, fn);
  119. });
  120. }
  121. fn(node);
  122. }
  123. function changeListOfDomPaths(rootNode) {
  124. treeRecursiveParser(rootNode, function(node) {
  125. if (node.data.callDetails && node.data.callDetails.context && node.data.callDetails.context.length > 0) {
  126. node.data.callDetails.context.elements = node.data.callDetails.context.elements.map(offendersHelpers.domPathToDomElementObj, offendersHelpers);
  127. }
  128. if (node.data.type === 'appendChild' || node.data.type === 'insertBefore' || node.data.type === 'getComputedStyle') {
  129. node.data.callDetails.arguments[0] = offendersHelpers.domPathToDomElementObj(node.data.callDetails.arguments[0]);
  130. }
  131. if (node.data.type === 'insertBefore') {
  132. node.data.callDetails.arguments[1] = offendersHelpers.domPathToDomElementObj(node.data.callDetails.arguments[1]);
  133. }
  134. });
  135. }
  136. // Returns the number of leafs (nodes without children)
  137. function countTreeLeafs(rootNode) {
  138. var count = 0;
  139. treeRecursiveParser(rootNode, function(node) {
  140. if (!node.children &&
  141. !node.error &&
  142. !node.windowPerformance &&
  143. node.data.type !== 'jQuery loaded') {
  144. count ++;
  145. }
  146. });
  147. return count;
  148. }
  149. function isPureString(str) {
  150. return typeof str === 'string' && str[0] !== '{' && str !== '(function)' && str !== '[Object]' && str !== '[Array]' && str !== 'true' && str !== 'false' && str !== 'undefined' && str !== 'unknown' && str !== 'null';
  151. }
  152. function isABindWithoutEventDelegation(node, contextLength) {
  153. // Count only on larger bindings
  154. if (contextLength <= 3) {
  155. return false;
  156. }
  157. if (node.data.type === 'jQuery - on' && node.data.callDetails.arguments[1] && !isPureString(node.data.callDetails.arguments[1])) {
  158. return true;
  159. }
  160. if (node.data.type.indexOf('jQuery - ') === 0 && node.children && node.children.length === 1) {
  161. var child = node.children[0];
  162. if (child.data.type === 'jQuery - on' && child.data.callDetails.arguments[1] && !isPureString(child.data.callDetails.arguments[1])) {
  163. return true;
  164. }
  165. }
  166. return false;
  167. }
  168. };
  169. module.exports = new jsExecutionTransformer();