Simplify AggregateCollection and fix UInt8 bug

Author: Bart Veneman

benchmark/readme.md

@@ -5,15 +5,15 @@
 `node benchmark/benchmark.js`
 
 ```
-Bol.com                 (468 kB):   8.88 ops/sec
-Bootstrap 5.0.0         (195 kB):  21.81 ops/sec
-CSS-Tricks              (195 kB):  21.14 ops/sec
-Facebook.com            (268 kB):  13.28 ops/sec
-GitHub.com              (514 kB):  10.28 ops/sec
+Bol.com                 (468 kB):   9.19 ops/sec
+Bootstrap 5.0.0         (195 kB):  21.28 ops/sec
+CSS-Tricks              (195 kB):  20.07 ops/sec
+Facebook.com            (268 kB):  13.70 ops/sec
+GitHub.com              (514 kB):  10.29 ops/sec
 Gazelle.nl              (972 kB):   3.14 ops/sec
-Lego.com                (246 kB):  16.51 ops/sec
-Smashing Magazine.com   (1.1 MB):   3.01 ops/sec
-Trello.com              (312 kB):  12.16 ops/sec
+Lego.com                (246 kB):  17.43 ops/sec
+Smashing Magazine.com   (1.1 MB):   3.29 ops/sec
+Trello.com              (312 kB):  12.23 ops/sec
 ```
 
 ## Parsing vs. analyzing

src/__fixtures__/bol-com-20190617.json

@@ -206,11 +206,11 @@
     },
     "selectors": {
       "min": 1,
-      "max": 160,
+      "max": 640,
       "mean": 2.1419753086419755,
       "mode": 1,
       "median": 1,
-      "range": 159,
+      "range": 639,
       "sum": 7634,
       "items": [
         1,
@@ -876,7 +876,7 @@
         5,
         5,
         5,
-        128,
+        640,
         2,
         42,
         5,

src/__fixtures__/github-20210501.json

@@ -2650,11 +2650,11 @@
     },
     "declarations": {
       "min": 1,
-      "max": 250,
+      "max": 762,
       "mean": 4.317063492063492,
       "mode": 1,
       "median": 1,
-      "range": 249,
+      "range": 761,
       "sum": 10879,
       "items": [
         5,
@@ -2699,15 +2699,15 @@
         1,
         2,
         2,
-        250,
-        250,
-        250,
-        250,
-        250,
-        250,
-        250,
-        250,
-        250,
+        762,
+        762,
+        762,
+        762,
+        762,
+        762,
+        762,
+        762,
+        762,
         2,
         1,
         1,

src/aggregate-collection.js

@@ -50,25 +50,21 @@ function Median(arr) {
 }
 
 class AggregateCollection {
-  constructor(size) {
+  constructor() {
     /** @type number[] */
-    this.items = new Uint8Array(size)
-    this.sum = 0
-    this.cursor = 0
+    this.items = []
   }
 
   /**
    * Add a new Integer at the end of this AggregateCollection
    * @param {number} item - The item to add
    */
   add(item) {
-    this.items[this.cursor] = item
-    this.sum += item
-    this.cursor++
+    this.items.push(item)
   }
 
   aggregate() {
-    if (this.cursor === 0) {
+    if (this.items.length === 0) {
       return {
         min: 0,
         max: 0,
@@ -81,33 +77,30 @@ class AggregateCollection {
     }
 
     /** @type Number[] */
-    const sorted = new Uint8Array(
-      this.items.slice(0, this.cursor)
-    ).sort((a, b) => a - b)
+    const sorted = this.items.slice().sort((a, b) => a - b)
     const min = sorted[0]
     const max = sorted[sorted.length - 1]
 
+    const sum = this.items.reduce((total, num) => (total += num))
     const mode = Mode(sorted)
     const median = Median(sorted)
 
     return {
       min,
       max,
-      mean: this.sum / this.cursor,
+      mean: sum / this.items.length,
       mode,
       median,
       range: max - min,
-      sum: this.sum,
+      sum,
     }
   }
 
   /**
    * @returns {number[]} All items in this collection
    */
   toArray() {
-    return Array.from(
-      this.items.subarray(0, this.cursor)
-    )
+    return this.items
   }
 }
 

src/aggregate-collection.test.js

@@ -5,7 +5,7 @@ import { AggregateCollection } from './aggregate-collection.js'
 const CollectionSuite = suite('AggregateCollection')
 
 CollectionSuite('aggregates correctly', () => {
-  const fixture = new AggregateCollection(6)
+  const fixture = new AggregateCollection()
   fixture.add(1)
   fixture.add(2)
   fixture.add(25)
@@ -28,7 +28,7 @@ CollectionSuite('aggregates correctly', () => {
 })
 
 CollectionSuite('handles collections without values', () => {
-  const fixture = new AggregateCollection(0)
+  const fixture = new AggregateCollection()
   const aggregate = fixture.aggregate()
   const items = fixture.toArray()
 

src/index.js

@@ -115,7 +115,7 @@ const analyze = (css) => {
             isKeyframeSelector: this.atrule && this.atrule.name.endsWith('keyframes')
           })
 
-          // Avoid further walking of selectors to not mess with
+          // Avoid deeper walking of selectors to not mess with
           // our specificity calculations in case of a selector
           // with :where() or :is() that contain SelectorLists
           // as children
@@ -193,34 +193,32 @@ const analyze = (css) => {
             }
           }
 
-          walk(value, {
-            enter: function (valueNode) {
-              switch (valueNode.type) {
-                case 'Hash': {
-                  colors.push(stringifyNode(valueNode), property)
+          walk(value, function (valueNode) {
+            switch (valueNode.type) {
+              case 'Hash': {
+                colors.push(stringifyNode(valueNode), property)
 
+                return this.skip
+              }
+              case 'Identifier': {
+                const { name } = valueNode
+                // Bail out if it can't be a color name
+                // 20 === 'lightgoldenrodyellow'.length
+                // 3 === 'red'.length
+                if (name.length > 20 || name.length < 3) {
                   return this.skip
                 }
-                case 'Identifier': {
-                  const { name } = valueNode
-                  // Bail out if it can't be a color name
-                  // 20 === 'lightgoldenrodyellow'.length
-                  // 3 === 'red'.length
-                  if (name.length > 20 || name.length < 3) {
-                    return this.skip
-                  }
-                  if (colorNames[name.toLowerCase()]) {
-                    colors.push(stringifyNode(valueNode), property)
-                  }
-                  return this.skip
+                if (colorNames[name.toLowerCase()]) {
+                  colors.push(stringifyNode(valueNode), property)
                 }
-                case 'Function': {
-                  if (colorFunctions[valueNode.name.toLowerCase()]) {
-                    colors.push(stringifyNode(valueNode), property)
-                  }
-                  // No this.skip here intentionally,
-                  // otherwise we'll miss colors in linear-gradient() etc.
+                return this.skip
+              }
+              case 'Function': {
+                if (colorFunctions[valueNode.name.toLowerCase()]) {
+                  colors.push(stringifyNode(valueNode), property)
                 }
+                // No this.skip here intentionally,
+                // otherwise we'll miss colors in linear-gradient() etc.
               }
             }
           })

src/rules/rules.js

@@ -4,8 +4,8 @@ import { AggregateCollection } from '../aggregate-collection.js'
 const analyzeRules = ({ rules }) => {
   /** @type number */
   const totalRules = rules.length
-  const selectorsPerRule = new AggregateCollection(totalRules)
-  const declarationsPerRule = new AggregateCollection(totalRules)
+  const selectorsPerRule = new AggregateCollection()
+  const declarationsPerRule = new AggregateCollection()
 
   let emptyRules = 0
 

src/selectors/selectors.js

@@ -12,11 +12,11 @@ const analyzeSelectors = ({ stringifyNode, selectors }) => {
   let maxSpecificity
   /** @type [number,number,number] */
   let minSpecificity
-  let specificityA = new AggregateCollection(totalSelectors)
-  let specificityB = new AggregateCollection(totalSelectors)
-  let specificityC = new AggregateCollection(totalSelectors)
+  let specificityA = new AggregateCollection()
+  let specificityB = new AggregateCollection()
+  let specificityC = new AggregateCollection()
   let totalUnique = 0
-  const complexityAggregator = new AggregateCollection(totalSelectors);
+  const complexityAggregator = new AggregateCollection()
 
   /** @type [number,number,number][] */
   const specificities = []