skip selectors that cannot be analyzed for complexity (#143)

* skip selectors that cannot be analyzed for complexity

* fix catch cause failing on node < 10

Author: bartveneman

package-lock.json

@@ -53,13 +53,13 @@
     ]
   },
   "dependencies": {
-    "brotli-size": "0.0.3",
+    "brotli-size": "^0.1.0",
     "color-sorter": "^3.0.0",
     "css-at-supports-browser-h4cks-analyzer": "^1.0.0",
     "css-media-query-browser-h4cks-analyzer": "^1.0.0",
     "css-property-browser-h4cks-analyzer": "^1.1.0",
     "css-selector-browser-h4cks-analyzer": "^1.1.0",
-    "css-selector-complexity": "^0.1.1",
+    "css-selector-complexity": "^0.1.2",
     "css-shorthand-expand": "^1.2.0",
     "css-unit-sort": "^3.3.0",
     "css-value-browser-h4cks-analyzer": "^1.0.1",

package.json

@@ -3,9 +3,17 @@ const uniquer = require('../../utils/uniquer')
 
 module.exports = selectors => {
   const all = selectors.map(selector => {
+    let complexity = 0
+
+    try {
+      complexity = selectorComplexity(selector)
+    } catch (error) {
+      // Fail silently, ignoring the error
+    }
+
     return {
       selector,
-      complexity: selectorComplexity(selector)
+      complexity
     }
   })
   const allComplexities = all.map(selector => selector.complexity)

src/analyzer/selectors/complexity.js

@@ -85,3 +85,35 @@ test('it calculates the average complexity per selector', t => {
 
   t.is(actual, 26 / 6)
 })
+
+test('it reports a default complexity of 1 in case of an invalid selector', t => {
+  const provider = ['+.box-group', '.w-(20: 20%']
+  const expected = {
+    max: {
+      value: 0,
+      count: 2,
+      selectors: [
+        {
+          value: '+.box-group',
+          count: 1
+        },
+        {
+          value: '.w-(20: 20%',
+          count: 1
+        }
+      ]
+    },
+    average: 0,
+    sum: 0,
+    unique: [
+      {
+        value: 0,
+        count: 2
+      }
+    ],
+    totalUnique: 1
+  }
+  const actual = analyze(provider)
+
+  t.deepEqual(actual, expected)
+})

test/analyzer/selectors/complexity.js

@@ -1,22 +1,23 @@
-const {readFileSync} = require('fs')
+const {readFile} = require('fs')
+const {promisify} = require('util')
 const {join} = require('path')
 const test = require('ava')
-const analyze = require('../../src/analyzer')
+const analyze = require('../..')
 
-test('it analyzes large CSS files without errors - facebook', async t => {
-  const css = readFileSync(join(__dirname, '/facebook-20190319.css'), 'utf8')
-  await t.notThrowsAsync(analyze(css))
-})
+const readFileAsync = promisify(readFile)
 
-test('it analyzes large CSS files without errors - css-tricks', async t => {
-  const css = readFileSync(join(__dirname, '/css-tricks-20190319.css'), 'utf8')
-  await t.notThrowsAsync(analyze(css))
-})
+const fileNames = [
+  'facebook-20190319',
+  'css-tricks-20190319',
+  'smashing-magazine-20190319',
+  'trello-20190617',
+  'bol-com-20190617',
+  'lego-20190617'
+]
 
-test('it analyzes large CSS files without errors - smashing magazine', async t => {
-  const css = readFileSync(
-    join(__dirname, '/smashing-magazine-20190319.css'),
-    'utf8'
-  )
-  await t.notThrowsAsync(analyze(css))
+fileNames.forEach(fileName => {
+  test(`It doesn't fail on real-life CSS - ${fileName}`, async t => {
+    const css = await readFileAsync(join(__dirname, `${fileName}.css`), 'utf8')
+    await t.notThrowsAsync(() => analyze(css))
+  })
 })