feat(JsSource): find tokens used as object keys

Author: patrickhulce

lib/sources/html-source.js

@@ -7,15 +7,6 @@ class HtmlSource extends ParsedSource {
     return 'html'
   }
 
-  _findWholeSelectorInTokens(selector) {
-    return this._tokensArray.find(token => ParsedSource.textContains(token, selector))
-  }
-
-  contains(selector) {
-    return Boolean(this._tokens.has(selector) ||
-      this._findWholeSelectorInTokens(selector))
-  }
-
   static get joiner() {
     return '\n<!-- joined by nukecss -->\n'
   }

lib/sources/js-source.js

@@ -1,46 +1,43 @@
+const _ = require('lodash')
 const esprima = require('esprima')
+const traverse = require('ast-traverse')
 const ParsedSource = require('./parsed-source')
 
 class JsSource extends ParsedSource {
   get type() {
     return 'js'
   }
 
-  _findWholeSelectorInTokens(selector) {
-    return this._tokensArray.find(token => ParsedSource.textContains(token, selector))
-  }
-
-  _findSelectorPartsInTokens(selector) {
-    if (selector.length === 0) {
-      return true
-    }
-
-    for (let i = 1; i <= selector.length; i++) {
-      const part = selector.substr(0, i)
-      const rest = selector.substr(i)
-      if (this._tokens.has(part) && this._findSelectorPartsInTokens(rest)) {
-        return true
-      }
-    }
-
-    return false
-  }
-
-  contains(selector) {
-    return Boolean(this._tokens.has(selector) ||
-      this._findWholeSelectorInTokens(selector) ||
-      this._findSelectorPartsInTokens(selector))
-  }
-
   static get joiner() {
     return ';\n/* joined by nukecss */\n'
   }
 
   static parse(text) {
-    const jsStrings = esprima.tokenize(text)
-      .filter(token => token.type === 'String')
-      .map(token => token.value.substr(1, token.value.length - 2).toLowerCase())
-    return new Set(jsStrings)
+    const ancestry = []
+    const tokens = new Set()
+    traverse(esprima.parse(text), {
+      pre(node) {
+        ancestry.push(node)
+        if (node.type === 'Literal' && typeof node.value === 'string') {
+          tokens.add(node.value)
+        } else if (node.type === 'AssignmentExpression') {
+          const identifierName = _.get(node, 'left.property.name')
+          if (identifierName) {
+            tokens.add(identifierName)
+          }
+        } else if (node.type === 'ObjectExpression') {
+          node.properties.forEach(property => {
+            if (property.key.type === 'Identifier') {
+              tokens.add(property.key.name)
+            }
+          })
+        }
+      },
+      post() {
+        ancestry.pop()
+      },
+    })
+    return tokens
   }
 }
 

lib/sources/parsed-source.js

@@ -6,16 +6,39 @@ class ParsedSource {
   constructor(text, tokens, opts = {}) {
     this._text = text
     this._options = opts
-    this._tokens = tokens
-    this._tokensArray = Array.from(tokens)
+    this._tokensArray = Array.from(tokens).map(t => t.toLowerCase())
+    this._tokens = new Set(this._tokensArray)
   }
 
   get type() {
     throw new Error('unimplemented')
   }
 
-  contains() {
-    throw new Error('unimplemented')
+  _findWholeSelectorInTokens(selector) {
+    return this._tokensArray.find(token => ParsedSource.textContains(token, selector))
+  }
+
+  _findSelectorPartsInTokens(selector) {
+    if (selector.length === 0) {
+      return true
+    }
+
+    for (let i = 1; i <= selector.length; i++) {
+      const part = selector.substr(0, i)
+      const rest = selector.substr(i)
+      if (this._tokens.has(part) && this._findSelectorPartsInTokens(rest)) {
+        return true
+      }
+    }
+
+    return false
+  }
+
+  contains(selector) {
+    selector = selector.toLowerCase()
+    return Boolean(this._tokens.has(selector) ||
+      this._findWholeSelectorInTokens(selector) ||
+      this._findSelectorPartsInTokens(selector))
   }
 
   join(that) {

package.json

@@ -47,6 +47,7 @@
     }
   },
   "dependencies": {
+    "ast-traverse": "^0.1.1",
     "debug": "^2.6.1",
     "esprima": "^3.1.3",
     "glob": "^7.1.1",

test/nuke.test.js

@@ -91,7 +91,7 @@ describe('nuke.js', () => {
       expect(nuked).to.not.contain('jsignored')
     })
 
-    it.skip('should remove unused rules mentioned in textnodes', () => {
+    it('should remove unused rules mentioned in textnodes', () => {
       expect(nuked).to.not.contain('html-ignored')
     })
 

test/sources/js-source.test.js

@@ -33,9 +33,16 @@ describe('sources/js-source.js', () => {
     context('when script is simple', () => {
       const script = `
         const myVar = 'the-class'
-        const otherVar = 'the-other-class'
+        const otherVar = 'the-OtHer-cLass'
         const html = '<div class="inner-class">Content</div>'
         const dynamicVar = ['fa', 'icon'].join('-')
+        const classes = {
+          inVisIble: true,
+          blocK__Element: true,
+        }
+
+        classes.aDditIonal_class = false
+        const no_find = window.should_not_be_found(classes.also_not_found)
       `
 
       const source = JsSource.from(script)
@@ -56,11 +63,27 @@ describe('sources/js-source.js', () => {
         expect(source).to.contain('fa-icon')
       })
 
+      it('should find tokens as object keys', () => {
+        expect(source).to.contain('invisible')
+        expect(source).to.contain('block__element')
+      })
+
+      it('should find tokens as object key assignment', () => {
+        expect(source).to.contain('additional_class')
+      })
+
       it('should not find tokens as identifiers', () => {
         expect(source).to.not.contain('const')
         expect(source).to.not.contain('myVar')
         expect(source).to.not.contain('otherVar')
         expect(source).to.not.contain('dynamicVar')
+        expect(source).to.not.contain('window')
+        expect(source).to.not.contain('no_find')
+      })
+
+      it('should not find tokens as object key access', () => {
+        expect(source).to.not.contain('should_not_be_found')
+        expect(source).to.not.contain('also_not_found')
       })
     })
 

yarn.lock

@@ -172,6 +172,10 @@ assertion-error@^1.0.1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/assertion-error/-/assertion-error-1.0.2.tgz#13ca515d86206da0bac66e834dd397d87581094c"
 
+ast-traverse@^0.1.1:
+  version "0.1.1"
+  resolved "https://registry.yarnpkg.com/ast-traverse/-/ast-traverse-0.1.1.tgz#69cf2b8386f19dcda1bb1e05d68fe359d8897de6"
+
 async@1.x, async@^1.4.0:
   version "1.5.2"
   resolved "https://registry.yarnpkg.com/async/-/async-1.5.2.tgz#ec6a61ae56480c0c3cb241c95618e20892f9672a"