Initial commit

node_modules/stylelint/lib/rules/no-duplicate-selectors/index.js

@@ -0,0 +1,81 @@
+"use strict"
+
+const findAtRuleContext = require("../../utils/findAtRuleContext")
+const isKeyframeRule = require("../../utils/isKeyframeRule")
+const nodeContextLookup = require("../../utils/nodeContextLookup")
+const report = require("../../utils/report")
+const ruleMessages = require("../../utils/ruleMessages")
+const validateOptions = require("../../utils/validateOptions")
+const _ = require("lodash")
+const normalizeSelector = require("normalize-selector")
+const resolvedNestedSelector = require("postcss-resolve-nested-selector")
+
+const ruleName = "no-duplicate-selectors"
+
+const messages = ruleMessages(ruleName, {
+  rejected: selector => `Unexpected duplicate selector "${selector}"`,
+})
+
+const rule = function (actual) {
+  return (root, result) => {
+    const validOptions = validateOptions(result, ruleName, { actual })
+    if (!validOptions) {
+      return
+    }
+
+    // The top level of this map will be rule sources.
+    // Each source maps to another map, which maps rule parents to a set of selectors.
+    // This ensures that selectors are only checked against selectors
+    // from other rules that share the same parent and the same source.
+    const selectorContextLookup = nodeContextLookup()
+
+    root.walkRules(rule => {
+      if (isKeyframeRule(rule)) {
+        return
+      }
+
+      const contextSelectorSet = selectorContextLookup.getContext(rule, findAtRuleContext(rule))
+      const resolvedSelectors = rule.selectors.reduce((result, selector) => {
+        return _.union(result, resolvedNestedSelector(selector, rule))
+      }, [])
+      const normalizedSelectorList = resolvedSelectors.map(normalizeSelector)
+
+      // Complain if the same selector list occurs twice
+
+      // Sort the selectors list so that the order of the constituents
+      // doesn't matter
+      const sortedSelectorList = normalizedSelectorList.slice().sort().join(",")
+      if (contextSelectorSet.has(sortedSelectorList)) {
+        // If the selector isn't nested we can use its raw value; otherwise,
+        // we have to approximate something for the message -- which is close enough
+        const isNestedSelector = resolvedSelectors.join(",") !== rule.selectors.join(",")
+        const selectorForMessage = isNestedSelector ? resolvedSelectors.join(", ") : rule.selector
+        return report({
+          result,
+          ruleName,
+          node: rule,
+          message: messages.rejected(selectorForMessage),
+        })
+      }
+
+      // We're treating the Map created by nodeContextLookup as a Set
+      contextSelectorSet.set(sortedSelectorList, null)
+
+      // Or complain if one selector list contains the same selector more than one
+      rule.selectors.forEach((selector, i) => {
+        if (_.includes(normalizedSelectorList.slice(0, i), normalizeSelector(selector))) {
+          report({
+            result,
+            ruleName,
+            node: rule,
+            message: messages.rejected(selector),
+          })
+        }
+      })
+    })
+  }
+}
+
+rule.ruleName = ruleName
+rule.messages = messages
+module.exports = rule