🐛 fix reference tracker false positive

mysticatea · mysticatea · commit 8f9e481ecc12 · 2019-10-20T21:43:49.000+09:00
See also eslint/eslint#12437.
diff --git a/src/reference-tracker.js b/src/reference-tracker.js
@@ -2,7 +2,6 @@ import { findVariable } from "./find-variable"
 import { getPropertyName } from "./get-property-name"
 import { getStringIfConstant } from "./get-string-if-constant"
 
-const SENTINEL_TYPE = /^(?:.+?Statement|.+?Declaration|(?:Array|ArrowFunction|Assignment|Call|Class|Function|Member|New|Object)Expression|AssignmentPattern|Program|VariableDeclarator)$/u
 const IMPORT_TYPE = /^(?:Import|Export(?:All|Default|Named))Declaration$/u
 const has = Function.call.bind(Object.hasOwnProperty)
 
@@ -26,6 +25,28 @@ function isModifiedGlobal(variable) {
     )
 }
 
+/**
+ * Check if the value of a given node is passed through to the parent syntax as-is.
+ * For example, `a` and `b` in (`a || b` and `c ? a : b`) are passed through.
+ * @param {Node} node A node to check.
+ * @returns {boolean} `true` if the node is passed through.
+ */
+function isPassThrough(node) {
+    const parent = node.parent
+
+    switch (parent && parent.type) {
+        case "ConditionalExpression":
+            return parent.consequent === node || parent.alternate === node
+        case "LogicalExpression":
+            return true
+        case "SequenceExpression":
+            return parent.expressions[parent.expressions.length - 1] === node
+
+        default:
+            return false
+    }
+}
+
 /**
  * The reference tracker.
  */
@@ -227,7 +248,7 @@ export class ReferenceTracker {
     //eslint-disable-next-line complexity
     *_iteratePropertyReferences(rootNode, path, traceMap) {
         let node = rootNode
-        while (!SENTINEL_TYPE.test(node.parent.type)) {
+        while (isPassThrough(node)) {
             node = node.parent
         }
 
diff --git a/test/reference-tracker.js b/test/reference-tracker.js
@@ -4,6 +4,7 @@ import { CALL, CONSTRUCT, ESM, READ, ReferenceTracker } from "../src/"
 
 const config = {
     parserOptions: { ecmaVersion: 2018, sourceType: "module" },
+    globals: { Reflect: false },
     rules: { test: "error" },
 }
 
@@ -369,6 +370,18 @@ describe("The 'ReferenceTracker' class:", () => {
                 },
                 expected: [],
             },
+            {
+                description:
+                    "should not iterate the references through unary/binary expressions.",
+                code: [
+                    'var construct = typeof Reflect !== "undefined" ? Reflect.construct : undefined',
+                    "construct()",
+                ].join("\n"),
+                traceMap: {
+                    Reflect: { [CALL]: 1 },
+                },
+                expected: [],
+            },
         ]) {
             it(description, () => {
                 const linter = new eslint.Linter()
