fix: false positive with deferred/promise.reject() in no-array-protot…

…ype-extensions (#1552)
ember-cli · Aug 2, 2022 · 4c5c086 · 4c5c086
1 parent da46812
commit 4c5c086
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Showing 2 changed files with 37 additions and 11 deletions.
diff --git a/lib/rules/no-array-prototype-extensions.js b/lib/rules/no-array-prototype-extensions.js
@@ -111,13 +111,14 @@ const KNOWN_NON_ARRAY_CLASSES = new Set([
 ]);
 
 /**
- * Ignore variables containing these words as they are likely to be instances of non-array classes.
- * Stored in lowercase.
+ * Ignore certain function calls made on variables containing certain words as they are likely to be instances of non-array classes.
+ * Words stored in lowercase.
  */
-const KNOWN_NON_ARRAY_WORDS_WITH_CLEAR_FN = new Set([
+const FN_NAMES_TO_KNOWN_NON_ARRAY_WORDS = new Map([
+  // These Promise-related objects have an overlapping reject() method.
+  ['reject', new Set(['deferred', 'promise'])],
   // These Set/Map data structure classes have an overlapping clear() method.
-  'set',
-  'map',
+  ['clear', new Set(['set', 'map'])],
 ]);
 
 /**
@@ -198,16 +199,23 @@ module.exports = {
         const nameParts = name.split('.');
         if (
           KNOWN_NON_ARRAY_FUNCTION_CALLS.has(name) ||
-          KNOWN_NON_ARRAY_OBJECTS.has(nameParts[nameParts.length - 2]) ||
-          (variableNameToWords(nameParts[nameParts.length - 2]).some((word) =>
-            KNOWN_NON_ARRAY_WORDS_WITH_CLEAR_FN.has(word)
-          ) &&
-            nameParts[nameParts.length - 1] === 'clear()')
+          KNOWN_NON_ARRAY_OBJECTS.has(nameParts[nameParts.length - 2])
         ) {
-          // Ignore any known non-array objects/function calls/variable names to reduce false positives.
+          // Ignore any known non-array objects/function calls to reduce false positives.
           return;
         }
 
+        for (const functionName of FN_NAMES_TO_KNOWN_NON_ARRAY_WORDS.keys()) {
+          const words = FN_NAMES_TO_KNOWN_NON_ARRAY_WORDS.get(functionName);
+          if (
+            nameParts[nameParts.length - 1] === `${functionName}()` &&
+            variableNameToWords(nameParts[nameParts.length - 2]).some((word) => words.has(word))
+          ) {
+            // We found a function call on a variable whose name contains a word that indicates this variable is not an array.
+            return;
+          }
+        }
+
         const nodeInitializedTo = getNodeOrNodeFromVariable(node.callee.object, scopeManager);
         if (
           nodeInitializedTo.type === 'NewExpression' &&

diff --git a/tests/lib/rules/no-array-prototype-extensions.js b/tests/lib/rules/no-array-prototype-extensions.js
@@ -57,6 +57,24 @@ ruleTester.run('no-array-prototype-extensions', rule, {
     'Ember.RSVP.reject();',
     'Ember.RSVP.Promise.reject();',
 
+    // `reject()` on instance of `RSVP.defer`.
+    `
+    import { defer } from 'rsvp';
+    const deferred = defer();
+    deferred.reject();`,
+    `
+    import { defer } from 'rsvp';
+    const requestDeferred = defer();
+    requestDeferred.reject();`,
+    `
+    import { defer } from 'rsvp';
+    const promise = defer();
+    promise.reject();`,
+    `
+    import { defer } from 'rsvp';
+    const fooPromise = defer();
+    fooPromise.reject();`,
+
     // Global non-array class (*storage.clear)
     'window.localStorage.clear();',
     'window.sessionStorage.clear();',