Fix false positive lint error with large number of branches (#24287)

* Switched RulesOfHooks.js to use BigInt. Added test and updated .eslintrc.js to use es2020. * Added BigInt as readonly global in eslintrc.cjs.js and eslintrc.cjs2015.js * Added comment to RulesOfHooks.js that gets rid of BigInt eslint error * Got rid of changes in .eslintrc.js and yarn.lock * Move global down Co-authored-by: stephen cyron <[email protected]> Co-authored-by: dan <[email protected]>
facebook · Apr 13, 2022 · 6ab1051 · 6ab1051
1 parent 3548c5d
commit 6ab1051
Show file tree

Hide file tree

Showing 4 changed files with 81 additions and 9 deletions.
diff --git a/packages/eslint-plugin-react-hooks/__tests__/ESLintRulesOfHooks-test.js b/packages/eslint-plugin-react-hooks/__tests__/ESLintRulesOfHooks-test.js
@@ -325,6 +325,75 @@ const tests = {
         useHook();
       }
     `,
+    `
+      // Valid because the neither the conditions before or after the hook affect the hook call
+      // Failed prior to implementing BigInt because pathsFromStartToEnd and allPathsFromStartToEnd were too big and had rounding errors
+      const useSomeHook = () => {};
+
+      const SomeName = () => {
+        const filler = FILLER ?? FILLER ?? FILLER;
+        const filler2 = FILLER ?? FILLER ?? FILLER;
+        const filler3 = FILLER ?? FILLER ?? FILLER;
+        const filler4 = FILLER ?? FILLER ?? FILLER;
+        const filler5 = FILLER ?? FILLER ?? FILLER;
+        const filler6 = FILLER ?? FILLER ?? FILLER;
+        const filler7 = FILLER ?? FILLER ?? FILLER;
+        const filler8 = FILLER ?? FILLER ?? FILLER;
+
+        useSomeHook();
+
+        if (anyConditionCanEvenBeFalse) {
+          return null;
+        }
+
+        return (
+          <React.Fragment>
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+            {FILLER ? FILLER : FILLER}
+          </React.Fragment>
+        );
+      };
+    `,
     `
       // Valid because the neither the condition nor the loop affect the hook call.
       function App(props) {

diff --git a/packages/eslint-plugin-react-hooks/src/RulesOfHooks.js b/packages/eslint-plugin-react-hooks/src/RulesOfHooks.js
@@ -5,6 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+/* global BigInt */
 /* eslint-disable no-for-of-loops/no-for-of-loops */
 
 'use strict';
@@ -175,7 +176,7 @@ export default {
               cyclic.add(cyclicSegment);
             }
 
-            return 0;
+            return BigInt('0');
           }
 
           // add the current segment to pathList
@@ -187,19 +188,19 @@ export default {
           }
 
           if (codePath.thrownSegments.includes(segment)) {
-            paths = 0;
+            paths = BigInt('0');
           } else if (segment.prevSegments.length === 0) {
-            paths = 1;
+            paths = BigInt('1');
           } else {
-            paths = 0;
+            paths = BigInt('0');
             for (const prevSegment of segment.prevSegments) {
               paths += countPathsFromStart(prevSegment, pathList);
             }
           }
 
           // If our segment is reachable then there should be at least one path
           // to it from the start of our code path.
-          if (segment.reachable && paths === 0) {
+          if (segment.reachable && paths === BigInt('0')) {
             cache.delete(segment.id);
           } else {
             cache.set(segment.id, paths);
@@ -246,7 +247,7 @@ export default {
               cyclic.add(cyclicSegment);
             }
 
-            return 0;
+            return BigInt('0');
           }
 
           // add the current segment to pathList
@@ -258,11 +259,11 @@ export default {
           }
 
           if (codePath.thrownSegments.includes(segment)) {
-            paths = 0;
+            paths = BigInt('0');
           } else if (segment.nextSegments.length === 0) {
-            paths = 1;
+            paths = BigInt('1');
           } else {
-            paths = 0;
+            paths = BigInt('0');
             for (const nextSegment of segment.nextSegments) {
               paths += countPathsToEnd(nextSegment, pathList);
             }

diff --git a/scripts/rollup/validate/eslintrc.cjs.js b/scripts/rollup/validate/eslintrc.cjs.js
@@ -7,6 +7,7 @@ module.exports = {
   },
   globals: {
     // ES 6
+    BigInt: 'readonly',
     Map: 'readonly',
     Set: 'readonly',
     Proxy: 'readonly',

diff --git a/scripts/rollup/validate/eslintrc.cjs2015.js b/scripts/rollup/validate/eslintrc.cjs2015.js
@@ -7,6 +7,7 @@ module.exports = {
   },
   globals: {
     // ES 6
+    BigInt: 'readonly',
     Map: 'readonly',
     Set: 'readonly',
     Proxy: 'readonly',