fix(eslint-plugin): [prefer-optional-chain] suggests optional chainin…

…g during strict null equality check (#8717) * fix [prefer-optional-chain] suggests optional chaining during strict null equality * fix [prefer-optional-chain] suggests optional chaining during strict null equality * Fix lint * Add prefer-optional-chain test * Fix lint * rebase and fix prefer optional chain on strict null equality * fix prefer optional chain on strict null equality * fix lint * tests: code review suggestion * Update packages/eslint-plugin/src/rules/prefer-optional-chain-utils/analyzeChain.ts --------- Co-authored-by: Marta Cardoso <up201304504@up.pt> Co-authored-by: Marta Cardoso <145560260+up201304504@users.noreply.github.com> Co-authored-by: Josh Goldberg ✨ <git@joshuakgoldberg.com>
typescript-eslint · Apr 24, 2024 · 4bed24d · 4bed24d
1 parent b0f7aa4
commit 4bed24d
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Showing 2 changed files with 18 additions and 5 deletions.
diff --git a/packages/eslint-plugin/src/rules/prefer-optional-chain-utils/analyzeChain.ts b/packages/eslint-plugin/src/rules/prefer-optional-chain-utils/analyzeChain.ts
@@ -61,13 +61,24 @@ const analyzeAndChainOperand: OperandAnalyzer = (
   chain,
 ) => {
   switch (operand.comparisonType) {
-    case NullishComparisonType.Boolean:
+    case NullishComparisonType.Boolean: {
+      const nextOperand = chain.at(index + 1);
+      if (
+        nextOperand?.comparisonType ===
+          NullishComparisonType.NotStrictEqualNull &&
+        operand.comparedName.type === AST_NODE_TYPES.Identifier
+      ) {
+        return null;
+      }
+      return [operand];
+    }
+
     case NullishComparisonType.NotEqualNullOrUndefined:
       return [operand];
 
     case NullishComparisonType.NotStrictEqualNull: {
       // handle `x !== null && x !== undefined`
-      const nextOperand = chain[index + 1] as ValidOperand | undefined;
+      const nextOperand = chain.at(index + 1);
       if (
         nextOperand?.comparisonType ===
           NullishComparisonType.NotStrictEqualUndefined &&
@@ -94,7 +105,7 @@ const analyzeAndChainOperand: OperandAnalyzer = (
 
     case NullishComparisonType.NotStrictEqualUndefined: {
       // handle `x !== undefined && x !== null`
-      const nextOperand = chain[index + 1] as ValidOperand | undefined;
+      const nextOperand = chain.at(index + 1);
       if (
         nextOperand?.comparisonType ===
           NullishComparisonType.NotStrictEqualNull &&
@@ -132,7 +143,7 @@ const analyzeOrChainOperand: OperandAnalyzer = (
 
     case NullishComparisonType.StrictEqualNull: {
       // handle `x === null || x === undefined`
-      const nextOperand = chain[index + 1] as ValidOperand | undefined;
+      const nextOperand = chain.at(index + 1);
       if (
         nextOperand?.comparisonType ===
           NullishComparisonType.StrictEqualUndefined &&
@@ -159,7 +170,7 @@ const analyzeOrChainOperand: OperandAnalyzer = (
 
     case NullishComparisonType.StrictEqualUndefined: {
       // handle `x === undefined || x === null`
-      const nextOperand = chain[index + 1] as ValidOperand | undefined;
+      const nextOperand = chain.at(index + 1);
       if (
         nextOperand?.comparisonType === NullishComparisonType.StrictEqualNull &&
         compareNodes(operand.comparedName, nextOperand.comparedName) ===

diff --git a/packages/eslint-plugin/tests/rules/prefer-optional-chain/prefer-optional-chain.test.ts b/packages/eslint-plugin/tests/rules/prefer-optional-chain/prefer-optional-chain.test.ts
@@ -793,6 +793,8 @@ describe('hand-crafted cases', () => {
       '(function () {}) && function () {}.name;',
       '(class Foo {}) && class Foo {}.constructor;',
       "new Map().get('a') && new Map().get('a').what;",
+      // https://github.com/typescript-eslint/typescript-eslint/issues/7654
+      'data && data.value !== null;',
       {
         code: '<div /> && (<div />).wtf;',
         parserOptions: { ecmaFeatures: { jsx: true } },