feat(eslint-plugin): [no-extra-non-null-assert] add fixer (#1468)

typescript-eslint · Jan 30, 2020 · 54201ab · 54201ab
1 parent bec4572
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Showing 3 changed files with 101 additions and 19 deletions.
diff --git a/packages/eslint-plugin/README.md b/packages/eslint-plugin/README.md
@@ -110,7 +110,7 @@ Pro Tip: For larger codebases you may want to consider splitting our linting int
 | [`@typescript-eslint/no-dynamic-delete`](./docs/rules/no-dynamic-delete.md)                                           | Disallow the delete operator with computed key expressions                                                              |                    | :wrench: |                   |
 | [`@typescript-eslint/no-empty-interface`](./docs/rules/no-empty-interface.md)                                         | Disallow the declaration of empty interfaces                                                                            | :heavy_check_mark: | :wrench: |                   |
 | [`@typescript-eslint/no-explicit-any`](./docs/rules/no-explicit-any.md)                                               | Disallow usage of the `any` type                                                                                        | :heavy_check_mark: | :wrench: |                   |
-| [`@typescript-eslint/no-extra-non-null-assertion`](./docs/rules/no-extra-non-null-assertion.md)                       | Disallow extra non-null assertion                                                                                       |                    |          |                   |
+| [`@typescript-eslint/no-extra-non-null-assertion`](./docs/rules/no-extra-non-null-assertion.md)                       | Disallow extra non-null assertion                                                                                       |                    | :wrench: |                   |
 | [`@typescript-eslint/no-extraneous-class`](./docs/rules/no-extraneous-class.md)                                       | Forbids the use of classes as namespaces                                                                                |                    |          |                   |
 | [`@typescript-eslint/no-floating-promises`](./docs/rules/no-floating-promises.md)                                     | Requires Promise-like values to be handled appropriately                                                                |                    |          | :thought_balloon: |
 | [`@typescript-eslint/no-for-in-array`](./docs/rules/no-for-in-array.md)                                               | Disallow iterating over an array with a for-in loop                                                                     | :heavy_check_mark: |          | :thought_balloon: |

diff --git a/packages/eslint-plugin/src/rules/no-extra-non-null-assertion.ts b/packages/eslint-plugin/src/rules/no-extra-non-null-assertion.ts
@@ -10,6 +10,7 @@ export default util.createRule({
       category: 'Stylistic Issues',
       recommended: false,
     },
+    fixable: 'code',
     schema: [],
     messages: {
       noExtraNonNullAssertion: 'Forbidden extra non-null assertion.',
@@ -20,12 +21,19 @@ export default util.createRule({
     function checkExtraNonNullAssertion(
       node: TSESTree.TSNonNullExpression,
     ): void {
-      context.report({ messageId: 'noExtraNonNullAssertion', node });
+      context.report({
+        node,
+        messageId: 'noExtraNonNullAssertion',
+        fix(fixer) {
+          return fixer.removeRange([node.range[1] - 1, node.range[1]]);
+        },
+      });
     }
 
     return {
       'TSNonNullExpression > TSNonNullExpression': checkExtraNonNullAssertion,
       'OptionalMemberExpression > TSNonNullExpression': checkExtraNonNullAssertion,
+      'OptionalCallExpression > TSNonNullExpression.callee': checkExtraNonNullAssertion,
     };
   },
 });
diff --git a/packages/eslint-plugin/tests/rules/no-extra-non-null-assertion.test.ts b/packages/eslint-plugin/tests/rules/no-extra-non-null-assertion.test.ts
@@ -31,21 +31,13 @@ function foo(bar?: { n: number }) {
     {
       code: `
 const foo: { bar: number } | null = null;
-const bar = foo!!!!.bar;
+const bar = foo!!.bar;
+      `,
+      output: `
+const foo: { bar: number } | null = null;
+const bar = foo!.bar;
       `,
       errors: [
-        {
-          messageId: 'noExtraNonNullAssertion',
-          endColumn: 19,
-          column: 13,
-          line: 3,
-        },
-        {
-          messageId: 'noExtraNonNullAssertion',
-          endColumn: 18,
-          column: 13,
-          line: 3,
-        },
         {
           messageId: 'noExtraNonNullAssertion',
           endColumn: 17,
@@ -58,6 +50,11 @@ const bar = foo!!!!.bar;
       code: `
 function foo(bar: number | undefined) {
   const bar: number = bar!!;
+}
+      `,
+      output: `
+function foo(bar: number | undefined) {
+  const bar: number = bar!;
 }
       `,
       errors: [
@@ -73,6 +70,11 @@ function foo(bar: number | undefined) {
       code: `
 function foo(bar?: { n: number }) {
   return bar!?.n;
+}
+      `,
+      output: `
+function foo(bar?: { n: number }) {
+  return bar?.n;
 }
       `,
       errors: [
@@ -87,29 +89,101 @@ function foo(bar?: { n: number }) {
     {
       code: `
 function foo(bar?: { n: number }) {
-  return bar!!!?.n;
+  return bar!?.();
+}
+      `,
+      output: `
+function foo(bar?: { n: number }) {
+  return bar?.();
 }
       `,
       errors: [
         {
           messageId: 'noExtraNonNullAssertion',
-          endColumn: 16,
+          endColumn: 14,
           column: 10,
           line: 3,
         },
+      ],
+    },
+    // parentheses
+    {
+      code: `
+const foo: { bar: number } | null = null;
+const bar = (foo!)!.bar;
+      `,
+      output: `
+const foo: { bar: number } | null = null;
+const bar = (foo)!.bar;
+      `,
+      errors: [
+        {
+          messageId: 'noExtraNonNullAssertion',
+          endColumn: 18,
+          column: 14,
+          line: 3,
+        },
+      ],
+    },
+    {
+      code: `
+function foo(bar?: { n: number }) {
+  return (bar!)?.n;
+}
+      `,
+      output: `
+function foo(bar?: { n: number }) {
+  return (bar)?.n;
+}
+      `,
+      errors: [
         {
           messageId: 'noExtraNonNullAssertion',
           endColumn: 15,
-          column: 10,
+          column: 11,
           line: 3,
         },
+      ],
+    },
+    {
+      code: `
+function foo(bar?: { n: number }) {
+  return (bar)!?.n;
+}
+      `,
+      output: `
+function foo(bar?: { n: number }) {
+  return (bar)?.n;
+}
+      `,
+      errors: [
         {
           messageId: 'noExtraNonNullAssertion',
-          endColumn: 14,
+          endColumn: 16,
           column: 10,
           line: 3,
         },
       ],
     },
+    {
+      code: `
+function foo(bar?: { n: number }) {
+  return (bar!)?.();
+}
+      `,
+      output: `
+function foo(bar?: { n: number }) {
+  return (bar)?.();
+}
+      `,
+      errors: [
+        {
+          messageId: 'noExtraNonNullAssertion',
+          endColumn: 15,
+          column: 11,
+          line: 3,
+        },
+      ],
+    },
   ],
 });