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ae91138701
`DisposableStore`/`MutableDisposable` properties should almost always be `readonly`. Otherwise it's easy to accidentally overwrite the property and leak the previous value. This commonly happens with code such as:
```ts
class Foo {
private disposables = new DisposableStore();
bar() {
this.disposables = new DisposableStore(); // leaks old values
...
}
```
This change adds an eslint rule to enforce this and adopts `readonly` for the caught cases. I only needed to add 2 suppression comments, which seems like an acceptable tradeoff for helping catch a common mistake
38 lines
1.4 KiB
TypeScript
38 lines
1.4 KiB
TypeScript
/*---------------------------------------------------------------------------------------------
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* Copyright (c) Microsoft Corporation. All rights reserved.
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* Licensed under the MIT License. See License.txt in the project root for license information.
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*--------------------------------------------------------------------------------------------*/
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import * as eslint from 'eslint';
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/**
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* Checks for potentially unsafe usage of `DisposableStore` / `MutableDisposable`.
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*
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* These have been the source of leaks in the past.
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*/
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export = new class implements eslint.Rule.RuleModule {
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create(context: eslint.Rule.RuleContext): eslint.Rule.RuleListener {
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function checkVariableDeclaration(inNode: any) {
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context.report({
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node: inNode,
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message: `Use const for 'DisposableStore' to avoid leaks by accidental reassignment.`
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});
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}
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function checkProperty(inNode: any) {
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context.report({
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node: inNode,
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message: `Use readonly for DisposableStore/MutableDisposable to avoid leaks through accidental reassignment.`
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});
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}
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return {
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'VariableDeclaration[kind!="const"] NewExpression[callee.name="DisposableStore"]': checkVariableDeclaration,
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'PropertyDefinition[readonly!=true][typeAnnotation.typeAnnotation.typeName.name=/DisposableStore|MutableDisposable/]': checkProperty,
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'PropertyDefinition[readonly!=true] NewExpression[callee.name=/DisposableStore|MutableDisposable/]': checkProperty,
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};
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}
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};
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