feat(eslint-plugin): add extension rule dot-notation (typescript-eslint#1867)

anikethsaha · web-flow · commit a85c3e1515d7 · 2020-04-26T12:41:31.000-07:00
diff --git a/packages/eslint-plugin/README.md b/packages/eslint-plugin/README.md
@@ -182,6 +182,7 @@ In these cases, we create what we call an extension rule; a rule within our plug
 | [`@typescript-eslint/brace-style`](./docs/rules/brace-style.md)                                 | Enforce consistent brace style for blocks                                      |                    | :wrench: |                   |
 | [`@typescript-eslint/comma-spacing`](./docs/rules/comma-spacing.md)                             | Enforces consistent spacing before and after commas                            |                    | :wrench: |                   |
 | [`@typescript-eslint/default-param-last`](./docs/rules/default-param-last.md)                   | Enforce default parameters to be last                                          |                    |          |                   |
+| [`@typescript-eslint/dot-notation`](./docs/rules/dot-notation.md)                               | enforce dot notation whenever possible                                         |                    | :wrench: | :thought_balloon: |
 | [`@typescript-eslint/func-call-spacing`](./docs/rules/func-call-spacing.md)                     | Require or disallow spacing between function identifiers and their invocations |                    | :wrench: |                   |
 | [`@typescript-eslint/indent`](./docs/rules/indent.md)                                           | Enforce consistent indentation                                                 |                    | :wrench: |                   |
 | [`@typescript-eslint/init-declarations`](./docs/rules/init-declarations.md)                     | require or disallow initialization in variable declarations                    |                    |          |                   |
diff --git a/packages/eslint-plugin/docs/rules/dot-notation.md b/packages/eslint-plugin/docs/rules/dot-notation.md
@@ -0,0 +1,46 @@
+# enforce dot notation whenever possible (`dot-notation`)
+
+## Rule Details
+
+This rule extends the base [`eslint/dot-notation`](https://eslint.org/docs/rules/dot-notation) rule.
+It adds support for optionally ignoring computed `private` member access.
+
+## How to use
+
+```cjson
+{
+  // note you must disable the base rule as it can report incorrect errors
+  "dot-notation": "off",
+  "@typescript-eslint/dot-notation": ["error"]
+}
+```
+
+## Options
+
+See [`eslint/dot-notation`](https://eslint.org/docs/rules/dot-notation#options) options.
+This rule adds the following options:
+
+```ts
+interface Options extends BaseDotNotationOptions {
+  allowPrivateClassPropertyAccess?: boolean;
+}
+const defaultOptions: Options = {
+  ...baseDotNotationDefaultOptions,
+  allowPrivateClassPropertyAccess: false,
+};
+```
+
+### `allowPrivateClassPropertyAccess`
+
+Example of a correct code when `allowPrivateClassPropertyAccess` is set to `true`
+
+```ts
+class X {
+  private priv_prop = 123;
+}
+
+const x = new X();
+x['priv_prop'] = 123;
+```
+
+<sup>Taken with ❤️ [from ESLint core](https://github.com/eslint/eslint/blob/master/docs/rules/dot-notation.md)</sup>
diff --git a/packages/eslint-plugin/src/configs/all.json b/packages/eslint-plugin/src/configs/all.json
@@ -15,6 +15,8 @@
     "@typescript-eslint/consistent-type-definitions": "error",
     "default-param-last": "off",
     "@typescript-eslint/default-param-last": "error",
+    "dot-notation": "off",
+    "@typescript-eslint/dot-notation": "error",
     "@typescript-eslint/explicit-function-return-type": "error",
     "@typescript-eslint/explicit-member-accessibility": "error",
     "@typescript-eslint/explicit-module-boundary-types": "error",
diff --git a/packages/eslint-plugin/src/rules/dot-notation.ts b/packages/eslint-plugin/src/rules/dot-notation.ts
@@ -0,0 +1,80 @@
+import { TSESTree } from '@typescript-eslint/experimental-utils';
+import * as ts from 'typescript';
+import baseRule from 'eslint/lib/rules/dot-notation';
+import {
+  InferOptionsTypeFromRule,
+  InferMessageIdsTypeFromRule,
+  createRule,
+  getParserServices,
+} from '../util';
+
+export type Options = InferOptionsTypeFromRule<typeof baseRule>;
+export type MessageIds = InferMessageIdsTypeFromRule<typeof baseRule>;
+
+export default createRule<Options, MessageIds>({
+  name: 'dot-notation',
+  meta: {
+    type: 'suggestion',
+    docs: {
+      description: 'enforce dot notation whenever possible',
+      category: 'Best Practices',
+      recommended: false,
+      extendsBaseRule: true,
+      requiresTypeChecking: true,
+    },
+    schema: [
+      {
+        type: 'object',
+        properties: {
+          allowKeywords: {
+            type: 'boolean',
+            default: true,
+          },
+          allowPattern: {
+            type: 'string',
+            default: '',
+          },
+          allowPrivateClassPropertyAccess: {
+            tyoe: 'boolean',
+            default: false,
+          },
+        },
+        additionalProperties: false,
+      },
+    ],
+    fixable: baseRule.meta.fixable,
+    messages: baseRule.meta.messages,
+  },
+  defaultOptions: [
+    {
+      allowPrivateClassPropertyAccess: false,
+      allowKeywords: true,
+      allowPattern: '',
+    },
+  ],
+  create(context, [options]) {
+    const rules = baseRule.create(context);
+    const allowPrivateClassPropertyAccess =
+      options.allowPrivateClassPropertyAccess;
+
+    const parserServices = getParserServices(context);
+    const typeChecker = parserServices.program.getTypeChecker();
+
+    return {
+      MemberExpression(node: TSESTree.MemberExpression): void {
+        const objectSymbol = typeChecker.getSymbolAtLocation(
+          parserServices.esTreeNodeToTSNodeMap.get(node.property),
+        );
+
+        if (
+          allowPrivateClassPropertyAccess &&
+          objectSymbol?.declarations[0]?.modifiers?.[0].kind ===
+            ts.SyntaxKind.PrivateKeyword
+        ) {
+          return;
+        }
+        rules.MemberExpression(node);
+      },
+    };
+  },
+});
diff --git a/packages/eslint-plugin/src/rules/index.ts b/packages/eslint-plugin/src/rules/index.ts
@@ -12,6 +12,7 @@ import commaSpacing from './comma-spacing';
 import consistentTypeAssertions from './consistent-type-assertions';
 import consistentTypeDefinitions from './consistent-type-definitions';
 import defaultParamLast from './default-param-last';
+import dotNotation from './dot-notation';
 import explicitFunctionReturnType from './explicit-function-return-type';
 import explicitMemberAccessibility from './explicit-member-accessibility';
 import explicitModuleBoundaryTypes from './explicit-module-boundary-types';
@@ -114,6 +115,7 @@ export default {
   'consistent-type-assertions': consistentTypeAssertions,
   'consistent-type-definitions': consistentTypeDefinitions,
   'default-param-last': defaultParamLast,
+  'dot-notation': dotNotation,
   'explicit-function-return-type': explicitFunctionReturnType,
   'explicit-member-accessibility': explicitMemberAccessibility,
   'explicit-module-boundary-types': explicitModuleBoundaryTypes,
diff --git a/packages/eslint-plugin/tests/rules/dot-notation.test.ts b/packages/eslint-plugin/tests/rules/dot-notation.test.ts
diff --git a/packages/eslint-plugin/typings/eslint-rules.d.ts b/packages/eslint-plugin/typings/eslint-rules.d.ts
