From bbc9e3540576891552dc2dc54b2acbc54104be9d Mon Sep 17 00:00:00 2001
From: Alex T <alexander.tarasyuk@outlook.com>
Date: Sun, 18 Oct 2020 22:49:58 +0300
Subject: [PATCH] feat(eslint-plugin): [dot-notation] add
 `allowProtectedClassPropertyAccess` option (#2622)

---
 .../eslint-plugin/docs/rules/dot-notation.md  | 15 +++++++++
 .../eslint-plugin/src/rules/dot-notation.ts   | 21 ++++++++++--
 .../tests/rules/dot-notation.test.ts          | 32 +++++++++++++++++++
 .../eslint-plugin/typings/eslint-rules.d.ts   |  1 +
 4 files changed, 66 insertions(+), 3 deletions(-)

diff --git a/packages/eslint-plugin/docs/rules/dot-notation.md b/packages/eslint-plugin/docs/rules/dot-notation.md
index bd1ea7487df..56097090e2e 100644
--- a/packages/eslint-plugin/docs/rules/dot-notation.md
+++ b/packages/eslint-plugin/docs/rules/dot-notation.md
@@ -23,10 +23,12 @@ This rule adds the following options:
 ```ts
 interface Options extends BaseDotNotationOptions {
   allowPrivateClassPropertyAccess?: boolean;
+  allowProtectedClassPropertyAccess?: boolean;
 }
 const defaultOptions: Options = {
   ...baseDotNotationDefaultOptions,
   allowPrivateClassPropertyAccess: false,
+  allowProtectedClassPropertyAccess: false,
 };
 ```
 
@@ -43,4 +45,17 @@ const x = new X();
 x['priv_prop'] = 123;
 ```
 
+### `allowProtectedClassPropertyAccess`
+
+Example of a correct code when `allowProtectedClassPropertyAccess` is set to `true`
+
+```ts
+class X {
+  protected protected_prop = 123;
+}
+
+const x = new X();
+x['protected_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/rules/dot-notation.ts b/packages/eslint-plugin/src/rules/dot-notation.ts
index 3cc2be22deb..2c9dd9f2351 100644
--- a/packages/eslint-plugin/src/rules/dot-notation.ts
+++ b/packages/eslint-plugin/src/rules/dot-notation.ts
@@ -38,6 +38,10 @@ export default createRule<Options, MessageIds>({
             type: 'boolean',
             default: false,
           },
+          allowProtectedClassPropertyAccess: {
+            type: 'boolean',
+            default: false,
+          },
         },
         additionalProperties: false,
       },
@@ -48,6 +52,7 @@ export default createRule<Options, MessageIds>({
   defaultOptions: [
     {
       allowPrivateClassPropertyAccess: false,
+      allowProtectedClassPropertyAccess: false,
       allowKeywords: true,
       allowPattern: '',
     },
@@ -56,20 +61,30 @@ export default createRule<Options, MessageIds>({
     const rules = baseRule.create(context);
     const allowPrivateClassPropertyAccess =
       options.allowPrivateClassPropertyAccess;
+    const allowProtectedClassPropertyAccess =
+      options.allowProtectedClassPropertyAccess;
 
     const parserServices = getParserServices(context);
     const typeChecker = parserServices.program.getTypeChecker();
 
     return {
       MemberExpression(node: TSESTree.MemberExpression): void {
-        if (allowPrivateClassPropertyAccess && node.computed) {
+        if (
+          (allowPrivateClassPropertyAccess ||
+            allowProtectedClassPropertyAccess) &&
+          node.computed
+        ) {
           // for perf reasons - only fetch the symbol if we have to
           const objectSymbol = typeChecker.getSymbolAtLocation(
             parserServices.esTreeNodeToTSNodeMap.get(node.property),
           );
+          const modifierKind = objectSymbol?.getDeclarations()?.[0]
+            ?.modifiers?.[0].kind;
           if (
-            objectSymbol?.getDeclarations()?.[0]?.modifiers?.[0].kind ===
-            ts.SyntaxKind.PrivateKeyword
+            (allowPrivateClassPropertyAccess &&
+              modifierKind == ts.SyntaxKind.PrivateKeyword) ||
+            (allowProtectedClassPropertyAccess &&
+              modifierKind == ts.SyntaxKind.ProtectedKeyword)
           ) {
             return;
           }
diff --git a/packages/eslint-plugin/tests/rules/dot-notation.test.ts b/packages/eslint-plugin/tests/rules/dot-notation.test.ts
index 797b111cb17..0d1f755b482 100644
--- a/packages/eslint-plugin/tests/rules/dot-notation.test.ts
+++ b/packages/eslint-plugin/tests/rules/dot-notation.test.ts
@@ -75,6 +75,18 @@ x['priv_prop'] = 123;
       `,
       options: [{ allowPrivateClassPropertyAccess: true }],
     },
+
+    {
+      code: `
+class X {
+  protected protected_prop = 123;
+}
+
+const x = new X();
+x['protected_prop'] = 123;
+      `,
+      options: [{ allowProtectedClassPropertyAccess: true }],
+    },
   ],
   invalid: [
     {
@@ -255,5 +267,25 @@ x.pub_prop = 123;
       options: [{ allowKeywords: false }],
       errors: [{ messageId: 'useBrackets', data: { key: 'if' } }],
     },
+    {
+      code: `
+class X {
+  protected protected_prop = 123;
+}
+
+const x = new X();
+x['protected_prop'] = 123;
+      `,
+      options: [{ allowProtectedClassPropertyAccess: false }],
+      output: `
+class X {
+  protected protected_prop = 123;
+}
+
+const x = new X();
+x.protected_prop = 123;
+      `,
+      errors: [{ messageId: 'useDot' }],
+    },
   ],
 });
diff --git a/packages/eslint-plugin/typings/eslint-rules.d.ts b/packages/eslint-plugin/typings/eslint-rules.d.ts
index d11c5589b38..8a6c89d529b 100644
--- a/packages/eslint-plugin/typings/eslint-rules.d.ts
+++ b/packages/eslint-plugin/typings/eslint-rules.d.ts
@@ -708,6 +708,7 @@ declare module 'eslint/lib/rules/dot-notation' {
         allowKeywords?: boolean;
         allowPattern?: string;
         allowPrivateClassPropertyAccess?: boolean;
+        allowProtectedClassPropertyAccess?: boolean;
       },
     ],
     {