From 816b1bb40c713b04eaf8c16248c1fa912b223be7 Mon Sep 17 00:00:00 2001
From: ryym <ryym.64@gmail.com>
Date: Sun, 22 Nov 2020 17:31:08 +0900
Subject: [PATCH 1/4] fix(eslint-plugin): [consistent-indexed-object-style]
 Skip readonly index signature

---
 .../src/rules/consistent-indexed-object-style.ts     |  4 ++++
 .../rules/consistent-indexed-object-style.test.ts    | 12 ++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts b/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts
index c1b86bf8c61..1791a959178 100644
--- a/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts
+++ b/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts
@@ -76,6 +76,10 @@ export default createRule<Options, MessageIds>({
         return;
       }
 
+      if (member.readonly) {
+        return;
+      }
+
       const [parameter] = member.parameters;
 
       if (!parameter) {
diff --git a/packages/eslint-plugin/tests/rules/consistent-indexed-object-style.test.ts b/packages/eslint-plugin/tests/rules/consistent-indexed-object-style.test.ts
index ebedccf424a..77a2cd3874e 100644
--- a/packages/eslint-plugin/tests/rules/consistent-indexed-object-style.test.ts
+++ b/packages/eslint-plugin/tests/rules/consistent-indexed-object-style.test.ts
@@ -51,6 +51,18 @@ type Foo = {
 };
     `,
 
+    // Readonly
+    `
+interface Foo {
+  readonly [key: string]: any;
+}
+    `,
+    `
+type Foo = {
+  readonly [key: string]: any;
+};
+    `,
+
     // Generic
     `
 type Foo = Generic<{

From 3212edb49ab5ad5a6bbd661d397617a6dbc3a89c Mon Sep 17 00:00:00 2001
From: ryym <ryym.64@gmail.com>
Date: Sun, 22 Nov 2020 17:40:01 +0900
Subject: [PATCH 2/4] docs(eslint-plugin): [consistent-indexed-object-style]
 Add readonly type to correct code examples

---
 .../docs/rules/consistent-indexed-object-style.md         | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/packages/eslint-plugin/docs/rules/consistent-indexed-object-style.md b/packages/eslint-plugin/docs/rules/consistent-indexed-object-style.md
index c98997c5e0a..a62ebaf214c 100644
--- a/packages/eslint-plugin/docs/rules/consistent-indexed-object-style.md
+++ b/packages/eslint-plugin/docs/rules/consistent-indexed-object-style.md
@@ -46,6 +46,14 @@ Examples of **correct** code with `record` option.
 
 ```ts
 type Foo = Record<string, unknown>;
+
+interface Foo {
+  readonly [key: string]: unknown;
+}
+
+type Foo = {
+  readonly [key: string]: unknown;
+};
 ```
 
 Examples of **incorrect** code with `index-signature` option.

From caf36b753d75b735649f781b74ebee68b152bc04 Mon Sep 17 00:00:00 2001
From: ryym <ryym.64@gmail.com>
Date: Mon, 23 Nov 2020 08:10:10 +0900
Subject: [PATCH 3/4] Revert "docs(eslint-plugin):
 [consistent-indexed-object-style] Add readonly type to correct code examples"

This reverts commit 3212edb49ab5ad5a6bbd661d397617a6dbc3a89c.
The rule should replace a readonly index signature with `Readonly<Record>`
instead of ignoring it.
---
 .../docs/rules/consistent-indexed-object-style.md         | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/packages/eslint-plugin/docs/rules/consistent-indexed-object-style.md b/packages/eslint-plugin/docs/rules/consistent-indexed-object-style.md
index a62ebaf214c..c98997c5e0a 100644
--- a/packages/eslint-plugin/docs/rules/consistent-indexed-object-style.md
+++ b/packages/eslint-plugin/docs/rules/consistent-indexed-object-style.md
@@ -46,14 +46,6 @@ Examples of **correct** code with `record` option.
 
 ```ts
 type Foo = Record<string, unknown>;
-
-interface Foo {
-  readonly [key: string]: unknown;
-}
-
-type Foo = {
-  readonly [key: string]: unknown;
-};
 ```
 
 Examples of **incorrect** code with `index-signature` option.

From ddd60119e38bcf3e061b324da313dd23235aa5a9 Mon Sep 17 00:00:00 2001
From: ryym <ryym.64@gmail.com>
Date: Mon, 23 Nov 2020 08:13:40 +0900
Subject: [PATCH 4/4] feat(eslint-plugin): [consistent-indexed-object-style]
 Convert readonly index signature to Readonly Record type

This replaces the fix of 816b1bb4.
Instead of just ignoring the readonly index signature, replace it with
`Readonly<Record<key, value>>` type.
---
 .../rules/consistent-indexed-object-style.ts  | 12 +--
 .../consistent-indexed-object-style.test.ts   | 77 ++++++++++++++++---
 2 files changed, 69 insertions(+), 20 deletions(-)

diff --git a/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts b/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts
index 1791a959178..bd48718c68b 100644
--- a/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts
+++ b/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts
@@ -76,10 +76,6 @@ export default createRule<Options, MessageIds>({
         return;
       }
 
-      if (member.readonly) {
-        return;
-      }
-
       const [parameter] = member.parameters;
 
       if (!parameter) {
@@ -105,10 +101,10 @@ export default createRule<Options, MessageIds>({
         fix(fixer) {
           const key = sourceCode.getText(keyType.typeAnnotation);
           const value = sourceCode.getText(valueType.typeAnnotation);
-          return fixer.replaceText(
-            node,
-            `${prefix}Record<${key}, ${value}>${postfix}`,
-          );
+          const record = member.readonly
+            ? `Readonly<Record<${key}, ${value}>>`
+            : `Record<${key}, ${value}>`;
+          return fixer.replaceText(node, `${prefix}${record}${postfix}`);
         },
       });
     }
diff --git a/packages/eslint-plugin/tests/rules/consistent-indexed-object-style.test.ts b/packages/eslint-plugin/tests/rules/consistent-indexed-object-style.test.ts
index 77a2cd3874e..31077fcf620 100644
--- a/packages/eslint-plugin/tests/rules/consistent-indexed-object-style.test.ts
+++ b/packages/eslint-plugin/tests/rules/consistent-indexed-object-style.test.ts
@@ -51,18 +51,6 @@ type Foo = {
 };
     `,
 
-    // Readonly
-    `
-interface Foo {
-  readonly [key: string]: any;
-}
-    `,
-    `
-type Foo = {
-  readonly [key: string]: any;
-};
-    `,
-
     // Generic
     `
 type Foo = Generic<{
@@ -152,6 +140,19 @@ type Foo = Record<string, any>;
       errors: [{ messageId: 'preferRecord', line: 2, column: 1 }],
     },
 
+    // Readonly interface
+    {
+      code: `
+interface Foo {
+  readonly [key: string]: any;
+}
+      `,
+      output: `
+type Foo = Readonly<Record<string, any>>;
+      `,
+      errors: [{ messageId: 'preferRecord', line: 2, column: 1 }],
+    },
+
     // Interface with generic parameter
     {
       code: `
@@ -165,6 +166,19 @@ type Foo<A> = Record<string, A>;
       errors: [{ messageId: 'preferRecord', line: 2, column: 1 }],
     },
 
+    // Readonly interface with generic parameter
+    {
+      code: `
+interface Foo<A> {
+  readonly [key: string]: A;
+}
+      `,
+      output: `
+type Foo<A> = Readonly<Record<string, A>>;
+      `,
+      errors: [{ messageId: 'preferRecord', line: 2, column: 1 }],
+    },
+
     // Interface with multiple generic parameters
     {
       code: `
@@ -178,6 +192,19 @@ type Foo<A, B> = Record<A, B>;
       errors: [{ messageId: 'preferRecord', line: 2, column: 1 }],
     },
 
+    // Readonly interface with multiple generic parameters
+    {
+      code: `
+interface Foo<A, B> {
+  readonly [key: A]: B;
+}
+      `,
+      output: `
+type Foo<A, B> = Readonly<Record<A, B>>;
+      `,
+      errors: [{ messageId: 'preferRecord', line: 2, column: 1 }],
+    },
+
     // Type literal
     {
       code: 'type Foo = { [key: string]: any };',
@@ -185,6 +212,13 @@ type Foo<A, B> = Record<A, B>;
       errors: [{ messageId: 'preferRecord', line: 1, column: 12 }],
     },
 
+    // Readonly type literal
+    {
+      code: 'type Foo = { readonly [key: string]: any };',
+      output: 'type Foo = Readonly<Record<string, any>>;',
+      errors: [{ messageId: 'preferRecord', line: 1, column: 12 }],
+    },
+
     // Generic
     {
       code: 'type Foo = Generic<{ [key: string]: any }>;',
@@ -192,6 +226,13 @@ type Foo<A, B> = Record<A, B>;
       errors: [{ messageId: 'preferRecord', line: 1, column: 20 }],
     },
 
+    // Readonly Generic
+    {
+      code: 'type Foo = Generic<{ readonly [key: string]: any }>;',
+      output: 'type Foo = Generic<Readonly<Record<string, any>>>;',
+      errors: [{ messageId: 'preferRecord', line: 1, column: 20 }],
+    },
+
     // Function types
     {
       code: 'function foo(arg: { [key: string]: any }) {}',
@@ -204,6 +245,18 @@ type Foo<A, B> = Record<A, B>;
       errors: [{ messageId: 'preferRecord', line: 1, column: 17 }],
     },
 
+    // Readonly function types
+    {
+      code: 'function foo(arg: { readonly [key: string]: any }) {}',
+      output: 'function foo(arg: Readonly<Record<string, any>>) {}',
+      errors: [{ messageId: 'preferRecord', line: 1, column: 19 }],
+    },
+    {
+      code: 'function foo(): { readonly [key: string]: any } {}',
+      output: 'function foo(): Readonly<Record<string, any>> {}',
+      errors: [{ messageId: 'preferRecord', line: 1, column: 17 }],
+    },
+
     // Never
     // Type literal
     {