From e42d18883bd689f5f14ec908272ffd65b64b613b Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Mon, 24 Jul 2023 11:19:45 -0700
Subject: [PATCH 1/2] Enable @typescript-eslint/ban-types

---
 .eslintrc.json               | 11 ++++++++++-
 src/compiler/sys.ts          |  2 +-
 src/harness/fourslashImpl.ts |  4 ++--
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/.eslintrc.json b/.eslintrc.json
index 30e6bb6ef2f65..3e172986d22e8 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -79,9 +79,18 @@
         "@typescript-eslint/no-namespace": "off",
         "@typescript-eslint/no-non-null-asserted-optional-chain": "off",
         "@typescript-eslint/no-var-requires": "off",
+        "@typescript-eslint/ban-types": [
+            "error",
+            {
+                "extendDefaults": true,
+                "types": {
+                    "Symbol": false, // This is theoretically good, but ts-eslint appears to mistake our declaration of Symbol for the global Symbol type.
+                    "{}": false // {} is a totally useful and valid type.
+                }
+            }
+        ],
 
         // Todo: For each of these, investigate whether we want to enable them ✨
-        "@typescript-eslint/ban-types": "off",
         "no-case-declarations": "off",
         "no-cond-assign": "off",
         "no-constant-condition": "off",
diff --git a/src/compiler/sys.ts b/src/compiler/sys.ts
index b7b73d4158312..db12d3a6dd96e 100644
--- a/src/compiler/sys.ts
+++ b/src/compiler/sys.ts
@@ -1711,7 +1711,7 @@ export let sys: System = (() => {
 
         function bufferFrom(input: string, encoding?: string): Buffer {
             // See https://github.com/Microsoft/TypeScript/issues/25652
-            return Buffer.from && (Buffer.from as Function) !== Int8Array.from
+            return Buffer.from && Buffer.from !== Int8Array.from
                 ? Buffer.from(input, encoding)
                 : new Buffer(input, encoding);
         }
diff --git a/src/harness/fourslashImpl.ts b/src/harness/fourslashImpl.ts
index b6ab758e7ebe3..6927acdbd3afa 100644
--- a/src/harness/fourslashImpl.ts
+++ b/src/harness/fourslashImpl.ts
@@ -442,11 +442,11 @@ export class TestState {
             for (const k of keys) {
                 const key = k as keyof typeof ls;
                 if (cacheableMembers.indexOf(key) === -1) {
-                    proxy[key] = (...args: any[]) => (ls[key] as Function)(...args);
+                    proxy[key] = (...args: any[]) => (ls[key] as (...args: any[]) => any)(...args);
                     continue;
                 }
                 const memo = Utils.memoize(
-                    (_version: number, _active: string, _caret: number, _selectEnd: number, _marker: string | undefined, ...args: any[]) => (ls[key] as Function)(...args),
+                    (_version: number, _active: string, _caret: number, _selectEnd: number, _marker: string | undefined, ...args: any[]) => (ls[key] as (...args: any[]) => any)(...args),
                     (...args) => args.map(a => a && typeof a === "object" ? JSON.stringify(a) : a).join("|,|")
                 );
                 proxy[key] = (...args: any[]) => memo(

From c7a8baeb14f23efcb9fdbc2c3c867a7d4e691593 Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Mon, 24 Jul 2023 11:31:31 -0700
Subject: [PATCH 2/2] Add comment pointing to Symbol issue

---
 .eslintrc.json | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/.eslintrc.json b/.eslintrc.json
index 3e172986d22e8..2bd9211a3d923 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -84,7 +84,9 @@
             {
                 "extendDefaults": true,
                 "types": {
-                    "Symbol": false, // This is theoretically good, but ts-eslint appears to mistake our declaration of Symbol for the global Symbol type.
+                    // This is theoretically good, but ts-eslint appears to mistake our declaration of Symbol for the global Symbol type.
+                    // See: https://github.com/typescript-eslint/typescript-eslint/issues/7306
+                    "Symbol": false,
                     "{}": false // {} is a totally useful and valid type.
                 }
             }