From 33e3e6f79ea21792ccb60b7f1ada74057ceb52e9 Mon Sep 17 00:00:00 2001
From: Brad Zacher <brad.zacher@gmail.com>
Date: Sat, 29 Feb 2020 12:17:52 -0800
Subject: [PATCH] fix(eslint-plugin): [no-implied-eval] correct logic for ts3.8
 (#1652)

---
 .../src/rules/no-implied-eval.ts              |  15 +--
 .../tests/rules/no-implied-eval.test.ts       | 126 ++++++------------
 2 files changed, 49 insertions(+), 92 deletions(-)

diff --git a/packages/eslint-plugin/src/rules/no-implied-eval.ts b/packages/eslint-plugin/src/rules/no-implied-eval.ts
index fe50beba050..0f611859786 100644
--- a/packages/eslint-plugin/src/rules/no-implied-eval.ts
+++ b/packages/eslint-plugin/src/rules/no-implied-eval.ts
@@ -3,6 +3,7 @@ import {
   TSESTree,
   AST_NODE_TYPES,
 } from '@typescript-eslint/experimental-utils';
+import * as tsutils from 'tsutils';
 import * as util from '../util';
 
 const FUNCTION_CONSTRUCTOR = 'Function';
@@ -68,8 +69,11 @@ export default util.createRule({
       const symbol = type.getSymbol();
 
       if (
-        symbol?.flags === ts.SymbolFlags.Function ||
-        symbol?.flags === ts.SymbolFlags.Method
+        symbol &&
+        tsutils.isSymbolFlagSet(
+          symbol,
+          ts.SymbolFlags.Function | ts.SymbolFlags.Method,
+        )
       ) {
         return true;
       }
@@ -79,12 +83,7 @@ export default util.createRule({
         ts.SignatureKind.Call,
       );
 
-      if (signatures.length) {
-        const [{ declaration }] = signatures;
-        return declaration?.kind === ts.SyntaxKind.FunctionType;
-      }
-
-      return false;
+      return signatures.length > 0;
     }
 
     function isFunction(node: TSESTree.Node): boolean {
diff --git a/packages/eslint-plugin/tests/rules/no-implied-eval.test.ts b/packages/eslint-plugin/tests/rules/no-implied-eval.test.ts
index 947044727d5..b92b61eff6a 100644
--- a/packages/eslint-plugin/tests/rules/no-implied-eval.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-implied-eval.test.ts
@@ -36,38 +36,31 @@ ruleTester.run('no-implied-eval', rule, {
     `window.execScript(() => {});`,
     `window['execScript'](() => {});`,
 
-    {
-      code: `
+    `
 const foo = () => {};
 
 setTimeout(foo, 0);
 setInterval(foo, 0);
 setImmediate(foo);
 execScript(foo);
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const foo = function () {};
 
 setTimeout(foo, 0);
 setInterval(foo, 0);
 setImmediate(foo);
 execScript(foo);
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 function foo() {};
 
 setTimeout(foo, 0);
 setInterval(foo, 0);
 setImmediate(foo);
 execScript(foo);
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const foo = {
   fn: () => {},
 }
@@ -76,10 +69,8 @@ setTimeout(foo.fn, 0);
 setInterval(foo.fn, 0);
 setImmediate(foo.fn);
 execScript(foo.fn);
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const foo = {
   fn: function () {},
 }
@@ -88,10 +79,8 @@ setTimeout(foo.fn, 0);
 setInterval(foo.fn, 0);
 setImmediate(foo.fn);
 execScript(foo.fn);
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const foo = {
   fn: function foo() {},
 }
@@ -100,10 +89,8 @@ setTimeout(foo.fn, 0);
 setInterval(foo.fn, 0);
 setImmediate(foo.fn);
 execScript(foo.fn);
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const foo = {
   fn() {},
 }
@@ -112,10 +99,8 @@ setTimeout(foo.fn, 0);
 setInterval(foo.fn, 0);
 setImmediate(foo.fn);
 execScript(foo.fn);
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const foo = {
   fn: () => {},
 }
@@ -125,10 +110,8 @@ setTimeout(foo[fn], 0);
 setInterval(foo[fn], 0);
 setImmediate(foo[fn]);
 execScript(foo[fn]);
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const foo = {
   fn: () => {},
 }
@@ -137,10 +120,8 @@ setTimeout(foo['fn'], 0);
 setInterval(foo['fn'], 0);
 setImmediate(foo['fn']);
 execScript(foo['fn']);
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const foo: () => void = () => {
 };
 
@@ -148,10 +129,8 @@ setTimeout(foo, 0);
 setInterval(foo, 0);
 setImmediate(foo);
 execScript(foo);
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const foo: (() => () => void) = () => {
   return () => {};
 }
@@ -160,30 +139,24 @@ setTimeout(foo(), 0);
 setInterval(foo(), 0);
 setImmediate(foo());
 execScript(foo());
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const foo: (() => () => void) = () => () => {};
 
 setTimeout(foo(), 0);
 setInterval(foo(), 0);
 setImmediate(foo());
 execScript(foo());
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const foo = () => () => {};
 
 setTimeout(foo(), 0);
 setInterval(foo(), 0);
 setImmediate(foo());
 execScript(foo());
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const foo = function foo () {
   return function foo() {}
 }
@@ -192,10 +165,8 @@ setTimeout(foo(), 0);
 setInterval(foo(), 0);
 setImmediate(foo());
 execScript(foo());
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const foo = function () {
   return function () {
     return '';
@@ -206,10 +177,8 @@ setTimeout(foo(), 0);
 setInterval(foo(), 0);
 setImmediate(foo());
 execScript(foo());
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const foo: (() => () => void) = function foo () {
   return function foo() {}
 }
@@ -218,10 +187,8 @@ setTimeout(foo(), 0);
 setInterval(foo(), 0);
 setImmediate(foo());
 execScript(foo());
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 function foo() {
   return function foo() {
     return () => {};
@@ -232,10 +199,8 @@ setTimeout(foo()(), 0);
 setInterval(foo()(), 0);
 setImmediate(foo()());
 execScript(foo()());
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 class Foo {
   static fn = () => {};
 }
@@ -244,10 +209,8 @@ setTimeout(Foo.fn, 0);
 setInterval(Foo.fn, 0);
 setImmediate(Foo.fn);
 execScript(Foo.fn);
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 class Foo {
   fn() {}
 }
@@ -258,10 +221,8 @@ setTimeout(foo.fn, 0);
 setInterval(foo.fn, 0);
 setImmediate(foo.fn);
 execScript(foo.fn);
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 class Foo {
   fn() {}
 }
@@ -272,18 +233,15 @@ setTimeout(fn.bind(null), 0);
 setInterval(fn.bind(null), 0);
 setImmediate(fn.bind(null));
 execScript(fn.bind(null));
-      `,
-    },
-    {
-      code: `
+    `,
+    `
 const fn = (foo: () => void) => {
   setTimeout(foo, 0);
   setInterval(foo, 0);
   setImmediate(foo);
   execScript(foo);
 }
-      `,
-    },
+    `,
   ],
 
   invalid: [