From eee6d49bbde8d7ff512a009d3dde10c430a6f6c5 Mon Sep 17 00:00:00 2001
From: Denys Kniazevych <webschik@gmail.com>
Date: Fri, 12 Apr 2019 00:25:03 +0200
Subject: [PATCH] fix(eslint-plugin): support BigInt in restrict-plus-operands
 rule (#344)

Fixes #309
---
 .../src/rules/restrict-plus-operands.ts       |  6 ++++-
 .../tests/fixtures/tsconfig.json              |  2 +-
 .../rules/restrict-plus-operands.test.ts      | 22 +++++++++++++++++++
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/packages/eslint-plugin/src/rules/restrict-plus-operands.ts b/packages/eslint-plugin/src/rules/restrict-plus-operands.ts
index 6b63f88a4f7..62b1b1f79ce 100644
--- a/packages/eslint-plugin/src/rules/restrict-plus-operands.ts
+++ b/packages/eslint-plugin/src/rules/restrict-plus-operands.ts
@@ -54,7 +54,11 @@ export default util.createRule({
 
       const stringType = typeChecker.typeToString(type);
 
-      if (stringType === 'number' || stringType === 'string') {
+      if (
+        stringType === 'number' ||
+        stringType === 'string' ||
+        stringType === 'bigint'
+      ) {
         return stringType;
       }
       return 'invalid';
diff --git a/packages/eslint-plugin/tests/fixtures/tsconfig.json b/packages/eslint-plugin/tests/fixtures/tsconfig.json
index 8702b63472b..bedda0e3dec 100644
--- a/packages/eslint-plugin/tests/fixtures/tsconfig.json
+++ b/packages/eslint-plugin/tests/fixtures/tsconfig.json
@@ -4,6 +4,6 @@
     "module": "commonjs",
     "strict": true,
     "esModuleInterop": true,
-    "lib": ["es2015", "es2017"]
+    "lib": ["es2015", "es2017", "esnext"]
   }
 }
diff --git a/packages/eslint-plugin/tests/rules/restrict-plus-operands.test.ts b/packages/eslint-plugin/tests/rules/restrict-plus-operands.test.ts
index 4cff2c7c5c1..ae4fe89af15 100644
--- a/packages/eslint-plugin/tests/rules/restrict-plus-operands.test.ts
+++ b/packages/eslint-plugin/tests/rules/restrict-plus-operands.test.ts
@@ -23,6 +23,8 @@ ruleTester.run('restrict-plus-operands', rule, {
     `var foo = parseInt("5.5", 10) + 10;`,
     `var foo = parseFloat("5.5", 10) + 10;`,
     `var foo = 1n + 1n;`,
+    `var foo = BigInt(1) + 1n`,
+    `var foo = 1n; foo + 2n`,
     `
 function test () : number { return 2; }
 var foo = test("5.5", 10) + 10;
@@ -283,5 +285,25 @@ var foo = pair + pair;
         },
       ],
     },
+    {
+      code: `var foo = 1n; foo + 1`,
+      errors: [
+        {
+          messageId: 'notBigInts',
+          line: 1,
+          column: 15,
+        },
+      ],
+    },
+    {
+      code: `var foo = 1; foo + 1n`,
+      errors: [
+        {
+          messageId: 'notBigInts',
+          line: 1,
+          column: 14,
+        },
+      ],
+    },
   ],
 });