From be7afede32e290f77e947ac911d16e6489318dd9 Mon Sep 17 00:00:00 2001
From: Lukas Taegert-Atkinson <lukastaegert@users.noreply.github.com>
Date: Sat, 5 Jan 2019 12:34:11 +0100
Subject: [PATCH] Treat bigints as unknown for now on all systems to avoid
 accidentally (#2640)

passing them to Math.pow or having "null" wrongly as a literal value
---
 package-lock.json                      |  6 ++++++
 package.json                           |  1 +
 src/ast/nodes/BinaryExpression.ts      |  3 ++-
 src/ast/nodes/Literal.ts               | 10 +++++++---
 test/form/samples/big-int/_config.js   |  8 ++++++++
 test/form/samples/big-int/_expected.js | 20 ++++++++++++++++++++
 test/form/samples/big-int/main.js      | 18 ++++++++++++++++++
 7 files changed, 62 insertions(+), 4 deletions(-)
 create mode 100644 test/form/samples/big-int/_config.js
 create mode 100644 test/form/samples/big-int/_expected.js
 create mode 100644 test/form/samples/big-int/main.js

diff --git a/package-lock.json b/package-lock.json
index 0ebec701df0..5ab0a91da24 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -159,6 +159,12 @@
       "resolved": "https://registry.npmjs.org/acorn/-/acorn-6.0.4.tgz",
       "integrity": "sha512-VY4i5EKSKkofY2I+6QLTbTTN/UvEQPCo6eiwzzSaSWfpaDhOmStMCMod6wmuPciNq+XS0faCglFu2lHZpdHUtg=="
     },
+    "acorn-bigint": {
+      "version": "0.3.1",
+      "resolved": "https://registry.npmjs.org/acorn-bigint/-/acorn-bigint-0.3.1.tgz",
+      "integrity": "sha512-WT9LheDC4/d/sD/jgC6L5UMq4U9X3KNMy0JrXp/MdJL83ZqcuPQuMkj50beOX0dMub8IoZUYycfN7bIVZuU5zg==",
+      "dev": true
+    },
     "acorn-dynamic-import": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/acorn-dynamic-import/-/acorn-dynamic-import-4.0.0.tgz",
diff --git a/package.json b/package.json
index f7b1b369a9f..d530760e2a8 100644
--- a/package.json
+++ b/package.json
@@ -66,6 +66,7 @@
     "@types/chokidar": "^1.7.5",
     "@types/minimist": "^1.2.0",
     "@types/pretty-ms": "^3.0.0",
+    "acorn-bigint": "^0.3.1",
     "acorn-dynamic-import": "^4.0.0",
     "acorn-import-meta": "^0.3.0",
     "acorn-jsx": "^5.0.1",
diff --git a/src/ast/nodes/BinaryExpression.ts b/src/ast/nodes/BinaryExpression.ts
index 759f836d0a2..ccef28f47da 100644
--- a/src/ast/nodes/BinaryExpression.ts
+++ b/src/ast/nodes/BinaryExpression.ts
@@ -28,7 +28,8 @@ const binaryOperators: {
 	'|': (left: any, right: any) => left | right,
 	'^': (left: any, right: any) => left ^ right,
 	'&': (left: any, right: any) => left & right,
-	'**': (left: any, right: any) => Math.pow(left, right),
+	// At the moment, "**" will be transpiled to Math.pow
+	'**': (left: any, right: any) => left ** right,
 	in: () => UNKNOWN_VALUE,
 	instanceof: () => UNKNOWN_VALUE
 };
diff --git a/src/ast/nodes/Literal.ts b/src/ast/nodes/Literal.ts
index ed94f374af9..77670b493fe 100644
--- a/src/ast/nodes/Literal.ts
+++ b/src/ast/nodes/Literal.ts
@@ -28,11 +28,15 @@ export default class Literal<T = LiteralValue> extends NodeBase {
 	private members: { [key: string]: MemberDescription };
 
 	getLiteralValueAtPath(path: ObjectPath): LiteralValueOrUnknown {
-		if (path.length > 0) {
+		if (
+			path.length > 0 ||
+			// unknown literals such as bigints can also be null but do not start with an "n"
+			(this.value === null && this.context.code.charCodeAt(this.start) !== 110) ||
+			typeof this.value === 'bigint'
+		) {
 			return UNKNOWN_VALUE;
 		}
-		// not sure why we need this type cast here
-		return <any>this.value;
+		return this.value as any;
 	}
 
 	getReturnExpressionWhenCalledAtPath(path: ObjectPath) {
diff --git a/test/form/samples/big-int/_config.js b/test/form/samples/big-int/_config.js
new file mode 100644
index 00000000000..80bcfbcb518
--- /dev/null
+++ b/test/form/samples/big-int/_config.js
@@ -0,0 +1,8 @@
+const bigInt = require('acorn-bigint');
+
+module.exports = {
+	description: 'supports bigint via acorn plugin',
+	options: {
+		acornInjectPlugins: [bigInt]
+	}
+};
diff --git a/test/form/samples/big-int/_expected.js b/test/form/samples/big-int/_expected.js
new file mode 100644
index 00000000000..88a90aaf59d
--- /dev/null
+++ b/test/form/samples/big-int/_expected.js
@@ -0,0 +1,20 @@
+if (1n > 0) {
+	console.log('ok');
+}
+
+if (1n + 1n > 0) {
+	console.log('ok');
+}
+
+if (1n ** 1n > 0) {
+	console.log('ok');
+}
+
+const max = 2n**64n;
+const min = -max;
+
+function isSafe (int) {
+	return min<=int && int<=max;
+}
+
+export default isSafe;
diff --git a/test/form/samples/big-int/main.js b/test/form/samples/big-int/main.js
new file mode 100644
index 00000000000..cff26413d9a
--- /dev/null
+++ b/test/form/samples/big-int/main.js
@@ -0,0 +1,18 @@
+if (1n > 0) {
+	console.log('ok');
+}
+
+if (1n + 1n > 0) {
+	console.log('ok');
+}
+
+if (1n ** 1n > 0) {
+	console.log('ok');
+}
+
+const max = 2n**64n;
+const min = -max;
+
+export default function isSafe (int) {
+	return min<=int && int<=max;
+};