From e1564f385c770ac37c550f7d9e164d6a846c191e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Schwarzkopf=20Bal=C3=A1zs?= <schwarzkopfb@icloud.com>
Date: Thu, 27 Aug 2020 11:00:38 +0200
Subject: [PATCH] fix(std/node): "events" and "util" modules (#7170)

---
 std/node/_utils.ts      | 18 ++++++++++++++++++
 std/node/events.ts      | 11 +++++++++--
 std/node/events_test.ts | 25 +++++++++++++++++++++++++
 std/node/os.ts          |  2 +-
 std/node/util.ts        | 17 -----------------
 5 files changed, 53 insertions(+), 20 deletions(-)

diff --git a/std/node/_utils.ts b/std/node/_utils.ts
index 0e8b26fb54..5bd4d10750 100644
--- a/std/node/_utils.ts
+++ b/std/node/_utils.ts
@@ -111,3 +111,21 @@ function slowCases(enc: string): string | undefined {
       if (enc === "") return "utf8";
   }
 }
+
+export function validateIntegerRange(
+  value: number,
+  name: string,
+  min = -2147483648,
+  max = 2147483647,
+): void {
+  // The defaults for min and max correspond to the limits of 32-bit integers.
+  if (!Number.isInteger(value)) {
+    throw new Error(`${name} must be 'an integer' but was ${value}`);
+  }
+
+  if (value < min || value > max) {
+    throw new Error(
+      `${name} must be >= ${min} && <= ${max}. Value was ${value}`,
+    );
+  }
+}
diff --git a/std/node/events.ts b/std/node/events.ts
index bc27731ca2..d7c2275a0a 100644
--- a/std/node/events.ts
+++ b/std/node/events.ts
@@ -21,7 +21,7 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-import { validateIntegerRange } from "./util.ts";
+import { validateIntegerRange } from "./_utils.ts";
 import { assert } from "../_util/assert.ts";
 
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
@@ -356,7 +356,14 @@ export default class EventEmitter {
    * Infinity (or 0) to indicate an unlimited number of listeners.
    */
   public setMaxListeners(n: number): this {
-    validateIntegerRange(n, "maxListeners", 0);
+    if (n !== Infinity) {
+      if (n === 0) {
+        n = Infinity;
+      } else {
+        validateIntegerRange(n, "maxListeners", 0);
+      }
+    }
+
     this.maxListeners = n;
     return this;
   }
diff --git a/std/node/events_test.ts b/std/node/events_test.ts
index adeae5b93f..a3285f24bc 100644
--- a/std/node/events_test.ts
+++ b/std/node/events_test.ts
@@ -61,6 +61,31 @@ Deno.test({
     EventEmitter.defaultMaxListeners = 20;
     assertEquals(EventEmitter.defaultMaxListeners, 20);
     EventEmitter.defaultMaxListeners = 10; //reset back to original value
+
+    assertThrows(() => {
+      new EventEmitter().setMaxListeners(-1);
+    });
+
+    const ee = new EventEmitter();
+    const noop = (): void => {};
+    const origWarn = console.warn;
+
+    for (let i = 10; i--;) {
+      ee.on("test", noop);
+    }
+
+    // there are only sync actions until it gets restored,
+    // so it's safe to overwrite this
+    console.warn = (): void => fail("Infinity listeners should be allowed");
+
+    ee.setMaxListeners(Infinity);
+    ee.on("test", noop);
+
+    // 0 means that unlimited listeners are allowed
+    ee.setMaxListeners(0);
+    ee.on("test", noop);
+
+    console.warn = origWarn;
   },
 });
 
diff --git a/std/node/os.ts b/std/node/os.ts
index c312ffe0c0..6714f071c4 100644
--- a/std/node/os.ts
+++ b/std/node/os.ts
@@ -19,7 +19,7 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 import { notImplemented } from "./_utils.ts";
-import { validateIntegerRange } from "./util.ts";
+import { validateIntegerRange } from "./_utils.ts";
 import { EOL as fsEOL } from "../fs/eol.ts";
 import process from "./process.ts";
 
diff --git a/std/node/util.ts b/std/node/util.ts
index e897931f2e..ce1c06b7c3 100644
--- a/std/node/util.ts
+++ b/std/node/util.ts
@@ -68,23 +68,6 @@ export function isPrimitive(value: unknown): boolean {
   );
 }
 
-export function validateIntegerRange(
-  value: number,
-  name: string,
-  min = -2147483648,
-  max = 2147483647,
-): void {
-  // The defaults for min and max correspond to the limits of 32-bit integers.
-  if (!Number.isInteger(value)) {
-    throw new Error(`${name} must be 'an integer' but was ${value}`);
-  }
-  if (value < min || value > max) {
-    throw new Error(
-      `${name} must be >= ${min} && <= ${max}.  Value was ${value}`,
-    );
-  }
-}
-
 import { _TextDecoder, _TextEncoder } from "./_utils.ts";
 
 /** The global TextDecoder */