From ba3c7ae1b2f72dbb02ed421e4574d8fe57165aac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Newton/m=C2=B2?=
 <27069811+newtondividedbysqm@users.noreply.github.com>
Date: Mon, 30 Mar 2026 19:48:50 +0200
Subject: [PATCH 1/6] fix assertString to throw TypeErrors on objects with
 custom constructor property

---
 src/lib/util/assertString.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib/util/assertString.js b/src/lib/util/assertString.js
index 3baa4452f..e62e1a624 100644
--- a/src/lib/util/assertString.js
+++ b/src/lib/util/assertString.js
@@ -1,4 +1,4 @@
 export default function assertString(input) {
   if (input === undefined || input === null) throw new TypeError(`Expected a string but received a ${input}`);
-  if (input.constructor.name !== 'String') throw new TypeError(`Expected a string but received a ${input.constructor.name}`);
+  if (typeof input !== 'string' && !(input instanceof String)) throw new TypeError(`Expected a string but received a ${input?.constructor?.name ?? typeof input}`)
 }

From 5dc7d99b3641194d25e957ec33df4fe438b9152f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Newton/m=C2=B2?=
 <27069811+newtondividedbysqm@users.noreply.github.com>
Date: Mon, 30 Mar 2026 19:57:14 +0200
Subject: [PATCH 2/6] Add tests for boxed strings and Objects pretending to be
 a string

---
 test/util.test.js | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/test/util.test.js b/test/util.test.js
index 0146a4e2c..5edbf0441 100644
--- a/test/util.test.js
+++ b/test/util.test.js
@@ -54,11 +54,23 @@ describe('assertString', () => {
     assert.throws(() => { assertString([]); }, TypeError);
   });
 
+  it('Should throw an error if argument provided is an Object pretending to be a \'string\'', () => {
+    assert.throws(() => { assertString({constructor: {name: "string"}}); }, TypeError);
+  });
+
+  it('Should throw an error if argument provided is an Object pretending to be a \'String\'', () => {
+    assert.throws(() => { assertString({constructor: {name: "String"}}); }, TypeError);
+  });
+
   it('Should not throw an error if the argument is an empty string', () => {
     assert.doesNotThrow(() => { assertString(''); });
   });
-
+  
   it('Should not throw an error if the argument is a String', () => {
     assert.doesNotThrow(() => { assertString('antidisestablishmentarianism'); });
   });
+
+  it('Should not throw an error if the argument is a boxed string', () => {
+    assert.doesNotThrow(() => { assertString(new String('antidisestablishmentarianism')); });
+  });
 });

From e17853b73292a9d7224871573db7e2bb92490253 Mon Sep 17 00:00:00 2001
From: Pascal <27069811+newtondividedbysqm@users.noreply.github.com>
Date: Thu, 16 Apr 2026 14:39:23 +0200
Subject: [PATCH 3/6] fix linters

---
 src/lib/util/assertString.js | 2 +-
 test/util.test.js            | 7 ++++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/lib/util/assertString.js b/src/lib/util/assertString.js
index e62e1a624..d9e9f3ec5 100644
--- a/src/lib/util/assertString.js
+++ b/src/lib/util/assertString.js
@@ -1,4 +1,4 @@
 export default function assertString(input) {
   if (input === undefined || input === null) throw new TypeError(`Expected a string but received a ${input}`);
-  if (typeof input !== 'string' && !(input instanceof String)) throw new TypeError(`Expected a string but received a ${input?.constructor?.name ?? typeof input}`)
+  if (typeof input !== 'string' && !(input instanceof String)) throw new TypeError(`Expected a string but received a ${input?.constructor?.name ?? typeof input}`);
 }
diff --git a/test/util.test.js b/test/util.test.js
index 5edbf0441..169789ad8 100644
--- a/test/util.test.js
+++ b/test/util.test.js
@@ -55,22 +55,23 @@ describe('assertString', () => {
   });
 
   it('Should throw an error if argument provided is an Object pretending to be a \'string\'', () => {
-    assert.throws(() => { assertString({constructor: {name: "string"}}); }, TypeError);
+    assert.throws(() => { assertString({ constructor: { name: 'string' } }); }, TypeError);
   });
 
   it('Should throw an error if argument provided is an Object pretending to be a \'String\'', () => {
-    assert.throws(() => { assertString({constructor: {name: "String"}}); }, TypeError);
+    assert.throws(() => { assertString({ constructor: { name: 'String' } }); }, TypeError);
   });
 
   it('Should not throw an error if the argument is an empty string', () => {
     assert.doesNotThrow(() => { assertString(''); });
   });
-  
+
   it('Should not throw an error if the argument is a String', () => {
     assert.doesNotThrow(() => { assertString('antidisestablishmentarianism'); });
   });
 
   it('Should not throw an error if the argument is a boxed string', () => {
+    // eslint-disable-next-line no-new-wrappers
     assert.doesNotThrow(() => { assertString(new String('antidisestablishmentarianism')); });
   });
 });

From 872f4189e759365c7ba286ad26af171a5aef314f Mon Sep 17 00:00:00 2001
From: Pascal <27069811+newtondividedbysqm@users.noreply.github.com>
Date: Thu, 16 Apr 2026 15:11:06 +0200
Subject: [PATCH 4/6] fix unreachable nullish-coalescing from within
 TypeErrorConstructor

---
 src/lib/util/assertString.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/lib/util/assertString.js b/src/lib/util/assertString.js
index d9e9f3ec5..14dba23a8 100644
--- a/src/lib/util/assertString.js
+++ b/src/lib/util/assertString.js
@@ -1,4 +1,7 @@
 export default function assertString(input) {
   if (input === undefined || input === null) throw new TypeError(`Expected a string but received a ${input}`);
-  if (typeof input !== 'string' && !(input instanceof String)) throw new TypeError(`Expected a string but received a ${input?.constructor?.name ?? typeof input}`);
+  if (typeof input !== 'string' && !(input instanceof String)) {
+    let inputConstructorName = input?.constructor?.name ? input.constructor.name : typeof input;
+    throw new TypeError(`Expected a string but received a ${inputConstructorName}`);
+  }
 }

From faf79661f739b3a36de6d8537aef634646da22bf Mon Sep 17 00:00:00 2001
From: Pascal <27069811+newtondividedbysqm@users.noreply.github.com>
Date: Thu, 16 Apr 2026 19:18:04 +0200
Subject: [PATCH 5/6] fix using ObjectToString over instanceof to prevent the
 check to fail when executed in a different context

---
 src/lib/util/assertString.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib/util/assertString.js b/src/lib/util/assertString.js
index 14dba23a8..475537806 100644
--- a/src/lib/util/assertString.js
+++ b/src/lib/util/assertString.js
@@ -1,6 +1,6 @@
 export default function assertString(input) {
   if (input === undefined || input === null) throw new TypeError(`Expected a string but received a ${input}`);
-  if (typeof input !== 'string' && !(input instanceof String)) {
+  if (typeof input !== 'string' && Object.prototype.toString.call(input) !== '[object String]') {
     let inputConstructorName = input?.constructor?.name ? input.constructor.name : typeof input;
     throw new TypeError(`Expected a string but received a ${inputConstructorName}`);
   }

From 36b9a1161879499dbaf662d6a55935e81b6c4fb8 Mon Sep 17 00:00:00 2001
From: Pascal <27069811+newtondividedbysqm@users.noreply.github.com>
Date: Thu, 16 Apr 2026 19:43:36 +0200
Subject: [PATCH 6/6] add test case for objects without constructor name

---
 test/util.test.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/test/util.test.js b/test/util.test.js
index 169789ad8..b73b7a254 100644
--- a/test/util.test.js
+++ b/test/util.test.js
@@ -74,4 +74,8 @@ describe('assertString', () => {
     // eslint-disable-next-line no-new-wrappers
     assert.doesNotThrow(() => { assertString(new String('antidisestablishmentarianism')); });
   });
+
+  it('Should use typeof as fallback in error message when input has no constructor name', () => {
+    assert.throws(() => { assertString(Object.create(null)); }, /^TypeError: Expected a string but received a object$/);
+  });
 });