From eb8e27abced19b1aa0d039d946c3570f019ad225 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ren=C3=A9=20Larch?= <renelarch@gmail.com>
Date: Wed, 21 Oct 2026 21:03:28 +0200
Subject: [PATCH] Throw the named error type from JSError.Throw*Error(string)

JSError.ThrowTypeError, ThrowRangeError and ThrowSyntaxError (with and
without a code) all called JSRuntime.ThrowError, so JS received a plain Error
instead of a TypeError / RangeError / SyntaxError. Call the matching runtime
method instead.

Fixes #509.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 src/NodeApi/JSError.cs       | 12 ++++----
 test/NodejsEmbeddingTests.cs | 55 ++++++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+), 6 deletions(-)

diff --git a/src/NodeApi/JSError.cs b/src/NodeApi/JSError.cs
index 33437ae9..74cf119f 100644
--- a/src/NodeApi/JSError.cs
+++ b/src/NodeApi/JSError.cs
@@ -290,22 +290,22 @@ public static void ThrowError(string code, string message)
         => JSValue.GetCurrentRuntime(out napi_env env).ThrowError(env, code, message);
 
     public static void ThrowTypeError(string message)
-        => JSValue.GetCurrentRuntime(out napi_env env).ThrowError(env, code: null, message);
+        => JSValue.GetCurrentRuntime(out napi_env env).ThrowTypeError(env, code: null, message);
 
     public static void ThrowTypeError(string code, string message)
-        => JSValue.GetCurrentRuntime(out napi_env env).ThrowError(env, code, message);
+        => JSValue.GetCurrentRuntime(out napi_env env).ThrowTypeError(env, code, message);
 
     public static void ThrowRangeError(string message)
-        => JSValue.GetCurrentRuntime(out napi_env env).ThrowError(env, code: null, message);
+        => JSValue.GetCurrentRuntime(out napi_env env).ThrowRangeError(env, code: null, message);
 
     public static void ThrowRangeError(string code, string message)
-        => JSValue.GetCurrentRuntime(out napi_env env).ThrowError(env, code, message);
+        => JSValue.GetCurrentRuntime(out napi_env env).ThrowRangeError(env, code, message);
 
     public static void ThrowSyntaxError(string message)
-        => JSValue.GetCurrentRuntime(out napi_env env).ThrowError(env, code: null, message);
+        => JSValue.GetCurrentRuntime(out napi_env env).ThrowSyntaxError(env, code: null, message);
 
     public static void ThrowSyntaxError(string code, string message)
-        => JSValue.GetCurrentRuntime(out napi_env env).ThrowError(env, code, message);
+        => JSValue.GetCurrentRuntime(out napi_env env).ThrowSyntaxError(env, code, message);
 
     /// <summary>
     /// Gets a JS error stack trace that also includes a .NET stack trace,
diff --git a/test/NodejsEmbeddingTests.cs b/test/NodejsEmbeddingTests.cs
index 1785decc..cc5fbc78 100644
--- a/test/NodejsEmbeddingTests.cs
+++ b/test/NodejsEmbeddingTests.cs
@@ -288,6 +288,61 @@ public void ThrowErrorFromCallback(string message)
         });
     }
 
+    [Theory]
+    [InlineData("Error", null)]
+    [InlineData("Error", "ERR_TEST")]
+    [InlineData("TypeError", null)]
+    [InlineData("TypeError", "ERR_TEST")]
+    [InlineData("RangeError", null)]
+    [InlineData("RangeError", "ERR_TEST")]
+    [InlineData("SyntaxError", null)]
+    [InlineData("SyntaxError", "ERR_TEST")]
+    public void ThrowTypedError(string errorType, string? code)
+    {
+        using NodeEmbeddingThreadRuntime nodejs = CreateNodeEmbeddingThreadRuntime();
+
+        nodejs.Run(() =>
+        {
+            JSValue.Global.SetProperty("throwError", JSValue.CreateFunction("throwError", (_) =>
+            {
+                Action<string> throwWithoutCode = errorType switch
+                {
+                    "Error" => JSError.ThrowError,
+                    "TypeError" => JSError.ThrowTypeError,
+                    "RangeError" => JSError.ThrowRangeError,
+                    "SyntaxError" => JSError.ThrowSyntaxError,
+                    _ => throw new ArgumentOutOfRangeException(nameof(errorType)),
+                };
+                Action<string, string> throwWithCode = errorType switch
+                {
+                    "Error" => JSError.ThrowError,
+                    "TypeError" => JSError.ThrowTypeError,
+                    "RangeError" => JSError.ThrowRangeError,
+                    "SyntaxError" => JSError.ThrowSyntaxError,
+                    _ => throw new ArgumentOutOfRangeException(nameof(errorType)),
+                };
+
+                if (code == null) throwWithoutCode("test");
+                else throwWithCode(code, "test");
+                return JSValue.Undefined;
+            }));
+
+            JSValue error = JSValue.RunScript("""
+                (() => {
+                    try { throwError(); } catch (e) { return e; }
+                    return null;
+                })()
+                """);
+            Assert.True(error.IsObject());
+            Assert.Equal(errorType, (string)error["name"]);
+            Assert.True((bool)JSValue.RunScript(
+                $"(e) => e instanceof {errorType}").Call(JSValue.Undefined, error));
+            Assert.Equal("test", (string)error["message"]);
+            if (code == null) Assert.True(error["code"].IsUndefined());
+            else Assert.Equal(code, (string)error["code"]);
+        });
+    }
+
     [Fact]
     public async Task WorkerIsMainThread()
     {