feat(napi): add `napi_get_value_bigint_words` (#2061)

* feat(napi): add `napi_get_value_bigint_words`

* fix(napi): handle `napi_get_value_bigint_words` arr too small

3 files changed, 44 insertions, 0 deletions

diff --git a/src/bun.js/bindings/napi.cpp b/src/bun.js/bindings/napi.cpp
index 574224939..ecae69427 100644
--- a/src/bun.js/bindings/napi.cpp
+++ b/src/bun.js/bindings/napi.cpp
@@ -1568,6 +1568,48 @@ extern "C" napi_status napi_typeof(napi_env env, napi_value val,
     return napi_generic_failure;
 }
 
+extern "C" napi_status napi_get_value_bigint_words(napi_env env,
+    napi_value value,
+    int* sign_bit,
+    size_t* word_count,
+    uint64_t* words)
+{
+    Zig::GlobalObject* globalObject = toJS(env);
+
+    JSC::JSValue jsValue = toJS(value);
+    if (UNLIKELY(!jsValue.isBigInt()))
+        return napi_invalid_arg;
+
+    JSC::JSBigInt* bigInt = jsValue.asHeapBigInt();
+    if (UNLIKELY(!bigInt))
+        return napi_invalid_arg;
+
+    if (UNLIKELY(word_count == nullptr))
+        return napi_invalid_arg;
+
+    size_t available_words = *word_count;
+    *word_count = bigInt->length();
+
+    // If both sign_bit and words are nullptr, we're just querying the word count
+    // Return ok in this case
+    if (sign_bit == nullptr) {
+        // However, if one of them is nullptr, we have an invalid argument
+        if (UNLIKELY(words != nullptr))
+            return napi_invalid_arg;
+
+        return napi_ok;
+    } else if (UNLIKELY(words == nullptr))
+        return napi_invalid_arg; // If sign_bit is not nullptr, words must not be nullptr
+
+    *sign_bit = (int)bigInt->sign();
+
+    size_t len = *word_count;
+    for (size_t i = 0; i < available_words && i < len; i++)
+        words[i] = bigInt->digit(i);
+
+    return napi_ok;
+}
+
 extern "C" napi_status napi_get_value_external(napi_env env, napi_value value,
     void** result)
 {
diff --git a/src/napi/napi.zig b/src/napi/napi.zig
index 73a633025..ba5040ca8 100644
--- a/src/napi/napi.zig
+++ b/src/napi/napi.zig
@@ -1504,6 +1504,7 @@ pub fn fixDeadCodeElimination() void {
     std.mem.doNotOptimizeAway(&napi_create_bigint_uint64);
     std.mem.doNotOptimizeAway(&napi_get_value_bigint_int64);
     std.mem.doNotOptimizeAway(&napi_get_value_bigint_uint64);
+    std.mem.doNotOptimizeAway(&napi_get_value_bigint_words);
     std.mem.doNotOptimizeAway(&napi_fatal_error);
     std.mem.doNotOptimizeAway(&napi_fatal_exception);
     std.mem.doNotOptimizeAway(&napi_create_buffer);
diff --git a/src/symbols.txt b/src/symbols.txt
index 72f24291d..16125adb3 100644
--- a/src/symbols.txt
+++ b/src/symbols.txt
@@ -81,6 +81,7 @@ _napi_get_undefined
 _napi_get_uv_event_loop
 _napi_get_value_bigint_int64
 _napi_get_value_bigint_uint64
+_napi_get_value_bigint_words
 _napi_get_value_bool
 _napi_get_value_double
 _napi_get_value_external