Implement `toMatchSnapshot()` (#2294)

* buggy snapshot

* error output for failed snapshot

* missing first

* hints

* open dir once, better cleanup

* update flag

* truncate on update

* object and class snapshot formatting

* array formatting

* no function name, single item is empty array

* string objects, maps, sets, promise

* avoid using invalid memory

* handle number objects

* handle extending `Number`

* boolean objects

* snapshot tests and test updates

* snapshot format for buffers

* safer snapshot parsing

* property matchers setup

* strings and tests

* generate classes with empty prototype

* optional `propertyMatchers` parameter

* new test folder structure

* strings.eqlLong

* globalObject.throwPretty() and expect.any tests

* add updateSnapshot flag to help

* move snapshot format out of `printErrorlikeObject`

* empty object snapshot format

* separate typed array, remove trailing comma

* use `isCell`, object trailing commas

* handle unicode

* todo for primitive constructors

* switch to `JSC.Node.Syscall.open` and `JSC.Maybe`

* use js parser for snapshot files

* deinit ast, log parse error

* copy/paste most of `exports.ZigConsoleClient`

* remove snapshot option

* remove ordered properties option

* remove snapshot format option from `exports.zig`

* remove extra newlines

* change mode

* update test runner output

* escape backticks faster

* `bunx jest` in temp dir

* remove buffered writer

* add `toMatchSnapshot` to types

* cleanup, switch to `pread`

* cli `--update` flag

* `--update-snapshots`

* remove string object format

1 files changed, 16 insertions, 2 deletions

diff --git a/src/bun.js/bindings/bindings.cpp b/src/bun.js/bindings/bindings.cpp
index 5c9cba7f0..d431a287f 100644
--- a/src/bun.js/bindings/bindings.cpp
+++ b/src/bun.js/bindings/bindings.cpp
@@ -3227,13 +3227,21 @@ void JSC__VM__releaseWeakRefs(JSC__VM* arg0)
 static auto function_string_view = MAKE_STATIC_STRING_IMPL("Function");
 void JSC__JSValue__getClassName(JSC__JSValue JSValue0, JSC__JSGlobalObject* arg1, ZigString* arg2)
 {
-    JSC::JSCell* cell = JSC::JSValue::decode(JSValue0).asCell();
+    JSValue value = JSValue::decode(JSValue0);
+    JSC::JSCell* cell = value.asCell();
     if (cell == nullptr) {
         arg2->len = 0;
         return;
     }
 
-    const char* ptr = cell->className();
+    JSObject* obj = value.toObject(arg1);
+    StringView calculated = StringView(JSObject::calculatedClassName(obj));
+    if (calculated.length() > 0) {
+        *arg2 = Zig::toZigString(calculated);
+        return;
+    }
+
+    const char* ptr = cell->classInfo()->className;
     auto view = WTF::StringView(ptr, strlen(ptr));
 
     // Fallback to .name if className is empty
@@ -3784,6 +3792,12 @@ void JSC__JSValue__forEachPropertyOrdered(JSC__JSValue JSValue0, JSC__JSGlobalOb
     }
 }
 
+bool JSC__JSValue__isConstructor(JSC__JSValue JSValue0)
+{
+    JSValue value = JSValue::decode(JSValue0);
+    return value.isConstructor();
+}
+
 extern "C" JSC__JSValue JSC__JSValue__createRopeString(JSC__JSValue JSValue0, JSC__JSValue JSValue1, JSC__JSGlobalObject* globalObject)
 {
     return JSValue::encode(JSC::jsString(globalObject, JSC::JSValue::decode(JSValue0).toString(globalObject), JSC::JSValue::decode(JSValue1).toString(globalObject)));