fix: expect().resolves and expect().rejects now return promises

Previously, matchers under `expect().resolves` and `expect().rejects`
would return `undefined` instead of a promise. This caused issues when
trying to chain or await matcher results.

This fix adds a helper function `returnMatcherValue()` that checks if
async flags (.resolves/.rejects) are set and returns a resolved promise
instead of undefined. All matchers now use this helper.

Fixes #23420

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/bun.js/test/expect.zig

@@ -848,7 +848,7 @@ pub const Expect = struct {
         if (existing_value) |saved_value| {
             if (strings.eqlLong(pretty_value.slice(), saved_value, true)) {
                 Jest.runner.?.snapshots.passed += 1;
-                return .js_undefined;
+                return this.returnMatcherValue(globalThis);
             }
 
             Jest.runner.?.snapshots.failed += 1;
@@ -863,7 +863,7 @@ pub const Expect = struct {
             return globalThis.throwPretty(fmt, .{diff_format});
         }
 
-        return .js_undefined;
+        return this.returnMatcherValue(globalThis);
     }
 
     pub fn getStaticNot(globalThis: *JSGlobalObject, _: JSValue, _: JSValue) bun.JSError!JSValue {
@@ -1231,6 +1231,16 @@ pub const Expect = struct {
         vm.autoGarbageCollect();
     }
 
+    /// Helper function for matchers to return the correct value based on whether
+    /// .resolves or .rejects was used. When async flags are set, returns a resolved promise.
+    /// Otherwise returns undefined.
+    pub inline fn returnMatcherValue(this: *const Expect, globalThis: *JSGlobalObject) JSValue {
+        if (this.flags.promise != .none) {
+            return JSPromise.resolvedPromiseValue(globalThis, .js_undefined);
+        }
+        return .js_undefined;
+    }
+
     pub fn doUnreachable(globalThis: *JSGlobalObject, callframe: *CallFrame) bun.JSError!JSValue {
         const arg = callframe.arguments_old(1).ptr[0];
 
@@ -2246,6 +2256,7 @@ const strings = bun.strings;
 const jsc = bun.jsc;
 const CallFrame = jsc.CallFrame;
 const JSGlobalObject = jsc.JSGlobalObject;
+const JSPromise = jsc.JSPromise;
 const JSValue = jsc.JSValue;
 const VirtualMachine = jsc.VirtualMachine;
 const ZigString = jsc.ZigString;

src/bun.js/test/expect/toBe.zig

@@ -22,7 +22,7 @@ pub fn toBe(
     var pass = try right.isSameValue(left, globalThis);
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toBeArray.zig

@@ -9,7 +9,7 @@ pub fn toBeArray(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFra
     const not = this.flags.not;
     const pass = value.jsType().isArray() != not;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeArrayOfSize.zig

@@ -24,7 +24,7 @@ pub fn toBeArrayOfSize(this: *Expect, globalThis: *JSGlobalObject, callFrame: *C
     var pass = value.jsType().isArray() and @as(i32, @intCast(try value.getLength(globalThis))) == size.toInt32();
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeBoolean.zig

@@ -9,7 +9,7 @@ pub fn toBeBoolean(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallF
     const not = this.flags.not;
     const pass = value.isBoolean() != not;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeCloseTo.zig

@@ -43,7 +43,7 @@ pub fn toBeCloseTo(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallF
     }
 
     if (std.math.isPositiveInf(expected) and std.math.isPositiveInf(received)) {
-        return .js_undefined;
+        return this.returnMatcherValue(globalThis);
     }
 
     const expected_diff = bun.pow(10, -precision) / 2;
@@ -53,7 +53,7 @@ pub fn toBeCloseTo(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallF
     const not = this.flags.not;
     if (not) pass = !pass;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeDate.zig

@@ -9,7 +9,7 @@ pub fn toBeDate(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFram
     const not = this.flags.not;
     const pass = value.isDate() != not;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeDefined.zig

@@ -9,7 +9,7 @@ pub fn toBeDefined(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallF
     const not = this.flags.not;
     var pass = !value.isUndefined();
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toBeEmpty.zig

@@ -61,7 +61,7 @@ pub fn toBeEmpty(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFra
     }
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     if (not) {
         const signature = comptime getSignature("toBeEmpty", "", true);

src/bun.js/test/expect/toBeEmptyObject.zig

@@ -10,7 +10,7 @@ pub fn toBeEmptyObject(this: *Expect, globalThis: *JSGlobalObject, callFrame: *C
     var pass = try value.isObjectEmpty(globalThis);
 
     if (not) pass = !pass;
-    if (pass) return thisValue;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeEven.zig

@@ -34,7 +34,7 @@ pub fn toBeEven(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFram
     }
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toBeFalse.zig

@@ -9,7 +9,7 @@ pub fn toBeFalse(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFra
     const not = this.flags.not;
     const pass = (value.isBoolean() and !value.toBoolean()) != not;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeFalsy.zig

@@ -14,7 +14,7 @@ pub fn toBeFalsy(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFra
     if (!truthy) pass = true;
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toBeFinite.zig

@@ -15,7 +15,7 @@ pub fn toBeFinite(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFr
     const not = this.flags.not;
     if (not) pass = !pass;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeFunction.zig

@@ -9,7 +9,7 @@ pub fn toBeFunction(this: *Expect, globalThis: *JSGlobalObject, callFrame: *Call
     const not = this.flags.not;
     const pass = value.isCallable() != not;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeGreaterThan.zig

@@ -38,7 +38,7 @@ pub fn toBeGreaterThan(this: *Expect, globalThis: *JSGlobalObject, callFrame: *C
     }
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toBeGreaterThanOrEqual.zig

@@ -38,7 +38,7 @@ pub fn toBeGreaterThanOrEqual(this: *Expect, globalThis: *JSGlobalObject, callFr
     }
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toBeInstanceOf.zig

@@ -24,7 +24,7 @@ pub fn toBeInstanceOf(this: *Expect, globalThis: *JSGlobalObject, callFrame: *Ca
     const not = this.flags.not;
     var pass = value.isInstanceOf(globalThis, expected_value);
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     const expected_fmt = expected_value.toFmt(&formatter);

src/bun.js/test/expect/toBeInteger.zig

@@ -9,7 +9,7 @@ pub fn toBeInteger(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallF
     const not = this.flags.not;
     const pass = value.isAnyInt() != not;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeLessThan.zig

@@ -38,7 +38,7 @@ pub fn toBeLessThan(this: *Expect, globalThis: *JSGlobalObject, callFrame: *Call
     }
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toBeLessThanOrEqual.zig

@@ -38,7 +38,7 @@ pub fn toBeLessThanOrEqual(this: *Expect, globalThis: *JSGlobalObject, callFrame
     }
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toBeNaN.zig

@@ -14,7 +14,7 @@ pub fn toBeNaN(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
     }
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toBeNegative.zig

@@ -15,7 +15,7 @@ pub fn toBeNegative(this: *Expect, globalThis: *JSGlobalObject, callFrame: *Call
     const not = this.flags.not;
     if (not) pass = !pass;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeNil.zig

@@ -9,7 +9,7 @@ pub fn toBeNil(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
     const not = this.flags.not;
     const pass = value.isUndefinedOrNull() != not;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeNull.zig

@@ -9,7 +9,7 @@ pub fn toBeNull(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFram
     const not = this.flags.not;
     var pass = value.isNull();
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toBeNumber.zig

@@ -9,7 +9,7 @@ pub fn toBeNumber(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFr
     const not = this.flags.not;
     const pass = value.isNumber() != not;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeObject.zig

@@ -9,7 +9,7 @@ pub fn toBeObject(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFr
     const not = this.flags.not;
     const pass = value.isObject() != not;
 
-    if (pass) return thisValue;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeOdd.zig

@@ -32,7 +32,7 @@ pub fn toBeOdd(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
     }
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toBeOneOf.zig

@@ -61,7 +61,7 @@ pub fn toBeOneOf(
     }
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toBePositive.zig

@@ -15,7 +15,7 @@ pub fn toBePositive(this: *Expect, globalThis: *JSGlobalObject, callFrame: *Call
     const not = this.flags.not;
     if (not) pass = !pass;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeString.zig

@@ -9,7 +9,7 @@ pub fn toBeString(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFr
     const not = this.flags.not;
     const pass = value.isString() != not;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeSymbol.zig

@@ -9,7 +9,7 @@ pub fn toBeSymbol(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFr
     const not = this.flags.not;
     const pass = value.isSymbol() != not;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeTrue.zig

@@ -9,7 +9,7 @@ pub fn toBeTrue(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFram
     const not = this.flags.not;
     const pass = (value.isBoolean() and value.toBoolean()) != not;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeTruthy.zig

@@ -12,7 +12,7 @@ pub fn toBeTruthy(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFr
     if (truthy) pass = true;
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toBeTypeOf.zig

@@ -65,7 +65,7 @@ pub fn toBeTypeOf(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFr
     pass = strings.eql(typeof, whatIsTheType);
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeUndefined.zig

@@ -10,7 +10,7 @@ pub fn toBeUndefined(this: *Expect, globalThis: *JSGlobalObject, callFrame: *Cal
     if (value.isUndefined()) pass = true;
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toBeValidDate.zig

@@ -10,7 +10,7 @@ pub fn toBeValidDate(this: *Expect, globalThis: *JSGlobalObject, callFrame: *Cal
     var pass = (value.isDate() and !std.math.isNan(value.getUnixTimestamp()));
     if (not) pass = !pass;
 
-    if (pass) return thisValue;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toBeWithin.zig

@@ -36,7 +36,7 @@ pub fn toBeWithin(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFr
     const not = this.flags.not;
     if (not) pass = !pass;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toContain.zig

@@ -73,7 +73,7 @@ pub fn toContain(
     }
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toContainAllKeys.zig

@@ -43,7 +43,7 @@ pub fn toContainAllKeys(
     }
 
     if (not) pass = !pass;
-    if (pass) return thisValue;
+    if (pass) return this.returnMatcherValue(globalObject);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalObject, .quote_strings = true };

src/bun.js/test/expect/toContainAllValues.zig

@@ -48,7 +48,7 @@ pub fn toContainAllValues(
     }
 
     if (not) pass = !pass;
-    if (pass) return thisValue;
+    if (pass) return this.returnMatcherValue(globalObject);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalObject, .quote_strings = true };

src/bun.js/test/expect/toContainAnyKeys.zig

@@ -41,7 +41,7 @@ pub fn toContainAnyKeys(
     }
 
     if (not) pass = !pass;
-    if (pass) return thisValue;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toContainAnyValues.zig

@@ -42,7 +42,7 @@ pub fn toContainAnyValues(
     }
 
     if (not) pass = !pass;
-    if (pass) return thisValue;
+    if (pass) return this.returnMatcherValue(globalObject);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalObject, .quote_strings = true };

src/bun.js/test/expect/toContainEqual.zig

@@ -82,7 +82,7 @@ pub fn toContainEqual(
     }
 
     if (not) pass = !pass;
-    if (pass) return thisValue;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toContainKey.zig

@@ -28,7 +28,7 @@ pub fn toContainKey(
     var pass = try value.hasOwnPropertyValue(globalThis, expected);
 
     if (not) pass = !pass;
-    if (pass) return thisValue;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
 

src/bun.js/test/expect/toContainKeys.zig

@@ -44,7 +44,7 @@ pub fn toContainKeys(
     };
 
     if (not) pass = !pass;
-    if (pass) return thisValue;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toContainValue.zig

@@ -33,7 +33,7 @@ pub fn toContainValue(
     }
 
     if (not) pass = !pass;
-    if (pass) return thisValue;
+    if (pass) return this.returnMatcherValue(globalObject);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalObject, .quote_strings = true };

src/bun.js/test/expect/toContainValues.zig

@@ -42,7 +42,7 @@ pub fn toContainValues(
     }
 
     if (not) pass = !pass;
-    if (pass) return thisValue;
+    if (pass) return this.returnMatcherValue(globalObject);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalObject, .quote_strings = true };

src/bun.js/test/expect/toEndWith.zig

@@ -32,7 +32,7 @@ pub fn toEndWith(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFra
     const not = this.flags.not;
     if (not) pass = !pass;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toEqual.zig

@@ -18,7 +18,7 @@ pub fn toEqual(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
     var pass = try value.jestDeepEquals(expected, globalThis);
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     const diff_formatter = DiffFormatter{

src/bun.js/test/expect/toEqualIgnoringWhitespace.zig

@@ -60,7 +60,7 @@ pub fn toEqualIgnoringWhitespace(this: *Expect, globalThis: *JSGlobalObject, cal
     }
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toHaveBeenCalled.zig

@@ -23,7 +23,7 @@ pub fn toHaveBeenCalled(this: *Expect, globalThis: *JSGlobalObject, callframe: *
 
     const not = this.flags.not;
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     if (not) {

src/bun.js/test/expect/toHaveBeenCalledOnce.zig

@@ -19,7 +19,7 @@ pub fn toHaveBeenCalledOnce(this: *Expect, globalThis: *JSGlobalObject, callfram
 
     const not = this.flags.not;
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     if (not) {

src/bun.js/test/expect/toHaveBeenCalledTimes.zig

@@ -26,7 +26,7 @@ pub fn toHaveBeenCalledTimes(this: *Expect, globalThis: *JSGlobalObject, callfra
 
     const not = this.flags.not;
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     if (not) {

src/bun.js/test/expect/toHaveBeenCalledWith.zig

@@ -47,7 +47,7 @@ pub fn toHaveBeenCalledWith(this: *Expect, globalThis: *JSGlobalObject, callfram
     }
 
     if (pass != this.flags.not) {
-        return .js_undefined;
+        return this.returnMatcherValue(globalThis);
     }
 
     // handle failure

src/bun.js/test/expect/toHaveBeenLastCalledWith.zig

@@ -43,7 +43,7 @@ pub fn toHaveBeenLastCalledWith(this: *Expect, globalThis: *JSGlobalObject, call
     }
 
     if (pass != this.flags.not) {
-        return .js_undefined;
+        return this.returnMatcherValue(globalThis);
     }
 
     // handle failure

src/bun.js/test/expect/toHaveBeenNthCalledWith.zig

@@ -51,7 +51,7 @@ pub fn toHaveBeenNthCalledWith(this: *Expect, globalThis: *JSGlobalObject, callf
     }
 
     if (pass != this.flags.not) {
-        return .js_undefined;
+        return this.returnMatcherValue(globalThis);
     }
 
     // handle failure

src/bun.js/test/expect/toHaveLastReturnedWith.zig

@@ -46,7 +46,7 @@ pub fn toHaveLastReturnedWith(this: *Expect, globalThis: *JSGlobalObject, callfr
     }
 
     if (pass != this.flags.not) {
-        return .js_undefined;
+        return this.returnMatcherValue(globalThis);
     }
 
     // Handle failure

src/bun.js/test/expect/toHaveLength.zig

@@ -50,7 +50,7 @@ pub fn toHaveLength(
     }
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     if (not) {

src/bun.js/test/expect/toHaveNthReturnedWith.zig

@@ -55,7 +55,7 @@ pub fn toHaveNthReturnedWith(this: *Expect, globalThis: *JSGlobalObject, callfra
     }
 
     if (pass != this.flags.not) {
-        return .js_undefined;
+        return this.returnMatcherValue(globalThis);
     }
 
     // Handle failure

src/bun.js/test/expect/toHaveProperty.zig

@@ -39,7 +39,7 @@ pub fn toHaveProperty(this: *Expect, globalThis: *JSGlobalObject, callFrame: *Ca
     }
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

src/bun.js/test/expect/toHaveReturned.zig

@@ -43,7 +43,7 @@ inline fn toHaveReturnedTimesFn(this: *Expect, globalThis: *JSGlobalObject, call
 
     const not = this.flags.not;
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     switch (not) {
         inline else => |is_not| {

src/bun.js/test/expect/toHaveReturnedWith.zig

@@ -52,7 +52,7 @@ pub fn toHaveReturnedWith(this: *Expect, globalThis: *JSGlobalObject, callframe:
     }
 
     if (pass != this.flags.not) {
-        return .js_undefined;
+        return this.returnMatcherValue(globalThis);
     }
 
     // Handle failure

src/bun.js/test/expect/toInclude.zig

@@ -32,7 +32,7 @@ pub fn toInclude(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFra
     const not = this.flags.not;
     if (not) pass = !pass;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toIncludeRepeated.zig

@@ -57,7 +57,7 @@ pub fn toIncludeRepeated(this: *Expect, globalThis: *JSGlobalObject, callFrame:
     pass = actual_count == countAsNum;
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toMatch.zig

@@ -39,7 +39,7 @@ pub fn toMatch(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
     };
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     const expected_fmt = expected_value.toFmt(&formatter);

src/bun.js/test/expect/toMatchObject.zig

@@ -37,7 +37,7 @@ pub fn toMatchObject(this: *Expect, globalThis: *JSGlobalObject, callFrame: *Cal
     var pass = try received_object.jestDeepMatch(property_matchers, globalThis, true);
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     const diff_formatter = DiffFormatter{

src/bun.js/test/expect/toSatisfy.zig

@@ -32,7 +32,7 @@ pub fn toSatisfy(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFra
     const not = this.flags.not;
     const pass = (result.isBoolean() and result.toBoolean()) != not;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toStartWith.zig

@@ -32,7 +32,7 @@ pub fn toStartWith(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallF
     const not = this.flags.not;
     if (not) pass = !pass;
 
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
     defer formatter.deinit();

src/bun.js/test/expect/toStrictEqual.zig

@@ -18,7 +18,7 @@ pub fn toStrictEqual(this: *Expect, globalThis: *JSGlobalObject, callFrame: *Cal
     var pass = try value.jestStrictDeepEquals(expected, globalThis);
 
     if (not) pass = !pass;
-    if (pass) return .js_undefined;
+    if (pass) return this.returnMatcherValue(globalThis);
 
     // handle failure
     const diff_formatter = DiffFormatter{ .received = value, .expected = expected, .globalThis = globalThis, .not = not };

src/bun.js/test/expect/toThrow.zig

@@ -39,7 +39,7 @@ pub fn toThrow(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
     if (not) {
         const signature = comptime getSignature("toThrow", "<green>expected<r>", true);
 
-        if (!did_throw) return .js_undefined;
+        if (!did_throw) return this.returnMatcherValue(globalThis);
 
         const result: JSValue = result_.?;
         var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
@@ -76,7 +76,7 @@ pub fn toThrow(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
                 defer expected_slice.deinit();
                 const received_slice = try received_message.toSliceOrNull(globalThis);
                 defer received_slice.deinit();
-                if (!strings.contains(received_slice.slice(), expected_slice.slice())) return .js_undefined;
+                if (!strings.contains(received_slice.slice(), expected_slice.slice())) return this.returnMatcherValue(globalThis);
             }
 
             return this.throw(globalThis, signature, "\n\nExpected substring: not <green>{any}<r>\nReceived message: <red>{any}<r>\n", .{
@@ -95,7 +95,7 @@ pub fn toThrow(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
             // TODO: REMOVE THIS GETTER! Expose a binding to call .test on the RegExp object directly.
             if (try expected_value.get(globalThis, "test")) |test_fn| {
                 const matches = test_fn.call(globalThis, expected_value, &.{received_message}) catch |err| globalThis.takeException(err);
-                if (!matches.toBoolean()) return .js_undefined;
+                if (!matches.toBoolean()) return this.returnMatcherValue(globalThis);
             }
 
             return this.throw(globalThis, signature, "\n\nExpected pattern: not <green>{any}<r>\nReceived message: <red>{any}<r>\n", .{
@@ -112,12 +112,12 @@ pub fn toThrow(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
             if (globalThis.hasException()) return .zero;
 
             // no partial match for this case
-            if (!try expected_message.isSameValue(received_message, globalThis)) return .js_undefined;
+            if (!try expected_message.isSameValue(received_message, globalThis)) return this.returnMatcherValue(globalThis);
 
             return this.throw(globalThis, signature, "\n\nExpected message: not <green>{any}<r>\n", .{expected_message.toFmt(&formatter)});
         }
 
-        if (!result.isInstanceOf(globalThis, expected_value)) return .js_undefined;
+        if (!result.isInstanceOf(globalThis, expected_value)) return this.returnMatcherValue(globalThis);
 
         var expected_class = ZigString.Empty;
         try expected_value.getClassName(globalThis, &expected_class);
@@ -126,7 +126,7 @@ pub fn toThrow(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
     }
 
     if (did_throw) {
-        if (expected_value == .zero or expected_value.isUndefined()) return .js_undefined;
+        if (expected_value == .zero or expected_value.isUndefined()) return this.returnMatcherValue(globalThis);
 
         const result: JSValue = if (result_.?.toError()) |r|
             r
@@ -146,7 +146,7 @@ pub fn toThrow(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
                 defer expected_slice.deinit();
                 const received_slice = try received_message.toSlice(globalThis, globalThis.allocator());
                 defer received_slice.deinit();
-                if (strings.contains(received_slice.slice(), expected_slice.slice())) return .js_undefined;
+                if (strings.contains(received_slice.slice(), expected_slice.slice())) return this.returnMatcherValue(globalThis);
             }
 
             // error: message from received error does not match expected string
@@ -171,7 +171,7 @@ pub fn toThrow(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
                 // TODO: REMOVE THIS GETTER! Expose a binding to call .test on the RegExp object directly.
                 if (try expected_value.get(globalThis, "test")) |test_fn| {
                     const matches = test_fn.call(globalThis, expected_value, &.{received_message}) catch |err| globalThis.takeException(err);
-                    if (matches.toBoolean()) return .js_undefined;
+                    if (matches.toBoolean()) return this.returnMatcherValue(globalThis);
                 }
             }
 
@@ -202,7 +202,7 @@ pub fn toThrow(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
             }
 
             if (is_equal) {
-                return .js_undefined;
+                return this.returnMatcherValue(globalThis);
             }
 
             var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };
@@ -219,7 +219,7 @@ pub fn toThrow(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
             const signature = comptime getSignature("toThrow", "<green>expected<r>", false);
 
             if (_received_message) |received_message| {
-                if (try received_message.isSameValue(expected_message, globalThis)) return .js_undefined;
+                if (try received_message.isSameValue(expected_message, globalThis)) return this.returnMatcherValue(globalThis);
             }
 
             // error: message from received error does not match expected error message.
@@ -237,7 +237,7 @@ pub fn toThrow(this: *Expect, globalThis: *JSGlobalObject, callFrame: *CallFrame
             return this.throw(globalThis, signature, "\n\nExpected message: <green>{any}<r>\nReceived value: <red>{any}<r>\n", .{ expected_fmt, received_fmt });
         }
 
-        if (result.isInstanceOf(globalThis, expected_value)) return .js_undefined;
+        if (result.isInstanceOf(globalThis, expected_value)) return this.returnMatcherValue(globalThis);
 
         // error: received error not instance of received error constructor
         var formatter = jsc.ConsoleObject.Formatter{ .globalThis = globalThis, .quote_strings = true };

test/regression/issue/23420.test.ts

@@ -0,0 +1,44 @@
+import { expect, test } from "bun:test";
+
+test("resolves matcher returns a Promise", () => {
+  const promise = Promise.resolve(42);
+  const matcherResult = expect(promise).resolves.toBe(42);
+  expect(matcherResult).toBeInstanceOf(Promise);
+  return matcherResult;
+});
+
+test("rejects matcher returns a Promise", () => {
+  const promise = Promise.reject(new Error("test error"));
+  const matcherResult = expect(promise).rejects.toThrow("test error");
+  expect(matcherResult).toBeInstanceOf(Promise);
+  return matcherResult;
+});
+
+test("resolves.not matcher returns a Promise", () => {
+  const promise = Promise.resolve(42);
+  const matcherResult = expect(promise).resolves.not.toBe(100);
+  expect(matcherResult).toBeInstanceOf(Promise);
+  return matcherResult;
+});
+
+test("rejects.not matcher returns a Promise", () => {
+  const promise = Promise.reject(42);
+  const matcherResult = expect(promise).rejects.not.toThrow("wrong error");
+  expect(matcherResult).toBeInstanceOf(Promise);
+  return matcherResult;
+});
+
+test("multiple resolves matchers can be chained with await", async () => {
+  const promise1 = Promise.resolve(1);
+  const promise2 = Promise.resolve(2);
+
+  await expect(promise1).resolves.toBe(1);
+  await expect(promise2).resolves.toBe(2);
+});
+
+test("resolves.toEqual returns a Promise", async () => {
+  const promise = Promise.resolve({ foo: "bar" });
+  const matcherResult = expect(promise).resolves.toEqual({ foo: "bar" });
+  expect(matcherResult).toBeInstanceOf(Promise);
+  await matcherResult;
+});