slightly hacky fix. all tests passing

packages/svelte/src/internal/client/constants.js

@@ -44,6 +44,7 @@ export const HEAD_EFFECT = 1 << 18;
 export const EFFECT_PRESERVED = 1 << 19;
 export const USER_EFFECT = 1 << 20;
 export const EFFECT_OFFSCREEN = 1 << 25;
+export const STATE_EAGER_EFFECT = 1 << 27;
 
 // Flags exclusive to deriveds
 /**

packages/svelte/src/internal/client/reactivity/batch.js

@@ -17,7 +17,8 @@ import {
 	ERROR_VALUE,
 	MANAGED_EFFECT,
 	REACTION_RAN,
-	CONNECTED
+	CONNECTED,
+	STATE_EAGER_EFFECT
 } from '#client/constants';
 import { async_mode_flag } from '../../flags/index.js';
 import { deferred, define_property, includes } from '../../shared/utils.js';
@@ -1211,7 +1212,7 @@ export function eager(fn) {
 		version.label = '<eager>';
 	}
 
-	eager_effect(() => {
+	var effect = eager_effect(() => {
 		if (initial) {
 			// the first time this runs, we create an eager effect
 			// that will run eagerly whenever the expression changes
@@ -1248,6 +1249,10 @@ export function eager(fn) {
 		}
 	});
 
+	// TODO ideally this wouldn't be necessary. I haven't figured out a way for these
+	// effects to correctly be marked dirty when `$state.eager(...)` arguments change
+	effect.f |= STATE_EAGER_EFFECT;
+
 	initial = false;
 
 	return value;

packages/svelte/src/internal/client/reactivity/sources.js

@@ -28,7 +28,8 @@ import {
 	ROOT_EFFECT,
 	ASYNC,
 	WAS_MARKED,
-	CONNECTED
+	CONNECTED,
+	STATE_EAGER_EFFECT
 } from '#client/constants';
 import * as e from '../errors.js';
 import { legacy_mode_flag, tracing_mode_flag } from '../../flags/index.js';
@@ -269,7 +270,7 @@ export function flush_eager_effects() {
 	eager_effects_deferred = false;
 
 	for (const effect of eager_effects) {
-		if (is_dirty(effect)) {
+		if ((effect.f & STATE_EAGER_EFFECT) !== 0 || is_dirty(effect)) {
 			update_effect(effect);
 		}
 	}