diff --git a/.changeset/eleven-cameras-sing.md b/.changeset/eleven-cameras-sing.md
new file mode 100644
index 000000000000..450ffdc68b97
--- /dev/null
+++ b/.changeset/eleven-cameras-sing.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/preact': major
+---
+
+Preact signals are now serialized correctly in arrays when they are given to components.
diff --git a/packages/astro/test/fixtures/preact-component/src/components/SignalsInArray.jsx b/packages/astro/test/fixtures/preact-component/src/components/SignalsInArray.jsx
new file mode 100644
index 000000000000..07ee24adaafc
--- /dev/null
+++ b/packages/astro/test/fixtures/preact-component/src/components/SignalsInArray.jsx
@@ -0,0 +1,8 @@
+import { h } from 'preact';
+
+export default ({ signalsArray }) => {
+ return
+
{signalsArray[0]} {signalsArray[3]}
+
{signalsArray[1].value}{signalsArray[2].value}{signalsArray[4].value}
+
+}
diff --git a/packages/astro/test/fixtures/preact-component/src/pages/signals.astro b/packages/astro/test/fixtures/preact-component/src/pages/signals.astro
index b68fde36d633..16d2efbe0c6e 100644
--- a/packages/astro/test/fixtures/preact-component/src/pages/signals.astro
+++ b/packages/astro/test/fixtures/preact-component/src/pages/signals.astro
@@ -1,7 +1,9 @@
---
import { signal } from '@preact/signals';
import Signals from '../components/Signals';
+import SignalsInArray from '../components/SignalsInArray';
const count = signal(1);
+const secondCount = signal(2);
---
@@ -10,5 +12,6 @@ const count = signal(1);
+
diff --git a/packages/astro/test/preact-component.test.js b/packages/astro/test/preact-component.test.js
index e8c89d5bf40c..8c84bf8e6c27 100644
--- a/packages/astro/test/preact-component.test.js
+++ b/packages/astro/test/preact-component.test.js
@@ -100,4 +100,26 @@ describe('Preact component', () => {
assert.notEqual(sigs1.count, undefined);
assert.equal(sigs1.count, sigs2.count);
});
+
+ it('Can use signals in array', async () => {
+ const html = await fixture.readFile('/signals/index.html');
+ const $ = cheerio.load(html);
+ const element = $('.preact-signal-array');
+ assert.equal(element.length, 1);
+
+ const sigs1Raw = $($('astro-island')[2]).attr('data-preact-signals');
+
+ const sigs1 = JSON.parse(sigs1Raw);
+
+ assert.deepEqual(sigs1, {
+ signalsArray: [
+ ['p0', 1],
+ ['p0', 2],
+ ['p1', 4],
+ ],
+ });
+
+ assert.equal($('.preact-signal-array h1').text(), "I'm not a signal 12345");
+ assert.equal($('.preact-signal-array p').text(), '112');
+ });
});
diff --git a/packages/integrations/preact/src/client.ts b/packages/integrations/preact/src/client.ts
index 3fb36d22a197..fdf615659ea5 100644
--- a/packages/integrations/preact/src/client.ts
+++ b/packages/integrations/preact/src/client.ts
@@ -18,13 +18,26 @@ export default (element: HTMLElement) =>
let signalsRaw = element.dataset.preactSignals;
if (signalsRaw) {
const { signal } = await import('@preact/signals');
- let signals: Record = JSON.parse(element.dataset.preactSignals!);
+ let signals: Record = JSON.parse(
+ element.dataset.preactSignals!,
+ );
for (const [propName, signalId] of Object.entries(signals)) {
- if (!sharedSignalMap.has(signalId)) {
- const signalValue = signal(props[propName]);
- sharedSignalMap.set(signalId, signalValue);
+ if (Array.isArray(signalId)) {
+ signalId.forEach(({ id, i }) => {
+ const [valueOfSignal, indexInProps] = props[propName][i];
+ if (!sharedSignalMap.has(id)) {
+ const signalValue = signal(valueOfSignal);
+ sharedSignalMap.set(id, signalValue);
+ }
+ props[propName][indexInProps] = sharedSignalMap.get(id);
+ });
+ } else {
+ if (!sharedSignalMap.has(signalId)) {
+ const signalValue = signal(props[propName]);
+ sharedSignalMap.set(signalId, signalValue);
+ }
+ props[propName] = sharedSignalMap.get(signalId);
}
- props[propName] = sharedSignalMap.get(signalId);
}
}
diff --git a/packages/integrations/preact/src/signals.ts b/packages/integrations/preact/src/signals.ts
index ea022b42225c..ad04ac9ce0cf 100644
--- a/packages/integrations/preact/src/signals.ts
+++ b/packages/integrations/preact/src/signals.ts
@@ -28,22 +28,27 @@ export function serializeSignals(
map: PropNameToSignalMap,
) {
// Check for signals
- const signals: Record = {};
+ const signals: Record = {};
for (const [key, value] of Object.entries(props)) {
- if (isSignal(value)) {
+ if (Array.isArray(value)) {
+ value.forEach((signal, index) => {
+ // find signals in array. The index is important!
+ if (isSignal(signal)) {
+ props[key] = props[key].map((v: SignalLike, i: number) =>
+ i === index ? [signal.peek(), i] : v,
+ );
+
+ map.set(key, [...((map.get(key) || []) as []), [signal, index]]);
+ signals[key] = [...((signals[key] || []) as []), [getSignalId(ctx, signal), index]];
+ }
+ });
+ } else if (isSignal(value)) {
// Set the value to the current signal value
// This mutates the props on purpose, so that it will be serialized correct.
props[key] = value.peek();
map.set(key, value);
- let id: string;
- if (ctx.signals.has(value)) {
- id = ctx.signals.get(value)!;
- } else {
- id = incrementId(ctx);
- ctx.signals.set(value, id);
- }
- signals[key] = id;
+ signals[key] = getSignalId(ctx, value);
}
}
@@ -51,3 +56,13 @@ export function serializeSignals(
attrs['data-preact-signals'] = JSON.stringify(signals);
}
}
+
+function getSignalId(ctx: Context, item: SignalLike) {
+ let id = ctx.signals.get(item);
+ if (!id) {
+ id = incrementId(ctx);
+ ctx.signals.set(item, id);
+ }
+
+ return id;
+}
diff --git a/packages/integrations/preact/src/types.ts b/packages/integrations/preact/src/types.ts
index 93f65bbc20ea..03f09cb4538e 100644
--- a/packages/integrations/preact/src/types.ts
+++ b/packages/integrations/preact/src/types.ts
@@ -7,7 +7,7 @@ export type SignalLike = {
peek(): any;
};
-export type PropNameToSignalMap = Map;
+export type PropNameToSignalMap = Map;
export type AstroPreactAttrs = {
['data-preact-signals']?: string;