From 0429f95c5644506031799e404ffb8083f1f9a5b7 Mon Sep 17 00:00:00 2001
From: eyelidlessness <gnosis@gmail.com>
Date: Wed, 3 Apr 2024 10:02:04 -0700
Subject: [PATCH] =?UTF-8?q?Fix:=20`childrenState`=20must=20be=20defined=20?=
 =?UTF-8?q?before=20other=20reactive=20node=20state=E2=80=A6?=
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… specifically, before calling `createComputedExpression` or anything else that may exercise the `SubscribableDependency` interface.

TODO(?): detect this condition and throw a more meaningful error?
---
 packages/xforms-engine/src/instance/Group.ts          | 4 +++-
 packages/xforms-engine/src/instance/RepeatInstance.ts | 7 ++++---
 packages/xforms-engine/src/instance/Root.ts           | 6 ++++--
 packages/xforms-engine/src/instance/Subtree.ts        | 4 +++-
 4 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/packages/xforms-engine/src/instance/Group.ts b/packages/xforms-engine/src/instance/Group.ts
index 76d07ef0a..1d6d9d505 100644
--- a/packages/xforms-engine/src/instance/Group.ts
+++ b/packages/xforms-engine/src/instance/Group.ts
@@ -42,6 +42,9 @@ export class Group
 		super(parent, definition);
 
 		const childrenState = createChildrenState<Group, GeneralChildNode>(this);
+
+		this.childrenState = childrenState;
+
 		const state = createSharedNodeState(
 			this.scope,
 			{
@@ -58,7 +61,6 @@ export class Group
 			}
 		);
 
-		this.childrenState = childrenState;
 		this.state = state;
 		this.engineState = state.engineState;
 		this.currentState = materializeCurrentStateChildren(state.currentState, childrenState);
diff --git a/packages/xforms-engine/src/instance/RepeatInstance.ts b/packages/xforms-engine/src/instance/RepeatInstance.ts
index 9818d6285..03f1e4da0 100644
--- a/packages/xforms-engine/src/instance/RepeatInstance.ts
+++ b/packages/xforms-engine/src/instance/RepeatInstance.ts
@@ -58,6 +58,10 @@ export class RepeatInstance
 	) {
 		super(parent, definition);
 
+		const childrenState = createChildrenState<RepeatInstance, GeneralChildNode>(this);
+
+		this.childrenState = childrenState;
+
 		options.precedingPrimaryInstanceNode.after(this.contextNode);
 
 		const { precedingInstance } = options;
@@ -66,8 +70,6 @@ export class RepeatInstance
 		const [currentIndex, setCurrentIndex] = createSignal(initialIndex);
 
 		this.currentIndex = currentIndex;
-
-		const childrenState = createChildrenState<RepeatInstance, GeneralChildNode>(this);
 		const state = createSharedNodeState(
 			this.scope,
 			{
@@ -84,7 +86,6 @@ export class RepeatInstance
 			}
 		);
 
-		this.childrenState = childrenState;
 		this.state = state;
 		this.engineState = state.engineState;
 		this.currentState = materializeCurrentStateChildren(state.currentState, childrenState);
diff --git a/packages/xforms-engine/src/instance/Root.ts b/packages/xforms-engine/src/instance/Root.ts
index e3546cea5..efade67ae 100644
--- a/packages/xforms-engine/src/instance/Root.ts
+++ b/packages/xforms-engine/src/instance/Root.ts
@@ -150,6 +150,10 @@ export class Root
 	) {
 		super(engineConfig, null, definition);
 
+		const childrenState = createChildrenState<Root, GeneralChildNode>(this);
+
+		this.childrenState = childrenState;
+
 		const reference = definition.nodeset;
 
 		this.rootReference = reference;
@@ -158,7 +162,6 @@ export class Root
 		const evaluator = instanceDOM.primaryInstanceEvaluator;
 		const { translations } = evaluator;
 		const { defaultLanguage, languages } = getInitialLanguageState(translations);
-		const childrenState = createChildrenState<Root, GeneralChildNode>(this);
 		const state = createSharedNodeState(
 			this.scope,
 			{
@@ -178,7 +181,6 @@ export class Root
 			}
 		);
 
-		this.childrenState = childrenState;
 		this.state = state;
 		this.engineState = state.engineState;
 		this.currentState = materializeCurrentStateChildren(state.currentState, childrenState);
diff --git a/packages/xforms-engine/src/instance/Subtree.ts b/packages/xforms-engine/src/instance/Subtree.ts
index eccb0c173..2d5a00267 100644
--- a/packages/xforms-engine/src/instance/Subtree.ts
+++ b/packages/xforms-engine/src/instance/Subtree.ts
@@ -39,6 +39,9 @@ export class Subtree
 		super(parent, definition);
 
 		const childrenState = createChildrenState<Subtree, GeneralChildNode>(this);
+
+		this.childrenState = childrenState;
+
 		const state = createSharedNodeState(
 			this.scope,
 			{
@@ -55,7 +58,6 @@ export class Subtree
 			}
 		);
 
-		this.childrenState = childrenState;
 		this.state = state;
 		this.engineState = state.engineState;
 		this.currentState = materializeCurrentStateChildren(state.currentState, childrenState);