Jetpack AI: guard every model-supplied list the review card indexes

affected_blocks was not the only one. conflict.positions and
edit.supported_by_reviewers are typed as required by the tool schema, but the
provider drops `strict`, so the model can omit either. Both are indexed
unguarded, so either one throws the same TypeError and unmounts the card.

A single toList() helper replaces the inline guard, so all three sites read the
same way and a new one is a one-liner rather than a guard to remember. The three
fields are now optional on the interface, which is what the payload actually
promises.

Author: t-wright

packages/jetpack-ai-sidebar/src/components/ai-editorial-review.test.tsx

@@ -465,6 +465,43 @@ describe( 'AiEditorialReview — smoke render', () => {
 		expect( mockedRecordTracksEvent ).not.toHaveBeenCalled();
 	} );
 
+	it( 'renders a conflict that omits positions', () => {
+		render(
+			<AiEditorialReview
+				{ ...basePayload( {
+					conflicts: [
+						{
+							subject: 'Tone of the opening',
+							guideline_anchor: null,
+							recommended_resolution: 'Use neutral phrasing.',
+						},
+					] as any,
+				} ) }
+			/>
+		);
+
+		expect( screen.getByText( 'Tone of the opening' ) ).toBeInTheDocument();
+	} );
+
+	it( 'renders a suggested edit that omits supported_by_reviewers', () => {
+		render(
+			<AiEditorialReview
+				{ ...basePayload( {
+					suggested_edits: [
+						{
+							block_index: 1,
+							current_text: 'voted last Tuesday',
+							suggested_text: 'voted on Tuesday',
+							rationale: 'Concise.',
+						},
+					] as any,
+				} ) }
+			/>
+		);
+
+		expect( screen.getByText( 'Concise.' ) ).toBeInTheDocument();
+	} );
+
 	it( 'renders an implication that omits affected_blocks', () => {
 		// The tool schema marks affected_blocks required but the tool is not strict,
 		// so the model can omit it. Indexing it directly used to blank the card.

packages/jetpack-ai-sidebar/src/components/ai-editorial-review.tsx

@@ -64,7 +64,7 @@ interface CandidateResolution {
 
 interface Conflict {
 	subject: string;
-	positions: ReviewerPosition[];
+	positions?: ReviewerPosition[];
 	guideline_anchor: string | null;
 	recommended_resolution: string;
 	candidate_resolutions?: CandidateResolution[];
@@ -84,7 +84,7 @@ interface SuggestedEdit {
 	suggested_text: string;
 	suggested_text_html?: string;
 	rationale: string;
-	supported_by_reviewers: string[];
+	supported_by_reviewers?: string[];
 	requires_manual?: boolean;
 	/** Optional short editorial category for the card badge (e.g. "Tone"). */
 	feedback_category?: string;
@@ -198,6 +198,15 @@ function formatRelativeTime( timestamp: number ): string {
 	);
 }
 
+/**
+ * Model-supplied list fields are typed as required by the tool schema, but the
+ * provider drops `strict`, so any of them can arrive missing or malformed.
+ * Reading `.length` or `.map` off one that did unmounts the whole card.
+ */
+function toList< T >( value: T[] | undefined ): T[] {
+	return Array.isArray( value ) ? value : [];
+}
+
 function getGuidelineCategoryLabel( category: GuidelineViolation[ 'category' ] ): string {
 	switch ( category ) {
 		case 'site':
@@ -1282,7 +1291,7 @@ export default function AiEditorialReview( {
 													) }
 												</header>
 												<ul className="jetpack-ai-editorial-review__positions">
-													{ conflict.positions.map( ( pos, j ) => (
+													{ toList( conflict.positions ).map( ( pos, j ) => (
 														<li
 															className="jetpack-ai-editorial-review__position"
 															key={ `pos-${ i }-${ j }` }
@@ -1391,9 +1400,7 @@ export default function AiEditorialReview( {
 									<ul>
 										{ implications.map( ( imp, i ) => {
 											// A non-strict payload can omit affected_blocks.
-											const affectedBlocks = Array.isArray( imp.affected_blocks )
-												? imp.affected_blocks
-												: [];
+											const affectedBlocks = toList( imp.affected_blocks );
 											return (
 												<li key={ `imp-${ i }` }>
 													<strong>{ imp.change }</strong> — { imp.implies }
@@ -1515,11 +1522,12 @@ export default function AiEditorialReview( {
 													element: 'text',
 												} );
 											}
+											const supportedByReviewers = toList( edit.supported_by_reviewers );
 											const footer =
-												edit.supported_by_reviewers.length > 0 ? (
+												supportedByReviewers.length > 0 ? (
 													<p className="jetpack-ai-editorial-review__reviewers">
 														{ __( 'Requested by:', __i18n_text_domain__ ) }{ ' ' }
-														{ edit.supported_by_reviewers.map( ( r, j ) => (
+														{ supportedByReviewers.map( ( r, j ) => (
 															<span key={ `edit-${ i }-rev-${ j }` }>
 																{ j > 0 && ' ' }
 																<ReviewerChip