fix: Add discriminated union types for jsonb_stats aggregates

Types in app/types.d.ts match jsonb_stats README exactly:
- NumericStatAgg: int_agg, float_agg, dec2_agg, nat_agg (with sum, min, max, mean, etc.)
- CategoricalStatAgg: str_agg, bool_agg (with counts)
- ArrayStatAgg: arr_agg (with count + counts)
- DateStatAgg: date_agg (with counts + min/max)

Remove duplicate type definitions from atoms/search.ts.
Fix .sum access with "sum" in metric narrowing across reports and hierarchy.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jhf

app/src/app/enterprises/[id]/statistical-variables/statistical-variables-form.tsx

@@ -27,7 +27,8 @@ export default function StatisticalVariablesForm({
   return (
     <form className="space-y-4">
       {statDefinitions.map((statDefinition) => {
-        const value = data?.stats_summary?.[statDefinition.code]?.sum;
+        const metric = data?.stats_summary?.[statDefinition.code];
+        const value = metric && "sum" in metric ? metric.sum : undefined;
         return (
           <DisplayFormField
             key={statDefinition.code}

app/src/app/reports/ReportsPageClient.tsx

@@ -65,15 +65,15 @@ export default function ReportsPageClient({
             ...(drillDown.available.region?.map((point) =>
               value === "count"
                 ? point.count
-                : ((point.stats_summary?.[value]?.sum as number) ?? 0)
+                : (() => { const m = point.stats_summary?.[value]; return m && "sum" in m ? (m.sum as number) : 0; })()
             ) || [])
           );
           const categoryMax = Math.max(
             0,
             ...(drillDown.available.activity_category?.map((point) =>
               value === "count"
                 ? point.count
-                : ((point.stats_summary?.[value]?.sum as number) ?? 0)
+                : (() => { const m = point.stats_summary?.[value]; return m && "sum" in m ? (m.sum as number) : 0; })()
             ) || [])
           );
 

app/src/app/reports/drill-down-chart.tsx

@@ -131,10 +131,11 @@ export const DrillDownChart = ({
   return <div ref={chartContainerRef} />;
 };
 
-const getStatValue = (point: DrillDownPoint, variable: string): number =>
-  variable === "count"
-    ? point.count
-    : ((point.stats_summary?.[variable]?.sum as number) ?? 0);
+const getStatValue = (point: DrillDownPoint, variable: string): number => {
+  if (variable === "count") return point.count;
+  const metric = point.stats_summary?.[variable];
+  return metric && "sum" in metric ? (metric.sum as number) : 0;
+};
 
 const toPointOptionObject = (point: DrillDownPoint, variable: string) => ({
   name: `${point.path} - ${point.name}`,

app/src/app/search/components/statistical-unit-table-row.tsx

@@ -379,13 +379,10 @@ export const StatisticalUnitTableRow = ({
                     const metric = unit.stats_summary[column.stat_code];
                     let valueToDisplay: number | string | null = null;
 
-                    if (metric && metric.type === "number") {
-                      // metric is NumberStatMetric, sum is number | undefined
+                    if (metric && ("sum" in metric)) {
                       valueToDisplay = metric.sum !== undefined ? metric.sum : null;
                     } else {
-                      // For other types or if metric is undefined, display a placeholder
-                      // as we are only asked to display 'sum' from 'number' type metrics.
-                      valueToDisplay = "-"; // Or null for an empty cell
+                      valueToDisplay = "-";
                     }
                     return thousandSeparator(valueToDisplay);
                   })()}

app/src/app/types.d.ts

@@ -12,10 +12,48 @@ interface ExternalIdents {
   [key: string]: number | string;
 }
 
+// jsonb_stats aggregate types — see jsonb_stats README.md "Structures in Detail"
+
+/** Numeric aggregate (int_agg, float_agg, dec2_agg, nat_agg) */
+interface NumericStatAgg {
+  type: "int_agg" | "float_agg" | "dec2_agg" | "nat_agg";
+  count: number;
+  sum: number;
+  min: number;
+  max: number;
+  mean: number;
+  sum_sq_diff: number;
+  variance: number | null;
+  stddev: number | null;
+  coefficient_of_variation_pct: number | null;
+}
+
+/** Categorical aggregate (str_agg, bool_agg) */
+interface CategoricalStatAgg {
+  type: "str_agg" | "bool_agg";
+  counts: { [value: string]: number };
+}
+
+/** Array aggregate */
+interface ArrayStatAgg {
+  type: "arr_agg";
+  count: number;
+  counts: { [element: string]: number };
+}
+
+/** Date aggregate */
+interface DateStatAgg {
+  type: "date_agg";
+  counts: { [isoDate: string]: number };
+  min: string;
+  max: string;
+}
+
+type StatAgg = NumericStatAgg | CategoricalStatAgg | ArrayStatAgg | DateStatAgg;
+
+/** stats_agg object: { type: "stats_agg", [statCode]: StatAgg } */
 interface StatsSummary {
-  [key: string]: {
-    [key: string]: number | string;
-  };
+  [statCode: string]: StatAgg;
 }
 
 interface StatisticalUnit extends Tables<"statistical_unit"> {

app/src/atoms/search.ts

@@ -233,39 +233,9 @@ export const resetSearchInitializationAtom = atom(
 // SELECTION ATOMS - Replace SelectionContext
 // ============================================================================
 
-interface ExternalIdents {
-  [key: string]: string;
-}
-
-// Define the structure for metrics within stats_summary
-interface BaseStatMetric {
-  type: "array" | "number" | "string" | "boolean";
-}
-
-export interface NumberStatMetric extends BaseStatMetric {
-  type: "number";
-  max?: number;
-  min?: number;
-  sum?: number; // If present, this is always a number
-  mean?: number;
-  count?: number;
-  stddev?: number;
-  variance?: number;
-  sum_sq_diff?: number;
-  coefficient_of_variation_pct?: number;
-}
-
-export interface CountsStatMetric extends BaseStatMetric {
-  type: "array" | "string" | "boolean";
-  counts: { [key: string]: number };
-}
-
-export type StatMetric = NumberStatMetric | CountsStatMetric;
-
-// Refined StatsSummary: Each key is a stat_code, value is its metric object or undefined
-interface StatsSummary {
-  [statCode: string]: StatMetric | undefined;
-}
+// Re-export discriminated union types from app/types.d.ts for use in search components
+export type { NumericStatAgg, CategoricalStatAgg, ArrayStatAgg, DateStatAgg, StatAgg } from '@/app/types';
+import type { StatsSummary, ExternalIdents } from '@/app/types';
 
 export type StatisticalUnit = Omit<Tables<"statistical_unit">, 'external_idents' | 'stats_summary'> & {
   external_idents: ExternalIdents;

app/src/components/statistical-unit-hierarchy/topology-item.tsx

@@ -110,8 +110,8 @@ export function TopologyItem({
               />
               {statDefinitions.map(
                 (statDefinition: Tables<"stat_definition_active">) => {
-                  const statsSum =
-                    stats?.stats_summary?.[statDefinition.code]?.sum;
+                  const metric = stats?.stats_summary?.[statDefinition.code];
+                  const statsSum = metric && "sum" in metric ? metric.sum : undefined;
                   const stat = unit.stat_for_unit?.find(
                     (s) => s.stat_definition_id === statDefinition.id
                   );

app/src/components/statistical-unit-hierarchy/types.d.ts

@@ -266,7 +266,7 @@ declare interface StatisticalUnitStats {
   unit_id: number;
   valid_from: string;
   valid_to: string;
-  stats: { [key: string]: number | string };
+  stats: { type: "stats"; [statCode: string]: { type: string; value: number | string | boolean } | string };
   stats_summary: StatsSummary;
 };