fix(settings): validate CLICKHOUSE_MAX_MEMORY_USAGE instead of silently ignoring invalid values

apps/mesh/src/settings/resolve-config.test.ts

@@ -132,6 +132,31 @@ describe("resolveConfig port", () => {
   );
 });
 
+describe("resolveConfig clickhouse max memory usage", () => {
+  it("defaults to undefined when unset", () => {
+    const result = resolveConfig(flags, {});
+
+    expect(result.settings.clickhouseMaxMemoryUsage).toBeUndefined();
+  });
+
+  it("uses CLICKHOUSE_MAX_MEMORY_USAGE when set", () => {
+    const result = resolveConfig(flags, {
+      CLICKHOUSE_MAX_MEMORY_USAGE: "1000000000",
+    });
+
+    expect(result.settings.clickhouseMaxMemoryUsage).toBe(1000000000);
+  });
+
+  it.each(["abc", "0", "-1", "1.5", "Infinity"])(
+    "throws for invalid value %p",
+    (value) => {
+      expect(() =>
+        resolveConfig(flags, { CLICKHOUSE_MAX_MEMORY_USAGE: value }),
+      ).toThrow("CLICKHOUSE_MAX_MEMORY_USAGE must be a positive integer");
+    },
+  );
+});
+
 describe("resolveConfig deployment admin emails", () => {
   it("defaults to an empty list when unset", () => {
     const result = resolveConfig(flags, {});

apps/mesh/src/settings/resolve-config.ts

@@ -57,6 +57,19 @@ function toPositiveIntegerOrDefault(
   return numberValue;
 }
 
+function toPositiveIntegerOrUndefined(
+  name: string,
+  value: string | undefined,
+): number | undefined {
+  if (value === undefined || value === "") return undefined;
+
+  const numberValue = Number(value);
+  if (!Number.isSafeInteger(numberValue) || numberValue <= 0) {
+    throw new Error(`${name} must be a positive integer`);
+  }
+  return numberValue;
+}
+
 /** Tri-state flag: unset/empty → `fallback`, otherwise parse as boolean. */
 function toBoolWithDefault(
   value: string | undefined,
@@ -160,8 +173,10 @@ export function resolveConfig(
 
     // Observability
     clickhouseUrl: envVars.CLICKHOUSE_URL,
-    clickhouseMaxMemoryUsage:
-      Number(envVars.CLICKHOUSE_MAX_MEMORY_USAGE) || undefined,
+    clickhouseMaxMemoryUsage: toPositiveIntegerOrUndefined(
+      "CLICKHOUSE_MAX_MEMORY_USAGE",
+      envVars.CLICKHOUSE_MAX_MEMORY_USAGE,
+    ),
     monitoringOtlpEndpoint: envVars.MONITORING_OTLP_ENDPOINT,
     otelServiceName: envVars.OTEL_SERVICE_NAME || "studio",