fix: ship sales tax rates with production runtime

src/modules/sales-utils/expectedSalesTax.ts

@@ -1,4 +1,5 @@
 import { readFileSync } from "fs";
+import { join } from "path";
 
 export interface SalesTaxAddressInput {
   line1?: string | null;
@@ -25,18 +26,26 @@ interface StateTaxRecord {
   local_jurisdictions?: LocalJurisdiction[];
 }
 
-const taxDataPath = new URL("./salesTaxRates.json", import.meta.url);
+const TAX_DATA_FALLBACK_URL = new URL("./salesTaxRates.json", import.meta.url);
+
+const TAX_DATA_CANDIDATE_PATHS: Array<string | URL> = [
+  process.env.SALES_TAX_RATES_PATH ?? "",
+  join(process.cwd(), "salesTaxRates.json"),
+  TAX_DATA_FALLBACK_URL,
+].filter(Boolean);
 
 const parseTaxData = (): StateTaxRecord[] => {
-  try {
-    const raw = readFileSync(taxDataPath, "utf-8");
-    const parsed = JSON.parse(raw) as StateTaxRecord[];
-
-    if (!Array.isArray(parsed)) return [];
-    return parsed;
-  } catch {
-    return [];
+  for (const source of TAX_DATA_CANDIDATE_PATHS) {
+    try {
+      const raw = readFileSync(source, "utf-8");
+      const parsed = JSON.parse(raw) as StateTaxRecord[];
+      if (Array.isArray(parsed)) return parsed;
+    } catch {
+      continue;
+    }
   }
+
+  return [];
 };
 
 const SALES_TAX_DATA = parseTaxData();