fix: expose client fetch and signed adjustments

packages/metering/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/metering",
-  "version": "0.8.2",
+  "version": "0.8.3",
   "private": true,
   "type": "module",
   "main": "src/index.ts",

packages/metering/src/index.ts

@@ -90,6 +90,10 @@ export function defineMeter(options: MeterOptions) {
     Number.isSafeInteger(units) && units > 0
       ? null
       : { ok: false, reason: `${label} must be a positive whole number` };
+  const validSigned = (units: number): MeterResult | null =>
+    Number.isSafeInteger(units) && units !== 0
+      ? null
+      : { ok: false, reason: `${label} adjustment must be a non-zero whole number` };
   const fault = (error: unknown, operation: string): MeterResult => {
     options.onFault?.(error, operation);
     return {
@@ -138,7 +142,15 @@ export function defineMeter(options: MeterOptions) {
       add("purchase", subjectId, units, reason, reference),
     refund: (subjectId: string, units: number, reason: string, reference = "") =>
       add("refund", subjectId, units, reason, reference),
-    adjust: (subjectId: string, units: number, reason: string, reference = "") =>
-      add("adjust", subjectId, units, reason, reference),
+    async adjust(subjectId: string, units: number, reason: string, reference = "") {
+      const invalid = validSigned(units);
+      if (invalid) return invalid;
+      try {
+        await options.store.write(subjectId, units, "adjust", reason, reference);
+        return { ok: true } as const;
+      } catch (error) {
+        return fault(error, "adjust");
+      }
+    },
   };
 }

packages/metering/test/metering.test.ts

@@ -40,3 +40,27 @@ test("meter distinguishes refusals from storage faults", async () => {
     fault: true,
   });
 });
+
+test("adjust accepts signed non-zero amounts while other additions stay positive", async () => {
+  const writes: number[] = [];
+  const meter = defineMeter({
+    store: {
+      balance: async () => 0,
+      reserve: async () => true,
+      write: async (_subject, units) => {
+        writes.push(units);
+      },
+    },
+  });
+  expect(await meter.adjust("u1", -25, "correction")).toEqual({ ok: true });
+  expect(await meter.adjust("u1", 10, "correction")).toEqual({ ok: true });
+  expect(await meter.adjust("u1", 0, "correction")).toEqual({
+    ok: false,
+    reason: "units adjustment must be a non-zero whole number",
+  });
+  expect(await meter.grant("u1", -1, "invalid")).toEqual({
+    ok: false,
+    reason: "units must be a positive whole number",
+  });
+  expect(writes).toEqual([-25, 10]);
+});