feat(rsi): read the account's store credit

__tests__/message-handler.test.ts

@@ -30,6 +30,7 @@ describe("onMessage", () => {
           "syncBuyback",
           "syncBuybackDetail",
           "syncBuybackPricing",
+          "syncStoreCredit",
           "verify-write",
           "verify-remove",
           "org-verify-write",
@@ -304,6 +305,74 @@ describe("onMessage", () => {
     expect(result.code).toBe(502);
   });
 
+  it("reads the store credit in USD from RSI's account query", async () => {
+    const sendResponse = vi.fn();
+    const fetchSpy = vi.spyOn(globalThis, "fetch").mockResolvedValue(
+      new Response(
+        JSON.stringify({
+          data: {
+            customer: {
+              ledgerCredit: {
+                amount: { value: 84956, currency: { code: "USD" } },
+              },
+            },
+          },
+        }),
+        { status: 200 }
+      )
+    );
+
+    await onMessage(
+      JSON.stringify({ action: "syncStoreCredit" }),
+      sendResponse,
+      vi.fn().mockResolvedValue("test-token"),
+      "1.0.0"
+    );
+
+    const result = JSON.parse(sendResponse.mock.calls[0]![0]);
+    expect(result).toEqual({
+      code: 200,
+      action: "syncStoreCredit",
+      payload: { credit: 849.56 },
+    });
+    const [url, init] = fetchSpy.mock.calls[0]!;
+    expect(url).toBe("https://robertsspaceindustries.com/graphql");
+    expect(JSON.parse(String(init?.body)).operationName).toBe("credit");
+  });
+
+  it("reads no store credit RSI answers without an amount", async () => {
+    const sendResponse = vi.fn();
+    vi.spyOn(globalThis, "fetch").mockResolvedValue(
+      new Response(JSON.stringify({ data: { customer: null } }), { status: 200 })
+    );
+
+    await onMessage(
+      JSON.stringify({ action: "syncStoreCredit" }),
+      sendResponse,
+      vi.fn().mockResolvedValue("test-token"),
+      "1.0.0"
+    );
+
+    const result = JSON.parse(sendResponse.mock.calls[0]![0]);
+    expect(result.code).toBe(502);
+  });
+
+  it("asks for no store credit without an RSI session", async () => {
+    const sendResponse = vi.fn();
+    const fetchSpy = vi.spyOn(globalThis, "fetch");
+
+    await onMessage(
+      JSON.stringify({ action: "syncStoreCredit" }),
+      sendResponse,
+      vi.fn().mockResolvedValue(null),
+      "1.0.0"
+    );
+
+    const result = JSON.parse(sendResponse.mock.calls[0]![0]);
+    expect(result.code).toBe(401);
+    expect(fetchSpy).not.toHaveBeenCalled();
+  });
+
   it("responds to syncBuyback action without token", async () => {
     const sendResponse = vi.fn();
     const getToken = vi.fn().mockResolvedValue(null);

lib/message-handler.ts

@@ -5,6 +5,7 @@ import {
   fetchBuybackDetail,
   setStoreAuthToken,
   fetchStorePricing,
+  fetchStoreCredit,
   fetchCitizenPage,
   updateBio,
   fetchOrgAdminPage,
@@ -39,6 +40,7 @@ export const SUPPORTED_ACTIONS = [
   "syncBuyback",
   "syncBuybackDetail",
   "syncBuybackPricing",
+  "syncStoreCredit",
   "verify-write",
   "verify-remove",
   "org-verify-write",
@@ -163,6 +165,24 @@ async function storePricing(token: string) {
   };
 }
 
+// The store credit on the account, in USD, as RSI's account panel shows it.
+// RSI keeps it in cents, and only in USD.
+async function storeCredit(token: string) {
+  const response = await fetchStoreCredit(token);
+  if (!response.ok) {
+    return { code: response.status, error: "Store credit failed" };
+  }
+
+  const body: any = await response.json().catch(() => undefined);
+  const amount = body?.data?.customer?.ledgerCredit?.amount;
+  const cents = amount?.value;
+  if (!Number.isInteger(cents) || cents < 0 || amount?.currency?.code !== "USD") {
+    return { code: 502, error: "Store credit unreadable" };
+  }
+
+  return { code: 200, payload: { credit: cents / 100 } };
+}
+
 // Requests for the same org (or the same bio) wait for each other: a remove
 // sent while a slow write is still out would read the draft before the write
 // lands, find nothing, and leave the token the write then publishes.
@@ -455,6 +475,22 @@ export async function onMessage(
         return { code: 500, error: "Store pricing failed" };
       });
 
+      sendResponse(JSON.stringify({ action: message.action, ...result }));
+    }
+  } else if (message?.action == "syncStoreCredit") {
+    const token = await getToken();
+
+    if (!token) {
+      sendResponse(
+        JSON.stringify({ code: 401, action: message.action, error: "No RSI session" })
+      );
+    } else {
+      const result = await storeCredit(token).catch((error) => {
+        console.error("FY Sync: Store credit failed", error);
+
+        return { code: 500, error: "Store credit failed" };
+      });
+
       sendResponse(JSON.stringify({ action: message.action, ...result }));
     }
   } else if (message?.action == "sync" || message?.action == "syncBuyback") {

lib/rsi.ts

@@ -93,6 +93,21 @@ export function fetchStorePricing(token: string) {
   });
 }
 
+// The balances RSI's account panel shows, from the same GraphQL query: store
+// credit in USD cents.
+export function fetchStoreCredit(token: string) {
+  return fetchRSIApi({
+    url: `${RSI_BASE_URL}/graphql`,
+    payload: {
+      operationName: "credit",
+      variables: {},
+      query:
+        "query credit { customer { ledgerCredit: ledger(ledgerCode: credit) { amount { value currency { code } } } } }",
+    },
+    rsiToken: token,
+  });
+}
+
 export function fetchCitizenPage(handle: string) {
   return fetch(`${RSI_BASE_URL}/en/citizens/${encodeURIComponent(handle)}`, {
     method: "GET",