[api] Fix #1602 - Format bignumber strings for /purchases endpoint (#…

…1619)

* fix #1602

* npm version prerelease

carbonmark-api/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@klimadao/carbonmark-api",
-  "version": "2.0.0-2",
+  "version": "2.0.0-3",
   "description": "An API for exploring Carbonmark project data, prices and activity.",
   "main": "app.ts",
   "scripts": {

carbonmark-api/src/models/Purchase.model.ts

@@ -8,8 +8,8 @@ export const PurchaseModel = Type.Object({
     ],
   }),
   amount: Type.String({
-    description: "Stringified 18 decimal BigNumber",
-    examples: ["1000000000000000000"],
+    description: "Quantity of credits purchased",
+    examples: ["1.0"],
   }),
   listing: Type.Object({
     id: Type.String({
@@ -38,8 +38,8 @@ export const PurchaseModel = Type.Object({
     }),
   }),
   price: Type.String({
-    description: "Stringified 6 decimal BigNumber",
-    examples: ["1000000"],
+    description: "Total purchase price (USDC)",
+    examples: ["5.0"],
   }),
 });
 

carbonmark-api/src/routes/purchases/[id]/get.ts

@@ -1,4 +1,5 @@
 import { Static } from "@sinclair/typebox";
+import { utils } from "ethers";
 import { FastifyInstance, FastifyReply, FastifyRequest } from "fastify";
 import { isNil } from "lodash";
 import { Purchase } from "../../../models/Purchase.model";
@@ -35,7 +36,9 @@ const handler = async (
   });
 
   const response: Purchase = {
-    ...purchase,
+    id: purchase.id,
+    amount: utils.formatUnits(purchase.amount, 18),
+    price: utils.formatUnits(purchase.price, 6),
     listing: {
       id: purchase.listing.id,
       project: {

carbonmark-api/test/fixtures/marketplace.ts

@@ -20,9 +20,9 @@ const projectWithListing = aProject({
 
 /** marketplace.getPurchaseById() */
 const purchase: GetPurchaseByIdQuery["purchase"] = {
-  amount: "1000000000000000000", // 1t
+  amount: "1000000000000000000", // 1 tonne
   id: "0xfe2949e3644b88d2e00e5f84f6266c191dbb0379a18e00a18192116de7c5c779",
-  price: "1000000", // $1
+  price: "5000000", // 5 USDC
   listing: {
     id: "0x01",
     project: {

carbonmark-api/test/routes/purchases/get.test.ts

@@ -9,6 +9,8 @@ import { DEV_URL, ERROR } from "../../test.constants";
 
 const purchaseModelFixture: Purchase = {
   ...marketplace.purchase,
+  amount: "1.0",
+  price: "5.0",
   listing: {
     id: marketplace.purchase.listing.id,
     project: {
@@ -43,7 +45,7 @@ describe("GET /purchases/:id", () => {
   });
 
   /** The happy path */
-  test("Success", async () => {
+  test("Returns and formats BigNumber values", async () => {
     // Mock the response from the graph
     nock(GRAPH_URLS["polygon"].marketplace)
       .post("")