Updates method to reflect correct payment provider API

packages/medusa/src/services/__mocks__/totals.js

@@ -1,6 +1,12 @@
 import { IdMap } from "medusa-test-utils"
 
 export const TotalsServiceMock = {
+  getTotal: jest.fn().mockImplementation(cart => {
+    if (cart.total) {
+      return cart.total
+    }
+    return 0
+  }),
   getSubtotal: jest.fn().mockImplementation(cart => {
     if (cart.subtotal) {
       return cart.subtotal

packages/medusa/src/services/__tests__/payment-provider.js

@@ -23,4 +23,60 @@ describe("ProductService", () => {
       }
     })
   })
+
+  describe("createSession", () => {
+    const createSession = jest.fn().mockReturnValue(Promise.resolve())
+    const container = {
+      totalsService: TotalsService,
+      pp_default_provider: {
+        createSession
+      }
+    }
+
+    const providerService = new PaymentProviderService(container)
+
+    it("successfully creates session", () => {
+      await providerService.createSession("default_provider", {
+        total: 100
+      })
+
+      expect(createSession).toBeCalledTimes(1)
+      expect(createSession).toBeCalledWith({
+        total: 100
+      })
+    })
+  })
+
+  describe("updateSession", () => {
+    const createSession = jest.fn().mockReturnValue(Promise.resolve())
+    const updateSession = jest.fn().mockReturnValue(Promise.resolve())
+
+    const container = {
+      totalsService: TotalsService,
+      pp_default_provider: {
+        createSession,
+        updateSession
+      }
+    }
+
+    const providerService = new PaymentProviderService(container)
+
+    it("successfully creates session", () => {
+      await providerService.createSession({
+        provider_id: "default_provider",
+        data: {
+          id: "1234"
+        }
+      }, {
+        total: 100
+      })
+
+      expect(TotalsService.getTotal).toBeCalledTimes(1)
+      expect(TotalsService.getTotal).toBeCalledWith({
+        total: 100
+      })
+
+      expect
+    })
+  })
 })