From 9b7ca917a246c9715f07349d8a53c29500db296b Mon Sep 17 00:00:00 2001
From: bouzuya <m@bouzuya.net>
Date: Thu, 30 Mar 2023 16:22:59 +0900
Subject: [PATCH] Add deleteTransaction tests

---
 app/accounts/[id]/transactions/index.tsx |  8 ++--
 lib/account.test.ts                      | 60 ++++++++++++++++++++++++
 lib/account.ts                           | 10 ++--
 3 files changed, 70 insertions(+), 8 deletions(-)

diff --git a/app/accounts/[id]/transactions/index.tsx b/app/accounts/[id]/transactions/index.tsx
index baf33ab..7c7acc6 100644
--- a/app/accounts/[id]/transactions/index.tsx
+++ b/app/accounts/[id]/transactions/index.tsx
@@ -113,10 +113,10 @@ export default function Transactions(): JSX.Element {
         onClickOk={() => {
           if (account === null || transactionId === null) return;
           // update local state
-          const [newAccount, newEvent] = deleteTransaction(
-            account,
-            transactionId
-          );
+          const result = deleteTransaction(account, transactionId);
+          // TODO: error handling
+          if (result.isErr()) return;
+          const [newAccount, newEvent] = result.value;
 
           // update remote state
           setAccount(newAccount);
diff --git a/lib/account.test.ts b/lib/account.test.ts
index d09eed7..082cfe5 100644
--- a/lib/account.test.ts
+++ b/lib/account.test.ts
@@ -4,6 +4,7 @@ import {
   createCategory,
   createTransaction,
   deleteCategory,
+  deleteTransaction,
 } from "./account";
 
 describe("createAccount", () => {
@@ -236,3 +237,62 @@ describe("deleteCategory", () => {
     });
   });
 });
+
+describe("deleteTransaction", () => {
+  describe("happy path", () => {
+    it("works", () => {
+      const v1 = createAccount("account name 1")._unsafeUnwrap()[0];
+      const v2 = createCategory(v1, "category name 1")._unsafeUnwrap()[0];
+      const selectedCategory = v2.categories[0];
+      if (selectedCategory === undefined) throw new Error();
+      const v3 = createTransaction(v2, {
+        amount: "123",
+        categoryId: selectedCategory.id,
+        comment: "comment1",
+        date: "2023-01-02",
+      })._unsafeUnwrap()[0];
+      const selectedTransaction = v3.transactions[0];
+      if (selectedTransaction === undefined) throw new Error();
+      const transactionId = selectedTransaction.id;
+      const result = deleteTransaction(v3, transactionId);
+      if (result.isErr()) throw new Error();
+      const [v4, event] = result.value;
+
+      expect(v4.categories).toStrictEqual(v3.categories);
+      expect(v4.events).not.toStrictEqual(v3.events);
+      expect(v4.id).toStrictEqual(v3.id);
+      expect(v4.name).toStrictEqual(v3.name);
+      expect(v4.transactions).not.toStrictEqual(v3.transactions);
+
+      if (event.type !== "transactionDeleted") throw new Error();
+      const transactionDeleted = event;
+      expect(v4.events[v4.events.length - 1]).toStrictEqual(event);
+      expect(transactionDeleted.accountId).toStrictEqual(v4.id);
+      expect(transactionDeleted.at).not.toStrictEqual("");
+      expect(transactionDeleted.id).not.toStrictEqual("");
+      expect(transactionDeleted.transactionId).toStrictEqual(transactionId);
+
+      expect(v4.transactions.length).toBe(0);
+    });
+  });
+
+  describe("when transactionId is invalid", () => {
+    it("returns err", () => {
+      const v1 = createAccount("account name 1")._unsafeUnwrap()[0];
+      const v2 = createCategory(v1, "category name 1")._unsafeUnwrap()[0];
+      const selectedCategory = v2.categories[0];
+      if (selectedCategory === undefined) throw new Error();
+      const v3 = createTransaction(v2, {
+        amount: "123",
+        categoryId: selectedCategory.id,
+        comment: "comment1",
+        date: "2023-01-02",
+      })._unsafeUnwrap()[0];
+      const selectedTransaction = v3.transactions[0];
+      if (selectedTransaction === undefined) throw new Error();
+      const transactionId = selectedTransaction.id + "s"; // invalid
+      const result = deleteTransaction(v2, transactionId);
+      expect(result.isErr()).toBe(true);
+    });
+  });
+});
diff --git a/lib/account.ts b/lib/account.ts
index 4980887..5ff4289 100644
--- a/lib/account.ts
+++ b/lib/account.ts
@@ -128,15 +128,17 @@ export const deleteCategory = (
 export const deleteTransaction = (
   self: Account,
   transactionId: string
-): [Account, AccountEvent] => {
+): Result<[Account, AccountEvent], string> => {
+  if (!self.transactions.some(({ id }) => id === transactionId))
+    return err("transactionId not found");
   const event: TransactionDeleted = {
-    type: "transactionDeleted",
-    transactionId,
     accountId: self.id,
     at: new Date().toISOString(),
     id: generateUuidV4(),
+    transactionId,
+    type: "transactionDeleted",
   };
-  return [applyEvent(self, event), event];
+  return ok([applyEvent(self, event), event]);
 };
 
 // query