From 463f0a060111430a9408dda632cb068941232117 Mon Sep 17 00:00:00 2001
From: Moriz Wahl <moriz.wahl@gmx.de>
Date: Wed, 12 Oct 2022 19:30:06 +0200
Subject: [PATCH] feat: Global Jest Extension for Decimal Equal

---
 backend/jest.config.js                        |  1 +
 .../graphql/resolver/AdminResolver.test.ts    |  2 +-
 backend/test/extensions.ts                    | 31 +++++++++++++++++++
 3 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 backend/test/extensions.ts

diff --git a/backend/jest.config.js b/backend/jest.config.js
index 6ab44002c..a472df316 100644
--- a/backend/jest.config.js
+++ b/backend/jest.config.js
@@ -5,6 +5,7 @@ module.exports = {
   collectCoverage: true,
   collectCoverageFrom: ['src/**/*.ts', '!**/node_modules/**', '!src/seeds/**', '!build/**'],
   setupFiles: ['<rootDir>/test/testSetup.ts'],
+  setupFilesAfterEnv: ['<rootDir>/test/extensions.ts'],
   modulePathIgnorePatterns: ['<rootDir>/build/'],
   moduleNameMapper: {
     '@/(.*)': '<rootDir>/src/$1',
diff --git a/backend/src/graphql/resolver/AdminResolver.test.ts b/backend/src/graphql/resolver/AdminResolver.test.ts
index b1b4e469e..34888b2df 100644
--- a/backend/src/graphql/resolver/AdminResolver.test.ts
+++ b/backend/src/graphql/resolver/AdminResolver.test.ts
@@ -1990,7 +1990,7 @@ describe('AdminResolver', () => {
                 deletedAt: null,
                 code: expect.stringMatching(/^[0-9a-f]{24,24}$/),
                 linkEnabled: true,
-                // amount: '200',
+                amount: expect.decimalEqual(200),
                 // maxAmountPerMonth: '200',
               }),
             )
diff --git a/backend/test/extensions.ts b/backend/test/extensions.ts
new file mode 100644
index 000000000..49a92f521
--- /dev/null
+++ b/backend/test/extensions.ts
@@ -0,0 +1,31 @@
+import Decimal from 'decimal.js-light'
+
+expect.extend({
+  decimalEqual(received, value) {
+    const pass = new Decimal(value).equals(received.toString())
+    if (pass) {
+      return {
+        message: () => `expected ${received} to not equal ${value}`,
+        pass: true,
+      }
+    } else {
+      return {
+        message: () => `expected ${received} to equal ${value}`,
+        pass: false,
+      }
+    }
+  },
+})
+
+interface CustomMatchers<R = unknown> {
+  decimalEqual(value: number): R
+}
+
+declare global {
+  // eslint-disable-next-line @typescript-eslint/no-namespace
+  namespace jest {
+    type Expect = CustomMatchers
+    type Matchers<R> = CustomMatchers<R>
+    type InverseAsymmetricMatchers = CustomMatchers
+  }
+}