feat: add tests (#3)

* Revert "feat: remove all tests related files (#2)"

This reverts commit 7cb60d8.

* build: add patch for js-waku not found (#7)

When running the test with `jest`, it errored with
```
Cannot find module 'js-waku' from 'node_modules/@xmtp/xmtp-js/dist/cjs/src/utils.js'
```

The problem seems to be this issue
waku-org/js-waku#770.

Until this is resolved, we use a local patch as this only occurs when running tests.

* Add unit and integration tests

* Implement review remarks

Co-authored-by: Dong-Ha Kim <[email protected]>
Co-authored-by: Dennis Furrer <[email protected]>

README.md

@@ -77,10 +77,12 @@ await client.encodeAndSendMessage(messageObj, recipient);</pre>
                 <pre>npm run build</pre>
             </li>
         </ul>
-    <li>Test (TODO)</li>
+    <li>Test</li>
         <ul>
             <li>
-                <pre>npm run test</pre>
+                <pre>npm run test:all
+npm run test:unit
+npm run test:integration</pre>
             </li>
         </ul>
     <li>Lint</li>

jest.config.js

@@ -0,0 +1,17 @@
+module.exports = {
+  preset: "ts-jest",
+  testEnvironment: "node",
+  collectCoverage: true,
+  coverageDirectory: "coverage",
+  collectCoverageFrom: ["src/**/*.{ts,js}", "!src/example/*.{ts,js}"],
+  coverageReporters: ["json", "text"],
+  coveragePathIgnorePatterns: ["jest.config.js", "/node_modules/", "/dist/"],
+  globals: {
+    "ts-jest": {
+      tsconfig: "tsconfig.tests.json"
+    }
+  },
+  roots: ["<rootDir>"],
+  modulePaths: ["<rootDir>"],
+  moduleDirectories: ["node_modules"]
+};