diff --git a/jest.config.js b/jest.config.js
new file mode 100644
index 0000000..8bb3720
--- /dev/null
+++ b/jest.config.js
@@ -0,0 +1,5 @@
+/** @type {import('ts-jest').JestConfigWithTsJest} */
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+}
diff --git a/package.json b/package.json
index 39b84c7..d88074c 100644
--- a/package.json
+++ b/package.json
@@ -19,7 +19,7 @@
     "cli": "yarn workspace client start",
     "lint": "eslint --ext .js,.vue .",
     "format": "prettier --ignore-path .prettierignore --write app server",
-    "test": "yarn node --experimental-vm-modules $(yarn bin jest)",
+    "test": "yarn jest",
     "test:e2e": "yarn workspace tests test",
     "test:open": "yarn workspace tests test:open",
     "analytics": "yarn workspace analytics dev",
diff --git a/packages/file-graph/package.json b/packages/file-graph/package.json
index 1b7b087..0f763f1 100644
--- a/packages/file-graph/package.json
+++ b/packages/file-graph/package.json
@@ -6,6 +6,7 @@
   "types": "dist/index.d.ts",
   "license": "MIT",
   "scripts": {
-    "build": "tsc && node post-build-script.js"
+    "build": "tsc && node post-build-script.js",
+    "test": "yarn build && jest"
   }
 }
diff --git a/packages/file-graph/src/file.js b/packages/file-graph/src/file.js
deleted file mode 100644
index 983cbeb..0000000
--- a/packages/file-graph/src/file.js
+++ /dev/null
@@ -1,21 +0,0 @@
-import { basename } from './utils.js'
-
-export default class File {
-  constructor({ path, type, discovered }) {
-    this.path = path.trimEnd('/')
-    this.name = basename(path)
-    this.type = type
-    this.discovered = discovered
-  }
-
-  isDirectory() {
-    return this.type === 'folder'
-  }
-
-  contains(file) {
-    if (!this.isDirectory()) return false
-    if (this.path === file.path) return true
-    const parentPath = this.path.endsWith('/') ? this.path : `${this.path}/`
-    return file.path.startsWith(parentPath)
-  }
-}
diff --git a/packages/file-graph/tests/file.test.js b/packages/file-graph/src/file.test.ts
similarity index 92%
rename from packages/file-graph/tests/file.test.js
rename to packages/file-graph/src/file.test.ts
index f1f84ce..1637a96 100644
--- a/packages/file-graph/tests/file.test.js
+++ b/packages/file-graph/src/file.test.ts
@@ -1,4 +1,6 @@
-import File from './file.js'
+import { describe, expect, test } from '@jest/globals'
+
+import File from './file'
 
 describe('File', () => {
   let file
diff --git a/packages/file-graph/src/file.ts b/packages/file-graph/src/file.ts
new file mode 100644
index 0000000..e416bf2
--- /dev/null
+++ b/packages/file-graph/src/file.ts
@@ -0,0 +1,33 @@
+/* eslint-disable lines-between-class-members */
+import { basename } from './utils'
+
+interface FileObject {
+  path: string
+  type: string
+  discovered: boolean
+}
+
+export default class File implements FileObject {
+  path: string
+  name: string
+  type: string
+  discovered: boolean
+
+  constructor(obj: FileObject) {
+    this.path = obj.path.trimEnd()
+    this.name = basename(obj.path)
+    this.type = obj.type
+    this.discovered = obj.discovered
+  }
+
+  isDirectory() {
+    return this.type === 'folder'
+  }
+
+  contains(file: FileObject) {
+    if (!this.isDirectory()) return false
+    if (this.path === file.path) return true
+    const parentPath = this.path.endsWith('/') ? this.path : `${this.path}/`
+    return file.path.startsWith(parentPath)
+  }
+}
diff --git a/packages/file-graph/tests/fileGraph.test.js b/packages/file-graph/src/fileGraph.test.js
similarity index 97%
rename from packages/file-graph/tests/fileGraph.test.js
rename to packages/file-graph/src/fileGraph.test.js
index 509b33d..34c146b 100644
--- a/packages/file-graph/tests/fileGraph.test.js
+++ b/packages/file-graph/src/fileGraph.test.js
@@ -1,5 +1,5 @@
-import FileGraph from './fileGraph.js'
-import FileNode from './fileNode.js'
+import FileGraph from './fileGraph'
+import FileNode from './fileNode'
 
 describe('FileGraph', () => {
   let root
diff --git a/packages/file-graph/src/fileNode.js b/packages/file-graph/src/fileNode.js
index 15b439a..716cadf 100644
--- a/packages/file-graph/src/fileNode.js
+++ b/packages/file-graph/src/fileNode.js
@@ -1,4 +1,4 @@
-import File from './file.js'
+import File from './file'
 import {
   DuplicateItemError,
   ParentNotExistsError,
diff --git a/packages/file-graph/tests/fileNode.test.js b/packages/file-graph/src/fileNode.test.js
similarity index 99%
rename from packages/file-graph/tests/fileNode.test.js
rename to packages/file-graph/src/fileNode.test.js
index 3690cf1..6969996 100644
--- a/packages/file-graph/tests/fileNode.test.js
+++ b/packages/file-graph/src/fileNode.test.js
@@ -1,5 +1,5 @@
 import { DuplicateItemError, ParentNotExistsError } from './errors'
-import FileNode from './fileNode.js'
+import FileNode from './fileNode'
 
 function createNodeFromFiles(files) {
   const node = new FileNode(files[0])
diff --git a/packages/file-graph/src/index.js b/packages/file-graph/src/index.js
index 4b1fcda..de0c671 100644
--- a/packages/file-graph/src/index.js
+++ b/packages/file-graph/src/index.js
@@ -1,3 +1,3 @@
-export { default as File } from './file.js'
+export { default as File } from './file'
 export { default as FileNode } from './fileNode.js'
 export { default as FileGraph } from './fileGraph.js'