From 98748ec925945756c035a7287fe9f67f5b6fb092 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nedim=20Salki=C4=87?= <nedim.salkic@fuel.sh>
Date: Thu, 18 Jul 2024 16:06:19 +0200
Subject: [PATCH] fix: verification of `fuel-core` node killing (#2759)

---
 .changeset/neat-bikes-melt.md                 |  4 ++++
 .../launchNode-singular-test.test.ts          | 22 ------------------
 .../account/src/test-utils/launchNode.test.ts | 23 +++++++++++++++++++
 3 files changed, 27 insertions(+), 22 deletions(-)
 create mode 100644 .changeset/neat-bikes-melt.md
 delete mode 100644 packages/account/src/test-utils/launchNode-singular-test.test.ts

diff --git a/.changeset/neat-bikes-melt.md b/.changeset/neat-bikes-melt.md
new file mode 100644
index 00000000000..7ff5dd841f7
--- /dev/null
+++ b/.changeset/neat-bikes-melt.md
@@ -0,0 +1,4 @@
+---
+---
+
+fix: verification of all test nodes being killed
diff --git a/packages/account/src/test-utils/launchNode-singular-test.test.ts b/packages/account/src/test-utils/launchNode-singular-test.test.ts
deleted file mode 100644
index 17237e00692..00000000000
--- a/packages/account/src/test-utils/launchNode-singular-test.test.ts
+++ /dev/null
@@ -1,22 +0,0 @@
-import { launchNode } from './launchNode';
-
-/**
- * The test runner creates a test environment per file,
- * which we can use to isolate the faulty behavior.
- */
-/**
- * @group node
- */
-describe('launchNode-singular-test', () => {
-  const killedNode = {
-    url: '',
-  };
-  afterEach(async () => {
-    await expect(fetch(killedNode.url)).rejects.toThrow('fetch failed');
-  });
-  test('synchronous cleanup kills node before test runner exits', async () => {
-    const { cleanup, url } = await launchNode({ loggingEnabled: false });
-    killedNode.url = url;
-    cleanup();
-  });
-});
diff --git a/packages/account/src/test-utils/launchNode.test.ts b/packages/account/src/test-utils/launchNode.test.ts
index 83530780948..52b59d2a69b 100644
--- a/packages/account/src/test-utils/launchNode.test.ts
+++ b/packages/account/src/test-utils/launchNode.test.ts
@@ -46,6 +46,29 @@ describe('launchNode', () => {
     await waitUntilUnreachable(url);
   });
 
+  /**
+   * Spawning the child process in a detached state
+   * Results in the OS assigning a process group to the child.
+   * Combining that with `process.kill(-pid)`,
+   * which sends a "kill process group" signal to the OS,
+   * ensures that the node will be killed.
+   */
+  it('spawns the fuel-core node in a detached state and kills the process group on cleanup', async () => {
+    const spawnSpy = vi.spyOn(childProcessMod, 'spawn');
+    const killSpy = vi.spyOn(process, 'kill');
+
+    const { cleanup, pid } = await launchNode();
+
+    const spawnOptions = spawnSpy.mock.calls[0][2];
+    expect(spawnOptions.detached).toBeTruthy();
+
+    cleanup();
+
+    expect(killSpy).toHaveBeenCalledTimes(1);
+    // adding a minus prefix kills the process group
+    expect(killSpy).toHaveBeenCalledWith(-pid);
+  });
+
   test('should start `fuel-core` node using system binary', async () => {
     const spawnSpy = vi.spyOn(childProcessMod, 'spawn');