diff --git a/lib/manager/cargo/artifacts.spec.ts b/lib/manager/cargo/artifacts.spec.ts
index aa867d7a8729570dcd7584012b3f40053df160e4..fcffac55b09d06a5d93b8a1c7ace970dd57130f5 100644
--- a/lib/manager/cargo/artifacts.spec.ts
+++ b/lib/manager/cargo/artifacts.spec.ts
@@ -1,24 +1,17 @@
-import { exec as _exec } from 'child_process';
-import _fs from 'fs-extra';
 import { join } from 'upath';
-import { envMock, mockExecAll } from '../../../test/exec-util';
-import { git, mocked } from '../../../test/util';
+import { envMock, exec, mockExecAll } from '../../../test/exec-util';
+import { env, fs, git } from '../../../test/util';
 import { GlobalConfig } from '../../config/global';
 import type { RepoGlobalConfig } from '../../config/types';
 import * as docker from '../../util/exec/docker';
-import * as _env from '../../util/exec/env';
 import type { UpdateArtifactsConfig } from '../types';
 import * as cargo from './artifacts';
 
-jest.mock('fs-extra');
 jest.mock('child_process');
 jest.mock('../../util/exec/env');
 jest.mock('../../util/git');
 jest.mock('../../util/http');
-
-const fs: jest.Mocked<typeof _fs> = _fs as any;
-const exec: jest.Mock<typeof _exec> = _exec as any;
-const env = mocked(_env);
+jest.mock('../../util/fs');
 
 const config: UpdateArtifactsConfig = {};
 
@@ -39,6 +32,7 @@ describe('manager/cargo/artifacts', () => {
   afterEach(() => {
     GlobalConfig.reset();
   });
+
   it('returns null if no Cargo.lock found', async () => {
     fs.stat.mockRejectedValue(new Error('not found!'));
     const updatedDeps = [
@@ -55,6 +49,7 @@ describe('manager/cargo/artifacts', () => {
       })
     ).toBeNull();
   });
+
   it('returns null if updatedDeps is empty', async () => {
     expect(
       await cargo.updateArtifacts({
@@ -65,11 +60,14 @@ describe('manager/cargo/artifacts', () => {
       })
     ).toBeNull();
   });
+
   it('returns null if unchanged', async () => {
     fs.stat.mockResolvedValueOnce({ name: 'Cargo.lock' } as any);
-    fs.readFile.mockResolvedValueOnce('Current Cargo.lock' as any);
+    fs.findLocalSiblingOrParent.mockResolvedValueOnce('Cargo.lock');
+    fs.readLocalFile.mockResolvedValueOnce('Current Cargo.lock');
     const execSnapshots = mockExecAll(exec);
-    fs.readFile.mockResolvedValueOnce('Current Cargo.lock' as any);
+    fs.findLocalSiblingOrParent.mockResolvedValueOnce('Cargo.lock');
+    fs.readLocalFile.mockResolvedValueOnce('Current Cargo.lock');
 
     const updatedDeps = [
       {
@@ -86,11 +84,14 @@ describe('manager/cargo/artifacts', () => {
     ).toBeNull();
     expect(execSnapshots).toMatchSnapshot();
   });
+
   it('returns updated Cargo.lock', async () => {
     fs.stat.mockResolvedValueOnce({ name: 'Cargo.lock' } as any);
+    fs.findLocalSiblingOrParent.mockResolvedValueOnce('Cargo.lock');
     git.getFile.mockResolvedValueOnce('Old Cargo.lock');
     const execSnapshots = mockExecAll(exec);
-    fs.readFile.mockResolvedValueOnce('New Cargo.lock' as any);
+    fs.findLocalSiblingOrParent.mockResolvedValueOnce('Cargo.lock');
+    fs.readLocalFile.mockResolvedValueOnce('New Cargo.lock');
     const updatedDeps = [
       {
         depName: 'dep1',
@@ -111,7 +112,8 @@ describe('manager/cargo/artifacts', () => {
     fs.stat.mockResolvedValueOnce({ name: 'Cargo.lock' } as any);
     git.getFile.mockResolvedValueOnce('Old Cargo.lock');
     const execSnapshots = mockExecAll(exec);
-    fs.readFile.mockResolvedValueOnce('New Cargo.lock' as any);
+    fs.findLocalSiblingOrParent.mockResolvedValueOnce('Cargo.lock');
+    fs.readLocalFile.mockResolvedValueOnce('New Cargo.lock');
     const updatedDeps = [
       {
         depName: 'renamedDep1',
@@ -136,7 +138,8 @@ describe('manager/cargo/artifacts', () => {
 
     git.getFile.mockResolvedValueOnce('Old Cargo.lock');
     const execSnapshots = mockExecAll(exec);
-    fs.readFile.mockResolvedValueOnce('New Cargo.lock' as any);
+    fs.findLocalSiblingOrParent.mockResolvedValueOnce('Cargo.lock');
+    fs.readLocalFile.mockResolvedValueOnce('New Cargo.lock');
     const updatedDeps = [
       {
         depName: 'dep1',
@@ -157,7 +160,8 @@ describe('manager/cargo/artifacts', () => {
     fs.stat.mockResolvedValueOnce({ name: 'Cargo.lock' } as any);
     git.getFile.mockResolvedValueOnce('Old Cargo.lock');
     const execSnapshots = mockExecAll(exec);
-    fs.readFile.mockResolvedValueOnce('New Cargo.lock' as any);
+    fs.findLocalSiblingOrParent.mockResolvedValueOnce('Cargo.lock');
+    fs.readLocalFile.mockResolvedValueOnce('New Cargo.lock');
     expect(
       await cargo.updateArtifacts({
         packageFileName: 'Cargo.toml',
@@ -174,7 +178,8 @@ describe('manager/cargo/artifacts', () => {
     GlobalConfig.set({ ...adminConfig, binarySource: 'docker' });
     git.getFile.mockResolvedValueOnce('Old Cargo.lock');
     const execSnapshots = mockExecAll(exec);
-    fs.readFile.mockResolvedValueOnce('New Cargo.lock' as any);
+    fs.findLocalSiblingOrParent.mockResolvedValueOnce('Cargo.lock');
+    fs.readLocalFile.mockResolvedValueOnce('New Cargo.lock');
     const updatedDeps = [
       {
         depName: 'dep1',
@@ -192,8 +197,9 @@ describe('manager/cargo/artifacts', () => {
   });
   it('catches errors', async () => {
     fs.stat.mockResolvedValueOnce({ name: 'Cargo.lock' } as any);
-    fs.readFile.mockResolvedValueOnce('Current Cargo.lock' as any);
-    fs.outputFile.mockImplementationOnce(() => {
+    fs.findLocalSiblingOrParent.mockResolvedValueOnce('Cargo.lock');
+    fs.readLocalFile.mockResolvedValueOnce('Current Cargo.lock');
+    fs.writeLocalFile.mockImplementationOnce(() => {
       throw new Error('not found');
     });
     const updatedDeps = [