fix(manager/flux): fix system manifest artifacts (#13912)

lib/manager/flux/artifacts.spec.ts

 import { exec, mockExecAll } from '../../../test/exec-util';
+import { fs } from '../../../test/util';
+import { GlobalConfig } from '../../config/global';
 import { updateArtifacts } from '.';
 
 jest.mock('child_process');
+jest.mock('../../util/fs');
 
 describe('manager/flux/artifacts', () => {
-  beforeEach(() => {
-    jest.resetAllMocks();
+  beforeAll(() => {
+    GlobalConfig.set({
+      localDir: '',
+    });
   });
 
   it('replaces existing value', async () => {
-    mockExecAll(exec, { stdout: 'test', stderr: '' });
+    mockExecAll(exec, { stdout: '', stderr: '' });
+    fs.readLocalFile.mockResolvedValueOnce('old');
+    fs.readLocalFile.mockResolvedValueOnce('test');
 
     const res = await updateArtifacts({
       packageFileName: 'clusters/my-cluster/flux-system/gotk-components.yaml',
@@ -40,6 +47,19 @@ describe('manager/flux/artifacts', () => {
     expect(res).toBeNull();
   });
 
+  it('ignores unchanged system manifests', async () => {
+    fs.readLocalFile.mockResolvedValueOnce('old');
+    fs.readLocalFile.mockResolvedValueOnce('old');
+    const res = await updateArtifacts({
+      packageFileName: 'clusters/my-cluster/flux-system/gotk-components.yaml',
+      updatedDeps: [{ newVersion: '1.0.1' }],
+      newPackageFileContent: undefined,
+      config: {},
+    });
+
+    expect(res).toBeNull();
+  });
+
   it('ignores system manifests without a new version', async () => {
     const res = await updateArtifacts({
       packageFileName: 'clusters/my-cluster/flux-system/gotk-components.yaml',
@@ -51,7 +71,7 @@ describe('manager/flux/artifacts', () => {
     expect(res).toBeNull();
   });
 
-  it('failed to generate manifests', async () => {
+  it('failed to generate system manifest', async () => {
     mockExecAll(exec, new Error('failed'));
     const res = await updateArtifacts({
       packageFileName: 'clusters/my-cluster/flux-system/gotk-components.yaml',
@@ -60,8 +80,34 @@ describe('manager/flux/artifacts', () => {
       config: {},
     });
 
-    expect(res[0].artifactError.lockFile).toBe(
-      'clusters/my-cluster/flux-system/gotk-components.yaml'
-    );
+    expect(res).toStrictEqual([
+      {
+        artifactError: {
+          lockFile: 'clusters/my-cluster/flux-system/gotk-components.yaml',
+          stderr: 'failed',
+        },
+      },
+    ]);
+  });
+
+  it('failed to read system manifest', async () => {
+    mockExecAll(exec, { stdout: '', stderr: 'Error' });
+    fs.readLocalFile.mockResolvedValueOnce('old');
+    fs.readLocalFile.mockResolvedValueOnce('');
+    const res = await updateArtifacts({
+      packageFileName: 'clusters/my-cluster/flux-system/gotk-components.yaml',
+      updatedDeps: [{ newVersion: '1.0.1' }],
+      newPackageFileContent: undefined,
+      config: {},
+    });
+
+    expect(res).toStrictEqual([
+      {
+        artifactError: {
+          lockFile: 'clusters/my-cluster/flux-system/gotk-components.yaml',
+          stderr: 'Error',
+        },
+      },
+    ]);
   });
 });

lib/manager/flux/artifacts.ts

+import { quote } from 'shlex';
 import { logger } from '../../logger';
 import { exec } from '../../util/exec';
 import type { ExecOptions } from '../../util/exec/types';
+import { readLocalFile } from '../../util/fs';
 import type { UpdateArtifact, UpdateArtifactsResult } from '../types';
 import { isSystemManifest } from './common';
 
@@ -11,9 +13,10 @@ export async function updateArtifacts({
   if (!isSystemManifest(packageFileName) || !updatedDeps[0]?.newVersion) {
     return null;
   }
+  const existingFileContent = await readLocalFile(packageFileName);
   try {
     logger.debug(`Updating Flux system manifests`);
-    const cmd = 'flux install --export';
+    const cmd = `flux install --export > ${quote(packageFileName)}`;
     const execOptions: ExecOptions = {
       docker: {
         image: 'sidecar',
@@ -27,12 +30,29 @@ export async function updateArtifacts({
     };
     const result = await exec(cmd, execOptions);
 
+    const newFileContent = await readLocalFile(packageFileName);
+    if (!newFileContent) {
+      logger.debug('Cannot read new flux file content');
+      return [
+        {
+          artifactError: {
+            lockFile: packageFileName,
+            stderr: result.stderr,
+          },
+        },
+      ];
+    }
+    if (newFileContent === existingFileContent) {
+      logger.debug('Flux contents are unchanged');
+      return null;
+    }
+
     return [
       {
         file: {
           type: 'addition',
           path: packageFileName,
-          contents: result.stdout,
+          contents: newFileContent,
         },
       },
     ];