Refine subscription import and refresh flow

test/server/state-contract.test.js

@@ -114,11 +114,32 @@ setInterval(() => {}, 60_000);
   fs.writeFileSync(singboxPath, workingSingbox);
   fs.chmodSync(singboxPath, 0o755);
 
-  const subscriptionServer = http.createServer((req, res) => {
+  let providerFetchCount = 0;
+  let delayedPath = '';
+  let invalidNextPath = '';
+  let delayedRequestStarted = null;
+  let releaseDelayedRequest = null;
+  const subscriptionServer = http.createServer(async (req, res) => {
+    providerFetchCount += 1;
+    if (req.url === '/timeout') return;
     if (req.url === '/unavailable') {
       res.writeHead(503);
       return res.end('unavailable');
     }
+    if (req.url === '/invalid') {
+      res.writeHead(200, { 'content-type': 'text/plain' });
+      return res.end('not a subscription');
+    }
+    if (req.url === invalidNextPath) {
+      invalidNextPath = '';
+      res.writeHead(200, { 'content-type': 'text/plain' });
+      return res.end('not a subscription');
+    }
+    if (req.url === delayedPath) {
+      delayedRequestStarted?.();
+      await new Promise((resolve) => { releaseDelayedRequest = resolve; });
+      delayedPath = '';
+    }
     res.writeHead(200, {
       'content-type': 'application/json',
       'subscription-userinfo': 'upload=10; download=20; total=100',
@@ -147,6 +168,7 @@ setInterval(() => {}, 60_000);
       PORT: String(port),
       PATH: `${binDir}:${process.env.PATH}`,
       HARBOR_HOST_NETWORK_STATE: path.join(dir, 'missing-network.json'),
+      SUBSCRIPTION_TIMEOUT_MS: '50',
     },
     stdio: ['ignore', 'ignore', 'pipe'],
   });
@@ -206,6 +228,36 @@ setInterval(() => {}, 60_000);
   assert.equal(providerUnavailable.payload.error.code, 'PROVIDER_UNAVAILABLE');
   assert.equal(providerUnavailable.payload.error.retryable, true);
 
+  const preservedSubscription = {
+    state: JSON.parse(fs.readFileSync(path.join(dir, 'state.json'), 'utf8')),
+    cache: fs.readFileSync(path.join(dir, 'subscription-cache.json'), 'utf8'),
+    config: fs.readFileSync(path.join(dir, 'sing-box-config.json'), 'utf8'),
+  };
+  for (const [pathname, expectedCode] of [
+    ['/timeout', 'PROVIDER_UNAVAILABLE'],
+    ['/invalid', 'SUBSCRIPTION_INVALID'],
+  ]) {
+    const failedImport = await rawRequest(
+      port,
+      '/api/subscription/fetch',
+      'POST',
+      { url: `http://127.0.0.1:${subscriptionPort}${pathname}` },
+    );
+    assert.equal(failedImport.payload.error.code, expectedCode);
+    const storedAfterFailure = JSON.parse(fs.readFileSync(path.join(dir, 'state.json'), 'utf8'));
+    assert.equal(storedAfterFailure.subscriptionUrl, preservedSubscription.state.subscriptionUrl);
+    assert.equal(storedAfterFailure.selectedTag, preservedSubscription.state.selectedTag);
+    assert.deepEqual(storedAfterFailure.servers, preservedSubscription.state.servers);
+    assert.equal(
+      fs.readFileSync(path.join(dir, 'subscription-cache.json'), 'utf8'),
+      preservedSubscription.cache,
+    );
+    assert.equal(
+      fs.readFileSync(path.join(dir, 'sing-box-config.json'), 'utf8'),
+      preservedSubscription.config,
+    );
+  }
+
   const missingServer = await rawRequest(
     port,
     '/api/apply',
@@ -230,14 +282,25 @@ setInterval(() => {}, 60_000);
     return result;
   }
 
-  await stateResponse('/api/subscription/validate', 'POST', { url: subscriptionUrl });
+  const fetchesBeforeImport = providerFetchCount;
   await mutation('/api/subscription/fetch', 'POST', { url: subscriptionUrl });
+  assert.equal(providerFetchCount, fetchesBeforeImport + 1);
   const applied = await mutation('/api/apply', 'POST', { selectedTag: 'test-vpn' });
   assert.deepEqual(applied.state.selection, {
     desiredServerId: 'test-vpn',
     appliedServerId: 'test-vpn',
   });
   assert.equal(applied.state.connection.process, 'running');
+  const cacheBeforeFailedRefresh = fs.readFileSync(path.join(dir, 'subscription-cache.json'), 'utf8');
+  const configBeforeFailedRefresh = fs.readFileSync(path.join(dir, 'sing-box-config.json'), 'utf8');
+  invalidNextPath = '/subscription/test';
+  const failedRefresh = await rawRequest(port, '/api/subscription/refresh', 'POST');
+  assert.equal(failedRefresh.response.status, 400);
+  assert.equal(failedRefresh.payload.error.code, 'SUBSCRIPTION_INVALID');
+  assert.equal(JSON.parse(fs.readFileSync(path.join(dir, 'state.json'), 'utf8')).selectedTag, 'test-vpn');
+  assert.equal(fs.readFileSync(path.join(dir, 'subscription-cache.json'), 'utf8'), cacheBeforeFailedRefresh);
+  assert.equal(fs.readFileSync(path.join(dir, 'sing-box-config.json'), 'utf8'), configBeforeFailedRefresh);
+  revision = (await request(port, '/api/state')).revision;
   assert.equal((await mutation('/api/singbox/stop')).state.connection.desired, 'stopped');
   assert.equal((await mutation('/api/singbox/restart')).state.connection.desired, 'running');
 
@@ -341,7 +404,19 @@ if (process.argv[2] === 'check') {
   fs.writeFileSync(singboxPath, workingSingbox);
   fs.chmodSync(singboxPath, 0o755);
 
-  await mutation('/api/subscription/refresh');
+  const delayedRequest = new Promise((resolve) => { delayedRequestStarted = resolve; });
+  delayedPath = '/subscription/test';
+  const staleRefresh = rawRequest(port, '/api/subscription/refresh', 'POST');
+  await delayedRequest;
+  const replacementUrl = `http://127.0.0.1:${subscriptionPort}/subscription/replacement`;
+  await mutation('/api/subscription/fetch', 'POST', { url: replacementUrl });
+  releaseDelayedRequest();
+  const staleRefreshResult = await staleRefresh;
+  assert.equal(staleRefreshResult.response.status, 409);
+  assert.equal(staleRefreshResult.payload.error.code, 'STATE_CONFLICT');
+  assert.equal(JSON.parse(fs.readFileSync(path.join(dir, 'state.json'), 'utf8')).subscriptionUrl, replacementUrl);
+  assert.equal(JSON.parse(fs.readFileSync(path.join(dir, 'subscription-cache.json'), 'utf8')).url, replacementUrl);
+  revision = (await request(port, '/api/state')).revision;
   assert.equal((await mutation('/api/gateway-auto', 'POST', { enabled: false })).state.gatewayAuto.enabled, false);
   const forgotten = await mutation('/api/subscription', 'DELETE');
   assert.equal(forgotten.state.subscription.status, 'missing');