From 5e9cbec038ac6462d4891adabdff446e8cf8fc87 Mon Sep 17 00:00:00 2001
From: Raphael Manke <raphael.manke@dash0.com>
Date: Thu, 27 Aug 2026 14:23:49 +0200
Subject: [PATCH] ci: split integration tests into groups for isolated reruns

Groups tests by failure domain (node/python/java/db/tracing/sls-plugin/
other) using vitest projects, and fans the integration-test CI job out
into a fail-fast:false matrix over those groups. A flake in one group no
longer cancels or blocks the others, and GitHub's rerun-failed-jobs only
reruns the group that actually failed instead of all 25 test files.
---
 .github/workflows/ci.yml                 | 10 ++++--
 integration-tests/tests/vitest.config.ts | 27 +++++++++++-----
 integration-tests/tests/vitest.groups.ts | 40 ++++++++++++++++++++++++
 3 files changed, 68 insertions(+), 9 deletions(-)
 create mode 100644 integration-tests/tests/vitest.groups.ts

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b8a908fb..8d29c983 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -197,11 +197,17 @@ jobs:
           TEST_MYSQL_PASSWORD: ${{ secrets.TEST_MYSQL_PASSWORD }}
 
   integration-test:
-    name: Integration Test
+    name: Integration Test (${{ matrix.group }})
     if: github.event.pull_request.head.repo.full_name == github.repository
     needs: [deploy-cdk, deploy-sls]
     runs-on: ubuntu-latest
     environment: staging
+    strategy:
+      # One group flaking must not cancel or block the others.
+      fail-fast: false
+      matrix:
+        # Keep in sync with the group names in integration-tests/tests/vitest.groups.ts
+        group: [node, python, java, db, tracing, sls-plugin, other]
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
@@ -218,7 +224,7 @@ jobs:
         run: npm ci
       - name: Run integration tests
         working-directory: integration-tests/tests
-        run: npm run test
+        run: npm run test -- --project ${{ matrix.group }}
         env:
           DASH0_DEV_API_TOKEN: ${{ secrets.DASH0_DEV_API_TOKEN }}
 
diff --git a/integration-tests/tests/vitest.config.ts b/integration-tests/tests/vitest.config.ts
index 94d41143..fd331fec 100644
--- a/integration-tests/tests/vitest.config.ts
+++ b/integration-tests/tests/vitest.config.ts
@@ -1,13 +1,26 @@
 import { defineConfig } from 'vitest/config';
+import { groups } from './vitest.groups';
+
+const sharedTestConfig = {
+    exclude: ['**/test-sanity*'],
+    globals: true,
+    // Allow more in-file tests to run at once (default is 5)
+    maxConcurrency: 12,
+    pool: 'threads' as const,
+    maxWorkers: 12,
+};
 
 export default defineConfig({
     test: {
-        include: ['**/*.{test,spec}.{js,mjs,cjs,ts,mts,cts,jsx,tsx}'],
-        exclude: ['**/test-sanity*'],
-        globals: true,
-        // Allow more in-file tests to run at once (default is 5)
-        maxConcurrency: 12,
-        pool: 'threads',
-        maxWorkers: 12,
+        ...sharedTestConfig,
+        // Running `vitest run` with no --project runs every group, same as before the split.
+        projects: groups.map(({ name, include, exclude }) => ({
+            test: {
+                ...sharedTestConfig,
+                name,
+                include,
+                exclude: [...sharedTestConfig.exclude, ...(exclude ?? [])],
+            },
+        })),
     },
 });
diff --git a/integration-tests/tests/vitest.groups.ts b/integration-tests/tests/vitest.groups.ts
new file mode 100644
index 00000000..7bf7f98d
--- /dev/null
+++ b/integration-tests/tests/vitest.groups.ts
@@ -0,0 +1,40 @@
+// Single source of truth for how integration test files are split into
+// CI groups. vitest.config.ts builds its `projects` from this list.
+// ci.yml's matrix.group list must be kept in sync with these names by hand.
+export const groups = [
+    {
+        name: 'node',
+        include: ['**/test-node-*.test.ts', '**/test-manual-node.test.ts', '**/test-commonjs-bundle.test.ts'],
+        // test-node-single-traced.test.ts belongs to the `tracing` group instead — see below.
+        exclude: ['**/test-node-single-traced.test.ts'],
+    },
+    {
+        name: 'python',
+        include: ['**/test-python-*.test.ts'],
+    },
+    {
+        name: 'java',
+        include: ['**/test-java-*.test.ts'],
+    },
+    {
+        name: 'db',
+        include: ['**/test-db.test.ts'],
+    },
+    {
+        name: 'tracing',
+        include: ['**/test-tracing-scenarios-*.test.ts', '**/test-node-single-traced.test.ts'],
+    },
+    {
+        name: 'sls-plugin',
+        include: ['**/test-serverless-plugin.test.ts'],
+    },
+    {
+        name: 'other',
+        include: [
+            '**/test-00-retries.test.ts',
+            '**/test-500-error.test.ts',
+            '**/test-payload-truncation.test.ts',
+            '**/test-dockerized-lambda.test.ts',
+        ],
+    },
+];