Speed up CI: nextest + scope Cargo cache to deps only

.github/workflows/reusable-rust-test.yml

@@ -23,12 +23,23 @@ on:
         required: false
         type: string
         default: './run-tests.sh'
+      shard-count:
+        description: 'Total number of test shards'
+        required: false
+        type: number
+        default: 1
+      shard-indexes:
+        description: 'JSON array of shard indexes to run (e.g. [0,1])'
+        required: false
+        type: string
+        default: '[0]'
 jobs:
   test:
     strategy:
       matrix:
         rust-version: ${{ fromJSON(inputs.rust-versions) }}
         platform: ${{ fromJSON(inputs.platforms) }}
+        shard-index: ${{ fromJSON(inputs.shard-indexes) }}
     runs-on: ${{ matrix.platform }}
     steps:
       - name: Checkout code
@@ -49,4 +60,7 @@ jobs:
           key: ${{ runner.os }}-cargo-${{ matrix.rust-version }}-${{ hashFiles('**/Cargo.lock') }}
           restore-keys: ${{ runner.os }}-cargo-${{ matrix.rust-version }}-
       - name: Test
-        run: ${{ inputs.test-script }}
+        run: ${{ inputs.test-script }}
+        env:
+          TEST_SHARD_TOTAL: ${{ inputs.shard-count }}
+          TEST_SHARD_INDEX: ${{ matrix.shard-index }}

.github/workflows/test.yml

@@ -32,17 +32,74 @@ jobs:
     with:
       enable-commit-changes: true
 
+  build:
+    if: >
+      (github.event.pull_request.draft == false &&
+       !contains(github.event.pull_request.labels.*.name, 'ci/skip') &&
+       !contains(github.event.pull_request.head.ref, 'datadog-api-spec/test/')) ||
+      github.event_name == 'schedule'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          repository: DataDog/datadog-api-client-rust
+      - name: Install Rust
+        run: rustup toolchain install stable --profile minimal --no-self-update && rustup default stable
+        shell: bash
+      - name: Cache Cargo
+        uses: actions/cache@d4323d4df104b026a6aa633fdb11d772146be0bf # v4.2.2
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
+          key: ${{ runner.os }}-cargo-stable-${{ hashFiles('**/Cargo.toml') }}
+          restore-keys: ${{ runner.os }}-cargo-stable-
+      - name: Compile test binary
+        run: cargo test --test main --no-run
+        shell: bash
+      - name: License check
+        run: ./scripts/license-check.sh
+        shell: bash
+      - name: Stage test binary
+        shell: bash
+        run: |
+          BINARY=$(find target/debug/deps -name 'main-*' -executable -type f | head -1)
+          echo "Uploading binary: $BINARY"
+          cp "$BINARY" test-binary
+      - name: Upload test binary
+        uses: actions/upload-artifact@v4
+        with:
+          name: test-binary
+          path: test-binary
+          retention-days: 1
+
   test:
     if: >
       (github.event.pull_request.draft == false &&
        !contains(github.event.pull_request.labels.*.name, 'ci/skip') &&
        !contains(github.event.pull_request.head.ref, 'datadog-api-spec/test/')) ||
       github.event_name == 'schedule'
-    uses: ./.github/workflows/reusable-rust-test.yml
-    with:
-      rust-versions: '["stable"]'
-      platforms: '["ubuntu-latest"]'
-      test-script: './run-tests.sh'
+    needs: build
+    strategy:
+      matrix:
+        shard: [0, 1, 2, 3]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          repository: DataDog/datadog-api-client-rust
+      - name: Download test binary
+        uses: actions/download-artifact@v4
+        with:
+          name: test-binary
+      - name: Run test shard
+        shell: bash
+        run: |
+          chmod +x test-binary
+          TEST_SHARD_TOTAL=4 TEST_SHARD_INDEX=${{ matrix.shard }} ./test-binary
 
   examples:
     if: >

tests/main.rs

@@ -56,6 +56,14 @@ async fn main() {
         .unwrap_or("false".to_string())
         .to_lowercase();
     let is_replay = !record_mode.eq("true") && !record_mode.eq("none");
+    let shard_total: usize = env::var("TEST_SHARD_TOTAL")
+        .ok()
+        .and_then(|s| s.parse().ok())
+        .unwrap_or(1);
+    let shard_index: usize = env::var("TEST_SHARD_INDEX")
+        .ok()
+        .and_then(|s| s.parse().ok())
+        .unwrap_or(0);
     let concurrent_scenarios = match is_replay {
         true => 64,
         false => 1,
@@ -105,6 +113,12 @@ async fn main() {
                 false
             } else if is_replay && sc.tags.contains(&"integration-only".into()) {
                 false
+            } else if shard_total > 1 {
+                // FNV-1a: stable across Rust versions, better avalanche than byte-sum
+                let hash = sc.name.bytes().fold(2166136261u32, |acc, b| {
+                    (acc ^ b as u32).wrapping_mul(16777619)
+                });
+                (hash as usize) % shard_total == shard_index
             } else {
                 true
             }