[nextest-runner] set NEXTEST_TEST_GLOBAL_SLOT and NEXTEST_TEST_GROUP_SLOT

sunshowers · sunshowers · commit 815be98b0d35 · 2025-02-12T12:54:01.000-08:00
Set these to environment variables that are *unique* for the lifetime of the
test, and *compact* (smallest possible number can be assigned).
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -58,7 +58,7 @@ enable-ansi-support = "0.2.1"
 env_logger = { version = "0.11.6", default-features = false }
 fixture-data = { path = "fixture-data" }
 fs-err = "3.1.0"
-future-queue = "0.3.0"
+future-queue = "0.4.0"
 futures = "0.3.31"
 globset = "0.4.15"
 guppy = "0.17.14"
@@ -156,8 +156,8 @@ strip = "none"
 nextest-workspace-hack = { path = "workspace-hack" }
 
 # Uncomment for testing.
-# [patch.crates-io]
 # cargo_metadata = { path = "../cargo_metadata" }
+# future-queue = { path = "../future-queue" }
 # target-spec = { path = "../guppy/target-spec" }
 # target-spec-miette = { path = "../guppy/target-spec-miette" }
 # quick-junit = { path = "../quick-junit" }
diff --git a/fixtures/nextest-tests/.config/nextest.toml b/fixtures/nextest-tests/.config/nextest.toml
@@ -33,6 +33,11 @@ leak-timeout = '1s'
 [profile.with-retries]
 retries = 2
 
+# Test out serial tests.
+[[profile.with-retries.overrides]]
+filter = "test(=test_success) | test(=test_execute_bin)"
+test-group = 'serial'
+
 # Run test_flaky_mod_6 with 5 retries (6 tries) rather than 2.
 [[profile.with-retries.overrides]]
 filter = "test(=test_flaky_mod_6)"
@@ -91,6 +96,9 @@ max-threads = 4
 [test-groups.unused]
 max-threads = 20
 
+[test-groups.serial]
+max-threads = 1
+
 [script.my-script-unix]
 command = './scripts/my-script.sh'
 
diff --git a/fixtures/nextest-tests/tests/basic.rs b/fixtures/nextest-tests/tests/basic.rs
@@ -3,6 +3,8 @@ use std::{env, io::Read, path::PathBuf};
 
 #[test]
 fn test_success() {
+    assert_with_retries_serial();
+
     // Check that MY_ENV_VAR (set by the setup script) isn't enabled.
     assert_eq!(
         std::env::var("MY_ENV_VAR"),
@@ -104,6 +106,7 @@ fn test_ignored_fail() {
 /// Test that a binary can be successfully executed.
 #[test]
 fn test_execute_bin() {
+    assert_with_retries_serial();
     nextest_tests::test_execute_bin_helper();
 }
 
@@ -157,6 +160,11 @@ fn test_cargo_env_vars() {
         .expect("NEXTEST_RUN_ID must be set")
         .parse::<uuid::Uuid>()
         .expect("NEXTEST_RUN_ID must be a UUID");
+    let global_slot = std::env::var("NEXTEST_TEST_GLOBAL_SLOT")
+        .expect("NEXTEST_TEST_GLOBAL_SLOT must be set")
+        .parse::<u64>()
+        .expect("NEXTEST_TEST_GLOBAL_SLOT must be a u64");
+    println!("NEXTEST_TEST_GLOBAL_SLOT = {global_slot}");
 
     assert_eq!(
         std::env::var("NEXTEST_EXECUTION_MODE").as_deref(),
@@ -369,3 +377,19 @@ fn test_stdin_closed() {
             .expect("reading from /dev/null succeeded")
     );
 }
+
+/// Asserts that if the with-retries profile is set, the test group slot is 0.
+///
+/// This should be called if and only if the test-group is serial.
+fn assert_with_retries_serial() {
+    let profile = std::env::var("NEXTEST_PROFILE").expect("NEXTEST_PROFILE should be set");
+    let group_slot =
+        std::env::var("NEXTEST_TEST_GROUP_SLOT").expect("NEXTEST_TEST_GROUP_SLOT should be set");
+    if profile == "with-retries" {
+        // Check that NEXTEST_TEST_GROUP_SLOT is set.
+        // This test is in a serial group, so the group slot should be 0.
+        assert_eq!(group_slot, "0", "NEXTEST_TEST_GROUP_SLOT should be 0");
+    } else {
+        assert_eq!(group_slot, "none", "NEXTEST_TEST_GROUP_SLOT should be none");
+    }
+}
diff --git a/integration-tests/tests/integration/snapshots/integration__show_config_test_groups-2.snap b/integration-tests/tests/integration/snapshots/integration__show_config_test_groups-2.snap
@@ -5,6 +5,8 @@ snapshot_kind: text
 ---
 group: flaky (max threads = 4)
     (no matches)
+group: serial (max threads = 1)
+    (no matches)
 group: unused (max threads = 20)
     (no matches)
 group: @global
diff --git a/integration-tests/tests/integration/snapshots/integration__show_config_test_groups-3.snap b/integration-tests/tests/integration/snapshots/integration__show_config_test_groups-3.snap
@@ -1,12 +1,17 @@
 ---
 source: integration-tests/tests/integration/main.rs
 expression: with_retries_output.stdout_as_str()
+snapshot_kind: text
 ---
 group: flaky (max threads = 4)
   * override for with-retries profile with filter 'test(test_flaky_mod) | test(~test_flaky_mod_4)':
       nextest-tests::basic:
           test_flaky_mod_4
           test_flaky_mod_6
+group: serial (max threads = 1)
+  * override for with-retries profile with filter 'test(=test_success) | test(=test_execute_bin)':
+      nextest-tests::basic:
+          test_execute_bin
+          test_success
 group: unused (max threads = 20)
     (no matches)
-
diff --git a/integration-tests/tests/integration/snapshots/integration__show_config_test_groups-4.snap b/integration-tests/tests/integration/snapshots/integration__show_config_test_groups-4.snap
@@ -8,6 +8,11 @@ group: flaky (max threads = 4)
       nextest-tests::basic:
           test_flaky_mod_4
           test_flaky_mod_6
+group: serial (max threads = 1)
+  * override for with-retries profile with filter 'test(=test_success) | test(=test_execute_bin)':
+      nextest-tests::basic:
+          test_execute_bin
+          test_success
 group: unused (max threads = 20)
     (no matches)
 group: @global
@@ -24,15 +29,13 @@ group: @global
       nextest-tests::basic:
           test_cargo_env_vars
           test_cwd
-          test_execute_bin
           test_failure_assert
           test_failure_error
           test_failure_should_panic
           test_result_failure
           test_stdin_closed
           test_subprocess_doesnt_exit
           test_subprocess_doesnt_exit_fail
-          test_success
           test_success_should_panic
       nextest-tests::other:
           other_test_success
diff --git a/integration-tests/tests/integration/snapshots/integration__show_config_test_groups-5.snap b/integration-tests/tests/integration/snapshots/integration__show_config_test_groups-5.snap
@@ -1,12 +1,14 @@
 ---
 source: integration-tests/tests/integration/main.rs
 expression: with_termination_output.stdout_as_str()
+snapshot_kind: text
 ---
 group: flaky (max threads = 4)
     (no matches)
+group: serial (max threads = 1)
+    (no matches)
 group: unused (max threads = 20)
     (no matches)
 group: @global
   * override for with-termination profile with filter 'test(=test_slow_timeout_2)':
       nextest-tests::basic:
-
diff --git a/integration-tests/tests/integration/snapshots/integration__show_config_test_groups-6.snap b/integration-tests/tests/integration/snapshots/integration__show_config_test_groups-6.snap
@@ -5,6 +5,8 @@ snapshot_kind: text
 ---
 group: flaky (max threads = 4)
     (no matches)
+group: serial (max threads = 1)
+    (no matches)
 group: unused (max threads = 20)
     (no matches)
 group: @global
diff --git a/integration-tests/tests/integration/snapshots/integration__show_config_test_groups.snap b/integration-tests/tests/integration/snapshots/integration__show_config_test_groups.snap
@@ -1,9 +1,11 @@
 ---
 source: integration-tests/tests/integration/main.rs
 expression: default_profile_output.stdout_as_str()
+snapshot_kind: text
 ---
 group: flaky (max threads = 4)
     (no matches)
+group: serial (max threads = 1)
+    (no matches)
 group: unused (max threads = 20)
     (no matches)
-
diff --git a/nextest-runner/src/runner/executor.rs b/nextest-runner/src/runner/executor.rs
@@ -33,6 +33,7 @@ use crate::{
     test_output::{CaptureStrategy, ChildExecutionOutput, ChildOutput, ChildSplitOutput},
     time::{PausableSleep, StopwatchStart},
 };
+use future_queue::FutureQueueContext;
 use nextest_metadata::FilterMatch;
 use quick_junit::ReportUuid;
 use rand::{distributions::OpenClosed01, thread_rng, Rng};
@@ -161,6 +162,7 @@ impl<'a> ExecutorContext<'a> {
     pub(super) async fn run_test_instance(
         &self,
         test_instance: TestInstance<'a>,
+        cx: FutureQueueContext,
         settings: TestSettings<'a>,
         resp_tx: UnboundedSender<ExecutorEvent<'a>>,
         setup_script_data: Arc<SetupScriptExecuteData<'a>>,
@@ -174,6 +176,10 @@ impl<'a> ExecutorContext<'a> {
         let mut backoff_iter = BackoffIter::new(retry_policy);
 
         if let FilterMatch::Mismatch { reason } = test_instance.test_info.filter_match {
+            debug_assert!(
+                false,
+                "this test should already have been skipped in a filter step"
+            );
             // Failure to send means the receiver was dropped.
             let _ = resp_tx.send(ExecutorEvent::Skipped {
                 test_instance,
@@ -234,6 +240,7 @@ impl<'a> ExecutorContext<'a> {
             // additional information later.
             let packet = TestPacket {
                 test_instance,
+                cx: cx.clone(),
                 retry_data,
                 settings: settings.clone(),
                 setup_script_data: setup_script_data.clone(),
@@ -619,7 +626,17 @@ impl<'a> ExecutorContext<'a> {
 
         // Debug environment variable for testing.
         command_mut.env("__NEXTEST_ATTEMPT", format!("{}", test.retry_data.attempt));
+
         command_mut.env("NEXTEST_RUN_ID", format!("{}", self.run_id));
+        command_mut.env(
+            "NEXTEST_TEST_GLOBAL_SLOT",
+            test.cx.global_slot().to_string(),
+        );
+        if let Some(group_slot) = test.cx.group_slot() {
+            command_mut.env("NEXTEST_TEST_GROUP_SLOT", group_slot.to_string());
+        } else {
+            command_mut.env("NEXTEST_TEST_GROUP_SLOT", "none");
+        }
         command_mut.stdin(Stdio::null());
         test.setup_script_data.apply(
             &test.test_instance.to_test_query(),
@@ -950,6 +967,7 @@ impl UnitPacket<'_> {
 #[derive(Clone, Debug)]
 pub(super) struct TestPacket<'a> {
     test_instance: TestInstance<'a>,
+    cx: FutureQueueContext,
     retry_data: RetryData,
     settings: Arc<TestSettings<'a>>,
     setup_script_data: Arc<SetupScriptExecuteData<'a>>,
diff --git a/nextest-runner/src/runner/imp.rs b/nextest-runner/src/runner/imp.rs
