Integration tests ergonomics (#7836)

Fixes #7785


  - [x] Update all integration tests with >1 files to follow the `main` pattern.
- [x] `crypto/eth2_key_derivation/tests`
- [x] `crypto/eth2_keystore/tests`
- [x] `crypto/eth2_wallet/tests`
- [x] `slasher/tests`
- [x] `common/eth2_interop_keypairs/tests`
- [x] `beacon_node/lighthouse_network/tests`
- [x] Set `debug_assertions` to false on `.vscode/settings.json`.
- [x] Document how to make rust analyzer work on integration tests files. In `book/src/contributing_setup.md`

---

Tracking a `rust-analyzer.toml` with settings like the one provided in `.vscode/settings.json` would be nicer. But this is not possible yet. For now, that config should be a good enough indicator for devs using editors different to VSCode.


Co-Authored-By: Daniel Ramirez-Chiquillo <hi@danielrachi.com>

Co-Authored-By: Michael Sproul <michael@sigmaprime.io>

Author: danielrachi1

.vscode/settings.json

@@ -0,0 +1,5 @@
+{
+    "rust-analyzer.cargo.cfgs": [
+        "!debug_assertions"
+    ]
+}

beacon_node/lighthouse_network/Cargo.toml

@@ -3,6 +3,7 @@ name = "lighthouse_network"
 version = "0.2.0"
 authors = ["Sigma Prime <contact@sigmaprime.io>"]
 edition = { workspace = true }
+autotests = false
 
 [features]
 libp2p-websocket = []
@@ -74,3 +75,7 @@ async-channel = { workspace = true }
 logging = { workspace = true }
 proptest = { workspace = true }
 tempfile = { workspace = true }
+
+[[test]]
+name = "lighthouse_network_tests"
+path = "tests/main.rs"

beacon_node/lighthouse_network/tests/main.rs

@@ -0,0 +1,2 @@
+mod common;
+mod rpc_tests;

beacon_node/lighthouse_network/tests/rpc_tests.rs

@@ -1,9 +1,8 @@
 #![cfg(test)]
 
-mod common;
-
+use crate::common;
 use crate::common::spec_with_all_forks_enabled;
-use common::{Protocol, build_tracing_subscriber};
+use crate::common::{Protocol, build_tracing_subscriber};
 use lighthouse_network::rpc::{RequestType, methods::*};
 use lighthouse_network::service::api_types::AppRequestId;
 use lighthouse_network::{NetworkEvent, ReportSource, Response};

book/src/contributing_setup.md

@@ -71,6 +71,47 @@ $ cargo nextest run -p safe_arith
      Summary [ 0.012s] 8 tests run: 8 passed, 0 skipped
 ```
 
+### Integration tests
+
+Due to the size and complexity of the test suite, Lighthouse uses a pattern that differs from how
+[integration tests are usually defined](https://doc.rust-lang.org/rust-by-example/testing/integration_testing.html).
+This pattern helps manage large test suites more effectively and ensures tests only run in release
+mode to avoid stack overflow issues.
+
+#### The "main pattern"
+
+For packages with integration tests that require more than one file, Lighthouse uses the following
+structure:
+
+- A `main.rs` file is defined at `package/tests/main.rs` that declares other test files as modules
+- In `package/Cargo.toml`, integration tests are explicitly configured:
+
+    ```toml
+    [package]
+    autotests = false
+
+    [[test]]
+    name = "package_tests"
+    path = "tests/main.rs"
+    ```
+
+#### Rust Analyzer configuration
+
+This pattern, combined with `#![cfg(not(debug_assertions))]` directives in test files (which
+prevent tests from running in debug mode), causes Rust Analyzer to not provide IDE services like
+autocomplete and error checking in integration test files by default.
+
+To enable IDE support for these test files, configure Rust Analyzer to disable debug assertions.
+For VSCode users, this is already configured in the repository's `.vscode/settings.json` file:
+
+```json
+{
+    "rust-analyzer.cargo.cfgs": [
+        "!debug_assertions"
+    ]
+}
+```
+
 ### test_logger
 
 The test_logger, located in `/common/logging/` can be used to create a `Logger` that by

common/eth2_interop_keypairs/Cargo.toml

@@ -3,6 +3,7 @@ name = "eth2_interop_keypairs"
 version = "0.2.0"
 authors = ["Paul Hauner <paul@paulhauner.com>"]
 edition = { workspace = true }
+autotests = false
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
@@ -15,3 +16,7 @@ serde_yaml = { workspace = true }
 
 [dev-dependencies]
 base64 = "0.13.0"
+
+[[test]]
+name = "eth2_interop_keypairs_tests"
+path = "tests/main.rs"

common/eth2_interop_keypairs/tests/main.rs

@@ -0,0 +1,2 @@
+mod from_file;
+mod generation;

crypto/eth2_key_derivation/Cargo.toml

@@ -3,6 +3,7 @@ name = "eth2_key_derivation"
 version = "0.1.0"
 authors = ["Paul Hauner <paul@paulhauner.com>"]
 edition = { workspace = true }
+autotests = false
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
@@ -14,3 +15,7 @@ zeroize = { workspace = true }
 
 [dev-dependencies]
 hex = { workspace = true }
+
+[[test]]
+name = "eth2_key_derivation_tests"
+path = "tests/main.rs"

crypto/eth2_key_derivation/tests/main.rs

@@ -0,0 +1,2 @@
+mod eip2333_vectors;
+mod tests;

crypto/eth2_keystore/Cargo.toml

@@ -3,6 +3,7 @@ name = "eth2_keystore"
 version = "0.1.0"
 authors = ["Pawan Dhananjay <pawan@sigmaprime.io", "Paul Hauner <paul@paulhauner.com>"]
 edition = { workspace = true }
+autotests = false
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
@@ -24,3 +25,7 @@ zeroize = { workspace = true }
 
 [dev-dependencies]
 tempfile = { workspace = true }
+
+[[test]]
+name = "eth2_keystore_tests"
+path = "tests/main.rs"