Reduce number of blobs used in tests to speed up CI (#8194)

`beacon-chain-tests` is now regularly taking 1h+ on CI since Fulu fork was added.

This PR attemtpts to reduce the test time by bringing down the number of blobs generated in tests - instead of generating 0..max_blobs, the generator now generates 0..1 blobs by default, and this can be modified by setting `harness.execution_block_generator.set_min_blob_count(n)`.

Note: The blobs are pre-generated and doesn't require too much CPU to generate however processing a larger number of them on the beacon chain does take a lot of time.

This PR also include a few other small improvements
- Our slowest test (`chain_segment_varying_chunk_size`) runs 3x faster in Fulu just by reusing chain segments
- Avoid re-running fork specific tests on all forks
- Fix a bunch of tests that depends on the harness's existing random blob generation, which is fragile


beacon chain test time on test machine is **~2x** faster:

### `unstable`

```
Summary [ 751.586s] 291 tests run: 291 passed (13 slow), 0 skipped
```

### this branch

```
Summary [ 373.792s] 291 tests run: 291 passed (2 slow), 0 skipped
```

The next set of tests to optimise is the ones that use [`get_chain_segment`](77a9af96de/beacon_node/beacon_chain/tests/block_verification.rs (L45)), as it by default build 320 blocks with supernode - an easy optimisation would be to build these blocks with cgc = 8 for tests that only require fullnodes.


  


Co-Authored-By: Jimmy Chen <jchen.tc@gmail.com>

Co-Authored-By: Jimmy Chen <jimmy@sigmaprime.io>

beacon_node/execution_layer/src/engine_api/http.rs

@@ -1479,8 +1479,7 @@ mod test {
 
     impl Tester {
         pub fn new(with_auth: bool) -> Self {
-            let spec = Arc::new(MainnetEthSpec::default_spec());
-            let server = MockServer::unit_testing(spec);
+            let server = MockServer::unit_testing();
 
             let rpc_url = SensitiveUrl::parse(&server.url()).unwrap();
             let echo_url = SensitiveUrl::parse(&format!("{}/echo", server.url())).unwrap();

beacon_node/execution_layer/src/test_utils/execution_block_generator.rs

@@ -13,6 +13,7 @@ use rand::{Rng, SeedableRng, rngs::StdRng};
 use serde::{Deserialize, Serialize};
 use ssz::Decode;
 use ssz_types::VariableList;
+use std::cmp::max;
 use std::collections::HashMap;
 use std::sync::Arc;
 use tree_hash::TreeHash;
@@ -157,7 +158,6 @@ pub struct ExecutionBlockGenerator<E: EthSpec> {
     pub blobs_bundles: HashMap<PayloadId, BlobsBundle<E>>,
     pub kzg: Option<Arc<Kzg>>,
     rng: Arc<Mutex<StdRng>>,
-    spec: Arc<ChainSpec>,
 }
 
 fn make_rng() -> Arc<Mutex<StdRng>> {
@@ -177,7 +177,6 @@ impl<E: EthSpec> ExecutionBlockGenerator<E> {
         prague_time: Option<u64>,
         osaka_time: Option<u64>,
         amsterdam_time: Option<u64>,
-        spec: Arc<ChainSpec>,
         kzg: Option<Arc<Kzg>>,
     ) -> Self {
         let mut generator = Self {
@@ -200,7 +199,6 @@ impl<E: EthSpec> ExecutionBlockGenerator<E> {
             blobs_bundles: <_>::default(),
             kzg,
             rng: make_rng(),
-            spec,
         };
 
         generator.insert_pow_block(0).unwrap();
@@ -732,11 +730,10 @@ impl<E: EthSpec> ExecutionBlockGenerator<E> {
 
         let fork_name = execution_payload.fork_name();
         if fork_name.deneb_enabled() {
-            // get random number between 0 and Max Blobs
+            // get random number between 0 and 1 blobs by default
+            // For tests that need higher blob count, consider adding a `set_max_blob_count` method
             let mut rng = self.rng.lock();
-            // TODO(EIP-7892): see FIXME below
-            // FIXME: this will break with BPO forks. This function needs to calculate the epoch based on block timestamp..
-            let max_blobs = self.spec.max_blobs_per_block_within_fork(fork_name) as usize;
+            let max_blobs = max(1, self.min_blobs_count);
             let num_blobs = rng.random_range(self.min_blobs_count..=max_blobs);
             let (bundle, transactions) = generate_blobs(num_blobs, fork_name)?;
             for tx in Vec::from(transactions) {
@@ -978,7 +975,6 @@ mod test {
         const TERMINAL_DIFFICULTY: u64 = 10;
         const TERMINAL_BLOCK: u64 = 10;
         const DIFFICULTY_INCREMENT: u64 = 1;
-        let spec = Arc::new(MainnetEthSpec::default_spec());
 
         let mut generator: ExecutionBlockGenerator<MainnetEthSpec> = ExecutionBlockGenerator::new(
             Uint256::from(TERMINAL_DIFFICULTY),
@@ -989,7 +985,6 @@ mod test {
             None,
             None,
             None,
-            spec,
             None,
         );
 

beacon_node/execution_layer/src/test_utils/mock_execution_layer.rs

@@ -63,7 +63,6 @@ impl<E: EthSpec> MockExecutionLayer<E> {
             prague_time,
             osaka_time,
             amsterdam_time,
-            spec.clone(),
             kzg,
         );
 

beacon_node/execution_layer/src/test_utils/mod.rs

@@ -22,7 +22,7 @@ use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4};
 use std::sync::{Arc, LazyLock};
 use tokio::{runtime, sync::oneshot};
 use tracing::info;
-use types::{ChainSpec, EthSpec, ExecutionBlockHash, Uint256};
+use types::{EthSpec, ExecutionBlockHash, Uint256};
 use warp::{Filter, Rejection, http::StatusCode};
 
 use crate::EngineCapabilities;
@@ -114,7 +114,7 @@ pub struct MockServer<E: EthSpec> {
 }
 
 impl<E: EthSpec> MockServer<E> {
-    pub fn unit_testing(chain_spec: Arc<ChainSpec>) -> Self {
+    pub fn unit_testing() -> Self {
         Self::new(
             &runtime::Handle::current(),
             JwtKey::from_slice(&DEFAULT_JWT_SECRET).unwrap(),
@@ -126,7 +126,6 @@ impl<E: EthSpec> MockServer<E> {
             None, // FIXME(electra): should this be the default?
             None, // FIXME(fulu): should this be the default?
             None, // FIXME(gloas): should this be the default?
-            chain_spec,
             None,
         )
     }
@@ -134,7 +133,6 @@ impl<E: EthSpec> MockServer<E> {
     pub fn new_with_config(
         handle: &runtime::Handle,
         config: MockExecutionConfig,
-        spec: Arc<ChainSpec>,
         kzg: Option<Arc<Kzg>>,
     ) -> Self {
         create_test_tracing_subscriber();
@@ -161,7 +159,6 @@ impl<E: EthSpec> MockServer<E> {
             prague_time,
             osaka_time,
             amsterdam_time,
-            spec,
             kzg,
         );
 
@@ -226,7 +223,6 @@ impl<E: EthSpec> MockServer<E> {
         prague_time: Option<u64>,
         osaka_time: Option<u64>,
         amsterdam_time: Option<u64>,
-        spec: Arc<ChainSpec>,
         kzg: Option<Arc<Kzg>>,
     ) -> Self {
         Self::new_with_config(
@@ -243,7 +239,6 @@ impl<E: EthSpec> MockServer<E> {
                 osaka_time,
                 amsterdam_time,
             },
-            spec,
             kzg,
         )
     }