feat: display blob params alongside hardfork info (#19358)

crates/chainspec/src/spec.rs

@@ -10,7 +10,7 @@ use crate::{
     sepolia::SEPOLIA_PARIS_BLOCK,
     EthChainSpec,
 };
-use alloc::{boxed::Box, sync::Arc, vec::Vec};
+use alloc::{boxed::Box, format, sync::Arc, vec::Vec};
 use alloy_chains::{Chain, NamedChain};
 use alloy_consensus::{
     constants::{
@@ -440,7 +440,26 @@ impl<H: BlockHeader> ChainSpec<H> {
 
     /// Returns the hardfork display helper.
     pub fn display_hardforks(&self) -> DisplayHardforks {
-        DisplayHardforks::new(self.hardforks.forks_iter())
+        // Create an iterator with hardfork, condition, and optional blob metadata
+        let hardforks_with_meta = self.hardforks.forks_iter().map(|(fork, condition)| {
+            // Generate blob metadata for timestamp-based hardforks that have blob params
+            let metadata = match condition {
+                ForkCondition::Timestamp(timestamp) => {
+                    // Try to get blob params for this timestamp
+                    // This automatically handles all hardforks with blob support
+                    EthChainSpec::blob_params_at_timestamp(self, timestamp).map(|params| {
+                        format!(
+                            "blob: (target: {}, max: {}, fraction: {})",
+                            params.target_blob_count, params.max_blob_count, params.update_fraction
+                        )
+                    })
+                }
+                _ => None,
+            };
+            (fork, condition, metadata)
+        });
+
+        DisplayHardforks::with_meta(hardforks_with_meta)
     }
 
     /// Get the fork id for the given hardfork.
@@ -1157,8 +1176,8 @@ Merge hard forks:
 - Paris                            @58750000000000000000000 (network is known to be merged)
 Post-merge hard forks (timestamp based):
 - Shanghai                         @1681338455
-- Cancun                           @1710338135
-- Prague                           @1746612311"
+- Cancun                           @1710338135          blob: (target: 3, max: 6, fraction: 3338477)
+- Prague                           @1746612311          blob: (target: 6, max: 9, fraction: 5007716)"
         );
     }
 

crates/ethereum/hardforks/src/display.rs

@@ -25,6 +25,8 @@ struct DisplayFork {
     activated_at: ForkCondition,
     /// An optional EIP (e.g. `EIP-1559`).
     eip: Option<String>,
+    /// Optional metadata to display alongside the fork (e.g. blob parameters)
+    metadata: Option<String>,
 }
 
 impl core::fmt::Display for DisplayFork {
@@ -38,6 +40,9 @@ impl core::fmt::Display for DisplayFork {
         match self.activated_at {
             ForkCondition::Block(at) | ForkCondition::Timestamp(at) => {
                 write!(f, "{name_with_eip:32} @{at}")?;
+                if let Some(metadata) = &self.metadata {
+                    write!(f, "          {metadata}")?;
+                }
             }
             ForkCondition::TTD { total_difficulty, .. } => {
                 // All networks that have merged are finalized.
@@ -45,6 +50,9 @@ impl core::fmt::Display for DisplayFork {
                     f,
                     "{name_with_eip:32} @{total_difficulty} (network is known to be merged)",
                 )?;
+                if let Some(metadata) = &self.metadata {
+                    write!(f, "          {metadata}")?;
+                }
             }
             ForkCondition::Never => unreachable!(),
         }
@@ -145,14 +153,27 @@ impl DisplayHardforks {
     pub fn new<'a, I>(hardforks: I) -> Self
     where
         I: IntoIterator<Item = (&'a dyn Hardfork, ForkCondition)>,
+    {
+        // Delegate to with_meta by mapping the iterator to include None for metadata
+        Self::with_meta(hardforks.into_iter().map(|(fork, condition)| (fork, condition, None)))
+    }
+
+    /// Creates a new [`DisplayHardforks`] from an iterator of hardforks with optional metadata.
+    pub fn with_meta<'a, I>(hardforks: I) -> Self
+    where
+        I: IntoIterator<Item = (&'a dyn Hardfork, ForkCondition, Option<String>)>,
     {
         let mut pre_merge = Vec::new();
         let mut with_merge = Vec::new();
         let mut post_merge = Vec::new();
 
-        for (fork, condition) in hardforks {
-            let mut display_fork =
-                DisplayFork { name: fork.name().to_string(), activated_at: condition, eip: None };
+        for (fork, condition, metadata) in hardforks {
+            let mut display_fork = DisplayFork {
+                name: fork.name().to_string(),
+                activated_at: condition,
+                eip: None,
+                metadata,
+            };
 
             match condition {
                 ForkCondition::Block(_) => {