RuntimeGenesiConfig: json macro added

cumulus/parachains/runtimes/assets/asset-hub-rococo/src/genesis_config_presets.rs

@@ -18,6 +18,7 @@
 use crate::*;
 use alloc::{vec, vec::Vec};
 use cumulus_primitives_core::ParaId;
+use frame_support::build_struct_json_patch;
 use hex_literal::hex;
 use parachains_common::{AccountId, AuraId};
 use sp_core::crypto::UncheckedInto;
@@ -33,15 +34,14 @@ fn asset_hub_rococo_genesis(
 	endowment: Balance,
 	id: ParaId,
 ) -> serde_json::Value {
-	let config = RuntimeGenesisConfig {
+	build_struct_json_patch!(RuntimeGenesisConfig {
 		balances: BalancesConfig {
 			balances: endowed_accounts.iter().cloned().map(|k| (k, endowment)).collect(),
 		},
-		parachain_info: ParachainInfoConfig { parachain_id: id, ..Default::default() },
+		parachain_info: ParachainInfoConfig { parachain_id: id },
 		collator_selection: CollatorSelectionConfig {
 			invulnerables: invulnerables.iter().cloned().map(|(acc, _)| acc).collect(),
 			candidacy_bond: ASSET_HUB_ROCOCO_ED * 16,
-			..Default::default()
 		},
 		session: SessionConfig {
 			keys: invulnerables
@@ -54,16 +54,9 @@ fn asset_hub_rococo_genesis(
 					)
 				})
 				.collect(),
-			..Default::default()
 		},
-		polkadot_xcm: PolkadotXcmConfig {
-			safe_xcm_version: Some(SAFE_XCM_VERSION),
-			..Default::default()
-		},
-		..Default::default()
-	};
-
-	serde_json::to_value(config).expect("Could not build genesis config.")
+		polkadot_xcm: PolkadotXcmConfig { safe_xcm_version: Some(SAFE_XCM_VERSION) },
+	})
 }
 
 /// Encapsulates names of predefined presets.

polkadot/runtime/westend/src/genesis_config_presets.rs

@@ -23,6 +23,7 @@ use crate::{
 #[cfg(not(feature = "std"))]
 use alloc::format;
 use alloc::{vec, vec::Vec};
+use frame_support::build_struct_json_patch;
 use pallet_staking::{Forcing, StakerStatus};
 use polkadot_primitives::{AccountId, AssignmentId, SchedulerParams, ValidatorId};
 use sp_authority_discovery::AuthorityId as AuthorityDiscoveryId;
@@ -170,7 +171,7 @@ fn westend_testnet_genesis(
 	const ENDOWMENT: u128 = 1_000_000 * WND;
 	const STASH: u128 = 100 * WND;
 
-	let config = RuntimeGenesisConfig {
+	build_struct_json_patch!(RuntimeGenesisConfig {
 		balances: BalancesConfig {
 			balances: endowed_accounts.iter().map(|k| (k.clone(), ENDOWMENT)).collect::<Vec<_>>(),
 		},
@@ -192,7 +193,6 @@ fn westend_testnet_genesis(
 					)
 				})
 				.collect::<Vec<_>>(),
-			..Default::default()
 		},
 		staking: StakingConfig {
 			minimum_validator_count: 1,
@@ -204,19 +204,12 @@ fn westend_testnet_genesis(
 			invulnerables: initial_authorities.iter().map(|x| x.0.clone()).collect::<Vec<_>>(),
 			force_era: Forcing::NotForcing,
 			slash_reward_fraction: Perbill::from_percent(10),
-			..Default::default()
 		},
-		babe: BabeConfig { epoch_config: BABE_GENESIS_EPOCH_CONFIG, ..Default::default() },
+		babe: BabeConfig { epoch_config: BABE_GENESIS_EPOCH_CONFIG },
 		sudo: SudoConfig { key: Some(root_key) },
 		configuration: ConfigurationConfig { config: default_parachains_host_configuration() },
-		registrar: RegistrarConfig {
-			next_free_para_id: polkadot_primitives::LOWEST_PUBLIC_ID,
-			..Default::default()
-		},
-		..Default::default()
-	};
-
-	serde_json::to_value(config).expect("Could not build genesis config.")
+		registrar: RegistrarConfig { next_free_para_id: polkadot_primitives::LOWEST_PUBLIC_ID },
+	})
 }
 
 // staging_testnet

prdoc/pr_5813.prdoc

@@ -0,0 +1,18 @@
+title: "build_struct_json_patch macro added"
+
+doc:
+  - audience: Runtime Dev
+    description: |
+      This PR adds a macro that allows to construct a RuntimeGenesisConfig preset 
+      containing only provided fields, while performing the validation of the
+      entire struct.
+
+      Related issue: https://github.com/paritytech/polkadot-sdk/issues/5700
+
+crates:
+  - name: frame-support
+    bump: minor
+  - name: asset-hub-rococo-runtime
+    bump: patch
+  - name: westend-runtime
+    bump: patch

substrate/frame/support/Cargo.toml

@@ -71,6 +71,7 @@ pretty_assertions = { workspace = true }
 sp-timestamp = { workspace = true }
 frame-system = { workspace = true, default-features = true }
 sp-crypto-hashing = { workspace = true, default-features = true }
+Inflector = { workspace = true }
 
 [features]
 default = ["std"]