Allow pallet in construct_runtime to have fixed index (#6969)

* implement index for pallet + some tests * add test and doc * remove deprecated and document behavior * update internal doc * Apply suggestions from code review Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com> * address review * use index for all module, break construct_runtime * fix line length * implement migration helper funciton in scheduler * fix start at index 0 * Update frame/scheduler/src/lib.rs Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com> * Update frame/support/procedural/src/lib.rs Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com> * bump frame-metadata crate * factorize * avoid some unwrap and remove nightly join * Update frame/support/src/event.rs Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com> * fix test * add test and improve error message * factorize test * keep iterator, and use slice instead of vec * refactor to avoid to have expects * small refactor * Test something * Make sure we update the `Cargo.lock` * Apply suggestions from code review Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com> * return 2 error * Apply suggestions from code review Co-authored-by: Alexander Popiak <alexander.popiak@parity.io> * Update frame/scheduler/src/lib.rs Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com> * fix typo * Revert "fix typo" This reverts commit f2de8f2db34e8ac72bc9c34437c60dca3fa4ac22. * Revert "Update frame/scheduler/src/lib.rs" This reverts commit 6feb4605c6f784b64591e229de7a6fec6dbffb4b. Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com> Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com> Co-authored-by: Bastian Köcher <git@kchr.de> Co-authored-by: Alexander Popiak <alexander.popiak@parity.io> Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
2026-04-26 14:37:57 +00:00 · 2020-09-22 16:54:03 +02:00
parent 86594727d9
commit 98951b33a9
21 changed files with 876 additions and 128 deletions
@@ -50,6 +50,17 @@ mod module1 {
 		}
 	}

+	#[derive(Clone, PartialEq, Eq, Debug, codec::Encode, codec::Decode)]
+	pub struct Origin<T, I: Instance = DefaultInstance>(pub core::marker::PhantomData::<(T, I)>);
+
+	frame_support::decl_event! {
+		pub enum Event<T, I: Instance = DefaultInstance> where
+			<T as system::Trait>::AccountId
+		{
+			A(AccountId),
+		}
+	}
+
 	frame_support::decl_error! {
 		pub enum Error for Module<T: Trait<I>, I: Instance> {
 			Something
@@ -81,6 +92,15 @@ mod module2 {
 		}
 	}

+	#[derive(Clone, PartialEq, Eq, Debug, codec::Encode, codec::Decode)]
+	pub struct Origin;
+
+	frame_support::decl_event! {
+		pub enum Event {
+			A,
+		}
+	}
+
 	frame_support::decl_error! {
 		pub enum Error for Module<T: Trait> {
 			Something
@@ -92,8 +112,7 @@ mod module2 {
 	}
 }

-impl module1::Trait<module1::Instance1> for Runtime {}
-impl module1::Trait<module1::Instance2> for Runtime {}
+impl<I> module1::Trait<I> for Runtime {}
 impl module2::Trait for Runtime {}

 pub type Signature = sr25519::Signature;
@@ -118,10 +137,17 @@ frame_support::construct_runtime!(
 		NodeBlock = Block,
 		UncheckedExtrinsic = UncheckedExtrinsic
 	{
-		System: system::{Module, Call, Event<T>},
-		Module1_1: module1::<Instance1>::{Module, Call, Storage},
-		Module2: module2::{Module, Call, Storage},
-		Module1_2: module1::<Instance2>::{Module, Call, Storage},
+		System: system::{Module, Call, Event<T>, Origin<T>} = 30,
+		Module1_1: module1::<Instance1>::{Module, Call, Storage, Event<T>, Origin<T>},
+		Module2: module2::{Module, Call, Storage, Event, Origin},
+		Module1_2: module1::<Instance2>::{Module, Call, Storage, Event<T>, Origin<T>},
+		Module1_3: module1::<Instance3>::{Module, Storage} = 6,
+		Module1_4: module1::<Instance4>::{Module, Call} = 3,
+		Module1_5: module1::<Instance5>::{Module, Event<T>},
+		Module1_6: module1::<Instance6>::{Module, Call, Storage, Event<T>, Origin<T>} = 1,
+		Module1_7: module1::<Instance7>::{Module, Call, Storage, Event<T>, Origin<T>},
+		Module1_8: module1::<Instance8>::{Module, Call, Storage, Event<T>, Origin<T>} = 12,
+		Module1_9: module1::<Instance9>::{Module, Call, Storage, Event<T>, Origin<T>},
 	}
 );

@@ -130,27 +156,47 @@ pub type Block = generic::Block<Header, UncheckedExtrinsic>;
 pub type UncheckedExtrinsic = generic::UncheckedExtrinsic<u32, Call, Signature, ()>;

 #[test]
-fn check_module1_1_error_type() {
+fn check_modules_error_type() {
 	assert_eq!(
 		Module1_1::fail(system::Origin::<Runtime>::Root.into()),
-		Err(DispatchError::Module { index: 1, error: 0, message: Some("Something") }),
+		Err(DispatchError::Module { index: 31, error: 0, message: Some("Something") }),
 	);
-}
-
-#[test]
-fn check_module1_2_error_type() {
-	assert_eq!(
-		Module1_2::fail(system::Origin::<Runtime>::Root.into()),
-		Err(DispatchError::Module { index: 3, error: 0, message: Some("Something") }),
-	);
-}
-
-#[test]
-fn check_module2_error_type() {
 	assert_eq!(
 		Module2::fail(system::Origin::<Runtime>::Root.into()),
+		Err(DispatchError::Module { index: 32, error: 0, message: Some("Something") }),
+	);
+	assert_eq!(
+		Module1_2::fail(system::Origin::<Runtime>::Root.into()),
+		Err(DispatchError::Module { index: 33, error: 0, message: Some("Something") }),
+	);
+	assert_eq!(
+		Module1_3::fail(system::Origin::<Runtime>::Root.into()),
+		Err(DispatchError::Module { index: 6, error: 0, message: Some("Something") }),
+	);
+	assert_eq!(
+		Module1_4::fail(system::Origin::<Runtime>::Root.into()),
+		Err(DispatchError::Module { index: 3, error: 0, message: Some("Something") }),
+	);
+	assert_eq!(
+		Module1_5::fail(system::Origin::<Runtime>::Root.into()),
+		Err(DispatchError::Module { index: 4, error: 0, message: Some("Something") }),
+	);
+	assert_eq!(
+		Module1_6::fail(system::Origin::<Runtime>::Root.into()),
+		Err(DispatchError::Module { index: 1, error: 0, message: Some("Something") }),
+	);
+	assert_eq!(
+		Module1_7::fail(system::Origin::<Runtime>::Root.into()),
 		Err(DispatchError::Module { index: 2, error: 0, message: Some("Something") }),
 	);
+	assert_eq!(
+		Module1_8::fail(system::Origin::<Runtime>::Root.into()),
+		Err(DispatchError::Module { index: 12, error: 0, message: Some("Something") }),
+	);
+	assert_eq!(
+		Module1_9::fail(system::Origin::<Runtime>::Root.into()),
+		Err(DispatchError::Module { index: 13, error: 0, message: Some("Something") }),
+	);
 }

 #[test]
@@ -159,14 +205,340 @@ fn integrity_test_works() {
 	assert_eq!(INTEGRITY_TEST_EXEC.with(|i| *i.borrow()), 1);
 }

+#[test]
+fn origin_codec() {
+	use codec::Encode;
+
+	let origin = OriginCaller::system(system::RawOrigin::None);
+	assert_eq!(origin.encode()[0], 30);
+
+	let origin = OriginCaller::module1_Instance1(module1::Origin(Default::default()));
+	assert_eq!(origin.encode()[0], 31);
+
+	let origin = OriginCaller::module2(module2::Origin);
+	assert_eq!(origin.encode()[0], 32);
+
+	let origin = OriginCaller::module1_Instance2(module1::Origin(Default::default()));
+	assert_eq!(origin.encode()[0], 33);
+
+	let origin = OriginCaller::module1_Instance6(module1::Origin(Default::default()));
+	assert_eq!(origin.encode()[0], 1);
+
+	let origin = OriginCaller::module1_Instance7(module1::Origin(Default::default()));
+	assert_eq!(origin.encode()[0], 2);
+
+	let origin = OriginCaller::module1_Instance8(module1::Origin(Default::default()));
+	assert_eq!(origin.encode()[0], 12);
+
+	let origin = OriginCaller::module1_Instance9(module1::Origin(Default::default()));
+	assert_eq!(origin.encode()[0], 13);
+}
+
+#[test]
+fn event_codec() {
+	use codec::Encode;
+
+	let event = system::Event::<Runtime>::ExtrinsicSuccess;
+	assert_eq!(Event::from(event).encode()[0], 30);
+
+	let event = module1::Event::<Runtime, module1::Instance1>::A(Default::default());
+	assert_eq!(Event::from(event).encode()[0], 31);
+
+	let event = module2::Event::A;
+	assert_eq!(Event::from(event).encode()[0], 32);
+
+	let event = module1::Event::<Runtime, module1::Instance2>::A(Default::default());
+	assert_eq!(Event::from(event).encode()[0], 33);
+
+	let event = module1::Event::<Runtime, module1::Instance5>::A(Default::default());
+	assert_eq!(Event::from(event).encode()[0], 4);
+
+	let event = module1::Event::<Runtime, module1::Instance6>::A(Default::default());
+	assert_eq!(Event::from(event).encode()[0], 1);
+
+	let event = module1::Event::<Runtime, module1::Instance7>::A(Default::default());
+	assert_eq!(Event::from(event).encode()[0], 2);
+
+	let event = module1::Event::<Runtime, module1::Instance8>::A(Default::default());
+	assert_eq!(Event::from(event).encode()[0], 12);
+
+	let event = module1::Event::<Runtime, module1::Instance9>::A(Default::default());
+	assert_eq!(Event::from(event).encode()[0], 13);
+}
+
+#[test]
+fn call_codec() {
+	use codec::Encode;
+	assert_eq!(Call::System(system::Call::noop()).encode()[0], 30);
+	assert_eq!(Call::Module1_1(module1::Call::fail()).encode()[0], 31);
+	assert_eq!(Call::Module2(module2::Call::fail()).encode()[0], 32);
+	assert_eq!(Call::Module1_2(module1::Call::fail()).encode()[0], 33);
+	assert_eq!(Call::Module1_4(module1::Call::fail()).encode()[0], 3);
+	assert_eq!(Call::Module1_6(module1::Call::fail()).encode()[0], 1);
+	assert_eq!(Call::Module1_7(module1::Call::fail()).encode()[0], 2);
+	assert_eq!(Call::Module1_8(module1::Call::fail()).encode()[0], 12);
+	assert_eq!(Call::Module1_9(module1::Call::fail()).encode()[0], 13);
+}
+
+#[test]
+fn test_metadata() {
+	use frame_metadata::*;
+	let expected_metadata: RuntimeMetadataLastVersion = RuntimeMetadataLastVersion {
+		modules: DecodeDifferent::Encode(&[
+			ModuleMetadata {
+				name: DecodeDifferent::Encode("System"),
+				storage: None,
+				calls: Some(DecodeDifferent::Encode(FnEncode(|| &[FunctionMetadata {
+					name: DecodeDifferent::Encode("noop"),
+					arguments: DecodeDifferent::Encode(&[]),
+					documentation: DecodeDifferent::Encode(&[]),
+				}]))),
+				event: Some(DecodeDifferent::Encode(FnEncode(|| &[
+					EventMetadata {
+						name: DecodeDifferent::Encode("ExtrinsicSuccess"),
+						arguments: DecodeDifferent::Encode(&[]),
+						documentation: DecodeDifferent::Encode(&[]),
+					},
+					EventMetadata {
+						name: DecodeDifferent::Encode("ExtrinsicFailed"),
+						arguments: DecodeDifferent::Encode(&[]),
+						documentation: DecodeDifferent::Encode(&[]),
+					},
+					EventMetadata {
+						name: DecodeDifferent::Encode("Ignore"),
+						arguments: DecodeDifferent::Encode(&["BlockNumber"]),
+						documentation: DecodeDifferent::Encode(&[]),
+					},
+				]))),
+				constants: DecodeDifferent::Encode(FnEncode(|| &[])),
+				errors: DecodeDifferent::Encode(FnEncode(|| &[])),
+				index: 30,
+			},
+			ModuleMetadata {
+				name: DecodeDifferent::Encode("Module1_1"),
+				storage: Some(DecodeDifferent::Encode(FnEncode(|| StorageMetadata {
+					prefix: DecodeDifferent::Encode("Instance1Module"),
+					entries: DecodeDifferent::Encode(&[]),
+				}))),
+				calls: Some(DecodeDifferent::Encode(FnEncode(|| &[
+					FunctionMetadata {
+						name: DecodeDifferent::Encode("fail"),
+						arguments: DecodeDifferent::Encode(&[]),
+						documentation: DecodeDifferent::Encode(&[]),
+					},
+				]))),
+				event: Some(DecodeDifferent::Encode(FnEncode(|| &[EventMetadata {
+					name: DecodeDifferent::Encode("A"),
+					arguments: DecodeDifferent::Encode(&["AccountId"]),
+					documentation: DecodeDifferent::Encode(&[]),
+				}]))),
+				constants: DecodeDifferent::Encode(FnEncode(|| &[])),
+				errors: DecodeDifferent::Encode(FnEncode(|| &[])),
+				index: 31,
+			},
+			ModuleMetadata {
+				name: DecodeDifferent::Encode("Module2"),
+				storage: Some(DecodeDifferent::Encode(FnEncode(|| StorageMetadata {
+					prefix: DecodeDifferent::Encode("Module"),
+					entries: DecodeDifferent::Encode(&[]),
+				}))),
+				calls: Some(DecodeDifferent::Encode(FnEncode(|| &[
+					FunctionMetadata {
+						name: DecodeDifferent::Encode("fail"),
+						arguments: DecodeDifferent::Encode(&[]),
+						documentation: DecodeDifferent::Encode(&[]),
+					},
+				]))),
+				event: Some(DecodeDifferent::Encode(FnEncode(|| &[
+					EventMetadata {
+						name: DecodeDifferent::Encode("A"),
+						arguments: DecodeDifferent::Encode(&[]),
+						documentation: DecodeDifferent::Encode(&[]),
+					},
+				]))),
+				constants: DecodeDifferent::Encode(FnEncode(|| &[])),
+				errors: DecodeDifferent::Encode(FnEncode(|| &[])),
+				index: 32,
+			},
+			ModuleMetadata {
+				name: DecodeDifferent::Encode("Module1_2"),
+				storage: Some(DecodeDifferent::Encode(FnEncode(|| StorageMetadata {
+					prefix: DecodeDifferent::Encode("Instance2Module"),
+					entries: DecodeDifferent::Encode(&[]),
+				}))),
+				calls: Some(DecodeDifferent::Encode(FnEncode(|| &[FunctionMetadata {
+					name: DecodeDifferent::Encode("fail"),
+					arguments: DecodeDifferent::Encode(&[]),
+					documentation: DecodeDifferent::Encode(&[]),
+				}]))),
+				event: Some(DecodeDifferent::Encode(FnEncode(|| &[EventMetadata {
+					name: DecodeDifferent::Encode("A"),
+					arguments: DecodeDifferent::Encode(&["AccountId"]),
+					documentation: DecodeDifferent::Encode(&[]),
+				}]))),
+				constants: DecodeDifferent::Encode(FnEncode(|| &[])),
+				errors: DecodeDifferent::Encode(FnEncode(|| &[])),
+				index: 33,
+			},
+			ModuleMetadata {
+				name: DecodeDifferent::Encode("Module1_3"),
+				storage: Some(DecodeDifferent::Encode(FnEncode(|| StorageMetadata {
+					prefix: DecodeDifferent::Encode("Instance3Module"),
+					entries: DecodeDifferent::Encode(&[]),
+				}))),
+				calls: None,
+				event: None,
+				constants: DecodeDifferent::Encode(FnEncode(|| &[])),
+				errors: DecodeDifferent::Encode(FnEncode(|| &[])),
+				index: 6,
+			},
+			ModuleMetadata {
+				name: DecodeDifferent::Encode("Module1_4"),
+				storage: None,
+				calls: Some(DecodeDifferent::Encode(FnEncode(|| &[FunctionMetadata {
+					name: DecodeDifferent::Encode("fail"),
+					arguments: DecodeDifferent::Encode(&[]),
+					documentation: DecodeDifferent::Encode(&[]),
+				}]))),
+				event: None,
+				constants: DecodeDifferent::Encode(FnEncode(|| &[])),
+				errors: DecodeDifferent::Encode(FnEncode(|| &[])),
+				index: 3,
+			},
+			ModuleMetadata {
+				name: DecodeDifferent::Encode("Module1_5"),
+				storage: None,
+				calls: None,
+				event: Some(DecodeDifferent::Encode(FnEncode(|| &[EventMetadata {
+					name: DecodeDifferent::Encode("A"),
+					arguments: DecodeDifferent::Encode(&["AccountId"]),
+					documentation: DecodeDifferent::Encode(&[]),
+				}]))),
+				constants: DecodeDifferent::Encode(FnEncode(|| &[])),
+				errors: DecodeDifferent::Encode(FnEncode(|| &[])),
+				index: 4,
+			},
+			ModuleMetadata {
+				name: DecodeDifferent::Encode("Module1_6"),
+				storage: Some(DecodeDifferent::Encode(FnEncode(|| StorageMetadata {
+					prefix: DecodeDifferent::Encode("Instance6Module"),
+					entries: DecodeDifferent::Encode(&[]),
+				}))),
+				calls: Some(DecodeDifferent::Encode(FnEncode(|| &[FunctionMetadata {
+					name: DecodeDifferent::Encode("fail"),
+					arguments: DecodeDifferent::Encode(&[]),
+					documentation: DecodeDifferent::Encode(&[]),
+				}]))),
+				event: Some(DecodeDifferent::Encode(FnEncode(|| &[EventMetadata {
+					name: DecodeDifferent::Encode("A"),
+					arguments: DecodeDifferent::Encode(&["AccountId"]),
+					documentation: DecodeDifferent::Encode(&[]),
+				}]))),
+				constants: DecodeDifferent::Encode(FnEncode(|| &[])),
+				errors: DecodeDifferent::Encode(FnEncode(|| &[])),
+				index: 1,
+			},
+			ModuleMetadata {
+				name: DecodeDifferent::Encode("Module1_7"),
+				storage: Some(DecodeDifferent::Encode(FnEncode(|| StorageMetadata {
+					prefix: DecodeDifferent::Encode("Instance7Module"),
+					entries: DecodeDifferent::Encode(&[]),
+				}))),
+				calls: Some(DecodeDifferent::Encode(FnEncode(|| &[FunctionMetadata {
+					name: DecodeDifferent::Encode("fail"),
+					arguments: DecodeDifferent::Encode(&[]),
+					documentation: DecodeDifferent::Encode(&[]),
+				}]))),
+				event: Some(DecodeDifferent::Encode(FnEncode(|| &[EventMetadata {
+					name: DecodeDifferent::Encode("A"),
+					arguments: DecodeDifferent::Encode(&["AccountId"]),
+					documentation: DecodeDifferent::Encode(&[]),
+				}]))),
+				constants: DecodeDifferent::Encode(FnEncode(|| &[])),
+				errors: DecodeDifferent::Encode(FnEncode(|| &[])),
+				index: 2,
+			},
+			ModuleMetadata {
+				name: DecodeDifferent::Encode("Module1_8"),
+				storage: Some(DecodeDifferent::Encode(FnEncode(|| StorageMetadata {
+					prefix: DecodeDifferent::Encode("Instance8Module"),
+					entries: DecodeDifferent::Encode(&[]),
+				}))),
+				calls: Some(DecodeDifferent::Encode(FnEncode(|| &[FunctionMetadata {
+					name: DecodeDifferent::Encode("fail"),
+					arguments: DecodeDifferent::Encode(&[]),
+					documentation: DecodeDifferent::Encode(&[]),
+				}]))),
+				event: Some(DecodeDifferent::Encode(FnEncode(|| &[EventMetadata {
+					name: DecodeDifferent::Encode("A"),
+					arguments: DecodeDifferent::Encode(&["AccountId"]),
+					documentation: DecodeDifferent::Encode(&[]),
+				}]))),
+				constants: DecodeDifferent::Encode(FnEncode(|| &[])),
+				errors: DecodeDifferent::Encode(FnEncode(|| &[])),
+				index: 12,
+			},
+			ModuleMetadata {
+				name: DecodeDifferent::Encode("Module1_9"),
+				storage: Some(DecodeDifferent::Encode(FnEncode(|| StorageMetadata {
+					prefix: DecodeDifferent::Encode("Instance9Module"),
+					entries: DecodeDifferent::Encode(&[]),
+				}))),
+				calls: Some(DecodeDifferent::Encode(FnEncode(|| &[FunctionMetadata {
+					name: DecodeDifferent::Encode("fail"),
+					arguments: DecodeDifferent::Encode(&[]),
+					documentation: DecodeDifferent::Encode(&[]),
+				}]))),
+				event: Some(DecodeDifferent::Encode(FnEncode(|| &[EventMetadata {
+					name: DecodeDifferent::Encode("A"),
+					arguments: DecodeDifferent::Encode(&["AccountId"]),
+					documentation: DecodeDifferent::Encode(&[]),
+				}]))),
+				constants: DecodeDifferent::Encode(FnEncode(|| &[])),
+				errors: DecodeDifferent::Encode(FnEncode(|| &[])),
+				index: 13,
+			},
+		]),
+		extrinsic: ExtrinsicMetadata {
+			version: 4,
+			signed_extensions: vec![DecodeDifferent::Encode("UnitSignedExtension")],
+		},
+	};
+	pretty_assertions::assert_eq!(Runtime::metadata().1, RuntimeMetadata::V12(expected_metadata));
+}
+
 #[test]
 fn pallet_in_runtime_is_correct() {
-	assert_eq!(PalletInfo::index::<System>().unwrap(), 0);
+	assert_eq!(PalletInfo::index::<System>().unwrap(), 30);
 	assert_eq!(PalletInfo::name::<System>().unwrap(), "System");

-	assert_eq!(PalletInfo::index::<Module1_2>().unwrap(), 3);
+	assert_eq!(PalletInfo::index::<Module1_1>().unwrap(), 31);
+	assert_eq!(PalletInfo::name::<Module1_1>().unwrap(), "Module1_1");
+
+	assert_eq!(PalletInfo::index::<Module2>().unwrap(), 32);
+	assert_eq!(PalletInfo::name::<Module2>().unwrap(), "Module2");
+
+	assert_eq!(PalletInfo::index::<Module1_2>().unwrap(), 33);
 	assert_eq!(PalletInfo::name::<Module1_2>().unwrap(), "Module1_2");

-	assert_eq!(PalletInfo::index::<Module2>().unwrap(), 2);
-	assert_eq!(PalletInfo::name::<Module2>().unwrap(), "Module2");
+	assert_eq!(PalletInfo::index::<Module1_3>().unwrap(), 6);
+	assert_eq!(PalletInfo::name::<Module1_3>().unwrap(), "Module1_3");
+
+	assert_eq!(PalletInfo::index::<Module1_4>().unwrap(), 3);
+	assert_eq!(PalletInfo::name::<Module1_4>().unwrap(), "Module1_4");
+
+	assert_eq!(PalletInfo::index::<Module1_5>().unwrap(), 4);
+	assert_eq!(PalletInfo::name::<Module1_5>().unwrap(), "Module1_5");
+
+	assert_eq!(PalletInfo::index::<Module1_6>().unwrap(), 1);
+	assert_eq!(PalletInfo::name::<Module1_6>().unwrap(), "Module1_6");
+
+	assert_eq!(PalletInfo::index::<Module1_7>().unwrap(), 2);
+	assert_eq!(PalletInfo::name::<Module1_7>().unwrap(), "Module1_7");
+
+	assert_eq!(PalletInfo::index::<Module1_8>().unwrap(), 12);
+	assert_eq!(PalletInfo::name::<Module1_8>().unwrap(), "Module1_8");
+
+	assert_eq!(PalletInfo::index::<Module1_9>().unwrap(), 13);
+	assert_eq!(PalletInfo::name::<Module1_9>().unwrap(), "Module1_9");
 }
@@ -0,0 +1,14 @@
+use frame_support::construct_runtime;
+
+construct_runtime! {
+	pub enum Runtime where
+		UncheckedExtrinsic = UncheckedExtrinsic,
+		Block = Block,
+		NodeBlock = Block,
+	{
+		System: system::{},
+		Pallet1: pallet1::{} = 0,
+	}
+}
+
+fn main() {}
@@ -0,0 +1,11 @@
+error: Module indices are conflicting: Both modules System and Pallet1 are at index 0
+ --> $DIR/conflicting_index.rs:9:3
+  |
+9 |         System: system::{},
+  |         ^^^^^^
+
+error: Module indices are conflicting: Both modules System and Pallet1 are at index 0
+  --> $DIR/conflicting_index.rs:10:3
+   |
+10 |         Pallet1: pallet1::{} = 0,
+   |         ^^^^^^^
@@ -0,0 +1,16 @@
+use frame_support::construct_runtime;
+
+construct_runtime! {
+	pub enum Runtime where
+		UncheckedExtrinsic = UncheckedExtrinsic,
+		Block = Block,
+		NodeBlock = Block,
+	{
+		System: system::{} = 5,
+		Pallet1: pallet1::{} = 3,
+		Pallet2: pallet2::{},
+		Pallet3: pallet3::{},
+	}
+}
+
+fn main() {}
@@ -0,0 +1,11 @@
+error: Module indices are conflicting: Both modules System and Pallet3 are at index 5
+ --> $DIR/conflicting_index_2.rs:9:3
+  |
+9 |         System: system::{} = 5,
+  |         ^^^^^^
+
+error: Module indices are conflicting: Both modules System and Pallet3 are at index 5
+  --> $DIR/conflicting_index_2.rs:12:3
+   |
+12 |         Pallet3: pallet3::{},
+   |         ^^^^^^^
@@ -0,0 +1,14 @@
+use frame_support::construct_runtime;
+
+construct_runtime! {
+	pub enum Runtime where
+		UncheckedExtrinsic = UncheckedExtrinsic,
+		Block = Block,
+		NodeBlock = Block,
+	{
+		System: system::{} = 255,
+		Pallet256: pallet256::{},
+	}
+}
+
+fn main() {}
@@ -0,0 +1,5 @@
+error: Module index doesn't fit into u8, index is 256
+  --> $DIR/more_than_256_modules.rs:10:3
+   |
+10 |         Pallet256: pallet256::{},
+   |         ^^^^^^^^^
@@ -31,7 +31,10 @@ pub trait Trait: 'static + Eq + Clone {
 }

 frame_support::decl_module! {
-	pub struct Module<T: Trait> for enum Call where origin: T::Origin, system=self {}
+	pub struct Module<T: Trait> for enum Call where origin: T::Origin, system=self {
+		#[weight = 0]
+		fn noop(origin) {}
+	}
 }

 impl<T: Trait> Module<T> {