Add execute_with to TestExternalities (#3793)

This function executes the given closure in a context where the test
externalities are set. This makes the srml tests easier to write, as the
test externalities need to be created anyway.

substrate/core/sr-primitives/Cargo.toml

@@ -16,7 +16,6 @@ runtime_io = { package = "sr-io", path = "../sr-io", default-features = false }
 log = { version = "0.4.8", optional = true }
 paste = "0.1.6"
 rand = { version = "0.7.2", optional = true }
-externalities = { package = "substrate-externalities", path = "../externalities", optional = true }
 impl-trait-for-tuples = "0.1.2"
 
 [dev-dependencies]
@@ -38,5 +37,4 @@ std = [
 	"primitives/std",
 	"app-crypto/std",
 	"rand",
-	"externalities",
 ]

substrate/core/sr-primitives/src/lib.rs

@@ -73,9 +73,6 @@ pub use sr_arithmetic::helpers_128bit;
 /// Re-export big_uint stiff.
 pub use sr_arithmetic::biguint;
 
-#[cfg(feature = "std")]
-pub use externalities::set_and_run_with_externalities;
-
 /// An abstraction over justification for a block's validity under a consensus algorithm.
 ///
 /// Essentially a finality proof. The exact formulation will vary between consensus

substrate/core/sr-primitives/src/offchain/http.rs

@@ -512,7 +512,6 @@ impl<'a> HeadersIterator<'a> {
 #[cfg(test)]
 mod tests {
 	use super::*;
-	use crate::set_and_run_with_externalities;
 	use runtime_io::TestExternalities;
 	use substrate_offchain::testing;
 	use primitives::offchain::OffchainExt;
@@ -523,7 +522,7 @@ mod tests {
 		let mut t = TestExternalities::default();
 		t.register_extension(OffchainExt::new(offchain));
 
-		set_and_run_with_externalities(&mut t, || {
+		t.execute_with(|| {
 			let request: Request = Request::get("http://localhost:1234");
 			let pending = request
 				.add_header("X-Auth", "hunter2")
@@ -564,7 +563,7 @@ mod tests {
 		let mut t = TestExternalities::default();
 		t.register_extension(OffchainExt::new(offchain));
 
-		set_and_run_with_externalities(&mut t, || {
+		t.execute_with(|| {
 			let pending = Request::default()
 				.method(Method::Post)
 				.url("http://localhost:1234")

substrate/core/state-machine/src/testing.rs

@@ -113,6 +113,13 @@ impl<H: Hasher<Out=H256>, N: ChangesTrieBlockNumber> TestExternalities<H, N> {
 
 		self.backend.update(top.chain(children).collect())
 	}
+
+	/// Execute the given closure while `self` is set as externalities.
+	///
+	/// Returns the result of the given closure.
+	pub fn execute_with<R>(&mut self, execute: impl FnOnce() -> R) -> R {
+		externalities::set_and_run_with_externalities(self, execute)
+	}
 }
 
 impl<H: Hasher<Out=H256>, N: ChangesTrieBlockNumber> std::fmt::Debug for TestExternalities<H, N> {

substrate/core/test-runtime/src/system.rs

@@ -321,7 +321,6 @@ mod tests {
 
 	use runtime_io::TestExternalities;
 	use substrate_test_runtime_client::{AccountKeyring, Sr25519Keyring};
-	use sr_primitives::set_and_run_with_externalities;
 	use crate::{Header, Transfer, WASM_BINARY};
 	use primitives::{NeverNativeValue, map, traits::CodeExecutor};
 	use substrate_executor::{NativeExecutor, WasmExecutionMethod, native_executor_instance};
@@ -371,18 +370,14 @@ mod tests {
 			extrinsics: vec![],
 		};
 
-		set_and_run_with_externalities(&mut new_test_ext(), || polish_block(&mut b));
+		new_test_ext().execute_with(|| polish_block(&mut b));
 
 		block_executor(b, &mut new_test_ext());
 	}
 
 	#[test]
 	fn block_import_works_native() {
-		block_import_works(|b, ext| {
-			set_and_run_with_externalities(ext, || {
-				execute_block(b);
-			});
-		});
+		block_import_works(|b, ext| ext.execute_with(|| execute_block(b)));
 	}
 
 	#[test]
@@ -420,7 +415,7 @@ mod tests {
 		};
 
 		let mut dummy_ext = new_test_ext();
-		set_and_run_with_externalities(&mut dummy_ext, || polish_block(&mut b1));
+		dummy_ext.execute_with(|| polish_block(&mut b1));
 
 		let mut b2 = Block {
 			header: Header {
@@ -446,26 +441,26 @@ mod tests {
 			],
 		};
 
-		set_and_run_with_externalities(&mut dummy_ext, || polish_block(&mut b2));
+		dummy_ext.execute_with(|| polish_block(&mut b2));
 		drop(dummy_ext);
 
 		let mut t = new_test_ext();
 
-		set_and_run_with_externalities(&mut t, || {
+		t.execute_with(|| {
 			assert_eq!(balance_of(AccountKeyring::Alice.into()), 111);
 			assert_eq!(balance_of(AccountKeyring::Bob.into()), 0);
 		});
 
 		block_executor(b1, &mut t);
 
-		set_and_run_with_externalities(&mut t, || {
+		t.execute_with(|| {
 			assert_eq!(balance_of(AccountKeyring::Alice.into()), 42);
 			assert_eq!(balance_of(AccountKeyring::Bob.into()), 69);
 		});
 
 		block_executor(b2, &mut t);
 
-		set_and_run_with_externalities(&mut t, || {
+		t.execute_with(|| {
 			assert_eq!(balance_of(AccountKeyring::Alice.into()), 0);
 			assert_eq!(balance_of(AccountKeyring::Bob.into()), 42);
 			assert_eq!(balance_of(AccountKeyring::Charlie.into()), 69);
@@ -474,11 +469,7 @@ mod tests {
 
 	#[test]
 	fn block_import_with_transaction_works_native() {
-		block_import_with_transaction_works(|b, ext| {
-			set_and_run_with_externalities(ext, || {
-				execute_block(b);
-			});
-		});
+		block_import_with_transaction_works(|b, ext| ext.execute_with(|| execute_block(b)));
 	}
 
 	#[test]