Configure group_imports

Configure `group_imports = "StdExternalCrate"`.

The benefit of this option is that it increases uniformity in the code
base over the default "Preserve", while saving devs needing to think
about where they place their import statements (for those that do not
use tooling to add them).

Author: tcharding

examples/htlc.rs

@@ -17,11 +17,12 @@
 extern crate bitcoin;
 extern crate miniscript;
 
+use std::str::FromStr;
+
 use bitcoin::Network;
 use miniscript::descriptor::Wsh;
 use miniscript::policy::{Concrete, Liftable};
 use miniscript::DescriptorTrait;
-use std::str::FromStr;
 
 fn main() {
     //HTLC policy with 10:1 odds for happy(co-operative) case compared to uncooperative case

examples/parse.rs

@@ -14,11 +14,11 @@
 
 //! Example: Parsing a descriptor from a string
 
+use std::str::FromStr;
+
 use bitcoin;
 use miniscript;
-
 use miniscript::{descriptor::DescriptorType, Descriptor, DescriptorTrait};
-use std::str::FromStr;
 
 fn main() {
     let my_descriptor = miniscript::Descriptor::<bitcoin::PublicKey>::from_str(

examples/psbt.rs

@@ -1,5 +1,4 @@
 use bitcoin;
-
 use bitcoin::consensus::encode::deserialize;
 use bitcoin::hashes::hex::FromHex;
 use miniscript::psbt::PsbtExt;

examples/sign_multisig.rs

@@ -14,14 +14,14 @@
 
 //! Example: Signing a 2-of-3 multisignature
 
-use bitcoin;
-use miniscript;
+use std::collections::HashMap;
+use std::str::FromStr;
 
+use bitcoin;
 use bitcoin::blockdata::witness::Witness;
 use bitcoin::secp256k1; // secp256k1 re-exported from rust-bitcoin
+use miniscript;
 use miniscript::DescriptorTrait;
-use std::collections::HashMap;
-use std::str::FromStr;
 
 fn main() {
     // Avoid repeatedly typing a pretty-common descriptor type

examples/verify_tx.rs

@@ -14,14 +14,14 @@
 
 //! Example: Verifying a signed transaction
 
-use bitcoin;
-use miniscript;
+use std::str::FromStr;
 
+use bitcoin;
 use bitcoin::consensus::Decodable;
 use bitcoin::util::sighash;
 use bitcoin::{secp256k1, TxOut}; // secp256k1 re-exported from rust-bitcoin
+use miniscript;
 use miniscript::interpreter::KeySigPair;
-use std::str::FromStr;
 
 fn main() {
     // tx `f27eba163c38ad3f34971198687a3f1882b7ec818599ffe469a8440d82261c98`

examples/xpub_descriptors.rs

@@ -14,10 +14,10 @@
 
 //! Example: Parsing a xpub and getting address
 
+use std::str::FromStr;
+
 use miniscript::bitcoin::{self, secp256k1};
 use miniscript::{Descriptor, DescriptorPublicKey, DescriptorTrait, TranslatePk2};
-
-use std::str::FromStr;
 fn main() {
     // For deriving from descriptors, we need to provide a secp context
     let secp_ctx = secp256k1::Secp256k1::verification_only();

rustfmt.toml

@@ -28,7 +28,7 @@ where_single_line = false
 imports_indent = "Block"
 imports_layout = "Mixed"
 imports_granularity = "Preserve"
-group_imports = "Preserve"
+group_imports = "StdExternalCrate" # Default "Preserve"
 reorder_imports = true
 reorder_modules = true
 reorder_impl_items = false

src/descriptor/bare.rs

@@ -22,6 +22,10 @@ use std::{fmt, str::FromStr};
 
 use bitcoin::{self, blockdata::script, Script};
 
+use super::{
+    checksum::{desc_checksum, verify_checksum},
+    DescriptorTrait,
+};
 use crate::expression::{self, FromTree};
 use crate::miniscript::context::ScriptContext;
 use crate::policy::{semantic, Liftable};
@@ -31,11 +35,6 @@ use crate::{
     TranslatePk,
 };
 
-use super::{
-    checksum::{desc_checksum, verify_checksum},
-    DescriptorTrait,
-};
-
 /// Create a Bare Descriptor. That is descriptor that is
 /// not wrapped in sh or wsh. This covers the Pk descriptor
 #[derive(Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]

src/descriptor/checksum.rs

@@ -101,9 +101,10 @@ pub(super) fn verify_checksum(s: &str) -> Result<&str, Error> {
 }
 #[cfg(test)]
 mod test {
-    use super::*;
     use std::str;
 
+    use super::*;
+
     macro_rules! check_expected {
         ($desc: expr, $checksum: expr) => {
             assert_eq!(desc_checksum($desc).unwrap(), $checksum);

src/descriptor/key.rs

@@ -715,11 +715,11 @@ impl MiniscriptKey for DescriptorPublicKey {
 
 #[cfg(test)]
 mod test {
-    use super::{DescriptorKeyParseError, DescriptorPublicKey, DescriptorSecretKey};
+    use std::str::FromStr;
 
     use bitcoin::secp256k1;
 
-    use std::str::FromStr;
+    use super::{DescriptorKeyParseError, DescriptorPublicKey, DescriptorSecretKey};
 
     #[test]
     fn parse_descriptor_key_errors() {