Configure formatting style to imports_granularity = "Module".

.github/workflows/format.yml

@@ -1,11 +1,11 @@
 on: [push, pull_request]
-name: Formatting on stable toolchain
+name: Formatting on nightly toolchain
 jobs:
   format:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: dtolnay/rust-toolchain@stable
+      - uses: dtolnay/rust-toolchain@nightly
         with:
           components: rustfmt
 

rustfmt.toml

@@ -0,0 +1 @@
+imports_granularity = "Module"

src/decode/lzma.rs

@@ -1,8 +1,7 @@
 use crate::decode::lzbuffer::{LzBuffer, LzCircularBuffer};
 use crate::decode::rangecoder;
 use crate::decode::rangecoder::RangeDecoder;
-use crate::decompress::Options;
-use crate::decompress::UnpackedSize;
+use crate::decompress::{Options, UnpackedSize};
 use crate::error;
 use byteorder::{LittleEndian, ReadBytesExt};
 use std::io;

src/decode/lzma2.rs

@@ -1,8 +1,6 @@
-use crate::decode::lzbuffer;
 use crate::decode::lzbuffer::LzBuffer;
-use crate::decode::lzma::DecoderState;
-use crate::decode::lzma::LzmaProperties;
-use crate::decode::rangecoder;
+use crate::decode::lzma::{DecoderState, LzmaProperties};
+use crate::decode::{lzbuffer, rangecoder};
 use crate::error;
 use byteorder::{BigEndian, ReadBytesExt};
 use std::io;

src/decode/util.rs

@@ -1,5 +1,4 @@
-use std::hash;
-use std::io;
+use std::{hash, io};
 
 pub fn read_tag<R: io::BufRead>(input: &mut R, tag: &[u8]) -> io::Result<bool> {
     let mut buf = vec![0; tag.len()];

src/encode/util.rs

@@ -1,5 +1,4 @@
-use std::hash;
-use std::io;
+use std::{hash, io};
 
 // A Write computing a digest on the bytes written.
 pub struct HasherWrite<'a, W, H>

src/encode/xz.rs

@@ -1,6 +1,5 @@
 use crate::decode;
-use crate::encode::lzma2;
-use crate::encode::util;
+use crate::encode::{lzma2, util};
 use crate::xz::{footer, header, CheckMethod, StreamFlags};
 use byteorder::{LittleEndian, WriteBytesExt};
 use crc::{crc32, Hasher32};

src/error.rs

@@ -1,8 +1,7 @@
 //! Error handling.
 
 use std::fmt::Display;
-use std::io;
-use std::result;
+use std::{io, result};
 
 /// Library errors.
 #[derive(Debug)]