Fix import_granularity option when the use tree has an alias

src/imports.rs

@@ -238,7 +238,8 @@ impl fmt::Display for UseSegment {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {
             UseSegment::Glob => write!(f, "*"),
-            UseSegment::Ident(ref s, _) => write!(f, "{}", s),
+            UseSegment::Ident(ref s, Some(ref alias)) => write!(f, "{} as {}", s, alias),
+            UseSegment::Ident(ref s, None) => write!(f, "{}", s),
             UseSegment::Slf(..) => write!(f, "self"),
             UseSegment::Super(..) => write!(f, "super"),
             UseSegment::Crate(..) => write!(f, "crate"),
@@ -622,7 +623,8 @@ impl UseTree {
     fn merge(&mut self, other: &UseTree, merge_by: SharedPrefix) {
         let mut prefix = 0;
         for (a, b) in self.path.iter().zip(other.path.iter()) {
-            if a.equal_except_alias(b) {
+            // only discard the alias at the root of the tree
+            if (prefix == 0 && a.equal_except_alias(b)) || a == b {
                 prefix += 1;
             } else {
                 break;

tests/source/5131_crate.rs

@@ -0,0 +1,14 @@
+// rustfmt-imports_granularity: Crate
+
+use foo::a;
+use foo::a;
+use foo::b;
+use foo::b as b2;
+use foo::b::f;
+use foo::b::g;
+use foo::b::g as g2;
+use foo::c;
+use foo::d::e;
+use qux::h;
+use qux::h as h2;
+use qux::i;

tests/source/5131_module.rs

@@ -0,0 +1,33 @@
+// rustfmt-imports_granularity: Module
+
+#![allow(dead_code)]
+
+mod a {
+    pub mod b {
+        pub struct Data {
+            pub a: i32,
+        }
+    }
+
+    use crate::a::b::Data;
+    use crate::a::b::Data as Data2;
+
+    pub fn data(a: i32) -> Data {
+        Data { a }
+    }
+
+    pub fn data2(a: i32) -> Data2 {
+        Data2 { a }
+    }
+
+    #[cfg(test)]
+    mod tests {
+        use super::*;
+
+        #[test]
+        pub fn test() {
+            data(1);
+            data2(1);
+        }
+    }
+}

tests/source/5131_one.rs

@@ -0,0 +1,15 @@
+// rustfmt-imports_granularity: One
+
+pub use foo::x;
+pub use foo::x as x2;
+pub use foo::y;
+use bar::a;
+use bar::b;
+use bar::b::f;
+use bar::b::f as f2;
+use bar::b::g;
+use bar::c;
+use bar::d::e;
+use bar::d::e as e2;
+use qux::h;
+use qux::i;

tests/target/5131_crate.rs

@@ -0,0 +1,9 @@
+// rustfmt-imports_granularity: Crate
+
+use foo::{
+    a, b, b as b2,
+    b::{f, g, g as g2},
+    c,
+    d::e,
+};
+use qux::{h, h as h2, i};

tests/target/5131_module.rs

@@ -0,0 +1,32 @@
+// rustfmt-imports_granularity: Module
+
+#![allow(dead_code)]
+
+mod a {
+    pub mod b {
+        pub struct Data {
+            pub a: i32,
+        }
+    }
+
+    use crate::a::b::{Data, Data as Data2};
+
+    pub fn data(a: i32) -> Data {
+        Data { a }
+    }
+
+    pub fn data2(a: i32) -> Data2 {
+        Data2 { a }
+    }
+
+    #[cfg(test)]
+    mod tests {
+        use super::*;
+
+        #[test]
+        pub fn test() {
+            data(1);
+            data2(1);
+        }
+    }
+}

tests/target/5131_one.rs

@@ -0,0 +1,12 @@
+// rustfmt-imports_granularity: One
+
+pub use foo::{x, x as x2, y};
+use {
+    bar::{
+        a,
+        b::{self, f, g},
+        c,
+        d::{e, e as e2},
+    },
+    qux::{h, i},
+};