fix(solc): flatten replacement target location (#846)

* adjust the end location

* upd changelog

CHANGELOG.md

@@ -38,6 +38,8 @@
 
 ### Unreleased
 
+- Fix flatten replacement target location
+  [#846](https://github.com/gakonst/ethers-rs/pull/846)
 - Fix duplicate files during flattening
   [#813](https://github.com/gakonst/ethers-rs/pull/813)
 - Add ability to flatten file imports

ethers-solc/src/resolver.rs

@@ -485,7 +485,8 @@ impl<T> SolDataUnit<T> {
     pub fn loc_by_offset(&self, offset: isize) -> (usize, usize) {
         (
             offset.saturating_add(self.loc.start as isize) as usize,
-            offset.saturating_add(self.loc.end as isize) as usize,
+            // make the end location exclusive
+            offset.saturating_add(self.loc.end as isize + 1) as usize,
         )
     }
 }

ethers-solc/tests/project.rs

@@ -376,4 +376,5 @@ fn can_flatten_file_with_duplicates() {
     assert_eq!(result.matches("contract Foo {").count(), 1);
     assert_eq!(result.matches("contract Bar {").count(), 1);
     assert_eq!(result.matches("contract FooBar {").count(), 1);
+    assert_eq!(result.matches(";").count(), 1);
 }