Fix else/if formatter.

crates/aiken-lang/src/format.rs

@@ -905,9 +905,9 @@ impl<'comments> Formatter<'comments> {
         let if_branches = self
             .if_branch(break_("if", "if "), branches.first())
             .append(join(
-                branches[1..]
+                branches[1..].iter().map(|branch| {
-                    .iter()
+                    self.if_branch(line().append(break_("} else if", "} else if ")), branch)
-                    .map(|branch| self.if_branch("else if".to_doc(), branch)),
+                }),
                 nil(),
             ));
 

crates/aiken-lang/src/tests/format.rs

@@ -173,6 +173,23 @@ fn test_format_nested_when() {
     assert_fmt(src, expected)
 }
 
+#[test]
+fn test_format_else_if() {
+    let src = indoc! {r#"
+        pub fn foo(xs: List<a>, n: Int) -> List<a> {
+          if n <= 0 {
+            xs
+          } else if n <= 10 {
+            xs
+          } else {
+            xs
+          }
+        }
+    "#};
+
+    assert_fmt(src, src)
+}
+
 #[test]
 fn test_format_imports() {
     let src = indoc! {r#"