feat: better apply indentation

src/alejandra_engine/src/rules/key_value.rs

@@ -6,9 +6,9 @@ pub(crate) fn rule(
 
     let mut children = crate::children::Children::new(build_ctx, node);
 
-    let vertical = children.has_comments()
-        || children.has_newlines()
-        || build_ctx.vertical;
+    let vertical = build_ctx.vertical
+        || children.has_comments()
+        || children.has_newlines();
 
     // a
     let child = children.get_next().unwrap();
@@ -103,7 +103,12 @@ pub(crate) fn rule(
         ) || (matches!(
             child_expr.kind(),
             rnix::SyntaxKind::NODE_APPLY
-        ) && !newlines)
+        )
+            && crate::utils::second_through_penultimate_line_are_indented(
+                build_ctx,
+                child_expr.clone(),
+                false,
+            ))
         {
             steps.push_back(crate::builder::Step::Whitespace);
         } else {

src/alejandra_engine/src/rules/paren.rs

@@ -28,9 +28,10 @@ pub(crate) fn rule(
                 | rnix::SyntaxKind::NODE_LAMBDA
                 | rnix::SyntaxKind::NODE_SELECT
                 | rnix::SyntaxKind::NODE_WITH
-        ) && second_through_penultimate_line_are_not_indented(
+        ) && !crate::utils::second_through_penultimate_line_are_indented(
             build_ctx,
             expression.element.clone(),
+            matches!(expression.element.kind(), rnix::SyntaxKind::NODE_LAMBDA),
         );
 
     // opener
@@ -96,31 +97,3 @@ pub(crate) fn rule(
 
     steps
 }
-
-fn second_through_penultimate_line_are_not_indented(
-    build_ctx: &crate::builder::BuildCtx,
-    element: rnix::SyntaxElement,
-) -> bool {
-    let mut build_ctx =
-        crate::builder::BuildCtx { force_wide: false, ..build_ctx.clone() };
-
-    let formatted =
-        crate::builder::build(&mut build_ctx, element).unwrap().to_string();
-
-    let formatted_lines: Vec<&str> = formatted.split('\n').collect();
-
-    if formatted_lines.len() <= 2 {
-        return false;
-    }
-
-    let whitespace = format!("{0:<1$}  ", "", 2 * build_ctx.indentation);
-    let lambda = format!("{0:<1$}}}:", "", 2 * build_ctx.indentation);
-    let in_ = format!("{0:<1$}in", "", 2 * build_ctx.indentation);
-
-    formatted_lines.iter().skip(1).rev().skip(1).any(|line| {
-        !line.is_empty()
-            && !(line.starts_with(&whitespace)
-                || line.starts_with(&lambda)
-                || line.starts_with(&in_))
-    })
-}

src/alejandra_engine/src/utils.rs

@@ -5,3 +5,32 @@ pub(crate) fn has_newlines(string: &str) -> bool {
 pub(crate) fn count_newlines(string: &str) -> usize {
     string.chars().filter(|c| *c == '\n').count()
 }
+
+pub(crate) fn second_through_penultimate_line_are_indented(
+    build_ctx: &crate::builder::BuildCtx,
+    element: rnix::SyntaxElement,
+    if_leq_than_two_lines: bool,
+) -> bool {
+    let mut build_ctx =
+        crate::builder::BuildCtx { force_wide: false, ..build_ctx.clone() };
+
+    let formatted =
+        crate::builder::build(&mut build_ctx, element).unwrap().to_string();
+
+    let formatted_lines: Vec<&str> = formatted.split('\n').collect();
+
+    if formatted_lines.len() <= 2 {
+        return if_leq_than_two_lines;
+    }
+
+    let whitespace = format!("{0:<1$}  ", "", 2 * build_ctx.indentation);
+    let lambda = format!("{0:<1$}}}:", "", 2 * build_ctx.indentation);
+    let in_ = format!("{0:<1$}in", "", 2 * build_ctx.indentation);
+
+    formatted_lines.iter().skip(1).rev().skip(1).all(|line| {
+        line.is_empty()
+            || line.starts_with(&lambda)
+            || line.starts_with(&in_)
+            || line.starts_with(&whitespace)
+    })
+}

src/alejandra_engine/tests/cases/apply/in

@@ -1,4 +1,6 @@
 [
+  (a
+  b)
   (
     (a  b)
     (a b)

src/alejandra_engine/tests/cases/apply/out

@@ -1,4 +1,6 @@
 [
+  (a
+    b)
   ((a b)
     (a b)
     (a
@@ -57,17 +59,19 @@
       asdf = 1;
     };
 
-    name2 = function arg {
-      asdf = 1;
-    }
-    argument;
+    name2 =
+      function arg {
+        asdf = 1;
+      }
+      argument;
 
-    name3 = function arg {
-      asdf = 1;
-    } {
-      qwer = 12345;
-    }
-    argument;
+    name3 =
+      function arg {
+        asdf = 1;
+      } {
+        qwer = 12345;
+      }
+      argument;
   }
   {
     name4 =
@@ -81,23 +85,26 @@
       argument;
   }
   {
-    option1 = function arg {asdf = 1;} {
-      qwer = 12345;
-      qwer2 = 54321;
-    }
-    lastArg;
+    option1 =
+      function arg {asdf = 1;} {
+        qwer = 12345;
+        qwer2 = 54321;
+      }
+      lastArg;
 
-    option2 = function arg {asdf = 1;} {
-      qwer = 12345;
-      qwer2 = 54321;
-    }
-    lastArg;
+    option2 =
+      function arg {asdf = 1;} {
+        qwer = 12345;
+        qwer2 = 54321;
+      }
+      lastArg;
 
-    option3 = function arg {asdf = 1;}
-    {
-      qwer = 12345;
-      qwer2 = 54321;
-    }
-    lastArg;
+    option3 =
+      function arg {asdf = 1;}
+      {
+        qwer = 12345;
+        qwer2 = 54321;
+      }
+      lastArg;
   }
 ]