check for needs_begin_end_wrapping instead of only checking for pipel…

…ines when emiting single-statement blocks fix gleam-lang#4154

CHANGELOG.md

@@ -50,3 +50,8 @@
 - Fixed a bug where build tool could fail to add new dependencies when
   dependencies with optional dependencies are present in the manifest.
   ([Louis Pilfold](https://github.com/lpil))
+
+- Fixed a bug where a block expression containing a singular record update would
+  produce invalid erlang.
+  ([yoshi](https://github.com/joshi-monster))
+

compiler-core/src/ast.rs

@@ -2377,13 +2377,6 @@ impl TypedStatement {
         }
     }
 
-    pub fn is_non_pipe_expression(&self) -> bool {
-        match self {
-            Statement::Expression(expression) => !expression.is_pipeline(),
-            _ => false,
-        }
-    }
-
     pub fn location(&self) -> SrcSpan {
         match self {
             Statement::Expression(expression) => expression.location(),

compiler-core/src/erlang.rs

@@ -944,8 +944,12 @@ where
 }
 
 fn block<'a>(statements: &'a Vec1<TypedStatement>, env: &mut Env<'a>) -> Document<'a> {
-    if statements.len() == 1 && statements.first().is_non_pipe_expression() {
-        return docvec!['(', statement(statements.first(), env), ')'];
+    if statements.len() == 1 {
+        if let Statement::Expression(expression) = statements.first() {
+            if !needs_begin_end_wrapping(expression) {
+                return docvec!['(', expr(expression, env), ')'];
+            }
+        }
     }
 
     let vars = env.current_scope_vars.clone();

compiler-core/src/erlang/tests/records.rs

@@ -383,3 +383,20 @@ pub fn main() {
 }"
     );
 }
+
+#[test]
+fn nested_record_update_with_blocks() {
+    assert_erl!(
+        "pub type A { A(b: B) }
+pub type B { B(c: C) }
+pub type C { C(val: Int) }
+
+pub fn main(a: A) {
+    A(..a, b: {
+        B(..a.b, c: {
+            C(..a.b.c, val: 0)
+        })
+    })
+}"
+    )
+}

compiler-core/src/erlang/tests/snapshots/gleam_core__erlang__tests__records__nested_record_update_with_blocks.snap

@@ -0,0 +1,43 @@
+---
+source: compiler-core/src/erlang/tests/records.rs
+expression: "pub type A { A(b: B) }\npub type B { B(c: C) }\npub type C { C(val: Int) }\n\npub fn main(a: A) {\n    A(..a, b: {\n        B(..a.b, c: {\n            C(..a.b.c, val: 0)\n        })\n    })\n}"
+---
+----- SOURCE CODE
+pub type A { A(b: B) }
+pub type B { B(c: C) }
+pub type C { C(val: Int) }
+
+pub fn main(a: A) {
+    A(..a, b: {
+        B(..a.b, c: {
+            C(..a.b.c, val: 0)
+        })
+    })
+}
+
+----- COMPILED ERLANG
+-module(my@mod).
+-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).
+
+-export([main/1]).
+-export_type([a/0, b/0, c/0]).
+
+-type a() :: {a, b()}.
+
+-type b() :: {b, c()}.
+
+-type c() :: {c, integer()}.
+
+-file("/root/project/test/my/mod.gleam", 5).
+-spec main(a()) -> a().
+main(A) ->
+    _record = A,
+    {a,
+        begin
+            _record@1 = erlang:element(2, A),
+            {b,
+                begin
+                    _record@2 = erlang:element(2, erlang:element(2, A)),
+                    {c, 0}
+                end}
+        end}.