Handle properly stringifying multiline (boolean) expressions

spec/compiler/parser/to_s_spec.cr

@@ -749,4 +749,86 @@ describe "ASTNode#to_s" do
         .map do |v| v end
     %}
     CR
+
+  expect_to_s <<-'CR'
+    {%
+      (
+        1
+      )
+    %}
+    CR
+
+  expect_to_s <<-'CR'
+    {%
+      (
+        1
+        2
+      )
+    %}
+    CR
+
+  expect_to_s <<-'CR'
+    {%
+      (
+        true ||
+        false
+      )
+    %}
+    CR
+
+  expect_to_s <<-'CR'
+    {%
+      (
+        true ||
+        false
+      ) && true
+    %}
+    CR
+
+  expect_to_s <<-'CR'
+    {%
+      true && (
+        true ||
+        false
+      )
+    %}
+    CR
+
+  expect_to_s <<-'CR', <<-'CR'
+    {%
+      if (v = 5) &&
+        (
+          1 < v ||
+          (v < 4 && 5 < 6)
+        )
+        123
+      end
+    %}
+    CR
+    {%
+      if (v = 5) &&
+      (
+        1 < v ||
+        (v < 4 && 5 < 6)
+      )
+        123
+      end
+    %}
+    CR
+
+  expect_to_s <<-'CR', <<-'CR'
+    {%
+      if (true || false) &&
+        true
+        1
+      end
+    %}
+    CR
+    {%
+      if (true || false) &&
+      true
+        1
+      end
+    %}
+    CR
 end

src/compiler/crystal/syntax/to_s.cr

@@ -269,9 +269,13 @@ module Crystal
     end
 
     def visit(node : Expressions)
+      is_multiline = false
+
       case node.keyword
       in .paren?
-        @str << '('
+        # Handled via dedicated #in_parenthesis call below
+        is_multiline = (loc = node.location) && (first_loc = node.expressions.first?.try &.location) && (first_loc.line_number > loc.line_number)
+        append_indent if is_multiline
       in .begin?
         @str << "begin"
         @indent += 1
@@ -280,33 +284,35 @@ module Crystal
         # Not a special condition
       end
 
-      if @inside_macro > 0
-        node.expressions.each &.accept self
-      else
-        last_node = nil
+      in_parenthesis node.keyword.paren?, is_multiline do
+        if @inside_macro > 0
+          node.expressions.each &.accept self
+        else
+          last_node = nil
 
-        node.expressions.each_with_index do |exp, i|
-          unless exp.nop?
-            write_extra_newlines (last_node || exp).end_location, exp.location
+          node.expressions.each_with_index do |exp, i|
+            unless exp.nop?
+              write_extra_newlines (last_node || exp).end_location, exp.location
 
-            append_indent unless node.keyword.paren? && i == 0
-            exp.accept self
+              append_indent unless node.keyword.paren? && i == 0
+              exp.accept self
 
-            if (root = @root_level_macro_expressions) && root.same?(node) && i == node.expressions.size - 1
-              # Do not add a trailing newline after the last node in the root `Expressions` within a `MacroExpression`.
-              # This is handled by the `MacroExpression` logic.
-            elsif !(node.keyword.paren? && i == node.expressions.size - 1)
-              newline
-            end
+              if (root = @root_level_macro_expressions) && root.same?(node) && i == node.expressions.size - 1
+                # Do not add a trailing newline after the last node in the root `Expressions` within a `MacroExpression`.
+                # This is handled by the `MacroExpression` logic.
+              elsif !(node.keyword.paren? && i == node.expressions.size - 1)
+                newline
+              end
 
-            last_node = exp
+              last_node = exp
+            end
           end
         end
       end
 
       case node.keyword
       in .paren?
-        @str << ')'
+        # Handled via dedicated #in_parenthesis call above
       in .begin?
         @indent -= 1
         append_indent
@@ -585,18 +591,28 @@ module Crystal
       end
     end
 
-    def in_parenthesis(need_parens, &)
-      if need_parens
-        @str << '('
-        yield
-        @str << ')'
-      else
-        yield
+    def in_parenthesis(need_parens, is_multiline = false, &)
+      @str << '(' if need_parens
+
+      if is_multiline
+        newline
+        @indent += 1
+        append_indent
       end
+
+      yield
+
+      if is_multiline
+        newline
+        @indent -= 1
+        append_indent
+      end
+
+      @str << ')' if need_parens
     end
 
-    def in_parenthesis(need_parens, node)
-      in_parenthesis(need_parens) do
+    def in_parenthesis(need_parens, node, is_multiline = false)
+      in_parenthesis(need_parens, is_multiline) do
         if node.is_a?(Expressions) && node.expressions.size == 1
           node.expressions.first.accept self
         else
@@ -1269,14 +1285,23 @@ module Crystal
 
     def to_s_binary(node, op)
       left_needs_parens = need_parens(node.left)
-      in_parenthesis(left_needs_parens, node.left)
+      left_parens_multiline = left_needs_parens && (begin_loc = node.left.location) && (end_loc = node.left.end_location) && (end_loc.line_number > begin_loc.line_number)
+      in_parenthesis(left_needs_parens, node.left, left_parens_multiline)
 
       @str << ' '
       @str << op
-      @str << ' '
+
+      if (right_loc = node.right.location) && (left_end_loc = node.left.end_location) && (right_loc.line_number > left_end_loc.line_number)
+        newline
+        append_indent
+      else
+        @str << ' '
+      end
 
       right_needs_parens = need_parens(node.right)
-      in_parenthesis(right_needs_parens, node.right)
+      right_parens_multiline = right_needs_parens && (begin_loc = node.right.location) && (end_loc = node.right.end_location) && (end_loc.line_number > begin_loc.line_number)
+      in_parenthesis(right_needs_parens, node.right, right_parens_multiline)
+
       false
     end