From e6c90504ac451bebddedf333e01d4690d4be3bc6 Mon Sep 17 00:00:00 2001
From: George Dietrich <dev@dietrich.pub>
Date: Fri, 20 Dec 2024 23:29:33 -0500
Subject: [PATCH 01/10] Handle properly stringifying multiline macro
 expressions

---
 spec/compiler/parser/parser_spec.cr   |  5 +++--
 spec/compiler/parser/to_s_spec.cr     |  6 ++++++
 src/compiler/crystal/syntax/ast.cr    | 18 +++++++++++++-----
 src/compiler/crystal/syntax/parser.cr | 10 ++++++++--
 src/compiler/crystal/syntax/to_s.cr   | 24 ++++++++++++++++++++----
 5 files changed, 50 insertions(+), 13 deletions(-)

diff --git a/spec/compiler/parser/parser_spec.cr b/spec/compiler/parser/parser_spec.cr
index 897e5bf7060c..a6aa70a37395 100644
--- a/spec/compiler/parser/parser_spec.cr
+++ b/spec/compiler/parser/parser_spec.cr
@@ -1118,7 +1118,7 @@ module Crystal
     it_parses "puts {{**1}}", Call.new(nil, "puts", MacroExpression.new(DoubleSplat.new(1.int32)))
     it_parses "{{a = 1 if 2}}", MacroExpression.new(If.new(2.int32, Assign.new("a".var, 1.int32)))
     it_parses "{% a = 1 %}", MacroExpression.new(Assign.new("a".var, 1.int32), output: false)
-    it_parses "{%\na = 1\n%}", MacroExpression.new(Assign.new("a".var, 1.int32), output: false)
+    it_parses "{%\n  a = 1\n%}", MacroExpression.new(Assign.new("a".var, 1.int32), output: false, multiline: true)
     it_parses "{% a = 1 if 2 %}", MacroExpression.new(If.new(2.int32, Assign.new("a".var, 1.int32)), output: false)
     it_parses "{% if 1; 2; end %}", MacroExpression.new(If.new(1.int32, 2.int32), output: false)
     it_parses "{%\nif 1; 2; end\n%}", MacroExpression.new(If.new(1.int32, 2.int32), output: false)
@@ -1128,7 +1128,8 @@ module Crystal
     it_parses "{% unless 1; 2; else 3; end %}", MacroExpression.new(Unless.new(1.int32, 2.int32, 3.int32), output: false)
     it_parses "{% unless 1\n  x\nend %}", MacroExpression.new(Unless.new(1.int32, "x".var), output: false)
     it_parses "{% x unless 1 %}", MacroExpression.new(Unless.new(1.int32, "x".var), output: false)
-    it_parses "{%\n1\n2\n3\n%}", MacroExpression.new(Expressions.new([1.int32, 2.int32, 3.int32] of ASTNode), output: false)
+    it_parses "{%\n  x unless 1\n%}", MacroExpression.new(Unless.new(1.int32, "x".var), output: false, multiline: true)
+    it_parses "{%\n  1\n  2\n  3\n%}", MacroExpression.new(Expressions.new([1.int32, 2.int32, 3.int32] of ASTNode), output: false, multiline: true)
 
     assert_syntax_error "{% unless 1; 2; elsif 3; 4; end %}"
     assert_syntax_error "{% unless 1 %} 2 {% elsif 3 %} 3 {% end %}"
diff --git a/spec/compiler/parser/to_s_spec.cr b/spec/compiler/parser/to_s_spec.cr
index 86464e197267..bfcce21aee2a 100644
--- a/spec/compiler/parser/to_s_spec.cr
+++ b/spec/compiler/parser/to_s_spec.cr
@@ -248,6 +248,12 @@ describe "ASTNode#to_s" do
   expect_to_s "1.//(2, &block)"
   expect_to_s %({% verbatim do %}\n  1{{ 2 }}\n  3{{ 4 }}\n{% end %})
   expect_to_s %({% for foo in bar %}\n  {{ if true\n  foo\n  bar\nend }}\n{% end %})
+  expect_to_s "{% a = 1 %}"
+  expect_to_s "{{ a = 1 }}"
+  expect_to_s "{%\n  1\n  2\n  3\n%}"
+  expect_to_s "{%\n  1\n%}"
+  expect_to_s "{%\n  2 + 2\n%}"
+
   expect_to_s %(asm("nop" ::::))
   expect_to_s %(asm("nop" : "a"(1), "b"(2) : "c"(3), "d"(4) : "e", "f" : "volatile", "alignstack", "intel"))
   expect_to_s %(asm("nop" :: "c"(3), "d"(4) ::))
diff --git a/src/compiler/crystal/syntax/ast.cr b/src/compiler/crystal/syntax/ast.cr
index 9ccd8dda1f69..66d18c308845 100644
--- a/src/compiler/crystal/syntax/ast.cr
+++ b/src/compiler/crystal/syntax/ast.cr
@@ -2187,13 +2187,21 @@ module Crystal
   end
 
   # A macro expression,
-  # surrounded by {{ ... }} (output = true)
-  # or by {% ... %} (output = false)
+  # surrounded by {{ ... }}` (output = true, multiline = false)
+  # or by `{% ... %}` (output = false, multiline = false)
+  #
+  # ```
+  # # (output = false, multiline = true)
+  # {%
+  #   ...
+  # %}
+  # ```
   class MacroExpression < ASTNode
     property exp : ASTNode
     property? output : Bool
+    property? multiline : Bool
 
-    def initialize(@exp : ASTNode, @output = true)
+    def initialize(@exp : ASTNode, @output = true, @multiline : Bool = false)
     end
 
     def accept_children(visitor)
@@ -2201,10 +2209,10 @@ module Crystal
     end
 
     def clone_without_location
-      MacroExpression.new(@exp.clone, @output)
+      MacroExpression.new(@exp.clone, @output, @multiline)
     end
 
-    def_equals_and_hash exp, output?
+    def_equals_and_hash exp, output?, multiline?
   end
 
   # Free text that is part of a macro
diff --git a/src/compiler/crystal/syntax/parser.cr b/src/compiler/crystal/syntax/parser.cr
index 569bbd4d9409..3cf31410b41b 100644
--- a/src/compiler/crystal/syntax/parser.cr
+++ b/src/compiler/crystal/syntax/parser.cr
@@ -3353,7 +3353,13 @@ module Crystal
 
     def parse_macro_control(start_location, macro_state = Token::MacroState.default)
       location = @token.location
-      next_token_skip_space_or_newline
+      next_token_skip_space
+      multiline = false
+
+      if @token.type.newline?
+        multiline = true
+        next_token_skip_space_or_newline
+      end
 
       case @token.value
       when Keyword::FOR
@@ -3440,7 +3446,7 @@ module Crystal
       exps = parse_expressions
       @in_macro_expression = false
 
-      MacroExpression.new(exps, output: false).at(location).at_end(token_end_location)
+      MacroExpression.new(exps, output: false, multiline: multiline).at(location).at_end(token_end_location)
     end
 
     def parse_macro_if(start_location, macro_state, check_end = true, is_unless = false)
diff --git a/src/compiler/crystal/syntax/to_s.cr b/src/compiler/crystal/syntax/to_s.cr
index 4ce9ca7efc43..a6537027ce5e 100644
--- a/src/compiler/crystal/syntax/to_s.cr
+++ b/src/compiler/crystal/syntax/to_s.cr
@@ -728,13 +728,29 @@ module Crystal
     end
 
     def visit(node : MacroExpression)
-      @str << (node.output? ? "{{" : "{% ")
-      @str << ' ' if node.output?
+      @str << (node.output? ? "{{ " : node.multiline? ? "{%" : "{% ")
+
+      if node.multiline?
+        newline
+        @indent += 1
+      end
+
       outside_macro do
+        # If the MacroExpression consists of a single node we need to manually handle appending indent and trailing newline if #multiline?
+        # Otherwise, the Expressions logic handles that for us
+        if !node.exp.is_a? Expressions
+          append_indent
+        end
+
         node.exp.accept self
       end
-      @str << ' ' if node.output?
-      @str << (node.output? ? "}}" : " %}")
+
+      if node.multiline?
+        @indent -= 1
+        newline if !node.exp.is_a? Expressions
+      end
+
+      @str << (node.output? ? " }}" : node.multiline? ? "%}" : " %}")
       false
     end
 

From 3408a66c08d8b86b366c4a6c11ad2b37c0dd37e5 Mon Sep 17 00:00:00 2001
From: George Dietrich <dev@dietrich.pub>
Date: Sat, 21 Dec 2024 09:31:56 -0500
Subject: [PATCH 02/10] Add specs with a newline at only one end

---
 spec/compiler/parser/to_s_spec.cr | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/spec/compiler/parser/to_s_spec.cr b/spec/compiler/parser/to_s_spec.cr
index bfcce21aee2a..a339b120d328 100644
--- a/spec/compiler/parser/to_s_spec.cr
+++ b/spec/compiler/parser/to_s_spec.cr
@@ -253,6 +253,8 @@ describe "ASTNode#to_s" do
   expect_to_s "{%\n  1\n  2\n  3\n%}"
   expect_to_s "{%\n  1\n%}"
   expect_to_s "{%\n  2 + 2\n%}"
+  expect_to_s "{%\n  a = 1 %}", "{%\n  a = 1\n%}"
+  expect_to_s "{% a = 1\n%}", "{% a = 1 %}"
 
   expect_to_s %(asm("nop" ::::))
   expect_to_s %(asm("nop" : "a"(1), "b"(2) : "c"(3), "d"(4) : "e", "f" : "volatile", "alignstack", "intel"))

From 3f32cf996d2da1e9c63258ef772f36d646097547 Mon Sep 17 00:00:00 2001
From: George Dietrich <dev@dietrich.pub>
Date: Sun, 22 Dec 2024 10:31:33 -0500
Subject: [PATCH 03/10] Properly increment indentation within some macro nodes

---
 spec/compiler/parser/to_s_spec.cr   | 66 ++++++++++++++++++++++++++++-
 src/compiler/crystal/syntax/to_s.cr | 13 +++++-
 2 files changed, 76 insertions(+), 3 deletions(-)

diff --git a/spec/compiler/parser/to_s_spec.cr b/spec/compiler/parser/to_s_spec.cr
index a339b120d328..276e0380b9fb 100644
--- a/spec/compiler/parser/to_s_spec.cr
+++ b/spec/compiler/parser/to_s_spec.cr
@@ -246,7 +246,13 @@ describe "ASTNode#to_s" do
   expect_to_s "1.+(&block)"
   expect_to_s "1.//(2, a: 3)"
   expect_to_s "1.//(2, &block)"
-  expect_to_s %({% verbatim do %}\n  1{{ 2 }}\n  3{{ 4 }}\n{% end %})
+  expect_to_s <<-'CR'
+    {% verbatim do %}
+      1{{ 2 }}
+      3{{ 4 }}
+    {% end %}
+    CR
+
   expect_to_s %({% for foo in bar %}\n  {{ if true\n  foo\n  bar\nend }}\n{% end %})
   expect_to_s "{% a = 1 %}"
   expect_to_s "{{ a = 1 }}"
@@ -256,6 +262,64 @@ describe "ASTNode#to_s" do
   expect_to_s "{%\n  a = 1 %}", "{%\n  a = 1\n%}"
   expect_to_s "{% a = 1\n%}", "{% a = 1 %}"
 
+  # FIXME: Should respect significant whitespace
+  expect_to_s <<-'CR', <<-'CR'
+    macro finished
+      {% verbatim do %}
+        {%
+          10
+
+          # Foo
+
+          20
+        %}
+      {% end %}
+    end
+    CR
+    macro finished
+      {% verbatim do %}
+        {%
+          10
+          20
+        %}
+      {% end %}
+    end
+    CR
+
+  # FIXME: Should respect significant whitespace
+  expect_to_s <<-'CR', <<-'CR'
+    macro finished
+      {% verbatim do %}
+        {%
+          10
+
+          # Foo
+          20
+        %}
+      {% end %}
+    end
+    CR
+    macro finished
+      {% verbatim do %}
+        {%
+          10
+          20
+        %}
+      {% end %}
+    end
+    CR
+
+  expect_to_s <<-'CR' # , focus: true
+    macro finished
+      {% verbatim do %}
+        {%
+          10
+          20
+        %}
+      {% end %}
+    end
+    CR
+
   expect_to_s %(asm("nop" ::::))
   expect_to_s %(asm("nop" : "a"(1), "b"(2) : "c"(3), "d"(4) : "e", "f" : "volatile", "alignstack", "intel"))
   expect_to_s %(asm("nop" :: "c"(3), "d"(4) ::))
diff --git a/src/compiler/crystal/syntax/to_s.cr b/src/compiler/crystal/syntax/to_s.cr
index a6537027ce5e..8206f92053d2 100644
--- a/src/compiler/crystal/syntax/to_s.cr
+++ b/src/compiler/crystal/syntax/to_s.cr
@@ -223,7 +223,9 @@ module Crystal
       else
         node.expressions.each_with_index do |exp, i|
           unless exp.nop?
-            append_indent unless node.keyword.paren? && i == 0
+            if !exp.is_a?(MacroLiteral) || !exp.value.blank?
+              append_indent unless node.keyword.paren? && i == 0
+            end
             exp.accept self
             newline unless node.keyword.paren? && i == node.expressions.size - 1
           end
@@ -717,9 +719,11 @@ module Crystal
       end
       newline
 
+      @indent += 1
       inside_macro do
         accept node.body
       end
+      @indent -= 1
 
       # newline
       append_indent
@@ -738,7 +742,7 @@ module Crystal
       outside_macro do
         # If the MacroExpression consists of a single node we need to manually handle appending indent and trailing newline if #multiline?
         # Otherwise, the Expressions logic handles that for us
-        if !node.exp.is_a? Expressions
+        if node.multiline? && !node.exp.is_a?(Expressions)
           append_indent
         end
 
@@ -747,6 +751,7 @@ module Crystal
 
       if node.multiline?
         @indent -= 1
+        append_indent
         newline if !node.exp.is_a? Expressions
       end
 
@@ -806,9 +811,13 @@ module Crystal
 
     def visit(node : MacroVerbatim)
       @str << "{% verbatim do %}"
+
+      @indent += 1
       inside_macro do
         node.exp.accept self
       end
+      @indent -= 1
+
       @str << "{% end %}"
       false
     end

From 18a8195e4a020fafc10e444331307a1a2bb4c36e Mon Sep 17 00:00:00 2001
From: George Dietrich <dev@dietrich.pub>
Date: Sun, 22 Dec 2024 10:32:12 -0500
Subject: [PATCH 04/10] Remove debug reference

---
 spec/compiler/parser/to_s_spec.cr | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/spec/compiler/parser/to_s_spec.cr b/spec/compiler/parser/to_s_spec.cr
index 276e0380b9fb..ed28ecd55dd1 100644
--- a/spec/compiler/parser/to_s_spec.cr
+++ b/spec/compiler/parser/to_s_spec.cr
@@ -309,7 +309,7 @@ describe "ASTNode#to_s" do
     end
     CR
 
-  expect_to_s <<-'CR' # , focus: true
+  expect_to_s <<-'CR'
     macro finished
       {% verbatim do %}
         {%

From 1264859017b75be86697955154e34c14cd897c7e Mon Sep 17 00:00:00 2001
From: George Dietrich <dev@dietrich.pub>
Date: Sun, 22 Dec 2024 10:39:19 -0500
Subject: [PATCH 05/10] This was erroneously included

---
 src/compiler/crystal/syntax/to_s.cr | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/compiler/crystal/syntax/to_s.cr b/src/compiler/crystal/syntax/to_s.cr
index 8206f92053d2..3da5b72fab4a 100644
--- a/src/compiler/crystal/syntax/to_s.cr
+++ b/src/compiler/crystal/syntax/to_s.cr
@@ -223,9 +223,7 @@ module Crystal
       else
         node.expressions.each_with_index do |exp, i|
           unless exp.nop?
-            if !exp.is_a?(MacroLiteral) || !exp.value.blank?
-              append_indent unless node.keyword.paren? && i == 0
-            end
+            append_indent unless node.keyword.paren? && i == 0
             exp.accept self
             newline unless node.keyword.paren? && i == node.expressions.size - 1
           end

From 12b061be342006133e77014d62161484d1948a7a Mon Sep 17 00:00:00 2001
From: George Dietrich <dev@dietrich.pub>
Date: Sun, 22 Dec 2024 18:44:11 -0500
Subject: [PATCH 06/10] Refactor to only touch `ToSVisitor`

---
 spec/compiler/parser/parser_spec.cr   |  6 ++---
 src/compiler/crystal/syntax/ast.cr    | 18 +++++----------
 src/compiler/crystal/syntax/parser.cr | 10 ++-------
 src/compiler/crystal/syntax/to_s.cr   | 32 +++++++++++++++------------
 4 files changed, 28 insertions(+), 38 deletions(-)

diff --git a/spec/compiler/parser/parser_spec.cr b/spec/compiler/parser/parser_spec.cr
index a6aa70a37395..53fbedbcd7c1 100644
--- a/spec/compiler/parser/parser_spec.cr
+++ b/spec/compiler/parser/parser_spec.cr
@@ -1118,7 +1118,7 @@ module Crystal
     it_parses "puts {{**1}}", Call.new(nil, "puts", MacroExpression.new(DoubleSplat.new(1.int32)))
     it_parses "{{a = 1 if 2}}", MacroExpression.new(If.new(2.int32, Assign.new("a".var, 1.int32)))
     it_parses "{% a = 1 %}", MacroExpression.new(Assign.new("a".var, 1.int32), output: false)
-    it_parses "{%\n  a = 1\n%}", MacroExpression.new(Assign.new("a".var, 1.int32), output: false, multiline: true)
+    it_parses "{%\n  a = 1\n%}", MacroExpression.new(Assign.new("a".var, 1.int32), output: false)
     it_parses "{% a = 1 if 2 %}", MacroExpression.new(If.new(2.int32, Assign.new("a".var, 1.int32)), output: false)
     it_parses "{% if 1; 2; end %}", MacroExpression.new(If.new(1.int32, 2.int32), output: false)
     it_parses "{%\nif 1; 2; end\n%}", MacroExpression.new(If.new(1.int32, 2.int32), output: false)
@@ -1128,8 +1128,8 @@ module Crystal
     it_parses "{% unless 1; 2; else 3; end %}", MacroExpression.new(Unless.new(1.int32, 2.int32, 3.int32), output: false)
     it_parses "{% unless 1\n  x\nend %}", MacroExpression.new(Unless.new(1.int32, "x".var), output: false)
     it_parses "{% x unless 1 %}", MacroExpression.new(Unless.new(1.int32, "x".var), output: false)
-    it_parses "{%\n  x unless 1\n%}", MacroExpression.new(Unless.new(1.int32, "x".var), output: false, multiline: true)
-    it_parses "{%\n  1\n  2\n  3\n%}", MacroExpression.new(Expressions.new([1.int32, 2.int32, 3.int32] of ASTNode), output: false, multiline: true)
+    it_parses "{%\n  x unless 1\n%}", MacroExpression.new(Unless.new(1.int32, "x".var), output: false)
+    it_parses "{%\n  1\n  2\n  3\n%}", MacroExpression.new(Expressions.new([1.int32, 2.int32, 3.int32] of ASTNode), output: false)
 
     assert_syntax_error "{% unless 1; 2; elsif 3; 4; end %}"
     assert_syntax_error "{% unless 1 %} 2 {% elsif 3 %} 3 {% end %}"
diff --git a/src/compiler/crystal/syntax/ast.cr b/src/compiler/crystal/syntax/ast.cr
index 66d18c308845..9ccd8dda1f69 100644
--- a/src/compiler/crystal/syntax/ast.cr
+++ b/src/compiler/crystal/syntax/ast.cr
@@ -2187,21 +2187,13 @@ module Crystal
   end
 
   # A macro expression,
-  # surrounded by {{ ... }}` (output = true, multiline = false)
-  # or by `{% ... %}` (output = false, multiline = false)
-  #
-  # ```
-  # # (output = false, multiline = true)
-  # {%
-  #   ...
-  # %}
-  # ```
+  # surrounded by {{ ... }} (output = true)
+  # or by {% ... %} (output = false)
   class MacroExpression < ASTNode
     property exp : ASTNode
     property? output : Bool
-    property? multiline : Bool
 
-    def initialize(@exp : ASTNode, @output = true, @multiline : Bool = false)
+    def initialize(@exp : ASTNode, @output = true)
     end
 
     def accept_children(visitor)
@@ -2209,10 +2201,10 @@ module Crystal
     end
 
     def clone_without_location
-      MacroExpression.new(@exp.clone, @output, @multiline)
+      MacroExpression.new(@exp.clone, @output)
     end
 
-    def_equals_and_hash exp, output?, multiline?
+    def_equals_and_hash exp, output?
   end
 
   # Free text that is part of a macro
diff --git a/src/compiler/crystal/syntax/parser.cr b/src/compiler/crystal/syntax/parser.cr
index 3cf31410b41b..569bbd4d9409 100644
--- a/src/compiler/crystal/syntax/parser.cr
+++ b/src/compiler/crystal/syntax/parser.cr
@@ -3353,13 +3353,7 @@ module Crystal
 
     def parse_macro_control(start_location, macro_state = Token::MacroState.default)
       location = @token.location
-      next_token_skip_space
-      multiline = false
-
-      if @token.type.newline?
-        multiline = true
-        next_token_skip_space_or_newline
-      end
+      next_token_skip_space_or_newline
 
       case @token.value
       when Keyword::FOR
@@ -3446,7 +3440,7 @@ module Crystal
       exps = parse_expressions
       @in_macro_expression = false
 
-      MacroExpression.new(exps, output: false, multiline: multiline).at(location).at_end(token_end_location)
+      MacroExpression.new(exps, output: false).at(location).at_end(token_end_location)
     end
 
     def parse_macro_if(start_location, macro_state, check_end = true, is_unless = false)
diff --git a/src/compiler/crystal/syntax/to_s.cr b/src/compiler/crystal/syntax/to_s.cr
index 3da5b72fab4a..d30e2dd52d7f 100644
--- a/src/compiler/crystal/syntax/to_s.cr
+++ b/src/compiler/crystal/syntax/to_s.cr
@@ -717,11 +717,11 @@ module Crystal
       end
       newline
 
-      @indent += 1
-      inside_macro do
-        accept node.body
+      with_indent do
+        inside_macro do
+          accept node.body
+        end
       end
-      @indent -= 1
 
       # newline
       append_indent
@@ -730,30 +730,34 @@ module Crystal
     end
 
     def visit(node : MacroExpression)
-      @str << (node.output? ? "{{ " : node.multiline? ? "{%" : "{% ")
+      # The node is considered multiline if its starting location is on a different line than its expression.
+      is_multiline = (start_loc = node.location) && (end_loc = node.exp.location) && end_loc.line_number > start_loc.line_number
+
+      @str << (node.output? ? "{{ " : is_multiline ? "{%" : "{% ")
 
-      if node.multiline?
+      if is_multiline
         newline
         @indent += 1
       end
 
       outside_macro do
-        # If the MacroExpression consists of a single node we need to manually handle appending indent and trailing newline if #multiline?
+        # If the MacroExpression consists of a single node we need to manually handle appending indent and trailing newline if *is_multiline*
         # Otherwise, the Expressions logic handles that for us
-        if node.multiline? && !node.exp.is_a?(Expressions)
+        if is_multiline && !node.exp.is_a?(Expressions)
           append_indent
         end
 
         node.exp.accept self
       end
 
-      if node.multiline?
+      # If the opening tag has a newline after it, force trailing tag to have one as well
+      if is_multiline
         @indent -= 1
         append_indent
         newline if !node.exp.is_a? Expressions
       end
 
-      @str << (node.output? ? " }}" : node.multiline? ? "%}" : " %}")
+      @str << (node.output? ? " }}" : is_multiline ? "%}" : " %}")
       false
     end
 
@@ -810,11 +814,11 @@ module Crystal
     def visit(node : MacroVerbatim)
       @str << "{% verbatim do %}"
 
-      @indent += 1
-      inside_macro do
-        node.exp.accept self
+      with_indent do
+        inside_macro do
+          node.exp.accept self
+        end
       end
-      @indent -= 1
 
       @str << "{% end %}"
       false

From ad601d0bb02ecc7c03cea9443bb4d1f5b2185bf9 Mon Sep 17 00:00:00 2001
From: George Dietrich <dev@dietrich.pub>
Date: Sun, 22 Dec 2024 18:45:27 -0500
Subject: [PATCH 07/10] Finish reverting changes to `parser_spec`

---
 spec/compiler/parser/parser_spec.cr | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/spec/compiler/parser/parser_spec.cr b/spec/compiler/parser/parser_spec.cr
index 53fbedbcd7c1..897e5bf7060c 100644
--- a/spec/compiler/parser/parser_spec.cr
+++ b/spec/compiler/parser/parser_spec.cr
@@ -1118,7 +1118,7 @@ module Crystal
     it_parses "puts {{**1}}", Call.new(nil, "puts", MacroExpression.new(DoubleSplat.new(1.int32)))
     it_parses "{{a = 1 if 2}}", MacroExpression.new(If.new(2.int32, Assign.new("a".var, 1.int32)))
     it_parses "{% a = 1 %}", MacroExpression.new(Assign.new("a".var, 1.int32), output: false)
-    it_parses "{%\n  a = 1\n%}", MacroExpression.new(Assign.new("a".var, 1.int32), output: false)
+    it_parses "{%\na = 1\n%}", MacroExpression.new(Assign.new("a".var, 1.int32), output: false)
     it_parses "{% a = 1 if 2 %}", MacroExpression.new(If.new(2.int32, Assign.new("a".var, 1.int32)), output: false)
     it_parses "{% if 1; 2; end %}", MacroExpression.new(If.new(1.int32, 2.int32), output: false)
     it_parses "{%\nif 1; 2; end\n%}", MacroExpression.new(If.new(1.int32, 2.int32), output: false)
@@ -1128,8 +1128,7 @@ module Crystal
     it_parses "{% unless 1; 2; else 3; end %}", MacroExpression.new(Unless.new(1.int32, 2.int32, 3.int32), output: false)
     it_parses "{% unless 1\n  x\nend %}", MacroExpression.new(Unless.new(1.int32, "x".var), output: false)
     it_parses "{% x unless 1 %}", MacroExpression.new(Unless.new(1.int32, "x".var), output: false)
-    it_parses "{%\n  x unless 1\n%}", MacroExpression.new(Unless.new(1.int32, "x".var), output: false)
-    it_parses "{%\n  1\n  2\n  3\n%}", MacroExpression.new(Expressions.new([1.int32, 2.int32, 3.int32] of ASTNode), output: false)
+    it_parses "{%\n1\n2\n3\n%}", MacroExpression.new(Expressions.new([1.int32, 2.int32, 3.int32] of ASTNode), output: false)
 
     assert_syntax_error "{% unless 1; 2; elsif 3; 4; end %}"
     assert_syntax_error "{% unless 1 %} 2 {% elsif 3 %} 3 {% end %}"

From 79641c7ac6291ab709470ff0fdb22364b534b807 Mon Sep 17 00:00:00 2001
From: George Dietrich <dev@dietrich.pub>
Date: Mon, 23 Dec 2024 10:37:19 -0500
Subject: [PATCH 08/10] Handle emitting significant whitespace as well

---
 spec/compiler/parser/to_s_spec.cr   | 15 +++++++++------
 src/compiler/crystal/syntax/to_s.cr | 27 ++++++++++++++++++++++++---
 2 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/spec/compiler/parser/to_s_spec.cr b/spec/compiler/parser/to_s_spec.cr
index ed28ecd55dd1..3ea28be4e46e 100644
--- a/spec/compiler/parser/to_s_spec.cr
+++ b/spec/compiler/parser/to_s_spec.cr
@@ -1,7 +1,7 @@
 require "../../support/syntax"
 
-private def expect_to_s(original, expected = original, emit_doc = false, file = __FILE__, line = __LINE__)
-  it "does to_s of #{original.inspect}", file, line do
+private def expect_to_s(original, expected = original, emit_doc = false, file = __FILE__, line = __LINE__, focus = false)
+  it "does to_s of #{original.inspect}", file, line, focus: focus do
     str = IO::Memory.new expected.bytesize
 
     source = original
@@ -262,8 +262,7 @@ describe "ASTNode#to_s" do
   expect_to_s "{%\n  a = 1 %}", "{%\n  a = 1\n%}"
   expect_to_s "{% a = 1\n%}", "{% a = 1 %}"
 
-  # FIXME: Should respect significant whitespace
-  expect_to_s <<-'CR', <<-'CR'
+  expect_to_s <<-'CR', <<-CR
     macro finished
       {% verbatim do %}
         {%
@@ -280,14 +279,16 @@ describe "ASTNode#to_s" do
       {% verbatim do %}
         {%
           10
+
+
+
           20
         %}
       {% end %}
     end
     CR
 
-  # FIXME: Should respect significant whitespace
-  expect_to_s <<-'CR', <<-'CR'
+  expect_to_s <<-'CR', <<-CR
     macro finished
       {% verbatim do %}
         {%
@@ -303,6 +304,8 @@ describe "ASTNode#to_s" do
       {% verbatim do %}
         {%
           10
+
+
           20
         %}
       {% end %}
diff --git a/src/compiler/crystal/syntax/to_s.cr b/src/compiler/crystal/syntax/to_s.cr
index d30e2dd52d7f..5d8d28820c68 100644
--- a/src/compiler/crystal/syntax/to_s.cr
+++ b/src/compiler/crystal/syntax/to_s.cr
@@ -55,6 +55,21 @@ module Crystal
       true
     end
 
+    private def add_whitespace_around(first_node_location : Location?, second_node_location : Location?, &) : Nil
+      # If any location information is missing, don't add any extra newlines.
+      if !first_node_location || !second_node_location
+        yield
+        return
+      end
+
+      # Only emit extra newlines. I.e. those more than the first handled via the Expressions visitor.
+      ((second_node_location.line_number - 1) - first_node_location.line_number).times do
+        newline
+      end
+
+      yield
+    end
+
     def visit(node : Nop)
       false
     end
@@ -221,11 +236,17 @@ module Crystal
       if @inside_macro > 0
         node.expressions.each &.accept self
       else
+        last_node = node.expressions.first
+
         node.expressions.each_with_index do |exp, i|
           unless exp.nop?
-            append_indent unless node.keyword.paren? && i == 0
-            exp.accept self
-            newline unless node.keyword.paren? && i == node.expressions.size - 1
+            self.add_whitespace_around last_node.end_location, exp.location do
+              append_indent unless node.keyword.paren? && i == 0
+              exp.accept self
+              newline unless node.keyword.paren? && i == node.expressions.size - 1
+            end
+
+            last_node = exp
           end
         end
       end

From 86e895986b23c2f387e61a6c7de0f9da52a3d32a Mon Sep 17 00:00:00 2001
From: George Dietrich <dev@dietrich.pub>
Date: Mon, 23 Dec 2024 12:59:00 -0500
Subject: [PATCH 09/10] Handle single node MacroExpressions some minor cleanup

---
 spec/compiler/parser/to_s_spec.cr   | 58 ++++++++++++++++++++++++++++-
 src/compiler/crystal/syntax/to_s.cr |  8 ++--
 2 files changed, 60 insertions(+), 6 deletions(-)

diff --git a/spec/compiler/parser/to_s_spec.cr b/spec/compiler/parser/to_s_spec.cr
index 3ea28be4e46e..d6d2ca79780d 100644
--- a/spec/compiler/parser/to_s_spec.cr
+++ b/spec/compiler/parser/to_s_spec.cr
@@ -262,7 +262,7 @@ describe "ASTNode#to_s" do
   expect_to_s "{%\n  a = 1 %}", "{%\n  a = 1\n%}"
   expect_to_s "{% a = 1\n%}", "{% a = 1 %}"
 
-  expect_to_s <<-'CR', <<-CR
+  expect_to_s <<-'CR', <<-'CR'
     macro finished
       {% verbatim do %}
         {%
@@ -288,7 +288,7 @@ describe "ASTNode#to_s" do
     end
     CR
 
-  expect_to_s <<-'CR', <<-CR
+  expect_to_s <<-'CR', <<-'CR'
     macro finished
       {% verbatim do %}
         {%
@@ -312,6 +312,50 @@ describe "ASTNode#to_s" do
     end
     CR
 
+  expect_to_s <<-'CR', <<-'CR'
+    macro finished
+      {% verbatim do %}
+        {%
+          10
+
+          # Foo
+
+          20
+          30
+
+          # Bar
+
+          40
+        %}
+        {%
+          50
+          60
+        %}
+      {% end %}
+    end
+    CR
+    macro finished
+      {% verbatim do %}
+        {%
+          10
+
+
+
+          20
+          30
+
+
+
+          40
+        %}
+        {%
+          50
+          60
+        %}
+      {% end %}
+    end
+    CR
+
   expect_to_s <<-'CR'
     macro finished
       {% verbatim do %}
@@ -323,6 +367,16 @@ describe "ASTNode#to_s" do
     end
     CR
 
+  expect_to_s <<-'CR'
+    macro finished
+      {% verbatim do %}
+        {%
+          10
+        %}
+      {% end %}
+    end
+    CR
+
   expect_to_s %(asm("nop" ::::))
   expect_to_s %(asm("nop" : "a"(1), "b"(2) : "c"(3), "d"(4) : "e", "f" : "volatile", "alignstack", "intel"))
   expect_to_s %(asm("nop" :: "c"(3), "d"(4) ::))
diff --git a/src/compiler/crystal/syntax/to_s.cr b/src/compiler/crystal/syntax/to_s.cr
index 5d8d28820c68..36c34cb045bb 100644
--- a/src/compiler/crystal/syntax/to_s.cr
+++ b/src/compiler/crystal/syntax/to_s.cr
@@ -55,14 +55,14 @@ module Crystal
       true
     end
 
-    private def add_whitespace_around(first_node_location : Location?, second_node_location : Location?, &) : Nil
+    private def write_extra_newlines(first_node_location : Location?, second_node_location : Location?, &) : Nil
       # If any location information is missing, don't add any extra newlines.
       if !first_node_location || !second_node_location
         yield
         return
       end
 
-      # Only emit extra newlines. I.e. those more than the first handled via the Expressions visitor.
+      # Only write the "extra" newlines. I.e. If there are more than one. The first newline is handled directly via the Expressions visitor.
       ((second_node_location.line_number - 1) - first_node_location.line_number).times do
         newline
       end
@@ -240,7 +240,7 @@ module Crystal
 
         node.expressions.each_with_index do |exp, i|
           unless exp.nop?
-            self.add_whitespace_around last_node.end_location, exp.location do
+            self.write_extra_newlines last_node.end_location, exp.location do
               append_indent unless node.keyword.paren? && i == 0
               exp.accept self
               newline unless node.keyword.paren? && i == node.expressions.size - 1
@@ -774,8 +774,8 @@ module Crystal
       # If the opening tag has a newline after it, force trailing tag to have one as well
       if is_multiline
         @indent -= 1
-        append_indent
         newline if !node.exp.is_a? Expressions
+        append_indent
       end
 
       @str << (node.output? ? " }}" : is_multiline ? "%}" : " %}")

From 0f32ebd0ef40a7ebd4d51f093570f5af65d75489 Mon Sep 17 00:00:00 2001
From: George Dietrich <dev@dietrich.pub>
Date: Mon, 23 Dec 2024 14:11:08 -0500
Subject: [PATCH 10/10] Fix bug related to empty expressions Update other specs
 to use new format

---
 spec/compiler/crystal/tools/expand_spec.cr            | 11 ++++++-----
 spec/compiler/semantic/restrictions_augmenter_spec.cr |  6 ++++++
 src/compiler/crystal/syntax/to_s.cr                   |  4 ++--
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/spec/compiler/crystal/tools/expand_spec.cr b/spec/compiler/crystal/tools/expand_spec.cr
index e8f9b770f3ec..4ebdfff6b836 100644
--- a/spec/compiler/crystal/tools/expand_spec.cr
+++ b/spec/compiler/crystal/tools/expand_spec.cr
@@ -157,7 +157,7 @@ describe "expand" do
     {% end %}
     CRYSTAL
 
-    assert_expand_simple code, "1\n2\n3\n"
+    assert_expand_simple code, "1\n\n2\n\n3\n"
   end
 
   it "expands macro control {% for %} with cursor inside it" do
@@ -167,7 +167,7 @@ describe "expand" do
     {% end %}
     CRYSTAL
 
-    assert_expand_simple code, "1\n2\n3\n"
+    assert_expand_simple code, "1\n\n2\n\n3\n"
   end
 
   it "expands macro control {% for %} with cursor at end of it" do
@@ -177,7 +177,7 @@ describe "expand" do
     ‸{% end %}
     CRYSTAL
 
-    assert_expand_simple code, "1\n2\n3\n"
+    assert_expand_simple code, "1\n\n2\n\n3\n"
   end
 
   it "expands macro control {% for %} with indent" do
@@ -195,7 +195,7 @@ describe "expand" do
     {% end %}
     CRYSTAL
 
-    assert_expand_simple code, original: original, expanded: "1\n2\n3\n"
+    assert_expand_simple code, original: original, expanded: "1\n\n2\n\n3\n"
   end
 
   it "expands simple macro" do
@@ -258,7 +258,7 @@ describe "expand" do
     ‸foo
     CRYSTAL
 
-    assert_expand_simple code, original: "foo", expanded: %("if true"\n"1"\n"2"\n"3"\n)
+    assert_expand_simple code, original: "foo", expanded: %("if true"\n\n\n"1"\n\n"2"\n\n"3"\n)
   end
 
   it "expands macros with 2 level" do
@@ -615,6 +615,7 @@ describe "expand" do
     def hello_str
       "hello"
     end
+
     # symbol of hello
     def hello_sym
       :hello
diff --git a/spec/compiler/semantic/restrictions_augmenter_spec.cr b/spec/compiler/semantic/restrictions_augmenter_spec.cr
index 2b7250658693..d77b61327f82 100644
--- a/spec/compiler/semantic/restrictions_augmenter_spec.cr
+++ b/spec/compiler/semantic/restrictions_augmenter_spec.cr
@@ -78,7 +78,9 @@ describe "Semantic: restrictions augmenter" do
           class Baz
           end
         end
+
         @x : Bar::Baz
+
         def initialize(value : ::Foo::Bar::Baz)
           @x = value
         end
@@ -110,7 +112,9 @@ describe "Semantic: restrictions augmenter" do
           class Baz
           end
         end
+
         @x : Bar::Baz
+
         def initialize(value : Bar::Baz)
           @x = value
         end
@@ -400,8 +404,10 @@ describe "Semantic: restrictions augmenter" do
       macro foo
         {{ yield }}
       end
+
       class Foo
       end
+
       class Bar
         @x : Foo
         def initialize(value : ::Foo)
diff --git a/src/compiler/crystal/syntax/to_s.cr b/src/compiler/crystal/syntax/to_s.cr
index 36c34cb045bb..ae3576051a87 100644
--- a/src/compiler/crystal/syntax/to_s.cr
+++ b/src/compiler/crystal/syntax/to_s.cr
@@ -236,11 +236,11 @@ module Crystal
       if @inside_macro > 0
         node.expressions.each &.accept self
       else
-        last_node = node.expressions.first
+        last_node = nil
 
         node.expressions.each_with_index do |exp, i|
           unless exp.nop?
-            self.write_extra_newlines last_node.end_location, exp.location do
+            self.write_extra_newlines((last_node || exp).end_location, exp.location) do
               append_indent unless node.keyword.paren? && i == 0
               exp.accept self
               newline unless node.keyword.paren? && i == node.expressions.size - 1