Handle properly stringifying multiline macro expressions

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

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
@@ -246,8 +246,137 @@ 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 }}"
+  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 <<-'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', <<-'CR'
+    macro finished
+      {% verbatim do %}
+        {%
+          10
+
+          # Foo
+          20
+        %}
+      {% end %}
+    end
+    CR
+    macro finished
+      {% verbatim do %}
+        {%
+          10
+
+
+          20
+        %}
+      {% end %}
+    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 %}
+        {%
+          10
+          20
+        %}
+      {% end %}
+    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) ::))

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)

src/compiler/crystal/syntax/to_s.cr

@@ -55,6 +55,21 @@ module Crystal
       true
     end
 
+    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 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
+
+      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 = nil
+
         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.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
+            end
+
+            last_node = exp
           end
         end
       end
@@ -717,8 +738,10 @@ module Crystal
       end
       newline
 
-      inside_macro do
-        accept node.body
+      with_indent do
+        inside_macro do
+          accept node.body
+        end
       end
 
       # newline
@@ -728,13 +751,34 @@ module Crystal
     end
 
     def visit(node : MacroExpression)
-      @str << (node.output? ? "{{" : "{% ")
-      @str << ' ' if node.output?
+      # 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 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 *is_multiline*
+        # Otherwise, the Expressions logic handles that for us
+        if is_multiline && !node.exp.is_a?(Expressions)
+          append_indent
+        end
+
         node.exp.accept self
       end
-      @str << ' ' if node.output?
-      @str << (node.output? ? "}}" : " %}")
+
+      # If the opening tag has a newline after it, force trailing tag to have one as well
+      if is_multiline
+        @indent -= 1
+        newline if !node.exp.is_a? Expressions
+        append_indent
+      end
+
+      @str << (node.output? ? " }}" : is_multiline ? "%}" : " %}")
       false
     end
 
@@ -790,9 +834,13 @@ module Crystal
 
     def visit(node : MacroVerbatim)
       @str << "{% verbatim do %}"
-      inside_macro do
-        node.exp.accept self
+
+      with_indent do
+        inside_macro do
+          node.exp.accept self
+        end
       end
+
       @str << "{% end %}"
       false
     end