Support Ruby 2.7.0

Author: kddnewton

.github/workflows/main.yml

@@ -8,7 +8,7 @@ jobs:
       fail-fast: false
       matrix:
         ruby:
-        - '2.7'
+        - '2.7.0'
         - '3.0'
         - '3.1'
         - head

Rakefile

@@ -12,8 +12,17 @@ end
 
 task default: :test
 
-SOURCE_FILES =
-  FileList[%w[Gemfile Rakefile syntax_tree.gemspec lib/**/*.rb test/*.rb]]
+configure = ->(task) do
+  task.source_files =
+    FileList[%w[Gemfile Rakefile syntax_tree.gemspec lib/**/*.rb test/*.rb]]
 
-SyntaxTree::Rake::CheckTask.new { |t| t.source_files = SOURCE_FILES }
-SyntaxTree::Rake::WriteTask.new { |t| t.source_files = SOURCE_FILES }
+  # Since Syntax Tree supports back to Ruby 2.7.0, we need to make sure that we
+  # format our code such that it's compatible with that version. This actually
+  # has very little effect on the output, the only change at the moment is that
+  # Ruby < 2.7.3 didn't allow a newline before the closing brace of a hash
+  # pattern.
+  task.target_ruby_version = Gem::Version.new("2.7.0")
+end
+
+SyntaxTree::Rake::CheckTask.new(&configure)
+SyntaxTree::Rake::WriteTask.new(&configure)

lib/syntax_tree/cli.rb

@@ -283,6 +283,12 @@ def parser
           opts.on("--print-width=NUMBER", Integer) do |print_width|
             @print_width = print_width
           end
+
+          # If there is a target ruby version specified on the command line,
+          # parse that out and use it when formatting.
+          opts.on("--target-ruby-version=VERSION") do |version|
+            Formatter::OPTIONS[:target_ruby_version] = Gem::Version.new(version)
+          end
         end
       end
     end

lib/syntax_tree/formatter.rb

@@ -14,7 +14,11 @@ class Formatter < PrettierPrint
     # Note that we're keeping this in a global-ish hash instead of just
     # overriding methods on classes so that other plugins can reference this if
     # necessary. For example, the RBS plugin references the quote style.
-    OPTIONS = { quote: "\"", trailing_comma: false }
+    OPTIONS = {
+      quote: "\"",
+      trailing_comma: false,
+      target_ruby_version: Gem::Version.new(RUBY_VERSION)
+    }
 
     COMMENT_PRIORITY = 1
     HEREDOC_PRIORITY = 2
@@ -23,14 +27,15 @@ class Formatter < PrettierPrint
 
     # These options are overridden in plugins to we need to make sure they are
     # available here.
-    attr_reader :quote, :trailing_comma
+    attr_reader :quote, :trailing_comma, :target_ruby_version
     alias trailing_comma? trailing_comma
 
     def initialize(
       source,
       *args,
       quote: OPTIONS[:quote],
-      trailing_comma: OPTIONS[:trailing_comma]
+      trailing_comma: OPTIONS[:trailing_comma],
+      target_ruby_version: OPTIONS[:target_ruby_version]
     )
       super(*args)
 
@@ -40,6 +45,7 @@ def initialize(
       # Memoizing these values per formatter to make access faster.
       @quote = quote
       @trailing_comma = trailing_comma
+      @target_ruby_version = target_ruby_version
     end
 
     def self.format(source, node)

lib/syntax_tree/node.rb

@@ -2132,8 +2132,7 @@ def format(q)
         in [
              Paren[
                contents: {
-                 body: [ArrayLiteral[contents: { parts: [_, _, *] }] => array]
-               }
+                 body: [ArrayLiteral[contents: { parts: [_, _, *] }] => array] }
              ]
            ]
           # Here we have a single argument that is a set of parentheses wrapping
@@ -5116,8 +5115,13 @@ def format(q)
           q.breakable
           contents.call
         end
-        q.breakable
-        q.text("}")
+
+        if q.target_ruby_version < Gem::Version.new("2.7.3")
+          q.text(" }")
+        else
+          q.breakable
+          q.text("}")
+        end
       end
     end
   end
@@ -5204,8 +5208,7 @@ def call(q, node)
             false
           in {
                statements: { body: [truthy] },
-               consequent: Else[statements: { body: [falsy] }]
-             }
+               consequent: Else[statements: { body: [falsy] }] }
             ternaryable?(truthy) && ternaryable?(falsy)
           else
             false

lib/syntax_tree/rake/check_task.rb

@@ -39,16 +39,22 @@ class CheckTask < ::Rake::TaskLib
       # Defaults to 80.
       attr_accessor :print_width
 
+      # The target Ruby version to use for formatting.
+      # Defaults to Gem::Version.new(RUBY_VERSION).
+      attr_accessor :target_ruby_version
+
       def initialize(
         name = :"stree:check",
         source_files = ::Rake::FileList["lib/**/*.rb"],
         plugins = [],
-        print_width = DEFAULT_PRINT_WIDTH
+        print_width = DEFAULT_PRINT_WIDTH,
+        target_ruby_version = Gem::Version.new(RUBY_VERSION)
       )
         @name = name
         @source_files = source_files
         @plugins = plugins
         @print_width = print_width
+        @target_ruby_version = target_ruby_version
 
         yield self if block_given?
         define_task
@@ -64,10 +70,15 @@ def define_task
       def run_task
         arguments = ["check"]
         arguments << "--plugins=#{plugins.join(",")}" if plugins.any?
+
         if print_width != DEFAULT_PRINT_WIDTH
           arguments << "--print-width=#{print_width}"
         end
 
+        if target_ruby_version != Gem::Version.new(RUBY_VERSION)
+          arguments << "--target-ruby-version=#{target_ruby_version}"
+        end
+
         SyntaxTree::CLI.run(arguments + Array(source_files))
       end
     end

lib/syntax_tree/rake/write_task.rb

@@ -39,16 +39,22 @@ class WriteTask < ::Rake::TaskLib
       # Defaults to 80.
       attr_accessor :print_width
 
+      # The target Ruby version to use for formatting.
+      # Defaults to Gem::Version.new(RUBY_VERSION).
+      attr_accessor :target_ruby_version
+
       def initialize(
         name = :"stree:write",
         source_files = ::Rake::FileList["lib/**/*.rb"],
         plugins = [],
-        print_width = DEFAULT_PRINT_WIDTH
+        print_width = DEFAULT_PRINT_WIDTH,
+        target_ruby_version = Gem::Version.new(RUBY_VERSION)
       )
         @name = name
         @source_files = source_files
         @plugins = plugins
         @print_width = print_width
+        @target_ruby_version = target_ruby_version
 
         yield self if block_given?
         define_task
@@ -64,10 +70,15 @@ def define_task
       def run_task
         arguments = ["write"]
         arguments << "--plugins=#{plugins.join(",")}" if plugins.any?
+
         if print_width != DEFAULT_PRINT_WIDTH
           arguments << "--print-width=#{print_width}"
         end
 
+        if target_ruby_version != Gem::Version.new(RUBY_VERSION)
+          arguments << "--target-ruby-version=#{target_ruby_version}"
+        end
+
         SyntaxTree::CLI.run(arguments + Array(source_files))
       end
     end

syntax_tree.gemspec

@@ -19,7 +19,7 @@ Gem::Specification.new do |spec|
         .reject { |f| f.match(%r{^(test|spec|features)/}) }
     end
 
-  spec.required_ruby_version = ">= 2.7.3"
+  spec.required_ruby_version = ">= 2.7.0"
 
   spec.bindir = "exe"
   spec.executables = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }

test/fixtures/args_forward.rb

@@ -1,4 +1,4 @@
-%
+% # >= 2.7.3
 def foo(...)
   bar(:baz, ...)
 end

test/fixtures/hshptn.rb

@@ -30,7 +30,7 @@
 case foo
 in **bar
 end
-%
+% # >= 2.7.3
 case foo
 in {
      foo:, # comment1