Support naked braces/brackets/parens, invert labels on banner

CHANGELOG.md

@@ -1,5 +1,6 @@
 ## HEAD (unreleased)
 
+- Support naked braces/brackets/parens, invert labels on banner (https://github.com/zombocom/dead_end/pull/89)
 - Handle mismatched end when using rescue without begin (https://github.com/zombocom/dead_end/pull/83)
 - CLI returns non-zero exit code when syntax error is found (https://github.com/zombocom/dead_end/pull/86)
 - Let -v respond with gem version instead of 'unknown' (https://github.com/zombocom/dead_end/pull/82)

lib/dead_end/banner.rb

@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+module DeadEnd
+  class Banner
+    attr_reader :invalid_obj
+
+    def initialize(invalid_obj:)
+      @invalid_obj = invalid_obj
+    end
+
+    def call
+      case invalid_obj.error_symbol
+      when :missing_end
+        <<~EOM
+          DeadEnd: Missing `end` detected
+
+          This code has a missing `end`. Ensure that all
+          syntax keywords (`def`, `do`, etc.) have a matching `end`.
+        EOM
+      when :unmatched_syntax
+        case unmatched_symbol
+        when :end
+          <<~EOM
+            DeadEnd: Unmatched `end` detected
+
+            This code has an unmatched `end`. Ensure that all `end` lines
+            in your code have a matching syntax keyword  (`def`,  `do`, etc.)
+            and that you don't have any extra `end` lines.
+          EOM
+        when :|
+          <<~EOM
+            DeadEnd: Unmatched `|` character detected
+
+            Example:
+
+              `do |x` should be `do |x|`
+          EOM
+        when *WhoDisSyntaxError::CHARACTERS.keys
+          <<~EOM
+            DeadEnd: Unmatched `#{unmatched_symbol}` character detected
+
+            It appears a `#{missing_character}` might be missing.
+          EOM
+        else
+          "DeadEnd: Unmatched `#{unmatched_symbol}` detected"
+        end
+      end
+    end
+
+    private def unmatched_symbol
+      invalid_obj.unmatched_symbol
+    end
+
+    private def missing_character
+      WhoDisSyntaxError::CHARACTERS[unmatched_symbol]
+    end
+  end
+end

lib/dead_end/display_invalid_blocks.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+require_relative "banner"
 require_relative "capture_code_context"
 require_relative "display_code_with_line_numbers"
 
@@ -54,43 +55,7 @@ def call
     end
 
     def banner
-      case @invalid_obj.error_symbol
-      when :missing_end
-        <<~EOM
-          DeadEnd: Missing `end` detected
-
-          This code has a missing `end`. Ensure that all
-          syntax keywords (`def`, `do`, etc.) have a matching `end`.
-        EOM
-      when :unmatched_syntax
-        case @invalid_obj.unmatched_symbol
-        when :end
-          <<~EOM
-            DeadEnd: Unmatched `end` detected
-
-            This code has an unmatched `end`. Ensure that all `end` lines
-            in your code have a matching syntax keyword  (`def`,  `do`, etc.)
-            and that you don't have any extra `end` lines.
-          EOM
-        when :|
-          <<~EOM
-            DeadEnd: Unmatched `|` character detected
-
-            Example:
-
-              `do |x` should be `do |x|`
-          EOM
-        when :"}"
-          <<~EOM
-            DeadEnd: Unmatched `}` character detected
-
-            This code has an unmatched `}`. Ensure that opening curly braces are
-            closed: `{ }`.
-          EOM
-        else
-          "DeadEnd: Unmatched `#{@invalid_obj.unmatched_symbol}` detected"
-        end
-      end
+      Banner.new(invalid_obj: @invalid_obj).call
     end
 
     def indent(string, with: "    ")

lib/dead_end/who_dis_syntax_error.rb

@@ -8,6 +8,7 @@ module DeadEnd
   #   puts WhoDisSyntaxError.new("def foo;").call.error_symbol
   #   # => :missing_end
   class WhoDisSyntaxError < Ripper
+    CHARACTERS = {"{": :"}", "}": :"{", "[": :"]", "]": :"[", "(": :")", ")": :"("}
     class Null
       def error_symbol
         :missing_end
@@ -59,6 +60,12 @@ def on_parse_error(msg)
         @unmatched_symbol = :end
         @error_symbol = :unmatched_syntax
       when /unexpected .* expecting ['`]?(?<unmatched_symbol>[^']*)/
+        if $1
+          character = $1.to_sym
+          @unmatched_symbol = CHARACTERS[character] || character
+        end
+        @error_symbol = :unmatched_syntax
+      when /unexpected '(?<unmatched_symbol>.*)'/
         @unmatched_symbol = $1.to_sym if $1
         @error_symbol = :unmatched_syntax
       when /unexpected `end'/, # Ruby 2.7 and 3.0

spec/unit/banner_spec.rb

@@ -0,0 +1,122 @@
+# frozen_string_literal: true
+
+require_relative "../spec_helper"
+
+module DeadEnd
+  RSpec.describe Banner do
+    it "Unmatched | banner" do
+      source = <<~EOM
+        Foo.call do |
+        end
+      EOM
+
+      invalid_obj = WhoDisSyntaxError.new(source)
+      banner = Banner.new(invalid_obj: invalid_obj)
+      expect(banner.call).to include("Unmatched `|` character detected")
+    end
+
+    it "Unmatched { banner" do
+      source = <<~EOM
+        class Cat
+          lol = {
+        end
+      EOM
+
+      invalid_obj = WhoDisSyntaxError.new(source)
+      banner = Banner.new(invalid_obj: invalid_obj)
+      expect(banner.call).to include("Unmatched `{` character detected")
+    end
+
+    it "Unmatched } banner" do
+      skip("Unsupported ruby version") unless Gem::Version.new(RUBY_VERSION) >= Gem::Version.new("2.7")
+
+      source = <<~EOM
+        def foo
+          lol = }
+        end
+      EOM
+
+      invalid_obj = WhoDisSyntaxError.new(source)
+      banner = Banner.new(invalid_obj: invalid_obj)
+      expect(banner.call).to include("Unmatched `}` character detected")
+    end
+
+    it "Unmatched [ banner" do
+      source = <<~EOM
+        class Cat
+          lol = [
+        end
+      EOM
+
+      invalid_obj = WhoDisSyntaxError.new(source)
+      banner = Banner.new(invalid_obj: invalid_obj)
+      expect(banner.call).to include("Unmatched `[` character detected")
+    end
+
+    it "Unmatched ] banner" do
+      source = <<~EOM
+        def foo
+          lol = ]
+        end
+      EOM
+
+      invalid_obj = WhoDisSyntaxError.new(source)
+      banner = Banner.new(invalid_obj: invalid_obj)
+      expect(banner.call).to include("Unmatched `]` character detected")
+    end
+
+    it "Unmatched end banner" do
+      source = <<~EOM
+        class Cat
+          end
+        end
+      EOM
+
+      invalid_obj = WhoDisSyntaxError.new(source)
+      banner = Banner.new(invalid_obj: invalid_obj)
+      expect(banner.call).to include("DeadEnd: Unmatched `end` detected")
+    end
+
+    it "Unmatched unknown banner" do
+      source = <<~EOM
+        class Cat
+          def meow
+            1 *
+          end
+        end
+      EOM
+
+      invalid_obj = WhoDisSyntaxError.new(source)
+      banner = Banner.new(invalid_obj: invalid_obj)
+      expect(banner.call).to include("DeadEnd: Unmatched `unknown` detected")
+    end
+
+    it "missing end banner" do
+      source = <<~EOM
+        class Cat
+          def meow
+        end
+      EOM
+
+      invalid_obj = WhoDisSyntaxError.new(source)
+      banner = Banner.new(invalid_obj: invalid_obj)
+      expect(banner.call).to include("DeadEnd: Missing `end` detected")
+    end
+
+    it "naked (closing) parenthesis" do
+      invalid_obj = WhoDisSyntaxError.new("def initialize; ); end").call
+
+      expect(
+        Banner.new(invalid_obj: invalid_obj).call
+      ).to include("Unmatched `)` character detected")
+    end
+
+    it "naked (opening) parenthesis" do
+      invalid_obj = WhoDisSyntaxError.new("def initialize; (; end").call
+
+      expect(
+        Banner.new(invalid_obj: invalid_obj).call
+      ).to include("Unmatched `(` character detected")
+    end
+  end
+end

spec/unit/display_invalid_blocks_spec.rb

@@ -4,87 +4,6 @@
 
 module DeadEnd
   RSpec.describe DisplayInvalidBlocks do
-    it "Unmatched | banner" do
-      source = <<~EOM
-        Foo.call do |
-        end
-      EOM
-      code_lines = code_line_array(source)
-
-      display = DisplayInvalidBlocks.new(
-        code_lines: code_lines,
-        blocks: CodeBlock.new(lines: code_lines),
-        invalid_obj: WhoDisSyntaxError.new(source)
-      )
-      expect(display.banner).to include("Unmatched `|` character detected")
-    end
-
-    it "Unmatched } banner" do
-      source = <<~EOM
-        class Cat
-          lol = {
-        end
-      EOM
-      code_lines = CleanDocument.new(source: source).call.lines
-
-      display = DisplayInvalidBlocks.new(
-        code_lines: code_lines,
-        blocks: CodeBlock.new(lines: code_lines),
-        invalid_obj: WhoDisSyntaxError.new(source)
-      )
-      expect(display.banner).to include("Unmatched `}` character detected")
-    end
-
-    it "Unmatched end banner" do
-      source = <<~EOM
-        class Cat
-          end
-        end
-      EOM
-      code_lines = code_line_array(source)
-
-      display = DisplayInvalidBlocks.new(
-        code_lines: code_lines,
-        blocks: CodeBlock.new(lines: code_lines),
-        invalid_obj: WhoDisSyntaxError.new(source)
-      )
-      expect(display.banner).to include("DeadEnd: Unmatched `end` detected")
-    end
-
-    it "Unmatched unknown banner" do
-      source = <<~EOM
-        class Cat
-          def meow
-            1 *
-          end
-        end
-      EOM
-      code_lines = code_line_array(source)
-
-      display = DisplayInvalidBlocks.new(
-        code_lines: code_lines,
-        blocks: CodeBlock.new(lines: code_lines),
-        invalid_obj: WhoDisSyntaxError.new(source)
-      )
-      expect(display.banner).to include("DeadEnd: Unmatched `unknown` detected")
-    end
-
-    it "missing end banner" do
-      source = <<~EOM
-        class Cat
-          def meow
-        end
-      EOM
-      code_lines = code_line_array(source)
-
-      display = DisplayInvalidBlocks.new(
-        code_lines: code_lines,
-        blocks: CodeBlock.new(lines: code_lines),
-        invalid_obj: WhoDisSyntaxError.new(source)
-      )
-      expect(display.banner).to include("DeadEnd: Missing `end` detected")
-    end
-
     it "works with valid code" do
       syntax_string = <<~EOM
         class OH