Allow skipping autocorrect from within autocorrect block

spec/spec_helper.cr

@@ -109,7 +109,10 @@ module Ameba
       return unless name.includes?("A")
 
       issue_for(node.name, message: "A to AA") do |corrector|
-        corrector.replace(node.name, name.sub("A", "AA"))
+        next unless location = node.name.location
+        next unless end_location = node.name.end_location
+
+        corrector.replace(location, end_location, name.sub("A", "AA"))
       end
     end
   end
@@ -126,7 +129,10 @@ module Ameba
       return unless name.includes?("A")
 
       issue_for(node.name, message: "A to B") do |corrector|
-        corrector.replace(node.name, name.tr("A", "B"))
+        next unless location = node.name.location
+        next unless end_location = node.name.end_location
+
+        corrector.replace(location, end_location, name.tr("A", "B"))
       end
     end
   end
@@ -143,7 +149,10 @@ module Ameba
       return unless name.includes?("B")
 
       issue_for(node.name, message: "B to A") do |corrector|
-        corrector.replace(node.name, name.tr("B", "A"))
+        next unless location = node.name.location
+        next unless end_location = node.name.end_location
+
+        corrector.replace(location, end_location, name.tr("B", "A"))
       end
     end
   end
@@ -160,7 +169,10 @@ module Ameba
       return unless name.includes?("B")
 
       issue_for(node.name, message: "B to C") do |corrector|
-        corrector.replace(node.name, name.tr("B", "C"))
+        next unless location = node.name.location
+        next unless end_location = node.name.end_location
+
+        corrector.replace(location, end_location, name.tr("B", "C"))
       end
     end
   end
@@ -177,7 +189,10 @@ module Ameba
       return unless name.includes?("C")
 
       issue_for(node.name, message: "C to A") do |corrector|
-        corrector.replace(node.name, name.tr("C", "A"))
+        next unless location = node.name.location
+        next unless end_location = node.name.end_location
+
+        corrector.replace(location, end_location, name.tr("C", "A"))
       end
     end
   end

src/ameba/issue.cr

@@ -35,8 +35,10 @@ module Ameba
       rule.is_a?(Rule::Lint::Syntax)
     end
 
-    def correctable?
-      [email protected]?
+    getter? correctable : Bool do
+      corrector = Source::Corrector.new(code)
+      correct(corrector)
+      !corrector.empty?
     end
 
     def correct(corrector)

src/ameba/rule/lint/comparison_to_boolean.cr

@@ -43,18 +43,21 @@ module Ameba::Rule::Lint
       end
 
       return unless bool && exp
-      return unless exp_code = node_source(exp, source.lines)
 
-      not =
-        case node.name
-        when "==", "===" then !bool.value # foo == false
-        when "!="        then bool.value  # foo != true
-        end
+      issue_for node, MSG do |corrector|
+        next unless location = node.location
+        next unless end_location = node.end_location
+        next unless exp_code = node_source(exp, source.lines)
 
-      exp_code = "!#{exp_code}" if not
+        not =
+          case node.name
+          when "==", "===" then !bool.value # foo == false
+          when "!="        then bool.value  # foo != true
+          end
 
-      issue_for node, MSG do |corrector|
-        corrector.replace(node, exp_code)
+        exp_code = "!#{exp_code}" if not
+
+        corrector.replace(location, end_location, exp_code)
       end
     end
   end

src/ameba/rule/lint/not_nil_after_no_bang.cr

@@ -47,14 +47,17 @@ module Ameba::Rule::Lint
       return unless obj.name.in?(obj.block ? BLOCK_CALL_NAMES : CALL_NAMES)
 
       return unless name_location = obj.name_location
-      return unless name_location_end = name_end_location(obj)
-      return unless end_location = name_end_location(node)
+      return unless name_end_location = name_end_location(node)
 
       msg = MSG % {obj.name, obj.name}
 
-      issue_for name_location, end_location, msg do |corrector|
+      issue_for name_location, name_end_location, msg do |corrector|
+        next unless location = node.location
+        next unless end_location = node.end_location
+        next unless name_location_end = name_end_location(obj)
+
         corrector.insert_after(name_location_end, '!')
-        corrector.remove_trailing(node, {{ ".not_nil!".size }})
+        corrector.remove_trailing(location, end_location, {{ ".not_nil!".size }})
       end
     end
   end

src/ameba/rule/style/is_a_nil.cr

@@ -35,7 +35,10 @@ module Ameba::Rule::Style
       return unless path_named?(const, "Nil")
 
       issue_for const, MSG do |corrector|
-        corrector.replace(node, "#{node.obj}.nil?")
+        next unless location = node.location
+        next unless end_location = node.end_location
+
+        corrector.replace(location, end_location, "#{node.obj}.nil?")
       end
     end
   end

src/ameba/rule/style/parentheses_around_condition.cr

@@ -57,7 +57,10 @@ module Ameba::Rule::Style
 
       if cond.is_a?(Crystal::Assign) && allow_safe_assignment?
         issue_for cond, MSG_MISSING do |corrector|
-          corrector.wrap(cond, '(', ')')
+          next unless location = cond.location
+          next unless end_location = cond.end_location
+
+          corrector.wrap(location, end_location, '(', ')')
         end
         return
       end
@@ -73,8 +76,11 @@ module Ameba::Rule::Style
       return unless strip_parentheses?(exp, is_ternary)
 
       issue_for cond, MSG_REDUNDANT do |corrector|
-        corrector.remove_trailing(cond, 1)
-        corrector.remove_leading(cond, 1)
+        next unless location = cond.location
+        next unless end_location = cond.end_location
+
+        corrector.remove_trailing(location, end_location, 1)
+        corrector.remove_leading(location, end_location, 1)
       end
     end
   end

src/ameba/rule/style/redundant_next.cr

@@ -116,12 +116,12 @@ module Ameba::Rule::Style
       return if allow_multi_next? && node.exp.is_a?(Crystal::TupleLiteral)
       return if allow_empty_next? && (node.exp.nil? || node.exp.try(&.nop?))
 
-      if exp_code = control_exp_code(node, source.lines)
-        issue_for node, MSG do |corrector|
-          corrector.replace(node, exp_code)
-        end
-      else
-        issue_for node, MSG
+      issue_for node, MSG do |corrector|
+        next unless location = node.location
+        next unless end_location = node.end_location
+        next unless exp_code = control_exp_code(node, source.lines)
+
+        corrector.replace(location, end_location, exp_code)
       end
     end
   end

src/ameba/rule/style/redundant_return.cr

@@ -113,12 +113,12 @@ module Ameba::Rule::Style
       return if allow_multi_return? && node.exp.is_a?(Crystal::TupleLiteral)
       return if allow_empty_return? && (node.exp.nil? || node.exp.try(&.nop?))
 
-      if exp_code = control_exp_code(node, source.lines)
-        issue_for node, MSG do |corrector|
-          corrector.replace(node, exp_code)
-        end
-      else
-        issue_for node, MSG
+      issue_for node, MSG do |corrector|
+        next unless location = node.location
+        next unless end_location = node.end_location
+        next unless exp_code = control_exp_code(node, source.lines)
+
+        corrector.replace(location, end_location, exp_code)
       end
     end
   end

src/ameba/rule/style/unless_else.cr

@@ -52,17 +52,12 @@ module Ameba::Rule::Style
     def test(source, node : Crystal::Unless)
       return if node.else.nop?
 
-      location = node.location
-      cond_end_location = node.cond.end_location
-      else_location = node.else_location
-      end_location = node.end_location
-
-      unless location && cond_end_location && else_location && end_location
-        issue_for node, MSG
-        return
-      end
-
       issue_for node, MSG do |corrector|
+        next unless location = node.location
+        next unless cond_end_location = node.cond.end_location
+        next unless else_location = node.else_location
+        next unless end_location = node.end_location
+
         keyword_begin_pos = source.pos(location)
         keyword_end_pos = keyword_begin_pos + {{ "unless".size }}
         keyword_range = keyword_begin_pos...keyword_end_pos

src/ameba/source/corrector.cr

@@ -13,6 +13,11 @@ class Ameba::Source
       @rewriter = Rewriter.new(code)
     end
 
+    # Returns `true` if no (non trivial) update has been recorded
+    def empty?
+      @rewriter.empty?
+    end
+
     # Replaces the code of the given range with *content*.
     def replace(location, end_location, content)
       @rewriter.replace(loc_to_pos(location), loc_to_pos(end_location) + 1, content)
@@ -140,58 +145,6 @@ class Ameba::Source
       @line_sizes[0...line - 1].sum + (column - 1)
     end
 
-    # Replaces the code of the given node with *content*.
-    def replace(node : Crystal::ASTNode, content)
-      replace(location(node), end_location(node), content)
-    end
-
-    # Inserts the given strings before and after the given node.
-    def wrap(node : Crystal::ASTNode, insert_before, insert_after)
-      wrap(location(node), end_location(node), insert_before, insert_after)
-    end
-
-    # Shortcut for `replace(node, "")`
-    def remove(node : Crystal::ASTNode)
-      remove(location(node), end_location(node))
-    end
-
-    # Shortcut for `wrap(node, content, nil)`
-    def insert_before(node : Crystal::ASTNode, content)
-      insert_before(location(node), content)
-    end
-
-    # Shortcut for `wrap(node, nil, content)`
-    def insert_after(node : Crystal::ASTNode, content)
-      insert_after(end_location(node), content)
-    end
-
-    # Removes *size* characters prior to the given node.
-    def remove_preceding(node : Crystal::ASTNode, size)
-      remove_preceding(location(node), end_location(node), size)
-    end
-
-    # Removes *size* characters from the beginning of the given node.
-    # If *size* is greater than the size of the node, the removed region can
-    # overrun the end of the node.
-    def remove_leading(node : Crystal::ASTNode, size)
-      remove_leading(location(node), end_location(node), size)
-    end
-
-    # Removes *size* characters from the end of the given node.
-    # If *size* is greater than the size of the node, the removed region can
-    # overrun the beginning of the node.
-    def remove_trailing(node : Crystal::ASTNode, size)
-      remove_trailing(location(node), end_location(node), size)
-    end
-
-    private def location(node : Crystal::ASTNode)
-      node.location || raise "Missing location"
-    end
-
-    private def end_location(node : Crystal::ASTNode)
-      node.end_location || raise "Missing end location"
-    end
-
     # Applies all scheduled changes and returns modified source as a new string.
     def process
       @rewriter.process