[ruby/irb] Clear all context usages in RubyLex

(https://github.com/ruby/irb/pull/684)

After this change, `RubyLex` will not interact with `Context` directly
in any way. This decoupling has a few benefits:

- It makes `RubyLex` easier to test as it no longer has a dependency on
  `Context`. We can see this from the removal of `build_context` from
  `test_ruby_lex.rb`.
- It will make `RubyLex` easier to understand as it will not be affected
  by state changes in `Context` objects.
- It allows `RubyLex` to be used in places where `Context` is not available.

https://github.com/ruby/irb/commit/d5b262a076

2 files changed, 10 insertions, 28 deletions

diff --git a/test/irb/test_irb.rb b/test/irb/test_irb.rb
index 4e5a94b1be..4870f35f39 100644
--- a/test/irb/test_irb.rb
+++ b/test/irb/test_irb.rb
@@ -584,7 +584,7 @@ module TestIRB
 
       def assert_indent_level(lines, expected)
         code = lines.map { |l| "#{l}\n" }.join # code should end with "\n"
-        _tokens, opens, _ = @irb.scanner.check_code_state(code)
+        _tokens, opens, _ = @irb.scanner.check_code_state(code, local_variables: [])
         indent_level = @irb.scanner.calc_indent_level(opens)
         error_message = "Calculated the wrong number of indent level for:\n #{lines.join("\n")}"
         assert_equal(expected, indent_level, error_message)
diff --git a/test/irb/test_ruby_lex.rb b/test/irb/test_ruby_lex.rb
index b9e55c7330..5cfd81dbe8 100644
--- a/test/irb/test_ruby_lex.rb
+++ b/test/irb/test_ruby_lex.rb
@@ -149,8 +149,7 @@ module TestIRB
     end
 
     def test_assignment_expression
-      context = build_context
-      ruby_lex = IRB::RubyLex.new(context)
+      ruby_lex = IRB::RubyLex.new
 
       [
         "foo = bar",
@@ -173,7 +172,7 @@ module TestIRB
         "foo\nfoo = bar",
       ].each do |exp|
         assert(
-          ruby_lex.assignment_expression?(exp),
+          ruby_lex.assignment_expression?(exp, local_variables: []),
           "#{exp.inspect}: should be an assignment expression"
         )
       end
@@ -186,20 +185,18 @@ module TestIRB
         "foo = bar\nfoo",
       ].each do |exp|
         refute(
-          ruby_lex.assignment_expression?(exp),
+          ruby_lex.assignment_expression?(exp, local_variables: []),
           "#{exp.inspect}: should not be an assignment expression"
         )
       end
     end
 
     def test_assignment_expression_with_local_variable
-      context = build_context
-      ruby_lex = IRB::RubyLex.new(context)
+      ruby_lex = IRB::RubyLex.new
       code = "a /1;x=1#/"
-      refute(ruby_lex.assignment_expression?(code), "#{code}: should not be an assignment expression")
-      context.workspace.binding.eval('a = 1')
-      assert(ruby_lex.assignment_expression?(code), "#{code}: should be an assignment expression")
-      refute(ruby_lex.assignment_expression?(""), "empty code should not be an assignment expression")
+      refute(ruby_lex.assignment_expression?(code, local_variables: []), "#{code}: should not be an assignment expression")
+      assert(ruby_lex.assignment_expression?(code, local_variables: [:a]), "#{code}: should be an assignment expression")
+      refute(ruby_lex.assignment_expression?("", local_variables: [:a]), "empty code should not be an assignment expression")
     end
 
     def test_initialising_the_old_top_level_ruby_lex
@@ -211,20 +208,6 @@ module TestIRB
 
     private
 
-    def build_context(local_variables = nil)
-      IRB.init_config(nil)
-      workspace = IRB::WorkSpace.new(TOPLEVEL_BINDING.dup)
-
-      if local_variables
-        local_variables.each do |n|
-          workspace.binding.local_variable_set(n, nil)
-        end
-      end
-
-      IRB.conf[:VERBOSE] = false
-      IRB::Context.new(nil, workspace, TestInputMethod.new)
-    end
-
     def assert_indent_level(lines, expected, local_variables: [])
       indent_level, _continue, _code_block_open = check_state(lines, local_variables: local_variables)
       error_message = "Calculated the wrong number of indent level for:\n #{lines.join("\n")}"
@@ -244,10 +227,9 @@ module TestIRB
     end
 
     def check_state(lines, local_variables: [])
-      context = build_context(local_variables)
       code = lines.map { |l| "#{l}\n" }.join # code should end with "\n"
-      ruby_lex = IRB::RubyLex.new(context)
-      tokens, opens, terminated = ruby_lex.check_code_state(code)
+      ruby_lex = IRB::RubyLex.new
+      tokens, opens, terminated = ruby_lex.check_code_state(code, local_variables: local_variables)
       indent_level = ruby_lex.calc_indent_level(opens)
       continue = ruby_lex.should_continue?(tokens)
       [indent_level, continue, !terminated]