diff options
| author | Étienne Barrié <[email protected]> | 2023-12-01 11:33:00 +0100 |
|---|---|---|
| committer | Jean Boussier <[email protected]> | 2024-03-19 09:26:49 +0100 |
| commit | 12be40ae6be78ac41e8e3f3c313cc6f63e7fa6c4 (patch) | |
| tree | f6b81fac770da6b705557623224dbf9b9c2d2847 /spec/ruby/core | |
| parent | 86b15316a748a579dd4fd4df42b6db42accebdc2 (diff) | |
Implement chilled strings
[Feature #20205]
As a path toward enabling frozen string literals by default in the future,
this commit introduce "chilled strings". From a user perspective chilled
strings pretend to be frozen, but on the first attempt to mutate them,
they lose their frozen status and emit a warning rather than to raise a
`FrozenError`.
Implementation wise, `rb_compile_option_struct.frozen_string_literal` is
no longer a boolean but a tri-state of `enabled/disabled/unset`.
When code is compiled with frozen string literals neither explictly enabled
or disabled, string literals are compiled with a new `putchilledstring`
instruction. This instruction is identical to `putstring` except it marks
the String with the `STR_CHILLED (FL_USER3)` and `FL_FREEZE` flags.
Chilled strings have the `FL_FREEZE` flag as to minimize the need to check
for chilled strings across the codebase, and to improve compatibility with
C extensions.
Notes:
- `String#freeze`: clears the chilled flag.
- `String#-@`: acts as if the string was mutable.
- `String#+@`: acts as if the string was mutable.
- `String#clone`: copies the chilled flag.
Co-authored-by: Jean Boussier <[email protected]>
Diffstat (limited to 'spec/ruby/core')
| -rw-r--r-- | spec/ruby/core/kernel/eval_spec.rb | 19 | ||||
| -rw-r--r-- | spec/ruby/core/string/chilled_string_spec.rb | 69 |
2 files changed, 80 insertions, 8 deletions
diff --git a/spec/ruby/core/kernel/eval_spec.rb b/spec/ruby/core/kernel/eval_spec.rb index 15c9d511fc..5d82f57e44 100644 --- a/spec/ruby/core/kernel/eval_spec.rb +++ b/spec/ruby/core/kernel/eval_spec.rb @@ -350,9 +350,11 @@ CODE end it "allows a magic encoding comment and a subsequent frozen_string_literal magic comment" do + frozen_string_default = "test".frozen? + code = <<CODE.b # encoding: UTF-8 -# frozen_string_literal: true +# frozen_string_literal: #{!frozen_string_default} class EvalSpecs Vπstring = "frozen" end @@ -362,7 +364,7 @@ CODE EvalSpecs.constants(false).should include(:"Vπstring") EvalSpecs::Vπstring.should == "frozen" EvalSpecs::Vπstring.encoding.should == Encoding::UTF_8 - EvalSpecs::Vπstring.frozen?.should be_true + EvalSpecs::Vπstring.frozen?.should == !frozen_string_default end it "allows a magic encoding comment and a frozen_string_literal magic comment on the same line in emacs style" do @@ -381,8 +383,9 @@ CODE end it "ignores the magic encoding comment if it is after a frozen_string_literal magic comment" do + frozen_string_default = "test".frozen? code = <<CODE.b -# frozen_string_literal: true +# frozen_string_literal: #{!frozen_string_default} # encoding: UTF-8 class EvalSpecs Vπfrozen_first = "frozen" @@ -396,24 +399,24 @@ CODE value = EvalSpecs.const_get(binary_constant) value.should == "frozen" value.encoding.should == Encoding::BINARY - value.frozen?.should be_true + value.frozen?.should == !frozen_string_default end it "ignores the frozen_string_literal magic comment if it appears after a token and warns if $VERBOSE is true" do - default_frozen_string_literal = "test".frozen? + frozen_string_default = "test".frozen? code = <<CODE some_token_before_magic_comment = :anything -# frozen_string_literal: true +# frozen_string_literal: #{!frozen_string_default} class EvalSpecs Vπstring_not_frozen = "not frozen" end CODE -> { eval(code) }.should complain(/warning: [`']frozen_string_literal' is ignored after any tokens/, verbose: true) - EvalSpecs::Vπstring_not_frozen.frozen?.should == default_frozen_string_literal + EvalSpecs::Vπstring_not_frozen.frozen?.should == frozen_string_default EvalSpecs.send :remove_const, :Vπstring_not_frozen -> { eval(code) }.should_not complain(verbose: false) - EvalSpecs::Vπstring_not_frozen.frozen?.should == default_frozen_string_literal + EvalSpecs::Vπstring_not_frozen.frozen?.should == frozen_string_default EvalSpecs.send :remove_const, :Vπstring_not_frozen end end diff --git a/spec/ruby/core/string/chilled_string_spec.rb b/spec/ruby/core/string/chilled_string_spec.rb new file mode 100644 index 0000000000..8de4fc421b --- /dev/null +++ b/spec/ruby/core/string/chilled_string_spec.rb @@ -0,0 +1,69 @@ +require_relative '../../spec_helper' + +describe "chilled String" do + guard -> { ruby_version_is "3.4" and !"test".equal?("test") } do + describe "#frozen?" do + it "returns true" do + "chilled".frozen?.should == true + end + end + + describe "#-@" do + it "returns a different instance" do + input = "chilled" + interned = (-input) + interned.frozen?.should == true + interned.object_id.should_not == input.object_id + end + end + + describe "#+@" do + it "returns a different instance" do + input = "chilled" + duped = (+input) + duped.frozen?.should == false + duped.object_id.should_not == input.object_id + end + end + + describe "#clone" do + it "preserves chilled status" do + input = "chilled".clone + -> { + input << "-mutated" + }.should complain(/literal string will be frozen in the future/) + input.should == "chilled-mutated" + end + end + + describe "mutation" do + it "emits a warning" do + input = "chilled" + -> { + input << "-mutated" + }.should complain(/literal string will be frozen in the future/) + input.should == "chilled-mutated" + end + + it "emits a warning on singleton_class creaation" do + -> { + "chilled".singleton_class + }.should complain(/literal string will be frozen in the future/) + end + + it "emits a warning on instance variable assignment" do + -> { + "chilled".instance_variable_set(:@ivar, 42) + }.should complain(/literal string will be frozen in the future/) + end + + it "raises FrozenError after the string was explictly frozen" do + input = "chilled" + input.freeze + -> { + input << "mutated" + }.should raise_error(FrozenError) + end + end + end +end |