August 2025 - ruby-core - ml.ruby-lang.org

[ruby-core:123113] [Ruby Feature#21555] Add support for predicate attribute reader names
by shan (Shannon Skipper) 16 Sep '25

16 Sep '25

Issue #21555 has been reported by shan (Shannon Skipper). ---------------------------------------- Feature #21555: Add support for predicate attribute reader names https://bugs.ruby-lang.org/issues/21555 * Author: shan (Shannon Skipper) * Status: Open ---------------------------------------- After manually aliasing predicate methods many times, I wanted to propose letting `attr_reader` take predicate method names that correspond to instance variables of the base name without a trailing question mark. https://github.com/ruby/ruby/pull/14391 If the base name method doesn't already exist, a predicate name defines a base name method attribute reader to alias then undefines the base name. For example, this creates an `enabled?` method that reads `@enabled`: ```ruby attr_reader :enabled? ``` This feature is only supported for `attr_reader` and `attr`, not `attr_writer` or `attr_accessor`, since setter methods cannot have question marks. Example: ```ruby class Example attr_reader :valid?, :meaning def initialize @valid = [true, false].sample @meaning = 42 end end Example.new.valid? #=> true ``` -- https://bugs.ruby-lang.org/

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[ruby-core:122086] [Ruby Bug#21337] Using `not` on the RHS of a logical operator becomes valid syntax with Prism
by koic (Koichi ITO) 15 Sep '25

15 Sep '25

Issue #21337 has been reported by koic (Koichi ITO). ---------------------------------------- Bug #21337: Using `not` on the RHS of a logical operator becomes valid syntax with Prism https://bugs.ruby-lang.org/issues/21337 * Author: koic (Koichi ITO) * Status: Open * ruby -v: ruby 3.4.3 (2025-04-14 revision d0b7e5b6a0) +PRISM [x86_64-darwin24] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- The following syntax behavior differs between Ruby 3.3 (parse.y by default) and Ruby 3.4 (Prism by default). ```ruby if true && not true; end ``` ## Expected In Ruby 3.3 and earlier, the following code results in a syntax error. The default parser is `parse.y`. ```console $ ruby -vce 'if true && not true; end' ruby 3.3.8 (2025-04-09 revision b200bad6cd) [x86_64-darwin24] -e:1: syntax error, unexpected `true', expecting '(' if true && not true; end ruby: compile error (SyntaxError) ``` The key point is that `not` is used on the right-hand side of a logical operator. ## Actual When the default parser is switched to Prism, it is accepted as valid syntax with Ruby 3.4+ (Prism by default): ```console $ ruby -vce 'if true && not true; end' ruby 3.4.3 (2025-04-14 revision d0b7e5b6a0) +PRISM [x86_64-darwin24] Syntax OK $ ruby -vce 'if true && not true; end' ruby 3.5.0dev (2025-05-13T02:05:19Z master 9b8c846bdf) +PRISM [x86_64-darwin24] Syntax OK ``` Specifying parse.y causes a syntax error, as before 3.3 (parse.y by default): ```console $ ruby -vce 'if true && not true; end' ruby 3.3.8 (2025-04-09 revision b200bad6cd) [x86_64-darwin24] -e:1: syntax error, unexpected `true', expecting '(' if true && not true; end ruby: compile error (SyntaxError) $ ruby --parser=parse.y -vce 'if true && not true; end' ruby 3.5.0dev (2025-05-13T02:05:19Z master 9b8c846bdf) [x86_64-darwin24] -e:1: syntax error, unexpected 'true', expecting '(' if true && not true; end ruby: compile error (SyntaxError) ``` The behavior seen in the parse.y producing a syntax error might be probably the expected one. Any case, it is likely that users would not expect such a discrepancy between parsers. This issue was noticed in the context of the following RuboCop issue: https://github.com/rubocop/rubocop/issues/14177 -- https://bugs.ruby-lang.org/

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[ruby-core:121390] [Ruby Bug#21188] PRISM does not end reading from tty with ^D twice
by nobu (Nobuyoshi Nakada) 15 Sep '25

15 Sep '25

Issue #21188 has been reported by nobu (Nobuyoshi Nakada). ---------------------------------------- Bug #21188: PRISM does not end reading from tty with ^D twice https://bugs.ruby-lang.org/issues/21188 * Author: nobu (Nobuyoshi Nakada) * Status: Open * Assignee: prism * Backport: 3.1: DONTNEED, 3.2: DONTNEED, 3.3: DONTNEED, 3.4: REQUIRED ---------------------------------------- When reading from tty, `^D` ends the text without the newline. ```console $ cat a ``` Typing `^D` here, only "a" is sent without a newline, and `cat` echos back it. Then by typing `^D` again, an empty read that means EOF causes `cat` to exit. `ruby --parser=parse.y` behaves in this manner: ```console $ ruby --parser=parse.y p __FILE__"-" ``` Typing `^D` twice just after `__FILE__`, and `p` prints `"-"`. However prism requires `^D` thrice. -- https://bugs.ruby-lang.org/

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[ruby-core:122953] [Ruby Bug#21540] prism allows `foo && return bar` when parse.y doesn't
by Earlopain (Earlopain _) 15 Sep '25

15 Sep '25

Issue #21540 has been reported by Earlopain (Earlopain _). ---------------------------------------- Bug #21540: prism allows `foo && return bar` when parse.y doesn't https://bugs.ruby-lang.org/issues/21540 * Author: Earlopain (Earlopain _) * Status: Open * ruby -v: ruby 3.5.0dev (2025-08-08T02:57:23Z master 3ad26d0501) [x86_64-linux] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Code such as `foo && return bar` has been disallowed in ruby since at least Ruby 2.0. Prism allows it though: ``` $ ruby -cve "a && return foo" ruby 3.5.0dev (2025-08-08T02:57:23Z master 3ad26d0501) +PRISM [x86_64-linux] Syntax OK $ ruby --parser=parse.y -cve "a && return foo" ruby 3.5.0dev (2025-08-08T02:57:23Z master 3ad26d0501) [x86_64-linux] -e:1: syntax error, unexpected local variable or method, expecting end-of-input a && return foo ruby: compile error (SyntaxError) ``` The code seems to behave like I'd expect it to and I wouldn't mind it being accepted but it is inconsistent. -- https://bugs.ruby-lang.org/

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[ruby-core:122972] [Ruby Bug#21546] `prefix` in ruby.pc is wrong when `--enable-load-relative`
by nobu (Nobuyoshi Nakada) 14 Sep '25

14 Sep '25

Issue #21546 has been reported by nobu (Nobuyoshi Nakada). ---------------------------------------- Bug #21546: `prefix` in ruby.pc is wrong when `--enable-load-relative` https://bugs.ruby-lang.org/issues/21546 * Author: nobu (Nobuyoshi Nakada) * Status: Open * Backport: 3.2: REQUIRED, 3.3: REQUIRED, 3.4: REQUIRED ---------------------------------------- It is relocatable and should reflect the installed location. ```console $ export PKG_CONFIG_PATH=/opt/local/lib/pkgconfig${PKG_CONFIG_PATH:+:$PKG_CONFIG_PATH} $ pkg-config --variable=prefix ruby-3.5 /. ``` Currently `pkg-config --define-prefix` works because it overrides the `prefix` value. ```console $ pkg-config --variable=prefix --define-prefix ruby-3.5 /opt/local ``` -- https://bugs.ruby-lang.org/

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[ruby-core:122501] [Ruby Bug#21402] ruby2_keywords affects methods/procs with post arguments
by jeremyevans0 (Jeremy Evans) 14 Sep '25

14 Sep '25

Issue #21402 has been reported by jeremyevans0 (Jeremy Evans). ---------------------------------------- Bug #21402: ruby2_keywords affects methods/procs with post arguments https://bugs.ruby-lang.org/issues/21402 * Author: jeremyevans0 (Jeremy Evans) * Status: Open * Backport: 3.2: REQUIRED, 3.3: REQUIRED, 3.4: REQUIRED ---------------------------------------- I believe this is an oversight. We forgot to consider post arguments during the development of `ruby2_keywords`. I believe we should not allow `ruby2_keywords` on methods/procs with post arguments. Example: ```ruby def a(*c, **kw) [c, kw] end def b(*a, b) a(*a, b) end ruby2_keywords(:b) b({foo: 1}, bar: 1) # Currently: [[{foo: 1}], {bar: 1}] # Expected: [[{foo: 1}, {bar: 1}], {}] ``` I think the current behavior is unexpected and undesired, because instead of flagging the last element in the splat array, it flags a post argument. I've submitted a pull request to fix this: https://github.com/ruby/ruby/pull/13475 -- https://bugs.ruby-lang.org/

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[ruby-core:123122] [Ruby Feature#21556] Add true? and false? methods to NilClass, TrueClass, FalseClass, and String
by Phalado (Raphael Cordeiro) 14 Sep '25

14 Sep '25

Issue #21556 has been reported by Phalado (Raphael Cordeiro). ---------------------------------------- Feature #21556: Add true? and false? methods to NilClass, TrueClass, FalseClass, and String https://bugs.ruby-lang.org/issues/21556 * Author: Phalado (Raphael Cordeiro) * Status: Open ---------------------------------------- Sometimes we need to check for an exact `true` or `false` value. This can be a string or a boolean value. Usually, what I do to solve this is something like `value.to_s == true`, this way covering for strings, booleans, and nil values. The idea of these new methods is to check for the exact value, being it a String, a Boolean, or even a Nil value. This is the result obtained: ``` ruby # String 'true'.true? # true 'false'.true? # false ''.true? # false 'true'.false? # false 'false'.false? # true ''.false? # false # Boolean true.true? # true true.false? # false false.true? # false false.false? # true # Nil nil.true? # false nil.false? # false ``` -- https://bugs.ruby-lang.org/

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[ruby-core:120819] [Ruby master Bug#21097] `x = a rescue b in c` and `def f = a rescue b in c` parsed differently between parse.y and prism
by tompng (tomoya ishida) 13 Sep '25

13 Sep '25

Issue #21097 has been reported by tompng (tomoya ishida). ---------------------------------------- Bug #21097: `x = a rescue b in c` and `def f = a rescue b in c` parsed differently between parse.y and prism https://bugs.ruby-lang.org/issues/21097 * Author: tompng (tomoya ishida) * Status: Open * ruby -v: ruby 3.5.0dev (2025-01-27T08:19:32Z master c3c7300b89) +YJIT +MN +PRISM [arm64-darwin22] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- ~~~ruby x = a rescue b in c (x = (a rescue b)) in c # parse.y, prism(ruby 3.4) x = (a rescue (b in c)) # prism(ruby 3.5) ~~~ ~~~ruby def f = a rescue b in c #=> true(parse.y), :f(prism) (def f = (a rescue b)) in c # parse.y def f = (a rescue (b in c)) # prism ~~~ There is no difference between prism and parse.y parsing these codes ~~~ruby a rescue b in c # a rescue (b in c) x = a rescue b # x = (a rescue b) x = b in c # (x = b) in c def f = a rescue b # def f = (a rescue b) def f = b in c # (def f = a) in b ~~~ -- https://bugs.ruby-lang.org/

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[ruby-core:122899] [Ruby Bug#21528] SyntaxError#message may have broken encoding with multibyte source under Prism
by alpaca-tc (Hiroyuki Ishii) 13 Sep '25

13 Sep '25

Issue #21528 has been reported by alpaca-tc (Hiroyuki Ishii). ---------------------------------------- Bug #21528: SyntaxError#message may have broken encoding with multibyte source under Prism https://bugs.ruby-lang.org/issues/21528 * Author: alpaca-tc (Hiroyuki Ishii) * Status: Open * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Since the introduction of Prism, when parsing Ruby source code that contains multibyte characters, SyntaxError#message can sometimes have invalid encoding. Here is a reproducible example: ``` begin RubyVM::InstructionSequence.compile(<<~CODE, nil, nil, 1) if a # 0000000000000ああああああ # CODE rescue SyntaxError => e $e = e puts e.message # string contains a multibyte character that is cut off mid-byte. \xE3 # <compiled>:3: syntax errors found # 1 | if a # > 2 | # 0000000000000あああああ\xE3 ... # | ^ expected an `end` to close the conditional clause # > 3 | # # | ^ unexpected end-of-input, assuming it is closing the parent top level context puts e.message.valid_encoding? #=> expected true, but got false end ``` This appears to be caused by a truncation process in prism's error message generating that does not consider multibyte character boundaries. See: The truncation logic around [prism_compile.c L10696-L10709](https://github.com/ruby/ruby//blob/30a20bc166bc37acd7dcb3788… I'm not sure how to correctly fix it due to lack of knowledge about safe byte truncation. I discovered this issue through irb, which attempts to display source code even when it contains syntax errors. Because irb uses `SyntaxError#message`, it raised an `ArgumentError: invalid byte sequence in UTF-8`. See: https://github.com/ruby/irb/blob/f60dfa8549f746f69e9a6d160604a7a4974ffac1/l… If this is considered an irb issue, I already have a patch for IRB that handles it. -- https://bugs.ruby-lang.org/

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[ruby-core:122315] [Ruby Bug#21378] variable pinning does not look for method arguments
by shyouhei (Shyouhei Urabe) 13 Sep '25

13 Sep '25

Issue #21378 has been reported by shyouhei (Shyouhei Urabe). ---------------------------------------- Bug #21378: variable pinning does not look for method arguments https://bugs.ruby-lang.org/issues/21378 * Author: shyouhei (Shyouhei Urabe) * Status: Open * Assignee: prism * ruby -v: ruby 3.5.0dev (2025-01-23T15:24:35Z origin/7ed08c4fd31.. 7ed08c4fd3) +PRISM [wasm32-wasi] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Is this intentional? ``` irb(main):001> def x?(y, z) = y in { x: ^z } <internal:kernel>:168:in 'Kernel#loop': (irb):1: syntax error found (SyntaxError) > 1 | def x?(y, z) = y in { x: ^z } | ^ z: no such local variable from eval_async:132:in '<main>' from /bundle/gems/js-2.7.1/lib/js.rb:109:in 'Kernel.eval' from /bundle/gems/js-2.7.1/lib/js.rb:109:in 'block in JS.__eval_async_rb' from /bundle/gems/js-2.7.1/lib/js.rb:120:in 'block in JS.__async' ``` -- https://bugs.ruby-lang.org/

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