test_bot: Bump some files to Sorbet typed: strict

[issyl0]

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• Part of Use Sorbet typed: strict in all (non-package) files in Homebrew organisation #17297.
• There's one left (as of 2025-11-09), test_bot/test.rb which shows >70 errors when moved to strict (as there's a lot of T.nilable(String) or Pathname for things like args), so I'm leaving that one for future us who are maybe less tired.

[Copilot]

Pull Request Overview

This PR migrates the test-bot codebase from typed: true to typed: strict mode in Sorbet, adding comprehensive type annotations throughout the codebase to enable stricter type checking.

Key changes:

• Upgraded Sorbet typing level from true to strict across all test-bot files
• Added explicit type signatures (sig) to all methods, attributes, and instance variables
• Used T.let to explicitly type all instance variable initializations
• Added T.must() calls where needed to satisfy Sorbet's strict null checking

Reviewed Changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
Library/Homebrew/test_bot/test_runner.rb	Added strict typing with method signatures and instance variable types; includes an initialize method for module (potential issue)
Library/Homebrew/test_bot/test_formulae.rb	Added comprehensive type annotations for attributes, methods, and complex instance variables including hashes and arrays
Library/Homebrew/test_bot/test_cleanup.rb	Added type signatures and converted repository parameters to use .to_s for git commands
Library/Homebrew/test_bot/test.rb	Added passed? helper method and upgraded to strict typing
Library/Homebrew/test_bot/tap_syntax.rb	Added method signature and upgraded to strict typing
Library/Homebrew/test_bot/step.rb	Added extensive type annotations for all attributes and methods; includes type assertions with T.must()
Library/Homebrew/test_bot/setup.rb	Added method signature with T.self_type return type
Library/Homebrew/test_bot/junit.rb	Added type signatures and moved require statement to top of file
Library/Homebrew/test_bot/formulae_detect.rb	Added comprehensive type signatures including complex parameter lists
Library/Homebrew/test_bot/formulae_dependents.rb	Added type signatures and extensive use of T.must() for nullable variables
Library/Homebrew/test_bot/formulae.rb	Added type annotations and fixed array wrapping pattern from Array.new to literal syntax
Library/Homebrew/test_bot/cleanup_before.rb	Added signature and simplified conditional logic
Library/Homebrew/test_bot/cleanup_after.rb	Added method signature and upgraded to strict typing
Library/Homebrew/test_bot/bottles_fetch.rb	Added type signatures for accessor and methods
Library/Homebrew/test_bot.rb	Added type annotations for constants and module methods

Comments suppressed due to low confidence (1)

Library/Homebrew/test_bot/setup.rb:21

• The run! method signature declares a return type of T.self_type, but the method doesn't have an explicit return statement. In Ruby, methods return the value of the last expression, which in this case would be the result of the last test call (either "brew", "doctor", "--debug", verbose: true or "brew", "doctor").

The method should either explicitly return self to match the signature, or the return type should be changed to match what test returns (which appears to be a Step object based on the Test class implementation).

      sig { params(args: Homebrew::CLI::Args).returns(T.self_type) }
      def run!(args:)
        test_header(:Setup)

        test "brew", "install-bundler-gems", "--add-groups=ast,audit,bottle,formula_test,livecheck,style"

        # Always output `brew config` output even when it doesn't fail.
        test "brew", "config", verbose: true

        if ENV["HOMEBREW_TEST_BOT_VERBOSE_DOCTOR"]
          test "brew", "doctor", "--debug", verbose: true
        else
          test "brew", "doctor"
        end
      end

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[Copilot]

Inconsistent use of T.must(). Only end_time is wrapped in T.must(), but start_time is not. Both start_time and end_time have the same type signature (T.nilable(Time)), so they should be treated consistently. Either both should be wrapped in T.must() or the method should ensure both are set before being called.

Suggested change

	(T.must(end_time) - start_time).to_f
	(T.must(end_time) - T.must(start_time)).to_f

[Copilot]

The type annotation for @status is incorrect. It's initialized to :running (a Symbol), but the type signature declares it as T.nilable(Symbol). However, the attr_reader's signature on line 19 says T.nilable(Symbol), which means it can be nil, but the initialization on line 47 declares it as just Symbol (not nilable).

This inconsistency will cause type checking issues. The attr_reader signature should match the T.let declaration, or vice versa.

Suggested change

	@status = T.let(:running, Symbol)
	@status = T.let(:running, T.nilable(Symbol))

[Copilot]

The return type annotation [Pathname, T.nilable(Integer)] is using incorrect syntax. In Sorbet, tuples are represented using T::Array with fixed sizes, not raw array syntax. This should be T::Array[T.any(Pathname, T.nilable(Integer))] or use a custom type alias.

The correct Sorbet syntax for a 2-tuple would be creating a custom type, or if this truly returns an array with a pathname at index 0 and an integer at index 1, consider using a more explicit structure like a hash or custom class.

[Copilot]

The TestRunner module uses module_function, which means all methods are module methods (class-level). Module methods cannot have instance variables like @skipped_or_failed_formulae_output_path. This initialize method will never be called, and the instance variable won't be accessible in other methods.

Consider refactoring this to use a class instead of a module with module_function, or handle @skipped_or_failed_formulae_output_path without relying on instance variables.

[Copilot]

The return type annotation [[Formula], [Formula], [Formula]] is invalid Sorbet syntax. This appears to be attempting to declare a 3-tuple of Formula arrays, but the syntax is incorrect.

The correct syntax would be T::Array[T::Array[Formula]] if returning an array of arrays, or if you want to indicate three separate arrays in a specific structure, consider using a more explicit return type like a hash with named keys or a custom type.

Suggested change

	sig { params(formula: Formula, formula_name: String, args: Cmd::TestBotCmd::Args).returns([[Formula], [Formula], [Formula]]) }
	sig { params(formula: Formula, formula_name: String, args: Cmd::TestBotCmd::Args).returns(T::Array[T::Array[Formula]]) }

[Copilot]

Type inconsistency: clean_if_needed has a signature declaring repository: String, but it's called from other methods that pass Pathname objects (e.g., line 141 passes a Pathname to default_origin_ref which then uses git commands expecting a path).

This should be Pathname to match the other similar methods in this class (reset_if_needed, checkout_branch_if_needed, cleanup_git_meta, and prune_if_needed all use Pathname).

Suggested change

	sig { params(repository: String).void }
	sig { params(repository: Pathname).void }

[Copilot]

The return type T.anything is overly broad and defeats the purpose of strict typing. The method should have a more specific return type.

Looking at the method implementation, it appears to return nil in several branches (lines 51, 56) but otherwise runs to completion without an explicit return, which would return the result of the last statement. Consider using void if no meaningful value is returned, or specify the actual return type if one is needed.

Suggested change

	sig { params(args: Cmd::TestBotCmd::Args).returns(T.anything) }
	sig { params(args: Cmd::TestBotCmd::Args).returns(void) }