Write Inline RBS Annotations

You are adding inline RBS type annotations directly in the Ruby source file at: $ARGUMENTS

Process

1. Load the RBS Skill

First, load the RBS skill for comprehensive type knowledge:

Use the Skill tool to load: ruby-inline-rbs

Then read the inline RBS subskill for syntax details:

• subskills/inline/SKILL.md

2. Analyze Target

Read the Ruby file(s) specified by the user:

• Understand class/module structure
• Note method signatures, parameters, return patterns
• Identify instance variables
• Look for DSL usage (attr_*, delegate, etc.)

3. Find Tests

Search for related test files:

Glob for: test/**/*{target_name}*_test.rb, spec/**/*{target_name}*_spec.rb

Read tests to understand:

• Expected method behavior
• Edge cases (nil returns, exceptions)
• Type expectations from assertions

4. Use Type Tracer (If Tests Exist)

If tests exist, consider running the type tracer:

# First locate type_tracer.rb in plugin directory using find
ruby <TRACER_SCRIPT> -c 'TargetClass' -f json path/to/test.rb

Review tracer output to inform type decisions.

5. Add Magic Comment

Ensure the file has the magic comment at the top:

# rbs_inline: enabled

6. Add Inline Annotations

Add type annotations using comment syntax:

Method signatures:

#: (String, Integer) -> String
def format(text, width)

Attributes:

attr_reader :name #: String
attr_accessor :count #: Integer?

Instance variables:

# @rbs @items: Array[String]

Blocks:

#: () { (String) -> void } -> void
def each(&block)

Generics:

# @rbs generic T
class Container

7. Generate and Validate

Generate RBS from inline annotations:

bundle exec rbs-inline --output lib

Then validate:

bundle exec steep check lib/target.rb

Fix any errors before completing.

Output

1. Modified Ruby file(s) with inline type annotations
2. Generated sig/generated/*.rbs files (if --output used)
3. Report what was typed and any decisions made

Tips

• Always add # rbs_inline: enabled at file top
• Use #: for concise method signatures
• Use # @rbs for structured annotations with comments
• Use # @rbs! for DSL-generated methods
• Check references/troubleshooting.md for common gotchas
• Instance variable nil checks need local variable assignment for narrowing