Module: T

Defined in:
lib/types/_types.rb,
lib/types/boolean.rb,
lib/sorbet-runtime.rb,
lib/types/compatibility_patches.rb,
lib/types/compatibility_patches.rb

Overview

Work around for sorbet-runtime wrapped methods.

When a sig is defined, sorbet-runtime will replace the sigged method with a wrapper. Those wrapper methods look like ‘foo(*args, &blk)` so that wrappers can handle and pass on all the arguments supplied.

However, that creates a problem with runtime reflection on the methods, since when a sigged method is introspected, it will always return its ‘arity` as `-1`, its `parameters` as `[[:rest, :args], [:block, :blk]]`, and its `source_location` as `[<some_file_in_sorbet>, <some_line_number>]`.

This might be a problem for some applications that rely on getting the correct information from these methods.

This compatibility module, when prepended to the ‘Method` class, would fix the return values of `arity`, `parameters` and `source_location`.

Examples:

require 'sorbet-runtime'
::Method.prepend(T::CompatibilityPatches::MethodExtensions)

Defined Under Namespace

Modules: AbstractUtils, Array, CompatibilityPatches, Configuration, Enumerable, Enumerator, Generic, Hash, Helpers, NonForcingConstants, Private, Props, Range, Set, Sig, Types, Utils Classes: Enum, ImmutableStruct, InexactStruct, InterfaceWrapper, Struct

Constant Summary collapse

Boolean =

T::Boolean is a type alias helper for the common ‘T.any(TrueClass, FalseClass)`. Defined separately from _types.rb because it has a dependency on T::Types::Union.

T.type_alias {T.any(TrueClass, FalseClass)}

Class Method Summary collapse

Class Method Details

.absurd(value) ⇒ Object

A way to ask Sorbet to prove that a certain branch of control flow never happens. Commonly used to assert that a case or if statement exhausts all possible cases.



234
235
236
237
238
239
240
241
242
243
244
245
246
247
 
# File 'lib/types/_types.rb', line 234

def self.absurd(value)
  msg = "Control flow reached T.absurd."

  case value
  when Kernel
    msg += " Got value: #{value}"
  end

  begin
    raise TypeError.new(msg)
  rescue TypeError => e # raise into rescue to ensure e.backtrace is populated
    T::Configuration.inline_type_error_handler(e, {kind: 'T.absurd', value: value, type: nil})
  end
end

.all(type_a, type_b, *types) ⇒ Object

T.all(<Type>, <Type>, …) – matches an object that has all of the types listed



51
52
53
 
# File 'lib/types/_types.rb', line 51

def self.all(type_a, type_b, *types)
  T::Types::Intersection.new([type_a, type_b] + types)
end

.any(type_a, type_b, *types) ⇒ Object

T.any(<Type>, <Type>, …) – matches any of the types listed



27
28
29
30
31
32
 
# File 'lib/types/_types.rb', line 27

def self.any(type_a, type_b, *types)
  type_a = T::Utils.coerce(type_a)
  type_b = T::Utils.coerce(type_b)
  types = types.map {|t| T::Utils.coerce(t)} if !types.empty?
  T::Types::Union::Private::Pool.union_of_types(type_a, type_b, types)
end

.assert_type!(value, type, checked: true) ⇒ Object

Tells the typechecker to ensure that ‘value` is of type `type` (if not, the typechecker will fail). Use this for debugging typechecking errors, or to ensure that type information is statically known and being checked appropriately. If `checked` is true, raises an exception at runtime if the value doesn’t match the type.



174
175
176
177
178
 
# File 'lib/types/_types.rb', line 174

def self.assert_type!(value, type, checked: true)
  return value unless checked

  Private::Casts.cast(value, type, cast_method: "T.assert_type!")
end

.attached_class ⇒ Object

Matches the instance type in a singleton-class context



72
73
74
 
# File 'lib/types/_types.rb', line 72

def self.attached_class
  T::Types::AttachedClassType::Private::INSTANCE
end

.bind(value, type, checked: true) ⇒ Object

Tells the type checker to treat ‘self` in the current block as `type`. Useful for blocks that are captured and executed later with instance_exec. Use like:

seconds = lambda do
  T.bind(self, NewBinding)
  ...
end

‘T.bind` behaves like `T.cast` in that it is assumed to be true statically.

If ‘checked` is true, raises an exception at runtime if the value doesn’t match the type (this is the default).



164
165
166
167
168
 
# File 'lib/types/_types.rb', line 164

def self.bind(value, type, checked: true)
  return value unless checked

  Private::Casts.cast(value, type, cast_method: "T.bind")
end

.cast(value, type, checked: true) ⇒ Object

Tells the typechecker that ‘value` is of type `type`. Use this to get additional checking after an expression that the typechecker is unable to analyze. If `checked` is true, raises an exception at runtime if the value doesn’t match the type.

Compared to ‘T.let`, `T.cast` is trusted by static system.



130
131
132
133
134
 
# File 'lib/types/_types.rb', line 130

def self.cast(value, type, checked: true)
  return value unless checked

  Private::Casts.cast(value, type, cast_method: "T.cast")
end

.class_of(klass) ⇒ Object

Matches any class that subclasses or includes the provided class or module



78
79
80
 
# File 'lib/types/_types.rb', line 78

def self.class_of(klass)
  T::Types::ClassOf.new(klass)
end

.deprecated_enum(values) ⇒ Object

Deprecated.

Use T::Enum instead.

Matches any of the listed values



57
58
59
 
# File 'lib/types/_types.rb', line 57

def self.deprecated_enum(values)
  T::Types::Enum.new(values)
end

.let(value, type, checked: true) ⇒ Object

Tells the typechecker to declare a variable of type ‘type`. Use like:

seconds = T.let(0.0, Float)

Compared to ‘T.cast`, `T.let` is checked by static system.

If ‘checked` is true, raises an exception at runtime if the value doesn’t match the type.



145
146
147
148
149
 
# File 'lib/types/_types.rb', line 145

def self.let(value, type, checked: true)
  return value unless checked

  Private::Casts.cast(value, type, cast_method: "T.let")
end

.must(arg) ⇒ Object

A convenience method to ‘raise` when the argument is `nil` and return it otherwise.

Intended to be used as:

needs_foo(T.must(maybe_gives_foo))

Equivalent to:

foo = maybe_gives_foo
raise "nil" if foo.nil?
needs_foo(foo)

Intended to be used to promise sorbet that a given nilable value happens to contain a non-nil value at this point.

‘sig T.nilable(A)).returns(A)`



213
214
215
216
217
218
219
220
221
222
 
# File 'lib/types/_types.rb', line 213

def self.must(arg)
  return arg if arg
  return arg if arg == false

  begin
    raise TypeError.new("Passed `nil` into T.must")
  rescue TypeError => e # raise into rescue to ensure e.backtrace is populated
    T::Configuration.inline_type_error_handler(e, {kind: 'T.must', value: arg, type: nil})
  end
end

.nilable(type) ⇒ Object

Shorthand for T.any(type, NilClass)



35
36
37
 
# File 'lib/types/_types.rb', line 35

def self.nilable(type)
  T::Types::Union::Private::Pool.union_of_types(T::Utils.coerce(type), T::Utils::Nilable::NIL_TYPE)
end

.noreturn ⇒ Object

Indicates a function never returns (e.g. “Kernel#raise”)



46
47
48
 
# File 'lib/types/_types.rb', line 46

def self.noreturn
  T::Types::NoReturn::Private::INSTANCE
end

.proc ⇒ Object

Creates a proc type



62
63
64
 
# File 'lib/types/_types.rb', line 62

def self.proc
  T::Private::Methods.start_proc
end

.reveal_type(value) ⇒ Object

A way to ask Sorbet to show what type it thinks an expression has. This can be useful for debugging and checking assumptions. In the runtime, merely returns the value passed in.



227
228
229
 
# File 'lib/types/_types.rb', line 227

def self.reveal_type(value)
  value
end

.self_type ⇒ Object

Matches ‘self`:



67
68
69
 
# File 'lib/types/_types.rb', line 67

def self.self_type
  T::Types::SelfType::Private::INSTANCE
end

.type_alias(type = nil, &blk) ⇒ Object

Constructs a type alias. Used to create a short name for a larger type. In Ruby this returns a wrapper that contains a proc that is evaluated to get the underlying type. This syntax however is needed for support by the static checker.

The name of the type alias is not preserved; Error messages will be printed with reference to the underlying type.

TODO Remove ‘type` parameter. This was left in to make life easier while migrating.

Examples:

NilableString = T.type_alias {T.nilable(String)}

sig {params(arg: NilableString, default: String).returns(String)}
def or_else(arg, default)
  arg || default
end


100
101
102
103
104
105
106
 
# File 'lib/types/_types.rb', line 100

def self.type_alias(type=nil, &blk)
  if blk
    T::Private::Types::TypeAlias.new(blk)
  else
    T::Utils.coerce(type)
  end
end

.type_parameter(name) ⇒ Object

References a type parameter which was previously defined with ‘type_parameters`.

This is used for generic methods.

Examples:

sig
.type_parameters(:U)
.params(
  blk: T.proc.params(arg0: Elem).returns(T.type_parameter(:U)),
)
.returns(T::Array[T.type_parameter(:U)])
def map(&blk); end


121
122
123
 
# File 'lib/types/_types.rb', line 121

def self.type_parameter(name)
  T::Types::TypeParameter.new(name)
end

.unsafe(value) ⇒ Object

For the static type checker, strips all type information from a value and returns the same value, but statically-typed as ‘T.untyped`. Can be used to tell the static checker to “trust you” by discarding type information you know to be incorrect. Use with care! (This has no effect at runtime.)

We can’t actually write this sig because we ourselves are inside the ‘T::` module and doing this would create a bootstrapping cycle. However, we also don’t actually need to do so; An untyped identity method works just as well here.

‘sig T.untyped).returns(T.untyped)`



192
193
194
 
# File 'lib/types/_types.rb', line 192

def self.unsafe(value)
  value
end

.untyped ⇒ Object

Matches any object. In the static checker, T.untyped allows any method calls or operations.



41
42
43
 
# File 'lib/types/_types.rb', line 41

def self.untyped
  T::Types::Untyped::Private::INSTANCE
end