View Source Changelog for Elixir v1.11
Over the last releases, the Elixir team has been focusing on the compiler, both in terms of catching more mistakes at compilation time and making it faster. Elixir v1.11 has made excellent progress on both fronts. This release also includes many other goodies, such as tighter Erlang integration, support for more guard expressions, built-in datetime formatting, and other calendar enhancements.
Tighter Erlang integration
Following Elixir v1.10, we have further integrated with Erlang's new logger by adding four new log levels: notice
, critical
, alert
, and emergency
, matching all log levels found in the Syslog standard. The Logger
module now supports structured logging by passing maps and keyword lists to its various functions. It is also possible to specify the log level per module, via the Logger.put_module_level/2
function. Log levels per application will be added in future releases.
IEx also has been improved to show the documentation for Erlang modules directly from your Elixir terminal. This works with Erlang/OTP 23+ and requires Erlang modules to have been compiled with documentation chunks.
Compiler checks: application boundaries
Elixir v1.11 builds on top of the recently added compilation tracers to track application boundaries. From this release, Elixir will warn if you invoke a function from an existing module but this module does not belong to any of your listed dependencies.
These two conditions may seem contradictory. After all, if a module is available, it must have come from a dependency. This is not true in two scenarios:
Modules from Elixir and Erlang/OTP are always available - even if their applications are not listed as a dependency
In an umbrella project, because all child applications are compiled within the same VM, you may have a module from a sibling project available, even if you don't depend on said sibling
This new compiler check makes sure that all modules that you invoke are listed as part of your dependencies, emitting a warning like below otherwise:
:ssl.connect/2 defined in application :ssl is used by the current
application but the current application does not directly depend
on :ssl. To fix this, you must do one of:
1. If :ssl is part of Erlang/Elixir, you must include it under
:extra_applications inside "def application" in your mix.exs
2. If :ssl is a dependency, make sure it is listed under "def deps"
in your mix.exs
3. In case you don't want to add a requirement to :ssl, you may
optionally skip this warning by adding [xref: [exclude: :ssl]
to your "def project" in mix.exs
This comes with extra benefits in umbrella projects, as it requires applications to depend on the siblings they depend on, which will fail if there are any cyclic dependencies.
Compiler checks: data constructors
In Elixir v1.11, the compiler also tracks structs and maps fields across a function body. For example, imagine you wanted to write this code:
def drive?(%User{age: age}), do: age >= 18
If there is either a typo on the :age
field or the :age
field was not yet defined, the compiler will fail accordingly. However, if you wrote this code:
def drive?(%User{} = user), do: user.age >= 18
The compiler would not catch the missing field and an error would only be raised at runtime. With v1.11, Elixir will track the usage of all maps and struct fields within the same function, emitting warnings for cases like above:
warning: undefined field `age` in expression:
# example.exs:7
user.age
expected one of the following fields: name, address
where "user" was given the type %User{} in:
# example.exs:7
%User{} = user
Conflict found at
example.exs:7: Check.drive?/1
The compiler also checks binary constructors. Consider you have to send a string over the wire with length-based encoding, where the string is prefixed by its length, up to 4MBs. Your initial attempt may be this:
def run_length(string) when is_binary(string) do
<<byte_size(string)::32, string>>
end
However, the code above has a bug. Each segment given between <<>>
must be an integer, unless specified otherwise. With Elixir v1.11, the compiler will let you know so:
warning: incompatible types:
binary() !~ integer()
in expression:
<<byte_size(string)::integer()-size(32), string>>
where "string" was given the type integer() in:
# foo.exs:4
<<byte_size(string)::integer()-size(32), string>>
where "string" was given the type binary() in:
# foo.exs:3
is_binary(string)
HINT: all expressions given to binaries are assumed to be of type integer()
unless said otherwise. For example, <<expr>> assumes "expr" is an integer.
Pass a modifier, such as <<expr::float>> or <<expr::binary>>, to change the
default behaviour.
Conflict found at
foo.exs:4: Check.run_length/1
Which can be fixed by adding ::binary
to the second component:
def run_length(string) when is_binary(string) do
<<byte_size(string)::32, string::binary>>
end
While some of those warnings could be automatically fixed by the compiler, future versions will also perform those checks across functions and potentially across modules, where automatic fixes wouldn't be desired (nor possible).
Compilation time improvements
Elixir v1.11 features many improvements to how the compiler tracks file dependencies, such that touching one file causes less files to be recompiled. In previous versions, Elixir tracked three types of dependencies:
- compile time dependencies - if A depends on B at compile time, such as by using a macro, whenever B changes, A is recompiled
- struct dependencies - if A depends on B's struct, whenever B's struct definition changed, A is recompiled
- runtime dependencies - if A depends on B at runtime, A is never recompiled
However, because dependencies are transitive, if A depends on B at compile time and B depends on C at runtime, A would depend on C at compile time. Therefore, it is very important to reduce the amount of compile time dependencies.
Elixir v1.11 replaces "struct dependencies" by "exports dependencies". In other words, if A depends on B, whenever B public's interface changes, A is recompiled. B's public interface is made by its struct definition and all of its public functions and macros.
This change allows us to mark import
s and require
s as "exports dependencies" instead of "compile time" dependencies. This simplifies the dependency graph considerably. For example, in the Hex.pm project, changing the user.ex
file in Elixir v1.10 would emit this:
$ touch lib/hexpm/accounts/user.ex && mix compile
Compiling 90 files (.ex)
In Elixir v1.11, we now get:
$ touch lib/hexpm/accounts/user.ex && mix compile
Compiling 16 files (.ex)
To make things even better, Elixir v1.11 also introduces a more granular file tracking for path dependencies. In previous versions, a module from a path dependency would always be treated as a compile time dependency. This often meant that if you have an umbrella project, changing an application would cause many modules in sibling applications to recompile. Fortunately, Elixir v1.11 will tag modules from dependencies as exports if appropriate, yielding dramatic improvements to those using path dependencies.
To round up the list of compiler enhancements, the --profile=time
option added in Elixir v1.10 now also includes the time to compile each individual file. For example, in the Plug project, one can now get:
[profile] lib/plug/conn.ex compiled in 935ms
[profile] lib/plug/ssl.ex compiled in 147ms (plus 744ms waiting)
[profile] lib/plug/static.ex compiled in 238ms (plus 654ms waiting)
[profile] lib/plug/csrf_protection.ex compiled in 237ms (plus 790ms waiting)
[profile] lib/plug/debugger.ex compiled in 719ms (plus 947ms waiting)
[profile] Finished compilation cycle of 60 modules in 1802ms
[profile] Finished group pass check of 60 modules in 75ms
While implementing those features, we have also made the --long-compilation-threshold
flag more precise. In previous versions, --long-compilation-threshold
would consider both the time a file spent to compile and the time spent waiting on other files. In Elixir v1.11, it considers only the compilation time. This means less false positives and you can now effectively get all files that take longer than 2s to compile by passing --long-compilation-threshold 2
.
mix xref graph
improvements
To bring visibility to the compiler tracking improvements described in the previous section, we have also added new features to mix xref
. mix xref
is a task that describes cross-references between files in your projects. The mix xref graph
subsection focuses on the dependency graph between them.
First we have made the existing --label
flag to consider transitive dependencies. Using --sink FILE
and --label compile
can be a powerful combo to find out which files will change whenever the given FILE
changes. For example, in the Hex.pm project, we get:
$ mix xref graph --sink lib/hexpm/accounts/user.ex --label compile
lib/hexpm/billing/hexpm.ex
└── lib/hexpm/billing/billing.ex (compile)
lib/hexpm/billing/local.ex
└── lib/hexpm/billing/billing.ex (compile)
lib/hexpm/emails/bamboo.ex
├── lib/hexpm/accounts/email.ex (compile)
└── lib/hexpm/accounts/user.ex (compile)
lib/hexpm/emails/emails.ex
└── lib/hexpm_web/views/email_view.ex (compile)
lib/hexpm_web/controllers/api/docs_controller.ex
└── lib/hexpm_web/controllers/auth_helpers.ex (compile)
lib/hexpm_web/controllers/api/key_controller.ex
└── lib/hexpm_web/controllers/auth_helpers.ex (compile)
lib/hexpm_web/controllers/api/organization_controller.ex
└── lib/hexpm_web/controllers/auth_helpers.ex (compile)
lib/hexpm_web/controllers/api/organization_user_controller.ex
└── lib/hexpm_web/controllers/auth_helpers.ex (compile)
lib/hexpm_web/controllers/api/owner_controller.ex
└── lib/hexpm_web/controllers/auth_helpers.ex (compile)
lib/hexpm_web/controllers/api/package_controller.ex
└── lib/hexpm_web/controllers/auth_helpers.ex (compile)
lib/hexpm_web/controllers/api/release_controller.ex
└── lib/hexpm_web/controllers/auth_helpers.ex (compile)
lib/hexpm_web/controllers/api/repository_controller.ex
└── lib/hexpm_web/controllers/auth_helpers.ex (compile)
lib/hexpm_web/controllers/api/retirement_controller.ex
└── lib/hexpm_web/controllers/auth_helpers.ex (compile)
lib/hexpm_web/controllers/blog_controller.ex
└── lib/hexpm_web/views/blog_view.ex (compile)
lib/hexpm_web/endpoint.ex
├── lib/hexpm_web/plug_parser.ex (compile)
└── lib/hexpm_web/session.ex (compile)
All the files at the root will recompile if lib/hexpm/accounts/user.ex
changes. Their children describe the why. For example, the repository_controller.ex
file will recompile if user changes because it has a compile time dependency on auth_helpers.ex
, which depends on user.ex
. This indirect compile time dependency is often the source of recompilations and Elixir v1.11 now makes it trivial to spot them, so they can be eventually addressed.
Another improvement to mix xref graph
is the addition of --format cycles
, which will print all cycles in your compilation dependency graph. A --min-cycle-size
flag can be used if you want to discard short cycles.
config/runtime.exs
and mix app.config
Elixir v1.9 introduced a new configuration file, specific to releases, called config/releases.exs
. A release is a self-contained artifact with the Erlang VM, Elixir and your application, ready to run in production.
The addition of config/releases.exs
has been a very useful one but, unfortunately, it applies only to releases. Developers not using releases must use the config/config.exs
file, which often loaded too early at compilation time. For any dynamic configuration, developers had to resort to third-party tools or workarounds to achieve the desired results.
Elixir v1.11 addresses this issue by introducing a new configuration file, called config/runtime.exs
. This new configuration file is loaded exactly before your application starts, when the code is already fully compiled. It is loaded in development, test, and production, regardless if you are using Mix or releases. Therefore it provides a unified API for runtime configuration in Elixir.
config/runtime.exs
works the same as any other configuration file. However, given config/runtime.exs
is meant to run with or without Mix, developers must not use Mix.env()
or Mix.target()
in config/runtime.exs
. Instead, they must use the new config_env()
and config_target()
, which have been added to the Config
module.
While config/releases.exs
will continue to be supported, developers can migrate to config/runtime.exs
without loss of functionality. For example, a config/releases.exs
file such as this one
# config/releases.exs
import Config
config :foo, ...
config :bar, ...
could run as is as config/runtime.exs
. However, given config/runtime.exs
runs in all environments, you may want to restrict part of your configuration to the :prod
environment:
# config/runtime.exs
import Config
if config_env() == :prod do
config :foo, ...
config :bar, ...
end
If both files are available, releases will pick the now preferred config/runtime.exs
instead of config/releases.exs
.
To wrap it all up, Mix
also includes a new task called mix app.config
. This task loads all applications and configures them, without starting them. Whenever you write your own Mix tasks, you will typically want to invoke either mix app.start
or mix app.config
before running your own code. Which one is better depends if you want your applications running or only configured.
Other improvements
Elixir v1.11 adds the is_struct/2
, is_exception/1
, and is_exception/2
guards. It also adds support for the map.field
syntax in guards.
The Calendar module ships with a new Calendar.strftime/3
function, which provides datetime formatting based on the strftime
format. The Date
module got new functions for working with weeks and months, such as Date.beginning_of_month/1
and Date.end_of_week/2
. Finally, all calendar types got conversion functions from and to gregorian timestamps, such as Date.from_gregorian_days/2
and NaiveDateTime.to_gregorian_seconds/1
.
Mix also includes two new tasks: mix app.config
, for application runtime configuration, and mix test.coverage
, which generates aggregated coverage reports for umbrella projects and for test suites partitioned across processes.
v1.11.2 (2020-11-03)
1. Bug fixes
Elixir
- [Code] Do not crash when getting docs for missing
erts
appdir - [Kernel] Raise meaningful error if
:erlang.is_record
is used in guards - [Kernel] Prune tracers when fetching
__ENV__
inside functions
Mix
- [mix] Fix regression where aliases could not call themselves recursively
- [mix compile] Do not discard tracers that are set programatically
v1.11.1 (2020-10-16)
1. Bug fixes
Elixir
- [Code] Ignore tracers if lexical tracker is dead or explicitly nil when evaling code with an environment
- [GenServer] Do not show warning when using
super
inGenServer.child_spec/1
- [Kernel] Do not crash when :reduce is set to
nil
in comprehensions - [Kernel] Fix a scenario where undefined function warnings were not being emitted
IEx
- [IEx.Helpers] Properly handle tags inside typespec when showing Erlang docs
Logger
- [Logger] Do not deadlock Logger if handler crashes on sync mode
Mix
- [Mix] Add inet6 fallback to Mix usage of httpc
- [mix compile.app] Do not list apps that do not match the current target
v1.11.0 (2020-10-06)
1. Enhancements
EEx
- [EEx] Track column information in EEx templates when enabled in the compiler
- [EEx] Show column information in EEx error messages
- [EEx] Support
:indentation
option when compiling EEx templates for proper column tracking
Elixir
- [Access] Add
Access.at!/1
- [Calendar] Add
Calendar.strftime/3
for datetime formatting - [Calendar] Add linear integer representations to Calendar modules:
Date.from_gregorian_days/2
,Date.to_gregorian_days/1
,NaiveDateTime.from_gregorian_seconds/3
,NaiveDateTime.to_gregorian_seconds/1
,Time.from_seconds_after_midnight/1
, andTime.to_seconds_after_midnight/1
- [Calendar] Add
new!
to Date/Time/NaiveDateTime/DateTime (new
has also been added toDateTime
for completeness) - [Calendar] Support custom starting day of the week in
Date.day_of_week/2
- [Calendar] Add
Date.beginning_of_month/1
andDate.end_of_month/1
- [Calendar] Add
Date.beginning_of_week/2
andDate.end_of_week/2
- [Code] Add
:column
toCode.string_to_quoted*/2
- [Code] Add
Code.can_await_module_compilation?/0
to check if the parallel compiler is enabled and it can await for other modules to be compiled - [Config] Support
config_env/0
andconfig_target/0
inconfig
files - [Config] Allow
import_config
to be disabled for some configuration files - [Enum] Allow a sorting function on
Enum.min_max_by/3,4
, including the newcompare/2
conventions - [Kernel] Add
is_struct/2
guard - [Kernel] Add
is_exception/1
andis_exception/2
guards - [Kernel] Support
map.field
syntax in guards - [Kernel] Add
+++
and---
with right associativity to the list of custom operators - [Kernel] Warn if a variable that looks like a compiler variable (such as
__MODULE__
) is unused - [Kernel.ParallelCompiler] Report individual file compilation times when
profile: :time
is given - [Kernel.ParallelCompiler] Improve precision of
:long_compilation_threshold
so it takes only compilation times into account (and not waiting times) - [Registry] Add
Registry.delete_meta/2
- [Task] Add
Task.await_many/2
ExUnit
- [ExUnit] Add support for coloring on Windows 10 consoles/shells
- [ExUnit] Add
ExUnit.fetch_test_supervisor/0
- [ExUnit] Add
@tag :tmp_dir
support to ExUnit. The temporary directory is automatically created and pruned before each test - [ExUnit] Add file and line to ExUnit's
--trace
- [ExUnit.Assertion] Allow receive timeouts to be computed at runtime
- [ExUnit.Case] Add
register_test/6
to speed up compilation of custom tests - [ExUnit.Doctest] Allow users to add tags to doctests
IEx
- [IEx] Add support for coloring on Windows 10 consoles/shells
- [IEx.Helpers] Show docs from Erlang modules that have been compiled with the docs chunk
Logger
- [Logger] Add
notice
,critical
,alert
, andemergency
log levels - [Logger] Support structured logging by logging maps or keyword lists
- [Logger] Allow level to be set per module with
Logger.put_module_level/2
- [Logger] Include
erl_level
in Logger's metadata
Mix
- [mix] Add
MIX_BUILD_ROOT
to config_build
dir - [mix] Introduce
MIX_XDG
as a simpler mechanism to opt-in to the XDG specification - [mix] Allow requirements for a Mix task to be listed via the
@requirements
module attribute - [mix] Allow optional dependencies to be defined in
:extra_applications
and:applications
- [mix app.config] Add new
mix app.config
task that compiles applications and loads runtime configuration - [mix archive.install] Support
--repo
option on Hex packages - [mix compile] Support the
__mix_recompile__?/0
callback for custom behaviour on when Mix should recompile a given module - [mix compile.elixir] Mark modules for path dependencies as "Export dependencies" if they changed but their public interface is the same
- [mix compile.elixir] Track application boundaries in the Elixir compiler. If you invoke code from Erlang or Elixir standard libraries and you don't depend on the proper applications, a warning will be emitted. A warning will also be emitted if you invoke code from an umbrella sibling that you don't depend on - effectively forbidding cyclic dependencies between apps
- [mix deps] Sort the dependencies alphabetically before printing
- [mix deps] Use
origin/HEAD
as the default Git ref in dependencies - [mix deps] Redact Git
username
/password
in output log - [mix deps] Support rebar3's
git_subdir
resource type - [mix deps.compile] Allow local deps to be skipped on
mix deps.compile
- [mix deps.unlock] Print which dependencies get unlocked when using the
--unused
flag - [mix escript.install] Support
--repo
option on Hex packages - [mix new] Add
@impl
to application generated bymix new --sup
- [mix release] Enable overriding
sys.config
location viaRELEASE_SYS_CONFIG
env var - [mix release] Boot a release under configuration in interactive mode and then swap to embedded mode (if running on Erlang/OTP 23+)
- [mix release] Add
rel_templates_path
to configure the source of template files such as "env.sh.eex", "vm.args.eex" and "overlays" - [mix release] Allow some chunks to be kept in the
:strip_beams
config - [mix test] Allow
:ignore_modules
inside:test_coverage
option - [mix test.coverage] Add
mix test.coverage
that aggregates coverage results from umbrellas and OS partitioning - [mix xref] Make the
--label
option formix xref graph
transitive by default and add--only-direct
for only direct dependencies - [mix xref] Add
--format cycles
support formix xref graph
- [mix xref] Add support to
mix xref graph
for using--source
and--sink
at the same time
2. Bug fixes
EEx
- [EEx] Make trimming behaviour via the
:trim
option more consistent
Elixir
- [Application] Warn if non-atom keys are given to
put_env
,get_env
,fetch_env
, anddelete_env
- [Code] Do not send language keyword through the
:static_atoms_encoder
inCode.string_to_quoted
- [Kernel] Validate values given to
:line
in quote to avoid emitting invalid ASTs - [Kernel] Report the correct line number when raising inside a macro
- [Kernel] Fix an issue where
elixirc
would not accept paths with backslash (\
) separators on Windows - [Kernel] Properly parse
&//2
(i.e. the capture of the division operator) - [Kernel] Raise
CompileError
when trying to define reserved types - [Kernel] Improve compiler error message when using
|
in adef
signature - [Kernel] Improve error message when trying to use invalid list operators in guards
- [Kernel.SpecialForms] Add
|/2
to the list of special forms to avoid inconsistent behaviour on overrides - [Keyword] Enforce keys to be atoms in
Keyword.keys/1
- [Record] Keep lexical ordering when creating records
- [Registry] Do not crash when a process with key-value has been registered using
:via
and it fails to start oninit
- [URI]
URI.decode_query/2
emits an empty string for parameters without values, according to URL's living standard - note this behaviour is not specified in the spec implemented by the URI module, so the living standard was chosen - [Version] Add defaults and enforce keys in
Version
struct
ExUnit
- [ExUnit.CaptureIO] Fix race condition where a dead capture would still be considered as active
- [ExUnit.Diff] Do not crash when failing to eval/inspect struct
- [ExUnit.Diff] Properly diff numbers in respect to
==
and===
operators
IEx
- [IEx] Fix tokenizer emitting repeated warnings in the REPL
- [IEx] Ensure
--dot-iex
is preserved when restarting the evaluator and after shell respawn - [IEx.Pry] Ensure
IEx.pry
can be triggered more than twice when invoked from the same process
Mix
- [mix cmd] Fix a bug where only the first --app option would be executed
- [mix compile] Fix an issue where new protocol implementations would not propagate when running
mix compile
from an umbrella root - [mix deps.compile] Use
gmake
instead ofmake
when compiling deps on NetBSD/DragonFlyBSD - [mix release] Load
.app
from dependencies path when it is a project dependency - [mix release] Always include "rel/overlays" in the list of overlays directories if available
- [mix release] Change
erts/bin/erl
binary mode to0o755
- [mix test] Compare to test coverage threshold inclusively
Logger
- [Logger] Print metadata for all types that implement String.Chars
3. Soft-deprecations (no warnings emitted)
Elixir
- [Exception]
Exception.exception?/1
is deprecated in favor ofKernel.is_exception/1
- [Regex]
Regex.regex?/1
is deprecated in favor ofKernel.is_struct/2
Logger
- [Logger]
warn
log level is deprecated in favor ofwarning
Mix
- [mix release]
config/releases.exs
is deprecated in favor of a more general purposeconfig/runtime.exs
4. Hard-deprecations
Elixir
- [Supervisor] Deprecate
Supervisor.start_child/2
andSupervisor.terminate_child/2
in favor ofDynamicSupervisor
- [Supervisor.Spec] Deprecate
Supervisor.Spec.worker/3
andSupervisor.Spec.supervisor/3
in favor of the new typespecs - [System] Deprecate
System.stacktrace/0
in favor of__STACKTRACE__
Mix
- [Mix.Project] Deprecate
Mix.Project.compile/2
in favor ofMix.Task.run("compile", args)
v1.10
The CHANGELOG for v1.10 releases can be found in the v1.10 branch.