1.3.0

Support an init/1 function in engines that will return the initial buffer (defaults to an empty string)

Add support for Access.all/0, Access.elem/1, Access.key/2 and Access.key!/1 for traversing nested data structures

Add Calendar and Date, Time, NaiveDateTime and DateTime types

Add --logger-otp-reports BOOL and --logger-sasl-reports BOOL switches

Emit a summary of compilation errors when modules are missing

Add Enum.group_by/3 that allows developers to map on the value being grouped

Make list values in maps returned by Enum.group_by/2 and Enum.group_by/3 preserve the order of the input enumerable instead of reversing it.

Add Enum.drop_every/2 that drops every nth, including the first one

Suggest possible functions on UndefinedFunctionError for existing modules

Warn if unknown fields are given to raise/2

Support IO devices in File.copy/3

Raise a more meaningful exit if you try to GenServer.call/3 yourself

Support :base option when inspecting binaries

Add IO.warn/2 that will print a warning message with stacktrace and notify the compiler a warning was printed (in case --warnings-as-errors was enabled)

Support generated: true in quote

Support Kernel.pop_in/1 and Kernel.pop_in/2 for yanking a value from a nested data structure

Allow variable struct names when matching, for example, %module{key: "value"} = struct

Allow guards on the left side of <- in for and with special forms

Support else chunks in with

Track {module, function, arity} imports and warn on unused ones when such are specified in :only

Add keyword/0 and keyword/1 built-in types to typespecs

Add sigils for date (~D[2015-04-17]), time (~T[08:00:00]) and naive date times ~N[2015-04-17 08:00:00]

Support @enforce_keys on defstruct/1 to guarantee some keys are explicitly given when building structs

Add support for :count switch type

Add parse!/2 and parse_head!/2 that raise OptionParser.ParseError in case of errors

Add Process.sleep/1

Range.range?/1 now checks the validity of a range.

Support :include_captures in Regex.split/3

Add String.myers_difference/2 for calculating the difference between two strings

Add System.os_time/0 and System.os_time/1

Add support for %{required(foo) => bar} and %{optional(foo) => bar} forms (Erlang 19 only)

Add support for @optional_callbacks to mark certain that certain callbacks may be optionally implemented

Introduce %{...} to mean any map (Erlang 19 only)

Add URI.merge/2

Add Version.parse!/1

Show pinned variables on failed assert ^left = right and assert match?(^left, right) assertions

Add ExUnit.Case.register_attribute which allow attributes to be cleaned up whenever a test is defined

Add ExUnit.Case.register_test and support the ability to tag "tests" by type. This will allow projects like QuickCheck to change the wording in formatters to say "10 properties" instead of "10 tests"

Support diffing of values when using == in assert

Start running tests as soon as cases are loaded. This feature is enabled by default when running tests through Mix

Raise a straight-forward error message in case a duplicate test name is defined

Bump the default number of max cases to double of schedulers to support both IO and CPU bound tests

Support for named setups in setup and setup_all

Support for bundling tests together with describe/2

Add nl/2 that loads a given module on a list of nodes

No longer restart applications on recompile/1

Improve IEx expand to handle functions after &

Introduce Logger.reset_metadata/0,1

Add mix xref and mix compile.xref that runs cross-reference checks, with the latter running after compilation by default

Add mix app.tree and mix deps.tree

Add Mix.Task.rerun/2 that reenables and re-runs a task

Integrate OptionParser.ParseError into Mix, automatically converting such exceptions into Mix.Error and embedding the task information

Support @preferred_cli_env attribute when defining tasks

Support mix test --raise that will raise when a test suite fails (instead of setting the exit code to 1)

Enable rebar3 manager by default for Hex dependencies

Add mix escript.install to install escripts

Print stacktraces for Mix.Error when MIX_DEBUG=1 is set

Add a user friendly error for merge conflicts on mix.lock

Track files between path dependencies. This means umbrella applications will no longer trigger full recompilation when a sibling changes. Instead it will only recompile the files affected by the sibling changes

No longer print every file being compiled. Instead a generic "Compiling N files (.ext)" will be printed and files will only be logged in case they take more than 5 seconds to compile. This threshold can be customized by passing the --long-compilation-threshold flag and the previous behaviour can be reenabled by giving --verbose to mix compile

Add mix test --stale that uses static analysis on source files to know which tests should run when source files changes. If any test file changes, it will also re-run. Changing a configuration file or the test helper will trigger a full recompilation

Float.to_string/2 and Float.to_char_list/2 has been soft-deprecated as Elixir will now attempt to print the shortest and most accurate representation by default. Developers can always fallback to :erlang.float_to_binary/2 and :erlang.float_to_list/2 if they need the previous functionality

to_char_list functions have been soft-deprecated in favor of to_charlist. This aligns with the naming conventions in both Erlang and Elixir

The confusing String.strip/2, String.lstrip/2 and String.rstrip/2 API has been soft deprecated in favor of String.trim/2, String.trim_leading/2 and String.trim_trailing/2

The confusing String.ljust/3 and String.rjust/3 API has been soft deprecated in favor of String.pad_leading/3 and String.pad_trailing/3

char_list is soft-deprecated in favor of charlist

Dict is no longer a behaviour and its functions will be deprecated in upcoming releases

Passing a dictionary to Enum.group_by/3 is deprecated

\x{H*} in strings/sigils/charlists is deprecated

Add deprecation for defdelegate list arguments and :append_first option. The previously undocumented and deprecated support for matching has been removed

Warn if a variable is assigned inside case/if/etc and used outside the block

Keyword.size/1 is deprecated in favor of Kernel.length/1

Map.size/1 is deprecated in favor of Kernel.map_size/1

The option /r (for ungreedy) has been deprecated in favor of /U

Set is no longer a behaviour and its functions will be deprecated in upcoming releases

String.valid_character?/1 is deprecated in favor of String.valid?/1 with pattern matching

Task.find/2 is deprecated in favor of explicit message matching

Passing a non-map to URI.decode_query/2 is deprecated