Tags:
- [New Feature]
- [Bug Fix]
- [Spec Compliancy]
- [Breaking Change]
- [Documentation]
- [Internal]
- [Polish]
Note: Gaps between patch versions are faulty/broken releases.
See CHANGELOG - 6to5 for the pre-4.0.0 version changelog.
- New Feature
- Added function bind syntax behind stage 0. Thanks @RReverser!
- Added
env
option. Especially handy when using the.babelrc
. - Bug Fix
- Fix files not properly being ignored when
babel.transform
ignores them when using$ babel
. - Fix scope tracking registering loop head bindings to their
VariableDeclaration
instead ofVariableDeclarator
. - Polish
- Normalise path separators for souce map paths when using
$ babel
. - Rework
PathHoister
to ignore global references and to not deopt on reassignments to referenced bindings, instead it tries to hoist to the highest scope. - Added missing exponential operator inlining. Thanks @nkt!
- Optimise
regenerator
transformer. Thanks @benjamn!
- Bug Fix
- Fix
minification.deadCodeElimination
transformer incorrectly trying to inline import declarations. - Fix
minification.inlineExpression
transformer getting into an infinite loop.
- Bug Fix
- Fix patterns not being considered when hoisting variables in the
es6.blockScoping
transformer.
- Bug Fix
- Fix unique export specifiers not being cloned when exploding class and function exports,
- Polish
- Turn import remaps to sequence expressions to remove their context and improve performance.
Speeeeeeed
- Spec Compliancy
- Allow trailing param commas for methods when using the
es7.trailingCommas
transformer. - Bug Fix
- Fix
es6.blockScoping
transformer not properly ignoringbreak
inSwitchCase
. - Fix lookahead context saving to avoid weird tokenizer state.
- Explode duplicate identifiers in export/import specifiers and property shorthand to create unique objects.
- Skip loose mode for class methods when they have decorators.
- When removing nodes, share their comments with their siblings.
- Properly hoist temp param declarations when doing TCO.
- Internal
- Add
--harmony_generators
flag to$ babel-node
. - Internal AST traversals have been minimised drastically. Transformers have been grouped together which means entire tree traversals are much fewer. Visiting nodes is now also skipped if the traversal context can detect that the handler is a noop. This sames precious cycles as it avoids constructing traversal paths and creating a new traversal context. See issues #1472 and #1486 for related discussion.
- Polish
- Move many
utility
transformers tominification
.
- Bug Fix
- Fix auxiliary comments not properly being attached to function declaration helpers.
- Add
Super
node type toast-types
patch. - Ignore parameter bindings when attempting to inline them in the
minification.deadCodeElimination
transformer. - Correct
extensions
arguments when using the Babel CLI.
- Bug Fix
- Fix plugins being disabled when using the whitelist.
- Fix correct function scope being passed to
nameMethod.property
when inferring the function name for class methods. - Fix incorrect extensions reference causing weird issues when using the Babel CLI.
- Fix destructuring param reference replacements not inheriting from their original param.
- Spec Compliancy
- Fix order that method decorators are ran in.
- Bug Fix
- Fix initializer descriptor add attempt if it doesn't exist.
- Bug Fix
- Fix bug with initializer decorators where the descriptors weren't being defined if there was no
initializer
property. - Internal
- Expose
retainLines
option to CLI. - Fix
retainLines
option not being taken into consideration when doing multiple variable declaration declarators generation. - Expose minified and unminified copies of dist scripts.
- Bug Fix
- Fix
ExportDeclaration
s being incorrectly removed when using theutility.deadCodeElimination
transformer. - Fix position of
utility
transformers. - New Feature
- Add built-in
esquery
support. - Internal
- Consolidate notion of "virtual types".
- Polish
- Make UID generation based on module declarations much nicer.
- Internal
- Remove internal check for traversal path replacement of self. This is a pattern that could come up in the wild and it could lead to pretty nasty code and may lead to internal regressions as the test coverage isn't 100% :( Instead, just put it in the fast path.
- Internal
- Rename
getModuleName
option togetModuleId
, doh.
- Bug Fix
- Fix numerous issues in
replaceWithSourceString
. Thanks @pangratz! - New Feature
- Add
getModuleName
option. Thanks @jayphelps!
- Bug Fix
- Fix
_blockHoist
transformer incorrectly sorting nodes on shitty environments that aren't spec compliant in their key order. - Fix broken
parse
API method reference to an undeclared import.
- Bug Fix
- Move
utility.deadCodeElimination
transformer up to avoid race conditions. - Fix shorthand property scope binding renaming.
- Polish
- Turn helper variable declarations into function declarations if possible.
- Internal
- Removed native inheritance support from classes.
- Added
replaceWithSourceString
path API. - Split up
es3.propertyLiterals
andes3.memberExpressionLiterals
transformers tominfication.propertyLiterals
andes3.memberExpressionLiterals
.
- Internal
- Fix transformer aliases being accidently set as deprecated ones.
- Expose
Pipeline
asTransformerPipeline
instead.
- Bug Fix
- Fix
parse
API not adding all the correct pipeline transformers.
- Bug Fix
- Fix race condition with the Node API being loaded awkwardly and not being able to initialise itself when used in the browser.
- Internal
- Expose
transform.pipeline
.
- Bug Fix
- Fix plugin containers being called with an undefined import. Thanks @timbur!
- Allow Flow object separators to be commas. Thanks @monsanto!
- Add missing
Statement
andDeclaration
node aliases to flow types.
- Internal
- Allow
util.arrayify
to take arbitrary types and coerce it into an array.
- Bug Fix
- Fix regression in
node/register
that causednode_modules
to not be ignored.
- Bug Fix
- Fix plugin strings splitting arbitrarily on
:
which caused full paths on Windows to fail as they include:
after the drive letter. - Call class property
initializer
s with their target instead of their descriptor. - Fix
ignore
andonly
not properly working on Windows path separators. Thanks @stagas! - Fix
resolveRc
running on files twice causing issues. Thanks @lukescott! - Fix shorthand properties not correctly being target for
isReferenced
checks. Thanks @monsanto! - Polish
- Allow passing an array of globs to
babel/register
only
andignore
options. Thanks @Mark-Simulacrum! - When inferring function names that collide with upper bindings, instead of doing the wrapper, instead rename them.
- Consider constant-like variable declaration functions to always refer to themselves so TOC can be performed.
- Process globs manually when using
$ babel
as some shells such as Windows don't explode them. Thanks @jden! - Add alternative way to execute plugins via a closure that's called with the current Babel instance.
- Internal
- Remove multiple internal transformers in favor of directly doing things when we need to. Previously, declarations such as
_ref
that we needed to create in specific scopes were done at the very end via the_declarations
transformer. Now, they're done and added to the scope right when they're needed. This gets rid of the crappy_declarations
property on scope nodes and fixes the crappy regenerator bug where it was creating a newBlockStatement
so the declarations were being lost. - Rework transformer traversal optimisation. Turns out that calling a
check
function for every single node in the AST is ridiculously expensive. 300,000 nodes timesed by ~30 transformers meant that it took tens of seconds to perform while it's quicker to just do the unnecessary traversal. Seems obvious in hindsight. - New Feature
- Add
jscript
transformer that turns named function expressions into function declarations to get around JScript's horribly broken function expression semantics. Thanks @kondi! - Add
@@hasInstance
support to objects when using thees6.spec.symbols
transformer. - Add
retainLines
option that retains the line (but not the columns!) of the input code.
- Polish
- Remove symbol check from
defineProperty
helper.
- Bug Fix
- Fix
resolveModuleSource
not being ran onExportAllDeclaration
s. - Fix
.babelrc
being resolved multiple times when using the require hook. - Fix parse error on spread properties in assignment position.
- Fix
externalHelpers
option being incorrectly listed as typestring
. - Internal
- Upgrade
core-js
to0.9.0
. - Spec Compliancy
- Fix object decorators not using the
initializer
pattern. - Remove property initializer descriptor reflection.
- Bug Fix
- Memoise and bind member expression decorators.
- Move JSX children cleaning to opening element visitor. Fixes elements not being cleaned in certain scenarios.
- Consider
SwitchStatement
s to beScopable
. - Fix
bluebirdCoroutines
callinginteropRequireWildcard
before it's defined. - Add space to
do...while
code generation. - Validate
super
use beforethis
onsuper
exit rather than entrance. - Polish
- Add Babel name to logger.
- Bug Fix
- Remove
makePredicate
from acorn in favor of anindexOf
. - Remove statements to expression explosion when inserting a block statement.
- Internal
- Remove runtime compatibility check.
- Bug Fix
- Fix class property initializers with
undefined
values not being correctly writable. - Fix self inferring generators incorrectly causing a stack error.
- Fix default export specifiers not triggering AMD
module
argument inclusion. - Fix assignments not having their module references properly remapped.
- Internal
- Upgrade to latest
acorn
. - Polish
- Make invalid LHS pattern error messages nicer.
- Bug Fix
- Only make parenthesized object pattern LHS illegal.
- Internal
- Add
parse
node API.
- Bug Fix
- Fix
runtime
built-in catchall not properly checking for local variables.
- Internal
- Bump
core-js
version.
- Polish
- Add missing
Reflect
methods to runtime transformer.
- Internal
- Switch entirely to vanilla regenerator.
- Clean up and make the parsing of decorators stateless.
- Bug Fix
- Don't do TCO on generators and async functions.
- Add missing
core-js
runtime definitions.
- Bug Fix
- Add
getIterator
andisIterable
tobabel-runtime
build script.
- Bug Fix
- Add missing runtime symbol definitions.
- Bug Fix
- Fix super reference when using decorators.
- Don't do array unpack optimisation when member expressions are present.
- Add missing descriptors for undecorated class properties.
- Don't consider
arguments
andeval
valid function names when doing function name inferrence. - Fix scope tracking of constants in loop heads.
- Parse
AwaitExpression
as a unary instead of an assignment. - Fix regex evaluation when attempting static evaluation.
- Don't emit tokens when doing a lookahead.
- Add missing
test
declaration toutility.deadCodeElimination
transformer. - Internal
- Upgrade
regenerator
to the latest and use my branch with the hope of eventually switching to vanilla regenerator. - Add support for the replacement of for loop
init
s with statements. - Upgrade dependencies.
- Polish
- When adding the scope IIFE when using default parameters, don't shadow the function expression, just
apply
this
andarguments
if necessary. - Use path basename as non-default import fallback.
- New Feature
- Add trailing function comma proposal. Thanks @AluisioASG!
- Add support for object literal decorators.
- Make core-js modular when using the
runtime
transformer.
- Bug Fix
- Fix incorrect remapping of module references inside of a function id redirection container.
- Bug Fix
- Fix new
for...of
loops not properly inheriting their original loop. - Internal
- Disable scope instance cache.
- Polish
- Allow comments in
.babelrc
JSON.
- Polish
- Use
moduleId
for UMD global name if available. - Bug Fix
- Fix UMD global
module
variable shadowing theamd
/common
module
variable. - Fix Flow param type annotation regression.
- Fix function name collision
toString
wrapper. Thanks @alawatthe!
- Bug Fix
- Fix falsy static class properties not being writable.
- Fix block scoping collisions not properly detecting modules and function clashes.
- Skip
this
beforesuper
for derived constructors on functions.
- New Feature
- Add
--ignore
and--only
support to the CLI. - Bug Fix
- Remove
HOMEPATH
environment variable from home resolution inbabel/register
cache. - Internal
- Disable WIP path resolution introducing infinite recursion in some code examples.
- Polish
- Add live binding to CommonJS default imports.
- Bug Fix
- Fix mangling of import references that collide with properties on
Object.prototype
. - Fix duplicate declarations incorrectly being reported for
var
.
- Internal
- Upgrade
core-js
. - Bug Fix
- Fix arrays not being supported in
util.list
.
- Polish
- Check for top level
breakConfig
inresolveRc
.
- Bug Fix
- Make relative location absolute before calling
resolveRc
. - Internal
- Switch to global UID registry.
- Add
breakConfig
option to prevent Babel from erroring when hitting that option.
- Bug Fix
- Fix duplicate declaration regression.
- Fix not being able to call non-writable methods.
- New Feature
- Decorators based on @wycat's stage 1 proposal.
- Class property initializers based on @jeffmo's stage 0 proposal.
- Export extensions based on @leebyron's stage 1 proposal.
- UMD module formatter now supports globals.
- Add
es3.runtime
,optimisation.react.inlineElements
andoptimisation.react.constantElements
transformers. - Add stage option that replaces the experimental one.
- Allow ES7 transformer to be enabled via
optional
instead of only viastage
. - Infer string quotes to use in the code generator.
- Consider
export { foo as default };
to be the same asexport default foo;
. - Add
nonStandard
option that can be set tofalse
to remove parser support for JSX and Flow. - Add
jsxPragma
option. - Automatically generate CLI options based on internal API options.
- Add support for
.babelrc
on absolute paths. - Plugin API!
- Internal
- Export
options
in browser API. - Rewritten parser.
- Don't block hoist when runtime transformer is enabled in system module formatter.
- Rewritten the internal traversal and node replacement API to use "paths" that abstracts out node relationships.
- Polish
- JSX output is now more inline with the official JSX transformer.
- Hoist block scoping IIFE - this improves memory usage and performance.
- Better IIFE detection - references are now checked to see if they're referencing the binding we're searching for.
- Check for import reassignments in constants transformer.
- Make method definitions with expression bodies illegal.
- Save register cache on tick instead of
SIGINT
. - Enable strict mode on babel-node eval flag.
- Bug Fixes
- Add support for live bindings. This change also increases the reliablity of export specifier renaming.
- Add support for super update and non equals assignment expressions.
- Rename shadow constructor binding in classes.
- Seed next iteration bindings with previous fresh bindings when reassinging loop block scoped variables.
- Fix new expression spread referencing the wrong constructor.
- Call
resolveModuleSource
on dynamic imports. - Added
param
to list of duplicate declaration kinds. - Breaking Changes
- The Babel playground has been removed.
- ES7 Abstract References have been removed.
- Experimental option has been removed in favor of a stage option.
- Rename
returnUsedHelpers
tometadataUsedHelpers
.
- Bug Fix
- Fix constructor spreading of typed arrays.
- Fix break/continue/return aliasing of non-loops in block scoping transformer.
- Bug Fix
- Fix constructor spreading of collections.
- Bug Fix
- Fix constructor spreading of
Promise
. - Internal
- Deprecate remaining playground transformers and abstract references.
- Bug Fix
- Handle comments on use strict directives.
- Fix assignment patterns with a left side pattern.
- Polish
- Special case
this
when doing expression memoisation.
- Bug Fix
- Deprecate
playground.methodBinding
.
- Bug Fix
- Fix unicode regexes stripping their unicode flag before being passed on two
regexpu
.
- Internal
- Deprecate
playground.methodBinding
andplayground.objectGetterMemoization
. - Bug Fix
- Fix
inputSourceMap
option. Thanks @Rich-Harris!
- Polish
- Allow
inputSourceMap
to be set tofalse
to skip the source map inference. - Infer computed literal property names.
- Bug Fix
- Fix nested labeled for-ofs.
- Fix block scoping
break
colliding with the parent switch case. - Internal
- Upgrade
acorn-babel
.
- Bug Fix
- Fix computed classes not properly setting symbols.
- Bug Fix
- Fix
types
API exposure.
- Bug Fix
- Fix non-Identifier/Literal computed class methods.
- Polish
- Add a fallback if
stack
on an error is unconfigurable. - Hoist
esModule
module declarations to the top of the file to handle circular dependencies better.
- Bug Fix
- Don't remap
break
s to call the iterator return. - Polish
- Use a different helper for computed classes for much nicer output. Also fixes a bug in symbols being non-enumerable so they wouldn't be set on the class.
- Bug Fix
- Rewrite named function expressions in optional async function transformers.
- Hoist directives.
- Remove
Number
from the list of validruntime
constructors. - Internal
spec.typeofSymbol
transformer has been renamed toes6.symbols
.
- New Feature
"both"
option forsourceMap
.- Add output types to external helpers. Thanks @neVERberleRfellerER!
- Bug Fix
- Fix node duplication sometimes resulting in a recursion error.
- Ignore
break
s within cases insidefor...of
. - Polish
- Split up variable declarations and export declarations to allow easier transformation.
- Bug Fix
- Add
alternate
to list ofSTATEMENT_OR_BLOCK
keys. - Add support for module specifiers to
t.isReferenced
. - New Feature
- Add
inputSourceMap
option. - Polish
- Throw an error on different
babel
andbabel-runtime
versions. - Replicate module environment for
babel-node
eval. - Clean up classes output.
- Spec Compliancy
- Make it illegal to use a rest parameter on a setter.
- Bug Fix
- Fix incorrect method call in
utility.deadCodeElimination
transformer. - Fix
es6.blockScopingTDZ
transformer duplicating binding nodes.
- Internal
useStrict
transformer has been renamed tostrict
.
- Bug Fix
- Fix
ForOfStatement
not proplery inheriting labels. - When in closure mode in block scoping transformer, properly check for variable shadowing.
- New Feature
- New
utility.inlineEnvironmentVariables
andutility.inlineExpression
transformers.
- Bug Fix
- Fix
arguments
being incorrectly aliased in arrow function rest parameter optimisation. - Make deoptimisation trigger safer.
- New Feature
- Flow types are now retained when blacklisting the
flow
transformer.
- Bug Fix
- Fix generators in template directory being transformed.
- Fix exposure of
util
for plugins.
- New Feature
- Desugar sticky regexes to a new constructor expression so it can be handled by a polyfill.
- Spec Compliancy
for...of
now outputs in a lengthytry...catch
this is to ensure spec compliancy in regards to iterator returns and abrupt completions. See google/traceur-compiler#1773 and babel/babel/#838 for more information.- Polish
- Rest parameters that are only refered to via number properties on member expressions are desugared into a direct
arguments
reference. Thanks @neVERberleRfellerER! $ babel
no longer exits on syntax errors.- Internal
- Upgrade
browserify
. - Upgrade
source-map
. - Publicly expose more internals.
- Polish
- Delete old extensions when overriding them in
babel/register
.
- Bug Fix
- Fix whitelisting logic for helper build script.
- New Feature
returnUsedHelpers
option and add whitelist tobuildHelpers
.- Bug Fix
- Fix function arity on self referencing inferred named functions.
- Internal
- Bump
acorn-babel
. - Start converting source to ES6...
Babel now compiles itself!
- New Feature
- Add
.babelrc
support. - Bug Fix
- Move use strict directives to the module formatter bodies.
- Internal
- Make default
bin/babel
behaviour to ignore non-compilable files and add a--copy-files
flag to revert to the old behaviour.
- Bug Fix
- Fix extending a class expression with no methods/only constructor. Thanks @neVERberleRfellerER!
- Allow
MemberExpression
as a validleft
ofForOfStatement
. - Polish
- Throw an error when people try and transpile code with the
@jsx React.DOM
pragma as it conflicts with the custom jsx constructo method detection. - Crawl all comments for
@jsx
pragma. - Internal
- Upgrade
chalk
. - Upgrade
core-js
.
- Internal
- Remove function self reference optimisation.
- Bug Fix
- Handle inferred function ids to be reassigned and deopt to a slower but working equivalent.
- Don't unpack array patterns that have more elements than their right hand array expression.
- Polish
- Improve syntax highlighting in the code frame. Thanks @lydell!
- Internal
- Upgrade
acorn-babel
.
- Bug Fix
- Fix
for...of
iterator break returns being duplicated. - Only call
return
on the iterator if it exists. - Internal
- Rename
selfContained
transformer toruntime
.
- New Feature
- Add
moduleId
option for specifying a custom module id.
- New Feature
/*** @jsx NAMESPACE **/
comments are now honored by thereact
transformer.getModuleName
option.- Infer function expression names. Thanks @RReverser!
- Bug Fix
- Add proper control flow for tail recursion optimisation.
- Internal
- Remove useless
format
options and move theformat.compact
option toformat
. - Polish
- Newline handling of the code generator has been heavily improved.
- Code generator now deopts whitespace if the input size is >100KB.
- Breaking Change
- Remove
commonStandard
module formatter and make it the default behaviour of all the strict module formatters.
- Polish
- Add auxiliary comment to let scoping closure flow control.
- Polish
- Use an assignment instead of a define for
__esModule
in loose mode. - Internal
- Add error for
eval();
usage and enable strict mode for parsing.
- New Feature
- Add
BABEL_CACHE_PATH
andBABEL_DISABLE_CACHE
environment variables. - Internal
- Replace many internal util functions with modules. Thanks @sindresorhus!
- Bug Fix
- Fix generators not properly propagating their internal declarations.
- Polish
- Update setter param length error message.
- Use ranges on dependencies.
- 6to5 is now known as Babel.
- Global helpers/runtime has now been given the more descriptive name of "external helpers".