Changelog.md

###master (next release)

###v0.23.1

• Fixed parsing of JSON files with duplicate object keys

###v0.23.0

Likely to cause new Flow errors:

• When you refine a mixed variable with typeof myVar === 'object', we used to refine the type of myVar to null | Object. Now it is refined to null | {[key: string]: mixed}. This means myVar.prop has the type mixed rather than any.
• Removed non-standard Promise methods. Previous versions of Flow specified the type of Promise.prototype.done and Promise.cast, which are not standard or implemented in browsers. If you rely on a polyfill that does provide these methods, you can redeclare the Promise class in your project's local libs folder. Note that you need to copy the entire class declaration from lib/core.js in order to add methods and properties. It's not currently possible to extend the builtin declarations, but it is possible to redefine them.

New features:

• Errors involving union or intersection types now include more information about why the various branches failed
• flow init now has more command line flags to specify what should be in the created .flowconfig
• flow ast now can parse JSON files
• Comments are now supported in .flowconfig files. Lines starting with # or ; are ignored
• In the [ignore] section of a .flowconfig you can now ignore a relative path with <PROJECT_ROOT>/path/to/ignored
• Most flow commands have an --ignore-version flag to skip the version check specified in the .flowconfig.
• Added a module.use_strict option to the .flowconfig. When it is true, Flow will treat every file as if it has the "use strict"; directive.
• Using strict equality, you can now refine the number type into number literal types. (e.g. after x === 0 Flow now knows that x has the type 0)
• Flow no longer requires return type annotations for exported functions if Flow can fully infer the type.
• flow force-recheck FILE1 FILE2 command tells the flow server that FILE1 and FILE2 have changed and that it should recheck. This is intended for tooling that might be racing the file system notifications.
• Flow is smarter about what !x evaluates to for various types of x.
• <Foo /> is now allowed when Foo is a string. If $JSXIntrinsics is defined, Foo must be a subtype of $Keys<$JSXIntrinsics>
• Support for class decorators in addition to property decorators (also gated behind the esproposal.decorators config option). Thanks @marudor!

Notable bug fixes:

• Disallow (obj: SomeClass) except for when obj instanceof SomeClass
• Fixed setting temp dir via the .flowconfig
• Added missing all flag to the .flowconfig
• Fixed a bug when destructuring a non-literal object type using a pattern with defaults
• Fixed the --strip-root flag for displaying errors
• Classes can now have properties named async
• Fixed refinements like if (foo[0]) { ... }, which should work like if (foo["prop"]) { ... } does. That is, Flow should remember that foo[0] exists and is truthy.
• Fixed parsing docblocks with CRLF line endings
• Fixed autocomplete within if statements

Misc:

• Added more info and structure to JSON output, without removing or existing fields
• Loads of improvements to the builtin libraries
• Bunch of perf improvements
• Clarified some errors messages and error locations
• flow start --json will start a server and output a JSON blob with info about the new server
• Slowly improving tracking side effects in switch statements
• Some improvements to pretty printing errors
• Object.values() and Object.entries return Array<mixed> and Array<[string, mixed]> respectively, since Flow currently is never sure that it knows about every property in an object.

###v0.22.1

• Patch release to fix some JSON parsing issues that went out in v0.22.0

###v0.22.0

Likely to cause new Flow errors:

• Overhaul of Flow's understanding of React APIs. Some of these updates remove old/deprecated React APIs. Check out the new React docs for an overview of how things work.

New features:

• Flow now gives precedence to library definitions over non-@flow implementation files. This means that it should no longer be necessary to specify a node_modules dependency in the [ignore] section of your .flowconfig if you have a library definition defined for that dependency.
• Significant improvements to Promise.all: We now preserve the type of each item in the array passed to Promise.all() so that it may be propogated through to the resulting .then() handler.
• We no longer try to parse files that are not marked with an @flow pragma. We anticipate this will improve performance for projects with large, non-Flow node_modules directories.
• Classes with static members are now subtype-compatible with structural object types
• It is now possible to specify a leading | or & for type aliases of long unions/intersections. This is useful, as one example, for disjoint unions with a large number of members (where each member sits on a new line):

type MyDisjointUnion =
  | {type: 'TypeOne', ...}
  | {type: 'TypeTwo', ...}
  | {type: 'TypeThree', ...}
  ...
;

Bug fixes:

• Fixed an issue where an intersection of two object types did not always properly combine to match objects with members on both sides (facebook/flow#1327)
• Fixed an issue where an object of some intersection type could not be used with the spread operator (facebook/flow#1329)
• Fixed an issue where refinement-testing on an object of an intersection type wouldn't always work (facebook/flow#1366)
• Fixed an issue where an intersection of function types with a common return type should type check against function types with union of param types
• Fixed an issue where refining obj['abc'] didn't behave quite the same as refining obj.abc
• Fixed an issue where usage of flow get-def on the left-hand side of a require() wouldn't hop through the require() and to the actual location of the definition
• Fixed an issue where Flow would not give a clear error when trying to use import type to get a non-type export
• Fixed an issue flow dump-types --json was not as robust as it could be against outputting valid JSON in the event of certain kinds of errors
• Fixed an issue where Flow would not give a parse error if multiple ES exports with the same name are exported from a single ES module
• declare class declarations now properly define a built-in name property (like real class declarations do)

###v0.21.0

Likely to cause new Flow errors:

• ES6 react classes without state should now extends React.Component<DefaultProps, Props, void> (previously it was extends React.Component<DefaultProps, Props, {}>)
• ES6 react classes with state should declare state: State;
• Before, it was possible to test for properties in objects which did not exist (if (o.noSuchP === foo) { ... }). These kinds of checks will now cause a type error.

New features:

• Autocomplete for jsx properties
• Typed JSX intrinsics. This means you can list which jsx intrinsics exist (like div, span, etc) and specify which properties they have.
• Syntax for declaring variance at definition. For example, interface Generator<+Yield,+Return,-Next> {...}. Still pending transpiler support though.
• Refining string and union types with string equality now properly refines the types.
• Support for export * as from @leebyron's Stage1 proposal. Babel support here

Notable bug fixes:

• Fixed bug with class expressions due to this type
• Fixed autocomplete for this
• Recognizes exhaustiveness in switch statements with default case.
• Fixed "Did not expect BoundT" errors
• Fixed infinite loop in certain recursive types
• Fixed an incremental mode issue with deleted files
• Fixed an incorrect refinement when assigning an object to a variable.

Misc:

• Some internal errors now will be made user visibile instead of silently failing. They generally mean that Flow has some bug or is making an untrue assumption/assertion. If you see these please report them!
• Improvements to how we report certain types (type application, optional types) via our APIs
• Various sentinel improvements, including boolean sentinels
• Various improvements to the buildin flow libraries (thanks everyone for the pull requests!)

###v0.20.1

Bug fixes:

• Ironed out some issues with the this type

Misc:

• find package.json using normal parsing phase

###v0.20.0

New features:

• Initial support for a this return type for class methods
• Big improvements on error messages for unions and intersections
• import typeof * as now allows for concise access to the type of the ModuleNamespace object
• Flow now understands how to require()/import a .json file

Bug fixes:

• Fixed an issue where nested unions and intersections might not typecheck as expected
• Fixed issue where declare type wouldn't work in a declare module that has an exports entry
• Fixed an issue where the error formatter could fatal in some rare cases
• Fixed a bug where Function.prototype.bind would lose the types of the params on the function it output
• Fixed some variance bugs in the built-in Array.prototype library definitions
• Fixed a bug where using a list that doesn't contain ".js" in module.file_ext would cause internal flow libs to be ignored
• Fixed autocomplete to work better with general Function types
• Fixed some issues with const refinement
• Fixed various issues with export * from (it should work fully now)
• Fixed a bug where Flow might crash when an export has a wildcard typeparam

Misc:

• Some improvements to DOM and Node libdefs
• Various error position relevancy improvements
• Significantly improved general understanding of special functions like Function.prototype.{bind,call,apply}
• Improved error messages for import statements where the remote exports don't exist (or may be typo'd)
• Improvements to understanding of deferred initialization of let variables
• flow get-def will now hop through lvalues in variable assignments for more fine-grained "hop-tracing" of a variable back to its definition
• Objects with a callable signature can now be passed in to type positions that expect a function with a matching signature
• Significant improvements to efficiency/perf when recalculating types based on a change to a file with an already-running Flow server

###v0.19.0

Likely to cause new Flow errors:

• Flow syntax is now disallowed in non-@flow files. Use @noflow to work around this
• import type * as Foo is now disallowed in favor of import type Foo
• require() can only take a string literal
• ES6 react classes without defaultProps should now extends React.Component<void, Props, State> (previously it was extends React.Component<{}, Props, State>)
• ES6 react classes with defaultProps should declare static defaultProps: DefaultProps;
• Flow notices errors it missed before in React.createClass() react components
• Flow is now stricter about using uninitialized variables
• Stricter checking of in keyword

New Features:

• flow coverage command
• null type annotation
• Support for class field initializers, gated by .flowconfig options
• You can now override flowlib definitions with local lib files
• Basic support for computed properties
• Declaration files (.flow files). Long story short, if foo.js and foo.js.flow exist, Flow will prefer the latter and ignore the former.
• declare export - a way to declare the exported types in a non-lib file
• Array rest destructuring assignment support

Notable Bug Fixes:

• Fix "package not found" error in some symlink situations
• Object indexer should not imply callable signature
• Default param values can reference earlier params
• Fixed a case where we weren't substituting type parameters properly
• Fixed a situation where Flow would prefer an unchecked module over a library definition

Misc:

• Add --root arg to most client commands
• More repositioning of error locations
• flow get-def: Jump to module named in import statement
• Lots of fixes to make flow commands smarter about connecting to the server
• Smarter refinement in a bunch of situations
• freeze imports on all modules, and require() on ES6 modules
• You can now spread classes, like var {x} = new Foo()
• Interfaces now can be callable
• If you've refined an object property, that refinement survives access through a destructured refinement
• Better autocomplete results for primitives, objects, functions and unions
• flow server will write to log file in addition to stdout/stderr

###v0.18.1

Likely to cause new Flow errors:

• Flow is now stricter (and more consistent) about how null works when used as an initialization value for object properties that are mutated later. So let o = {prop: null}; o.prop = 42; is now an error and requires that null be annotated: let o = {prop: (null: ?number)};.
• The return type of RegExp.prototype.match() is now properly annotated to return a nullable.

New Features:

• We now take advantage of the guarantee that const variables are read-only when doing refinements. This means that refinements of const variables now have much fewer caveats than refinements of lets or vars. For instance, it's safe to depend on the refined type of a const within a local function created in scope of the refinement, even if the function escapes.
• We now track which external variables a function actually modifies, and forget refinements to only those variables when a function gets called.
• New config options: esproposal.class_static_fields=warn|ignore and esproposal.class_instance_fields=warn|ignore. This allows the new ES class fields syntax to be ignored.
• New config option: module.system.node.resolve_dirname. This allows configuration of the name of the node_modules directory (or directories) used by the node module system. This is similar in behavior to webpack's resolve.moduleDirectories config option.
• Added support for a <PROJECT_ROOT> token in the template string for the module.name_mapper config option. This token will be replaced with the absolute path to the current project root before mapping the module name. For example: module.name_mapper='^\(.*\)$' -> '<PROJECT_ROOT>/src/\1' would canonicalize an import from "foo/bar/baz" to "/path/to/root/of/project/src/foo/bar/baz".

Notable Bug Fixes:

• Fixed a bug where we were enforcing TDZ on reads to let/const, but not on writes.
• Fixed a bug where any refinement clearing that occurred as a result of a function called in an if-statement was forgotten, meaning that lots of refinements were incorrectly allowed to stand.
• Fixed a bug where generator code couldn't previously call yield without an argument.
• Several improvements to generators.
• Various improvements and bug fixes for TDZ enforcement.
• Various other small improvements to refinements.
• Fixed an issue where errors could sometimes spew to stdout rather than stderr.

Misc:

• Removed flow single as it is effectively redundant with flow check --max-workers=1.
• The "server starting" output now gives more insight into progress.
• flow --version is now deprecated in favor of flow version.

###v0.17.0

New Features:

• New default error message format shows the code inline (thanks @frantic!)
• Autocomplete will keep trying even if the file fails to parse
• You can configure which file extensions Flow looks for (thanks @eyyub!)
• Support for negative number literal types.

Notable Bug Fixes:

• Incremental make on OSX now works when lib/ files change
• Fixed some issues around const destructuring
• Fixed some issues around destructuring in for-of and for-in loops
• Some emacs plugin fixes
• Object spreads are now handled in the correct order
• Generator return() and throw() methods are now supported
• Object types now allow keywords as the object keys (thanks @samwgoldman!)
• importing & exporting default using named specifiers is now supported
• Flow now understands this in class static methods and this.constructor in class instance methods (thanks @popham!)
• Fixed bug with array spreads
• Understand that all classes have a static name property

Misc:

• Improved flow find-module
• More error location improvements
• Object can now be called as a function to cast things to objects
• We've tried to standardize the error codes with which Flow exits. Some exit codes have changed, but the ones you probably use should be the same. At the moment they're only documented in the code
• Flow understands the value of a negated number literal

###v0.16.0

Likely to cause new Flow errors:

• Some module exports that didn't require annotations before may now require annotations

New Features:

• Let/const support! Finally! (Huge props to @samwgoldman...again :] )
• Support for mixins on declare class library definitions

Notable Bug Fixes:

• Improvements to types inferred from switch cases that fall through to a default cause
• Further improvements on symlink support

Misc:

• Significant performance improvements (both for initial start-up time and running re-calculation time)
• Improved --traces output

###v0.15.0

Likely to cause new Flow errors:

• Flow now treats class identifiers as being let bound. You cannot refer to a class before it is defined.
• If you accidentally use a tuple type instead of an array type for a rest param then Flow will complain
• You cannot use this before super() in a derived constructor, per ES6 semantics
• Our dictionary property (aka indexer property) support is much more robust and catches things it previously missed.
• We weren't properly enforcing optional properties in interfaces and declare class. Now we are.

New Features:

• Generators support, courtesy of @samwgoldman

• of worker processers is now configurable, defaults to the # of CPUs

• If Flow knows the value of a boolean expression, then it will know the value of that expression negated.
• Flow can remember refinements for things like if(x.y[a.b])
• export type {type1, type2} syntax

Notable Bug Fixes:

• Fixed issue where Flow would still read package.json for [ignore]'d path
• Fixed some leaky annotations that let data flow through them
• Fixed instance and class types to be considered truthy
• Flow still initializing message now fits in 80 chars, compliments of @spicyj
• No longer will report hoisted declarations as unreachable code
• Fixed issue with how Flow chooses its tmp dir
• An async function can return a T or a Promise<T> and it means the same thing
• Fixed Flow forgetting about optional properties after an assignment refinement
• Fixed parser issue around future reserved keywords
• Optional parameters and rest parameters now work better together

Misc:

• Updated error locations. We've spent a lot of time auditing our error locations and trying to move them closer to the actual errors.
• esproposal.decorators option to tell Flow to parse and ignore decorators
• Bunch of updates to the libraries
• Some perf work
• Test output is colorized

###v0.14.0

Likely to cause new Flow errors:

• Assignment now triggers a refinement. If you have a variable that is a ?string and you assign 'hello' to it, Flow refines its type to 'string'.

Likely to fix old Flow errors:

• We now treat missing type parameters as any. For example, previously ReactElement was treated as ReactElement<*, *, *>. Now it's treated as ReactElement<any, any, any>.

Misc:

• Basic unsafe support for getters & setters, gated behind the config option unsafe.enable_getters_and_setters
• Support for block comments inside of Flow's comment syntax
• Disable by default munging of class property names that start with an underscore, with an option to enable it
• Lots of small internal fixes and merged PRs
• Basic semver support for the .flowconfig version
• Support for declare type in lib files
• Type annotations are now opaque - other types will not flow through them
• You can configure the tmp dir that Flow uses

###v0.13.1

Likely to cause new Flow errors:

• Restricted + and += to only allow strings and numbers, and no longer implicitly cast objects, booleans, null or undefined. Use String(x) to explicitly cast these values.
• Fixed a few bugs where types shared between modules may have lost precision or weren't enforced.

Misc:

• Added import typeof feature that allows you to import the type of a value export from another module. It is sugar for: import MyThing_tmp from "MyModule"; type MyThing = typeof MyThing_tmp; (except it removes the need for the intermediate MyThing_tmp variable)
• Added flow ast command to print a serialized JSON ESTree AST. (Note that this AST does not include types, just syntactic structure for now)
• Added support for class expressions
• Added support for following symlinks
• Added support for number-literal and boolean-literal annotations. (useful for things like enum types and refinements based on tests of equivalence between two variables)
• Added support for ES6 binary and octal integer literals
• Added support for export type within a CommonJS module that also uses the module.exports = ... pattern
• Added support for refining some union types down to their disjoint members
• Added support for covariant Promise type parameters
• Added improved support for understanding ES5-style imperative class definitions (i.e. via functions + prototypes)
• Fixed passing undefined to optional parameters
• Fixed return-type tracking for tagged template usage
• Fixed an issue where library parse errors would cause the flow server to continuously restart upon initialization without giving an error

###v0.12.0

Likely to cause new Flow errors:

• Fixed a bug where declarations from libraries which are exported from one module are not checked properly in the module into which that module is imported (e.g. if A.foo() returns a Promise, and module B requires A and calls A.foo(), the return type of A.foo() was not being checked properly)
• Fixed enforcement of Object and Function type annotation arity, so that Object<K, V> errors
• Restricted valid computed properties, such that only strings and numbers are allowed (notably, disallows null and undefined)

New features:

• Added support for for-of and support for Iterable interface(s)
• Added support for async/await
• Added structural subtyping for interfaces -- anything can be an instance of an interface as long as it looks right
• Added support for type annotations of the form typeof x, where x is the name of an in-scope variable
• Added a new config option suppress_comment, a regexp which matches against comments and causes any Flow error on the next line to be suppressed. For example, suppress_comment=.*\$FlowFixMe.* will cause /* $FlowFixMe */\nvar x : number = "oops"; to not raise an error.
• Added a new config option module.name_mapper, a regexp -> replacement template tuple to be applied to any matching module names before the Flow system resolves the name and looks it up
• Added a --color=always|never|auto CLI option, useful when piping to less -R
• Added a --one-line CLI option which replaces \n with \\n in multiline error messages, useful when piping to grep

Misc:

• Many improvements to library files, especially node and ES6 APIs
• Improved warnings on unsupported class members [PR #461]
• Added support for export default class
• Fixed if (x instanceof Array)
• Fixed the type of x && y when x is an array, object or function
• Fixed the flow get-def command, especially around imported types
• Fixed a bug with == and improved comparison-related error messages
• Fixed file watching for individual files included via .flowconfig [includes]
• Fixed the build ID, so that the server restarts when accessed from a mismatched client version
• Added a new config option log.file which overrides the default log file path

###v0.11.0

• We are now syncing Flow's commit history to GitHub. No more huge updating diffs. We'll also filter the changelog to the most important things.
• Big React refactoring to support ES6 React classes
• Do you use any to workaround things that you want to fix later? Well, now you can use $FixMe instead of any and easily grep for these workarounds later.
• We now report parsing errors in non-@flow files that you are require()'ing/import'ing
• Better error messages and better error message positions
• Better error traces, with flow check --traces N, where N is the trace depth
• Basic support for Object.freeze()
• Assorted fixes and updates to the flow libs
• We're trying to be better about commenting the code

###v0.10.0

• Bump version to 0.10.0
• Support import/export type
• [PR #412] More fs implementation
• Support for static overloads
• Fix order of args matched with overloads
• Allow methods to have properties
• [PR #405] Make interface-defined modules work with CommonJS/ES6Module interop
• Refine mixed
• Fix typeof null === "object" refinement
• [PR #397] Facilitate debug builds
• [PR #401] Improve error message clarity in a few places
• Remove 'everything is a bool' implicit cast
• Fix issues with optional properties during InstanceT ~> ObjT
• Fix abnormals in catch blocks

###v0.9.2

• Fix lowercasing issue where "flow Path/To/Root" became "flow path/to/root"
• Fix "My Path/To Flow/flow path/to/root" not autostarting server due to spaces

###v0.9.1

• Unbreak the command line for "flow path/to/root" (thanks samwgoldman for the report!)

###v0.9.0

• Bump version to 0.9.0
• Add Video-, Audio and TextTrackList (+ dependencies)
• Refine switch cases
• Better Not_found error
• [PR #333] Partial fs module implementation
• Update parser to match esprima-fb
• [PR #370] Dom canvas context
• [PR #393] Symbol should be called statically. Fix #391
• Fix havoc_env to copy the for_type value
• add bash completion
• rewrite all the commands to use CommandSpec
• json_of_t
• [PR #384] Env printer
• [PR #383] Add some build/test artifacts to .gitignore
• [PR #377] Add missing HTMLImageElement properties
• [PR #367] Re-add merged out oneOfType proptype implementation
• Allow users to pin their .flowconfig to a specific version
• colorize test failure diffs
• Object spread fix
• [PR #322] Add type signature for node "url", "querystring" and "path" modules
• command parsing library
• look for package.json in include paths
• clear module errors properly
• add verbose mode

###v0.8.0

• Bump version to 0.8.0
• [PR #356] Add React.version to lib/react.js
• [PR #331] node http.get() implementation
• Fixes for indexers in object types and objects used as dictionaries
• Flow server speedup
• Support both commas and semicolons in object type patterns
• Fix object assign for unresolved objects
• Add prerr_endlinef
• Fix support for the mixin pattern of specifying super
• Incremental typechecking fix
• Fix up promises interface definition + more tests
• Perf win by loading master_cx once per job
• Support for-in of null and undefined
• Support typeof x === 'boolean'
• Refine true and false literals
• Fix refinement unit test
• Type declarations for Geolocation interface
• [PR #321] Support for React.cloneElement in 0.13
• Refine simple assignments (things like while (x = x.parent) { x.doStuff(); })

###v0.7.0

• Bump version to 0.7.0
• Initial support for ES6 import/export (with CommonJS interop)
• Updates to CSS/CSSOM interface definitions
• propTypes in React components now dictate the concrete type signature for this.props
• Show errors in type-at-pos output
• Flow now watches include paths specified in .flowconfig for file changes
• Interpret x != undefined and x != null as the same refinement
• Use Object.prototype.hasOwnProperty() calls as a refinement
• Updates to Element and HTMLElement interface definitions

###v0.6.0

• Bump version to 0.6.0
• Also watch for changes in include paths
• Fix the Function type to be any function
• Add Symbol global name to libs
• Support trailing commas in parser
• Make methods immutable
• Remove tuple array length limit
• [PR #315] Implement more PropTypes
• Update componentWillReceive spec
• Unsuppress library errors

###v0.5.0

• Bump version to 0.5.0
• Add HTMLAnchorElement
• [PR #295] Add one of proptype
• Update the parser to work with the new esprima-fb & ast-types
• [PR #299] Declare prompt function (fixes #204)
• [PR #303] Add String.prototype.endsWith()
• quick fix for react/es6 notation
• extend scope of type params to following bounds
• reasonless shortcut
• Add React.findDOMNode to lib/react.js
• move command documentation into each command
• fix path in --help usage example
• fix predicate filtering of null and undefined
• [PR #292] Types for React synthetic events
• basic support for bounded polymorphism
• infer falsiness
• node haste module support
• add Abnormal.string

###v0.4.0

** Flow comments should be ready for use **

• Bump version to 0.4.0
• [PR #259] Add declaration for Document.execCommand()
• [PR #265] flow status --json should exit 2 on errors
• Fix issue with switch statement breaks
• abnormal exit effects of fall-through cases in switch
• Let AnyObjT flow to KeyT
• invariant(false, ...) always throws
• Improve the "Object" annotations
• sealed object literals
• fix return types which could be undefined
• Support type annotations in comments
• [PR #263] disable colors when TERM=dumb
• Add lint checks for TRUE / FALSE / NULL
• class subtyping
• array literal inference
• Add unsafe_xhp typechecker option
• work around false positive conflict markers
• Better dumping types for debugging

###v0.3.0

** Type casts and import type should be ready for use **

• Bump version to 0.3.0
• Move haste module name preprocessing into module_js
• [PR #260] Add SyntheticEvent to lib/react.js
• Add import type to Flow
• [Parser] Add esprima tests for typecasts
• Add support for a module name preprocessor that can re-write require()d module names
• [Parser] Support import types
• Allow absolute paths for [libs] and [include]
• prepare flow-parser to be published to npm
• [PR #247] Resubmit #113 this fixes #155
• [PR #246] Fixes #195

###v0.2.0

• Bump version to 0.2.0
• Fix refinement of optional nullable types
• Typecast expressions (warning - not added to strip out transform yet)
• treat throw as similar to return
• Switch from React to react (React still included until facebook/react#3031)
• Fix types for sessionStorage and Storage
• tighter type for undefined values
• no lib paths fix
• Fix exporting types for builtin modules
• Add Number.isNaN and Number.isSafeInteger type annotations
• Optional properties in objects & optional type revamp

###v0.1.6

• Bump version to 0.1.6
• declare modules that redefine exports instead of exporting multiple things
• Object spread race condition fix
• Fix fallback path to flowlib.tar.gz
• [Parser] Type grouping bug fix
• Add Object.is
• uncomment delete method signatures
• Add MAX_SAFE_INTEGER and MIN_SAFE_INTEGER to Number
• make param annotations strict upper bounds

###v0.1.5

• Bump version to 0.1.5
• [PR #223] from commonlisp/master
• [PR #221] from teppeis/Javascript-to-JavaScript
• Better types for React.PropTypes
• Make React a module
• Check PropTypes as a normal object too
• Better support for object call properties
• Add range/offset information to Ast.Loc.t
• ignored react attributes key & ref passed in spread properties
• ignored react attributes key & ref
• Add some checks when upper bound object type has indexer
• fix type arg arity exception
• add traces to .flowconfig
• fix error message when undeclared prop is set by jsx
• [Parser] Actually test ArrayTypeAnnotation
• Fix problem with returns in catch
• JSX with spread attributes
• Incremental mode fix
• Add missing constructors to TypedArray declarations
• [Parser] Update Flow's test suite to match updated esprima

###v0.1.4

• Bump Flow version to 0.1.4
• [Flow] Unbreak the open source build
• [PR #200] from fmahnke/node_http_interface
• [PR #203] from rsolomo/node-net-isip
• [PR #201] from unknownexception/patch-1
• [Flow] Fill out Map definition
• try-catch
• missing annotation errors for type aliases
• Type refinement fixes for early return

###v0.1.3

• Handle strict undefined checks.
• Add theoretical support to print tuple types properly.
• Relax the callback type in Array.prototype.forEach
• Add basic autocomplete support for React classes.
• [Hack] Kill shell.ml entirely.
• Handle spread attributes in JSX syntax.
• [Parser] Allow most keywords as types
• Add Array.from to lib file
• [#161]: String literal keys for object type aliases
• Generalize mock module handling under Haste a bit.
• Improve autocomplete type printing
• misc cleanup
• [Parser] Improve type keywords
• [Parser] Stop vendoring in ast-types
• Add an ocaml wrapper for find path1 ... pathN -name pattern
• Restart if a known lib file changes
• Add ProgressEvent definition and update two onprogress types
• [Hack] Add client time to server start time.
• Improve control flow type refinements
• [Hack] Reduce dependencies on ParserHeap.
• Exit server on config change for now rather than restart to avoid some bugs
• [Parser] ArrowFunction object & array patterns must be wrapped with parens
• Properly functorize logging code too
• [Hack] Make GC parameters configurable.
• Refinements on method calls
• [Hack] Log whether we are loading from a saved state in INIT_END.
• [Hack] Improve error handling for saved states.
• [PR #137] from sverrejoh/master
• [PR #150] from unknownexception/fix/dom.js
• [PR #146] from k-bx/master
• [PR #151] from unknownexception/feature/no_flowlib
• [PR #144] from rsolomo/node-assert
• [PR #191] from Shraymonks/HTMLBaseElement
• [PR #145] from rsolomo/node-util
• [PR #192] from Shraymonks/HTMLScriptElement
• Add ES6 String.prototype.contains
• Add Promise.prototype.done() to Flow lib

###v0.1.2

• [#78] Fallback to index.js if no main attribute in package.json
• [#82] Added ES6 functions to the Math object
• [#94] Start a node stdlib interface file
• [#98] Declare optional parameters according to HTML standard
• [#108] Add buffer class to node.js interface
• [#115] Some more node std libs
• The module system can now be specified in the .flowconfig file
• Libraries can now be specified in the .flowconfig file
• Multiple library paths can be specified
• Added a command to typecheck a file passed on standard input (for IDEs)
• Added HTMLInputElement to the standard library
• Improvements to type printing in flow suggest and other commands
• Fixes to various issues where parser errors were being suppressed

###v0.1.1

• [Issue #4] Typecheck .jsx files
• [Issue #22] Return a nonzero exit code from 'flow check' if there are errors
• [IRC report] Autostart the Flow server on all commands
• Improve the printing of types in 'flow suggest'
• Add a --timeout option to all commands
• [PR #27] Clearer error message when 'flow init' hasn't been run
• [PR #39] Fix to Emacs bindings
• [PR #53] Support node modules that end in .js
• [PR #59] Fix example
• [PR #65] Fix dependencies in flux-chat example
• [PR #66] Add type definitions for HTMLCanvasElement

###v0.1.0

Initial release