Changelog.md

###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