CHANGELOG.md

Version 0.3.17 (Sep 29, 2018)

Codegen

• Fixed an issue that prevented macros from expanding properly to routes.

Version 0.3.16 (Aug 24, 2018)

Codegen

• Codegen was updated for 2018-08-23 nightly.
• Minimum required rustc is 1.30.0-nightly 2018-08-23.

Core

• Force close only the read end of connections. This allows responses to be sent even when the client transmits more data than expected.

Docs

• Add details on retrieving configuration extras to guide.

Version 0.3.15 (Jul 16, 2018)

Codegen

• The #[catch] decorator and catchers! macro were introduced, replacing #[error] and errors!.
• The #[error] decorator and errors! macro were deprecated.
• Codegen was updated for 2018-07-15 nightly.
• Minimum required rustc is 1.29.0-nightly 2018-07-15.

Version 0.3.14 (Jun 22, 2018)

Codegen

• Codegen was updated for 2018-06-22 nightly.
• Minimum required rustc is 1.28.0-nightly 2018-06-22.

Version 0.3.13 (Jun 16, 2018)

Codegen

• Codegen was updated for 2018-06-12 nightly.
• Minimum required rustc is 1.28.0-nightly 2018-06-12.

Version 0.3.12 (May 31, 2018)

Codegen

• Codegen was updated for 2018-05-30 nightly.
• Minimum required rustc is 1.28.0-nightly 2018-05-30.

Version 0.3.11 (May 19, 2018)

Core

• Core was updated for 2018-05-18 nightly.

Infrastructure

• Fixed injection of dependencies for codegen compile-fail tests.

Version 0.3.10 (May 05, 2018)

Core

• Fixed parsing of nested TOML structures in config environment variables.

Codegen

• Codegen was updated for 2018-05-03 nightly.
• Minimum required rustc is 1.27.0-nightly 2018-05-04.

Contrib

• Contrib was updated for 2018-05-03 nightly.

Docs

• Fixed database pool type in state guide.

Version 0.3.9 (Apr 26, 2018)

Core

• Core was updated for 2018-04-26 nightly.
• Minimum required rustc is 1.27.0-nightly 2018-04-26.
• Managed state retrieval cost was reduced to an unsynchronized HashMap lookup.

Codegen

• Codegen was updated for 2018-04-26 nightly.
• Minimum required rustc is 1.27.0-nightly 2018-04-26.

Contrib

• A 512-byte buffer is preallocated when deserializing JSON, improving performance.

Docs

• Fixed various typos in rustdocs and guide.

Version 0.3.8 (Apr 07, 2018)

Codegen

• Codegen was updated for 2018-04-06 nightly.
• Minimum required rustc is 1.27.0-nightly 2018-04-06.

Version 0.3.7 (Apr 03, 2018)

Core

• Fixed a bug where incoming request URIs would match routes with the same path prefix and suffix and ignore the rest.
• Added known media types for WASM, WEBM, OGG, and WAV.
• Fixed fragment URI parsing.

Codegen

• Codegen was updated for 2018-04-03 nightly.
• Minimum required rustc is 1.27.0-nightly 2018-04-03.

Contrib

• JSON data is read eagerly, improving deserialization performance.

Docs

• Database example and docs were updated for Diesel 1.1.
• Removed outdated README performance section.
• Fixed various typos in rustdocs and guide.

Infrastructure

• Removed gates for stabilized features: iterator_for_each, i128_type, conservative_impl_trait, never_type.
• Travis now tests in both debug and release mode.

Version 0.3.6 (Jan 12, 2018)

Core

• Rocket.state() method was added to retrieve managed state from Rocket instances.
• Nested calls to Rocket.attach() are now handled correctly.
• JSON API (application/vnd.api+json) is now a known media type.
• Uncached markers for ContentType and Accept headers are properly preserved on Request.clone().
• Minimum required rustc is 1.25.0-nightly 2018-01-12.

Codegen

• Codegen was updated for 2017-12-22 nightly.
• Minimum required rustc is 1.24.0-nightly 2017-12-22.

Docs

• Fixed typo in state guide: simple simply.
• Database example and docs were updated for Diesel 1.0.

Infrastructure

• Shell scripts now use git grep instead of egrep for faster searching.

Version 0.3.5 (Dec 18, 2017)

Codegen

• Codegen was updated for 2017-12-17 nightly.
• Minimum required rustc is 1.24.0-nightly 2017-12-17.

Version 0.3.4 (Dec 14, 2017)

Core

• NamedFile's Responder implementation now uses a sized body when the file's length is known.
• #[repr(C)] is used on str wrappers to guarantee correct structure layout across platforms.
• A status::BadRequest Responder was added.

Codegen

• Codegen was updated for 2017-12-13 nightly.
• Minimum required rustc is 1.24.0-nightly 2017-12-13.

Docs

• The rustdoc html_root_url now points to the correct address.
• Fixed typo in fairings guide: event events.
• Fixed typo in Outcome docs: users Users.

Version 0.3.3 (Sep 25, 2017)

Core

• Config's Debug implementation now respects formatting options.
• Cow<str> now implements FromParam.
• Vec<u8> now implements Responder.
• Added a Binary media type for application/octet-stream.
• Empty fairing collections are no longer logged.
• Emojis are no longer emitted to non-terminals.
• Minimum required rustc is 1.22.0-nightly 2017-09-13.

Codegen

• Improved "missing argument in handler" compile-time error message.
• Codegen was updated for 2017-09-25 nightly.
• Minimum required rustc is 1.22.0-nightly 2017-09-25.

Docs

• Fixed typos in site overview: by be, Reponder Responder.
• Markdown indenting was adjusted for CommonMark.

Infrastructure

• Shell scripts handle paths with spaces.

Version 0.3.2 (Aug 15, 2017)

Core

• Added conversion methods from and to Box<UncasedStr>.

Codegen

• Lints were removed due to compiler instability. Lints will likely return as a separate rocket_lints crate.

Version 0.3.1 (Aug 11, 2017)

Core

• Added support for ASCII colors on modern Windows consoles.
• Form field renames can now include any valid characters, not just idents.

Codegen

• Ignored named route parameters are now allowed (_ident).
• Fixed issue where certain paths would cause a lint assert! to fail (#367).
• Lints were updated for 2017-08-10 nightly.
• Minimum required rustc is 1.21.0-nightly (2017-08-10).

Contrib

• Tera errors that were previously skipped internally are now emitted.

Documentation

• Typos were fixed across the board.

Version 0.3.0 (Jul 14, 2017)

New Features

This release includes the following new features:

• Fairings, Rocket's structure middleware, were introduced.
• Native TLS support was introduced.
• Private cookies were introduced.
• A MsgPack type has been added to contrib for simple consumption and returning of MessagePack data.
• Launch failures (LaunchError) from Rocket::launch() are now returned for inspection without panicking.
• Routes without query parameters now match requests with or without query parameters.
• Default rankings range from -4 to -1, preferring static paths and routes with query string matches.
• A native Accept header structure was added.
• The Accept request header can be retrieved via Request::accept().
• Incoming form fields can be renamed via a new #[form(field = "name")] structure field attribute.
• All active routes can be retrieved via Rocket::routes().
• Response::body_string() was added to retrieve the response body as a String.
• Response::body_bytes() was added to retrieve the response body as a Vec<u8>.
• Response::content_type() was added to easily retrieve the Content-Type header of a response.
• Size limits on incoming data are now configurable.
• Request::limits() was added to retrieve incoming data limits.
• Responders may dynamically adjust their response based on the incoming request.
• Request::guard() was added for simple retrieval of request guards.
• Request::route() was added to retrieve the active route, if any.
• &Route is now a request guard.
• The base mount path of a Route can be retrieved via Route::base or Route::base().
• Cookies supports private (authenticated encryption) cookies, encryped with the secret_key config key.
• Config::{development, staging, production} constructors were added for Config.
• Config::get_datetime() was added to retrieve an extra as a Datetime.
• Forms can be now parsed leniently via the new LenientForm data guard.
• The ? operator can now be used with Outcome.
• Quoted string, array, and table based configuration parameters can be set via environment variables.
• Log coloring is disabled when stdout is not a TTY.
• FromForm is implemented for Option<T: FromForm>, Result<T: FromForm, T::Error>.
• The NotFound responder was added for simple 404 response construction.

Breaking Changes

This release includes many breaking changes. These changes are listed below along with a short note about how to handle the breaking change in existing applications.

• session_key was renamed to secret_key, requires a 256-bit base64 key

  It's unlikely that session_key was previously used. If it was, rename session_key to secret_key. Generate a random 256-bit base64 key using a tool like openssl: openssl rand -base64 32.

• The &Cookies request guard has been removed in favor of Cookies

  Change &Cookies in a request guard position to Cookies.

• Rocket::launch() now returns a LaunchError, doesn't panic.

  For the old behavior, suffix a call to .launch() with a semicolon: .launch();.

• Routes without query parameters match requests with or without query parameters.

  There is no workaround, but this change may allow manual ranks from routes to be removed.

• The format route attribute on non-payload requests matches against the Accept header.

  Excepting a custom request guard, there is no workaround. Previously, format always matched against the Content-Type header, regardless of whether the request method indicated a payload or not.

• A type of &str can no longer be used in form structures or parameters.

  Use the new &RawStr type instead.

• ContentType is no longer a request guard.

  Use &ContentType instead.

• Request::content_type() returns &ContentType instead of ContentType.

  Use .clone() on &ContentType if a type of ContentType is required.

• Response::header_values() was removed. Response::headers() now returns an &HeaderMap.

  A call to Response::headers() can be replaced with Response::headers().iter(). A call to Response::header_values(name) can be replaced with Response::headers().get(name).

• Route collisions result in a hard error and panic.

  There is no workaround. Previously, route collisions were a warning.

• The IntoOutcome trait has been expanded and made more flexible.

  There is no workaround. IntoOutcome::into_outcome() now takes a Failure value to use. IntoOutcome::or_forward() was added to return a Forward outcome if self indicates an error.

• The 'testing' feature was removed.

  Remove features = ["testing"] from Cargo.toml. Use the new local module for testing.

• serde was updated to 1.0.

  There is no workaround. Ensure all dependencies rely on serde 1.0.

• config::active() was removed.

  Use Rocket::config() to retrieve the configuration before launch. If needed, use managed state to store config information for later use.

• The Responder trait has changed.

  Responder::respond(self) was removed in favor of Responder::respond_to(self, &Request). Responders may dynamically adjust their response based on the incoming request.

• Outcome::of(Responder) was removed while Outcome::from(&Request, Responder) was added.

  Use Outcome::from(..) instead of Outcome::of(..).

• Usage of templates requires Template::fairing() to be attached.

  Call .attach(Template::fairing()) on the application's Rocket instance before launching.

• The Display implementation of Template was removed.

  Use Template::show() to render a template directly.

• Request::new() is no longer exported.

  There is no workaround.

• The FromForm trait has changed.

  Responder::from_form_items(&mut FormItems) was removed in favor of Responder::from_form(&mut FormItems, bool). The second parameter indicates whether parsing should be strict (if true) or lenient (if false).

• LoggingLevel was removed as a root reexport.

  It can now be imported from rocket::config::LoggingLevel.

• An Io variant was added to ConfigError.

  Ensure matches on ConfigError include an Io variant.

• ContentType::from_extension() returns an Option<ContentType>.

  For the old behvavior, use .unwrap_or(ContentType::Any).

• The IntoValue config trait was removed in favor of Into<Value>.

  There is no workaround. Use Into<Value> as necessary.

• The rocket_contrib::JSON type has been renamed to rocket_contrib::Json.

  Use Json instead of JSON.

• All structs in the content module use TitleCase names.

  Use Json, Xml, Html, and Css instead of JSON, XML, HTML, and CSS, respectively.

General Improvements

In addition to new features, Rocket saw the following improvements:

• "Rocket" is now capatilized in the Server HTTP header.
• The generic parameter of rocket_contrib::Json defaults to json::Value.
• The trailing '...' in the launch message was removed.
• The launch message prints regardless of the config environment.
• For debugging, FromData is implemented for Vec<u8> and String.
• The port displayed on launch is the port resolved, not the one configured.
• The uuid dependency was updated to 0.5.
• The base64 dependency was updated to 0.6.
• The toml dependency was updated to 0.4.
• The handlebars dependency was updated to 0.27.
• The tera dependency was updated to 0.10.
• yansi is now used for all terminal coloring.
• The dev rustc release channel is supported during builds.
• Config is now exported from the root.
• Request implements Clone and Debug.
• The workers config parameter now defaults to num_cpus * 2.
• Console logging for table-based config values is improved.
• PartialOrd, Ord, and Hash are now implemented for State.
• The format of a request is always logged when available.

Infrastructure

• All examples include a test suite.
• The master branch now uses a -dev version number.

Version 0.2.8 (Jun 01, 2017)

Codegen

• Lints were updated for 2017-06-01 nightly.
• Minimum required rustc is 1.19.0-nightly (2017-06-01).

Version 0.2.7 (May 26, 2017)

Codegen

• Codegen was updated for 2017-05-26 nightly.

Version 0.2.6 (Apr 17, 2017)

Codegen

• Allow k and v to be used as fields in FromForm structures by avoiding identifier collisions (#265).

Version 0.2.5 (Apr 16, 2017)

Codegen

• Lints were updated for 2017-04-15 nightly.
• Minimum required rustc is 1.18.0-nightly (2017-04-15).

Version 0.2.4 (Mar 30, 2017)

Codegen

• Codegen was updated for 2017-03-30 nightly.
• Minimum required rustc is 1.18.0-nightly (2017-03-30).

Version 0.2.3 (Mar 22, 2017)

Fixes

• Multiple header values for the same header name are now properly preserved (#223).

Core

• The get_slice and get_table methods were added to Config.
• The pub_restricted feature has been stabilized!

Codegen

• Lints were updated for 2017-03-20 nightly.
• Minimum required rustc is 1.17.0-nightly (2017-03-22).

Infrastructure

• The test script now denies trailing whitespace.

Version 0.2.2 (Feb 26, 2017)

Codegen

• Lints were updated for 2017-02-25 and 2017-02-26 nightlies.
• Minimum required rustc is 1.17.0-nightly (2017-02-26).

Version 0.2.1 (Feb 24, 2017)

Core Fixes

• Flash cookie deletion functions as expected regardless of the path.
• config properly accepts IPv6 addresses.
• Multiple Set-Cookie headers are properly set.

Core Improvements

• Display and Error were implemented for ConfigError.
• webp, ttf, otf, woff, and woff2 were added as known content types.
• Routes are presorted for faster routing.
• into_bytes and into_inner methods were added to Body.

Codegen

• Fixed unmanaged_state lint so that it works with prefilled type aliases.

Contrib

• Better errors are emitted on Tera template parse errors.

Documentation

• Fixed typos in manage and JSON docs.

Infrastructure

• Updated doctests for latest Cargo nightly.

Version 0.2.0 (Feb 06, 2017)

Detailed release notes for v0.2 can also be found on rocket.rs.

New Features

This release includes the following new features:

• Introduced managed state.
• Added lints that warn on unmanaged state and unmounted routes.
• Added the ability to set configuration parameters via environment variables.
• Config structures can be built via ConfigBuilder, which follows the builder pattern.
• Logging can be enabled or disabled on custom configuration via a second parameter to the Rocket::custom method.
• name and value methods were added to Header to retrieve the name and value of a header.
• A new configuration parameter, workers, can be used to set the number of threads Rocket uses.
• The address of the remote connection is available via Request.remote(). Request preprocessing overrides remote IP with value from the X-Real-IP header, if present.
• During testing, the remote address can be set via MockRequest.remote().
• The SocketAddr request guard retrieves the remote address.
• A UUID type has been added to contrib.
• rocket and rocket_codegen will refuse to build with an incompatible nightly version and emit nice error messages.
• Major performance and usability improvements were upstreamed to the cookie crate, including the addition of a CookieBuilder.
• When a checkbox isn't present in a form, bool types in a FromForm structure will parse as false.
• The FormItems iterator can be queried for a complete parse via completed and exhausted.
• Routes for OPTIONS requests can be declared via the options decorator.
• Strings can be percent-encoded via URI::percent_encode().

Breaking Changes

This release includes several breaking changes. These changes are listed below along with a short note about how to handle the breaking change in existing applications.

• Rocket::custom takes two parameters, the first being Config by value.

  A call in v0.1 of the form Rocket::custom(&config) is now Rocket::custom(config, false).

• Tera templates are named without their extension.

  A templated named name.html.tera is now simply name.

• JSON unwrap method has been renamed to into_inner.

  A call to .unwrap() should be changed to .into_inner().

• The map! macro was removed in favor of the json! macro.

  A call of the form map!{ "a" => b } can be written as: json!({ "a": b }).

• The hyper::SetCookie header is no longer exported.

  Use the Cookie type as an Into<Header> type directly.

• The Content-Type for String is now text/plain.

  Use content::HTML<String> for HTML-based String responses.

• Request.content_type() returns an Option<ContentType>.

  Use .unwrap_or(ContentType::Any) to get the old behavior.

• The ContentType request guard forwards when the request has no Content-Type header.

  Use an Option<ContentType> and .unwrap_or(ContentType::Any) for the old behavior.

• A Rocket instance must be declared before a MockRequest.

  Change the order of the rocket::ignite() and MockRequest::new() calls.

• A route with format specified only matches requests with the same format.

  Previously, a route with a format would match requests without a format specified. There is no workaround to this change; simply specify formats when required.

• FormItems can no longer be constructed directly.

  Instead of constructing as FormItems(string), construct as FormItems::from(string).

• from_from_string(&str) in FromForm removed in favor of from_form_items(&mut FormItems).

  Most implementation should be using FormItems internally; simply use the passed in FormItems. In other cases, the form string can be retrieved via the inner_str method of FormItems.

• Config::{set, default_for} are deprecated.

  Use the set_{param} methods instead of set, and new or build in place of default_for.

• Route paths must be absolute.

  Prepend a / to convert a relative path into an absolute one.

• Route paths cannot contain empty segments.

  Remove any empty segments, including trailing ones, from a route path.

Bug Fixes

A couple of bugs were fixed in this release:

• Handlebars partials were not properly registered (#122).
• Rocket::custom did not set the custom configuration as the active configuration.
• Route path segments containing more than one dynamic parameter were allowed.

General Improvements

In addition to new features, Rocket saw the following smaller improvements:

• Rocket no longer overwrites a catcher's response status.
• The port Config type is now a proper u16.
• Clippy issues injected by codegen are resolved.
• Handlebars was updated to 0.25.
• The PartialEq implementation of Config doesn't consider the path or secret key.
• Hyper dependency updated to 0.10.
• The Error type for JSON as FromData has been exposed as SerdeError.
• SVG was added as a known Content-Type.
• Serde was updated to 0.9.
• Form parse failure now results in a 422 error code.
• Tera has been updated to 0.7.
• pub(crate) is used throughout to enforce visibility rules.
• Query parameters in routes (/path?<param>) are now logged.
• Routes with and without query parameters no longer collide.

Infrastructure

• Testing was parallelized, resulting in 3x faster Travis builds.

Version 0.1.6 (Jan 26, 2017)

Infrastructure

• Hyper version pinned to 0.9.14 due to upstream non-semver breaking change.

Version 0.1.5 (Jan 14, 2017)

Core

• Fixed security checks in FromSegments implementation for PathBuf.

Infrastructure

• proc_macro feature removed from examples due to stability.

Version 0.1.4 (Jan 4, 2017)

Core

• Header names are treated as case-preserving.

Codegen

• Minimum supported nightly is 2017-01-03.

Version 0.1.3 (Dec 31, 2016)

Core

• Typo in Outcome formatting fixed (Succcess -> Success).
• Added ContentType::CSV.
• Dynamic segments parameters are properly resolved, even when mounted.
• Request methods are only overridden via _method field on POST.
• Form value Strings are properly decoded.

Codegen

• The _method field is now properly ignored in FromForm derivation.
• Unknown Content-Types in format no longer result in an error.
• Deriving FromForm no longer results in a deprecation warning.
• Codegen will refuse to build with incompatible rustc, presenting error message and suggestion.
• Added head as a valid decorator for HEAD requests.
• Added route(OPTIONS) as a valid decorator for OPTIONS requests.

Contrib

• Templates with the .tera extension are properly autoescaped.
• Nested template names are properly resolved on Windows.
• Template implements Display.
• Tera dependency updated to version 0.6.

Docs

• Todo example requirements clarified in its README.

Testing

• Tests added for config, optional_result, optional_redirect, and query_params examples.
• Testing script checks for and disallows tab characters.

Infrastructure

• New script (bump_version.sh) automates version bumps.
• Config script emits error when readlink/readpath support is bad.
• Travis badge points to public builds.

Version 0.1.2 (Dec 24, 2016)

Codegen

• Fix get_raw_segments index argument in route codegen (#41).
• Segments params (<param..>) respect prefixes.

Contrib

• Fix nested template name resolution (#42).

Infrastructure

• New script (publish.sh) automates publishing to crates.io.
• New script (bump_version.sh) automates version bumps.

Version 0.1.1 (Dec 23, 2016)

Core

• NamedFile Responder lost its body in the shuffle; it's back!

Version 0.1.0 (Dec 23, 2016)

This is the first public release of Rocket!

Breaking

All of the mentions to hyper types in core Rocket types are no more. Rocket now implements its own Request and Response types.

• ContentType uses associated constants instead of static methods.
• StatusCode removed in favor of new Status type.
• Response type alias superceded by Response type.
• Responder::respond no longer takes in hyper type.
• Responder::respond returns Response, takes self by move.
• Handler returns Outcome instead of Response type alias.
• ErrorHandler returns Result.
• All Hyper* types were moved to unprefixed versions in hyper::.
• MockRequest::dispatch now returns a Response type.
• URIBuf removed in favor of unified URI.
• Rocket panics when an illegal, dynamic mount point is used.

Core

• Rocket handles HEAD requests automatically.
• New Response and ResponseBuilder types.
• New Request, Header, Status, and ContentType types.

Testing

• MockRequest allows any type of header.
• MockRequest allows cookies.

Codegen

• Debug output disabled by default.
• The ROCKET_CODEGEN_DEBUG environment variables enables codegen logging.

Version 0.0.11 (Dec 11, 2016)

Streaming Requests

All incoming request data is now streamed. This resulted in a major change to the Rocket APIs. They are summarized through the following API changes:

• The form route parameter has been removed.
• The data route parameter has been introduced.
• Forms are now handled via the data parameter and Form type.
• Removed the data parameter from Request.
• Added FromData conversion trait and default implementation.
• FromData is used to automatically derive the data parameter.
• Responders are now final: they cannot forward to other requests.
• Responsers may only forward to catchers.

Breaking

• Request uri parameter is private. Use uri() method instead.
• form module moved under request module.
• response::data was renamed to response::content.
• Introduced Outcome with Success, Failure, and Forward variants.
• outcome module moved to top-level.
• Response is now a type alias to Outcome.
• Empty Responder was removed.
• StatusResponder removed in favor of response::status module.

Codegen

• Error handlers can now take 0, 1, or 2 parameters.
• FromForm derive now works on empty structs.
• Lifetimes are now properly stripped in code generation.
• Any valid ident is now allowed in single-parameter route parameters.

Core

• Route is now cloneable.
• Request no longer has any lifetime parameters.
• Handler type now includes a Data parameter.
• http module is public.
• Responder implemented for () type as an empty response.
• Add config::get() for global config access.
• Introduced testing module.
• Rocket.toml allows global configuration via [global] table.

Docs

• Added a raw_upload example.
• Added a pastebin example.
• Documented all public APIs.

Testing

• Now building and running tests with --all-features flag.
• Added appveyor config for Windows CI testing.

Version 0.0.10 (Oct 03, 2016)

Breaking

• Remove Rocket::new in favor of ignite method.
• Remove Rocket::mount_and_launch in favor of chaining mount(..).launch().
• mount and catch take Rocket type by value.
• All types related to HTTP have been moved into http module.
• Template::render in contrib now takes context by reference.

Core

• Rocket now parses option Rocket.toml for configuration, defaulting to sane values.
• ROCKET_ENV environment variable can be used to specify running environment.

Docs

• Document ContentType.
• Document Request.
• Add script that builds docs.

Testing

• Scripts can now be run from any directory.
• Cache Cargo directories in Travis for faster testing.
• Check that library version numbers match in testing script.

Version 0.0.9 (Sep 29, 2016)

Breaking

• Rename response::data_type to response::data.

Core

• Rocket interprets _method field in forms as the incoming request's method.
• Add Outcome::Bad to signify responses that failed internally.
• Add a NamedFile Responder type that uses a file's extension for the response's content type.
• Add a Stream Responder for streaming responses.

Contrib

• Introduce the contrib crate.
• Add JSON support via JSON, which implements FromRequest and Responder.
• Add templating support via Template which implements Responder.

Docs

• Initial guide-like documentation.
• Add documentation, testing, and contributing sections to README.

Testing

• Add a significant number of codegen tests.