This commit adds a new attribute to `#[wasm_bindgen]`: `start`. The
`start` attribute can be used to indicate that a function should be
executed when the module is loaded, configuring the `start` function of
the wasm executable. While this doesn't necessarily literally configure
the `start` section, it does its best!
Only one crate in a crate graph may indicate `#[wasm_bindgen(start)]`,
so it's not recommended to be used in libraries but only end-user
applications. Currently this still must be used with the `crate-type =
["cdylib"]` annotation in `Cargo.toml`.
The implementation here is somewhat tricky because of the circular
dependency between our generated JS and the wasm file that we emit. This
circular dependency makes running initialization routines (like the
`start` shim) particularly fraught with complications because one may
need to run before the other but bundlers may not necessarily respect
it. Workarounds have been implemented for various emission strategies,
for example calling the start function directly after exports are wired
up with `--no-modules` and otherwise working around what appears to be
a Webpack bug with initializers running in a different order than we'd
like. In any case, this in theory doesn't show up to the end user!
Closes#74
This shaves a little over 2MB off the download locally for Linux,
removing debuginfo (which no one's probably gonna use anyway) as well as
switching from jemalloc to the system allocator.
We've gotten a number of reports that the interactive tests are a bit surprising
and confusing (also because it barely prints anything!). Instead let's default
to headless testing which matches the Rust style of testing much better.
The error message for a missing WebDriver binary has been updated with a note of
how to *not* do headless testing and the message for interactive testing was
also updated to display more information as well.
This commit starts migrating the `wasm_bindgen` tests to the `wasm_bindgen_test`
framework, starting to assemble the coffin for
`wasm-bindgen-test-project-builder`. Over time all of the tests in
`tests/all/*.rs` should be migrated to `wasm_bindgen_test`, although they may
not all want to go into a monolithic test suite so we can continue to test for
some more subtle situations with `#[wasm_bindgen]`.
In the meantime those, the `tests/all/api.rs` tests can certainly migrate!
This commit adds support to the `wasm-bindgen-test-runner` binary to
perform headless testing via browsers. The previous commit introduced a
local server to serve up files and run tests in a browser, and this
commit adds support for executing that in an automated fashion.
The general idea here is that each browser has a binary that implements
the WebDriver specification. These binaries (typically `foodriver` for
the browser "Foo") are interfaced with using HTTP and JSON messages. The
implementation was simple enough and the crates.io support was lacking
enough that a small implementation of the WebDriver protocol was added
directly to this crate.
Currently Firefox (`geckodriver`), Chrome (`chromedriver`), and Safari
(`safaridriver`) are supported for running tests. The test harness will
recognize env vars like `GECKODRIVER=foo` to specifically use one or
otherwise detects the first driver in `PATH`. Eventually we may wish to
automatically download a driver if one isn't found, but that isn't
implemented yet.
Headless testing is turned on with the `CI=1` env var currently to be
amenable with things like Travis and AppVeyor, but this may wish to grow
an explicit option to run headless tests in the future.
This commit starts to add support for in-browser testing with
`wasm-bindgen-test-runner`. The current idea here is that somehow it'll be
configured and it'll spawn a little HTTP server serving up files from the
filesystem. This has been tested in various ways but isn't hooked up just yet,
wanted to make sure this was somewhat standalone! Future support for actually
running these tests will be coming in later commits.
