Because of some incorrect use of `js.push_str(..)`, we could sometimes emit code
before the ES modules imports, which is syntactically invalid:
const __exports = {};
import { Thing } from '...'; // Syntax error!
This has been fixed by making sure that the correct `imports` or `imports_post`
string is built up. We now also assert that the `js` string is empty at the
location where we add imports if we're using ES modules.
This commit fixes the `init` function when passed a
`WebAssembly.Module`. Upon closer reading of the [spec] we see there's
two possible return values from `WebAssembly.instantiate`. If passed a
`Module`, it will return only the `Instance`. If passed a buffer source,
though, it'll return an object with the module/instance.
The fix here is to check the result value is an `Instance`, and if so
assume the input must have been a module so it's paired up in the
output.
Closes#1418
[spec]: http://webassembly.github.io/spec/js-api/index.html#webassembly-namespace
This is work towards #1399, although it's just for one-argument closures
where the first argument is a reference. No other closures with
references in argument position are supported yet
Instead of doubling the size on each iteration, use precise upper limit (3 * JS length) if the string turned out not to be ASCII-only. This results in maximum of 1 reallocation instead of O(log N).
Some dummy examples of what this would change:
- 1000 of ASCII chars: no change, allocates 1000 bytes and bails out.
- 1000 ASCII chars + 1 '😃': before allocated 1000 bytes and reallocated to 2000; now allocates 1000 bytes and reallocates to 1006.
- 1000 of '😃' chars: before allocated 1000 bytes, reallocated to 2000, finally reallocated again to 4000; now allocates 1000 bytes and reallocates to 4000 right away.
Related issue: #1313
All numbers in WebAssembly are signed and then each operation on them
may optionally have an unsigned version. This means that when we pass
large signed numbers to JS they actually show up as large negative
numbers even though JS numbers can faithfully represent the type.
This is fixed by adding `>>>0` in a few locations in the generated
bindings to coerce the JS value into an unsigned value.
Closes#1388
Aside from visual deduplication, this actually fixes a bug in js2rust.rs where it didn't call `expose_is_like_none` but used `isLikeNone` inside of `arg.get_64()` branch.
Most of the CLI crates were already in the 2018 edition, and it turns
out that one of the macro crates was already in the 2018 edition so we
may as well move everything to the 2018 edition!
Always nice to remove those `extern crate` statements nowadays!
This commit also does a `cargo fmt --all` to make sure we're conforming
with style again.
This allows to significantly speed up iteration over small collections, where string encoding is the primary overhead.
Related to #1386, but works around only this partial case.
Node.js doesn't currently implement `TextEncoder::encodeInto`. I've raised an upstream issue to add it - https://github.com/nodejs/node/issues/26904 - but it's likely to take some time and will be available only in new releases.
In the meanwhile, it's worth noting that Node.js already has `Buffer::write` which has pretty similar semantics, but doesn't require creating an intermediate view using `.subarray` and instead accepts pointer and length directly.
Also, Node.js has `Buffer::byteLength` helper which allows to efficiently retrieve an encoded byte length of a string upfront, and so allows us to avoid a loop with reallocations.
This change takes leverage of these methods by generating an additional Buffer-based view into the WASM memory and using it for string operations.
I'm seeing up to 35% increase in performance in string-heavy library benchmarks.
We have very few tests today so this starts to add the basics of a test
suite which compiles Cargo projects on-the-fly which will hopefully help
us bolster the amount of assertions we can make about the output.
This commit implements [RFC 8], which enables transitive and transparent
dependencies on NPM. The `module` attribute, when seen and not part of a
local JS snippet, triggers detection of a `package.json` next to
`Cargo.toml`. If found it will cause the `wasm-bindgen` CLI tool to load
and parse the `package.json` within each crate and then create a merged
`package.json` at the end.
[RFC 8]: https://github.com/rustwasm/rfcs/pull/8
