rules_rust_wasm_bindgen

Bazel rules for generating wasm modules for Javascript using wasm-bindgen.

Rules

rust_wasm_bindgen
rust_wasm_bindgen_toolchain

Setup

To begin using the wasm-bindgen rules, users can load the necessary dependencies in their workspace by adding the following to their WORKSPACE.bazel file.

load("@rules_rust_wasm_bindgen//:repositories.bzl", "rust_wasm_bindgen_dependencies", "rust_wasm_bindgen_register_toolchains")

rust_wasm_bindgen_dependencies()

rust_wasm_bindgen_register_toolchains()

This should enable users to start using the rust_wasm_bindgen rule. However, it's common to want to control the version of wasm-bindgen in the workspace instead of relying on the one provided by rules_rust. In this case, users should avoid calling rust_wasm_bindgen_register_toolchains and instead use the rust_wasm_bindgen_toolchain rule to define their own toolchains to register in the workspace.

Interfacing with Javascript rules

Rules for doing so can be found at rules_js_rust_wasm_bindgen

rust_wasm_bindgen

load("@rules_rust_wasm_bindgen//:defs.bzl", "rust_wasm_bindgen")

rust_wasm_bindgen(name, bindgen_flags, out_name, target, target_arch, wasm_file)

Generates javascript and typescript bindings for a webassembly module using wasm-bindgen.

An example of this rule in use can be seen at @rules_rust//examples/wasm

ATTRIBUTES

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
bindgen_flags	Flags to pass directly to the wasm-bindgen executable. See https://github.com/rustwasm/wasm-bindgen/ for details.	List of strings	optional	`[]`
out_name	Set a custom output filename (Without extension. Defaults to target name).	String	optional	`""`
target	The type of output to generate. See https://rustwasm.github.io/wasm-bindgen/reference/deployment.html for details.	String	optional	`"bundler"`
target_arch	The target architecture to use for the wasm-bindgen command line option.	String	optional	`"wasm32"`
wasm_file	The `.wasm` crate to generate bindings for.	Label	required

rust_wasm_bindgen_toolchain

load("@rules_rust_wasm_bindgen//:defs.bzl", "rust_wasm_bindgen_toolchain")

rust_wasm_bindgen_toolchain(name, browser, browser_type, wasm_bindgen_cli, wasm_bindgen_test,
                            wasm_bindgen_test_runner, webdriver, webdriver_args, webdriver_json)

The tools required for the rust_wasm_bindgen rule.

In cases where users want to control or change the version of wasm-bindgen used by rust_wasm_bindgen, a unique toolchain can be created as in the example below:

load("@rules_rust_wasm_bindgen//:defs.bzl", "rust_wasm_bindgen_toolchain")

rust_wasm_bindgen_toolchain(
    wasm_bindgen_cli = "//3rdparty/crates:wasm_bindgen_cli__bin",
)

toolchain(
    name = "wasm_bindgen_toolchain",
    toolchain = "wasm_bindgen_toolchain_impl",
    toolchain_type = "@rules_rust_wasm_bindgen//:toolchain_type",
)

Now that you have your own toolchain, you need to register it by inserting the following statement in your WORKSPACE file:

register_toolchains("//my/toolchains:wasm_bindgen_toolchain")

For additional information, see the Bazel toolchains documentation.

ATTRIBUTES

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
browser	The browser entrypoint.	Label	optional	`None`
browser_type	The type of browser provided.	String	optional	`""`
wasm_bindgen_cli	The label of a `wasm-bindgen-cli` executable.	Label	optional	`None`
wasm_bindgen_test	The label of a `wasm-bindgen-test` crate.	Label	optional	`None`
wasm_bindgen_test_runner	The label of a `wasm-bindgen-test-runner` binary.	Label	optional	`None`
webdriver	The webdriver to use.	Label	optional	`None`
webdriver_args	Arguments to pass to the `webdriver` binary.	List of strings	optional	`[]`
webdriver_json	The `webdriver.json` config file for wasm-bindgen-test.	Label	optional	`None`

RustWasmBindgenInfo

load("@rules_rust_wasm_bindgen//:defs.bzl", "RustWasmBindgenInfo")

RustWasmBindgenInfo(js, root, snippets, ts, wasm)

Info about wasm-bindgen outputs.

FIELDS

Name	Description
js	Depset[File]: The Javascript files produced by `wasm-bindgen`.
root	str: The path to the root of the `wasm-bindgen --out-dir` directory.
snippets	File: The snippets directory produced by `wasm-bindgen`.
ts	Depset[File]: The Typescript files produced by `wasm-bindgen`.
wasm	File: The `.wasm` file generated by `wasm-bindgen`.

rust_wasm_bindgen_test

load("@rules_rust_wasm_bindgen//:defs.bzl", "rust_wasm_bindgen_test")

rust_wasm_bindgen_test(*, name, aliases, compile_data, crate_features, data, edition, env,
                       env_inherit, proc_macro_deps, rustc_env, rustc_env_files, rustc_flags,
                       target_arch, version, wasm, tags, **kwargs)

"A test rule for running wasm-bindgen tests."

PARAMETERS

Name	Description	Default Value
name	A unique name for this target.	none
aliases	Remap crates to a new name or moniker for linkage to this target.	`{}`
compile_data	List of files used by this rule at compile time.	`[]`
crate_features	List of features to enable for this crate.	`[]`
data	List of files used by this rule at compile time and runtime.	`[]`
edition	The rust edition to use for this crate. Defaults to the edition specified in the rust_toolchain.	`None`
env	Specifies additional environment variables to set when the test is executed by bazel test.	`{}`
env_inherit	Specifies additional environment variables to inherit from the external environment when the test is executed by bazel test.	`[]`
proc_macro_deps	List of `rust_proc_macro` targets used to help build this library target.	`[]`
rustc_env	Dictionary of additional `"key": "value"` environment variables to set for rustc.	`{}`
rustc_env_files	Files containing additional environment variables to set for rustc.	`[]`
rustc_flags	List of compiler flags passed to `rustc`.	`[]`
target_arch	The target architecture to use for the wasm-bindgen command line option.	`None`
version	A version to inject in the cargo environment variable.	`"0.0.0"`
wasm	The wasm target to test.	`None`
tags	Tags to apply to the target.	`[]`
kwargs	Additional keyword arguments.	none