Bazel rules for generating wasm modules for Javascript using wasm-bindgen.
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.
While it’s recommended for users to mantain their own , in the
@rules_rust//wasm_bindgen package there exists interface sub-packages for various
Javascript Bazel rules. E.g. build_bazel_rules_nodejs or aspect_rules_js. The
rules defined there are a more convenient way to use rust_wasm_bindgen with the
associated javascript rules due to the inclusion of additional providers. Each
directory contains a defs.bzl file that defines the different variants of
rust_wasm_bindgen. (e.g. nodejs_rust_wasm_bindgen for the rules_nodejs submodule).
rust_wasm_bindgen(name, bindgen_flags, target, 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 bindgen executable. See https://github.com/rustwasm/wasm-bindgen/ for details. | List of strings | optional | [] |
| target | The type of output to generate. See https://rustwasm.github.io/wasm-bindgen/reference/deployment.html for details. | String | optional | "bundler" |
| wasm_file | The .wasm file or crate to generate bindings for. |
Label | required |
rust_wasm_bindgen_toolchain(name, bindgen)
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//bindgen:bindgen.bzl", "rust_bindgen_toolchain")
rust_bindgen_toolchain(
bindgen = "//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 | |
| bindgen | The label of a wasm-bindgen-cli executable. |
Label | optional | None |
RustWasmBindgenInfo(js, ts, wasm)
Info about wasm-bindgen outputs.
FIELDS
| Name | Description |
|---|---|
| js | Depset[File]: The Javascript files 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_dependencies()
Declare dependencies needed for the rules_rust wasm-bindgen rules.
RETURNS
list[struct(repo=str, is_dev_dep=bool)]: A list of the repositories defined by this macro.
rust_wasm_bindgen_register_toolchains(register_toolchains)
Registers the default toolchains for the rules_rust wasm-bindgen rules.
PARAMETERS
| Name | Description | Default Value |
|---|---|---|
| register_toolchains | Whether or not to register toolchains. | True |