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).
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 |
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 |
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 . |
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.
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 |