Docs/Reference/Modules/rules_web

rules_web

Bazel toolchain types and rules for W3C/WHATWG web-standards specs (webidl/html/css/js) — decoupled from impl modules.

Latest	`0.0.1`
Versions	1
Category	Bazel rules
Maintainers	Matt Marshall
Registry	https://registry.tbzl.dev/modules/rules_web/
Source	github.com/tomato-bazel/rules_web

MODULE.bazelstarlark

bazel_dep(name = "rules_web", version = "0.0.1")

View source & releases on GitHub ↗

Bazel toolchain types and rules for W3C / WHATWG web-standards specs — WebIDL, HTML, CSS, JS. Consumers depend on this module for the interface (rule names, toolchain types, providers); the implementation comes from a separate module that registers the toolchain.

Toolchain types

Path	Toolchain type	Status	First implementation
`//web/webidl/...`	`webidl_toolchain_type`	v0	`firefox_webidl_parser` (WebIDL.py)
`//web/html/...`	`html_parser_toolchain_type`	stub	(planned: `firefox_html_parser`)
`//web/css/...`	`css_toolchain_type`	stub	(planned: `firefox_css_specs`)
`//web/js/...`	`js_engine_toolchain_type`	stub	(planned: `firefox_spidermonkey`)

Multiple implementations of the same toolchain type can coexist — Bazel’s toolchain resolution picks whichever is registered. This mirrors how rules_cc lets you swap between LLVM, Xcode clang, MSVC, etc., without touching the consumer.

Consumer usage (WebIDL — v0 shape)

# MODULE.bazel
bazel_dep(name = "rules_web", version = "0.0.1")
bazel_dep(name = "firefox_webidl_parser", version = "0.0.1")
register_toolchains("@firefox_webidl_parser//:webidl_toolchain")

# BUILD.bazel
load("@rules_web//web/webidl:rules.bzl", "webidl_library", "webidl_parse")

webidl_library(
    name = "html_details",
    srcs = ["HTMLDetailsElement.webidl"],
)

webidl_parse(
    name = "html_details_ast",
    src = ":html_details",
)

webidl_parse invokes the registered parser toolchain via ctx.actions.run. The output is a JSON AST consumable by downstream codegen (the polyglot AST HTML emitter is the v0 consumer).

Why split rules from impl

Consumers only pull in the narrowest closure (rules_web + the registered toolchain — not the whole Firefox source).
Implementations can be swapped without changing consumer BUILD files (Mozilla’s parser today, a Rust port tomorrow).
The same pattern scales to html / css / js — rules_web owns the vocabulary; implementations live elsewhere.

Status

v0 scaffold. WebIDL toolchain type + minimal webidl_library / webidl_parse rules; html / css / js subdirs are stubs awaiting first real consumer.

PRIVATE / NDA. Published in fastverk/bazel-registry-premium.

Conformance#

No gate findings. 8 contested atoms. See how gating works or the full report.

Contested atoms

Third-party modules where this module resolves a different version than others do. Not a violation of anything this module did — it is the actionable form of a registry-level convergence finding, and the sentence a maintainer can act on.

Atom	Resolved here	Elsewhere
`apple_support`	`1.24.2`	`2.2.0` ×1
`bazel_skylib`	`1.8.2`	`1.9.0` ×2
`nlohmann_json`	`3.6.1`	`3.12.0.bcr.1` ×1
`protobuf`	`33.4`	`34.0.bcr.1` ×2
`rules_jvm_external`	`6.7`	`6.8` ×4
`rules_python`	`1.7.0`	`2.0.1` ×1
`rules_swift`	`3.1.2`	`3.6.1` ×1
`upb`	`0.0.0-20220923-a547704`	`0.0.0-20230516-61a97ef` ×1

Dependencies#

rules_web in the registry graph — what it depends on (left) and what depends on it (right).

Depends on

platforms1.0.0bazel_skylib1.8.2rules_python1.7.0

Versions#

1 published version, newest first. Each resolves to an immutable, integrity-checked archive.

Version	Integrity (sha256)	Source archive
`0.0.1` latest	`UJlqPcfFhd58H81u…`	tag archive ↗

Changelog#

0.0.1 (in progress)

Initial scaffold. web/webidl/ v0 toolchain interface: webidl_toolchain_type, WebIDLToolchainInfo provider, WebIDLInfo provider for libraries, and the consumer-facing webidl_library + webidl_parse rules.
web/html/, web/css/, web/js/ subdirs stubbed with empty toolchain_type placeholders so the structure is in place when the first concrete consumer arrives (likely firefox_html_parser for the html toolchain).
Canonical WebIDL impl registered separately by firefox_webidl_parser.

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