ts_compile¶

Compiles TypeScript source files using Oxc. Optionally type-checks with tsgo.

Usage¶

load("@rules_typescript//ts:defs.bzl", "ts_compile")

ts_compile(
    name = "lib",
    srcs = ["index.ts", "math.ts"],
    deps = ["//other/package", "@npm//:zod"],
    target = "es2022",
    jsx_mode = "react-jsx",
    isolated_declarations = True,
    enable_check = True,
    visibility = ["//visibility:public"],
)

Attributes¶

Attribute	Type	Default	Description
`srcs`	`label_list`	required	`.ts`, `.tsx`, or `.d.ts` files
`deps`	`label_list`	`[]`	`ts_compile` or `ts_npm_package` targets
`target`	`string`	`"es2022"`	ECMAScript target version
`jsx_mode`	`string`	`"react-jsx"`	JSX transform: `react-jsx`, `react`, `preserve`
`isolated_declarations`	`bool`	`True`	Enable isolated declarations for fast `.d.ts` emit
`enable_check`	`bool`	`True`	Run tsgo type-checking (requires tsgo toolchain)

Outputs¶

For each source file foo.ts, ts_compile produces:

Output	Description
`foo.js`	Compiled JavaScript
`foo.js.map`	Source map
`foo.d.ts`	TypeScript declaration file (compilation boundary)

Providers¶

ts_compile returns:

JsInfo — transitive depset of .js files, used by ts_binary and ts_bundle
TsDeclarationInfo — depset of .d.ts files, used by downstream ts_compile targets for type resolution
OutputGroupInfo(_validation=...) — tsgo type-checking output, enabled by --output_groups=+_validation

Type Checking¶

Type-checking runs as a Bazel validation action in the _validation output group. It executes during bazel build but does not block downstream compilation — if package A's type check fails, package B (which depends on A) still compiles using A's .d.ts.

To surface type errors on every build, add to .bazelrc:

build --output_groups=+_validation

Isolated Declarations¶

When isolated_declarations = True, each .d.ts is generated from its source file alone with no cross-file inference. This requires all exported functions and variables to have explicit type annotations.

When isolated_declarations = False, Oxc falls back to emitting .d.ts with inferred types. Builds still work, but the .d.ts boundary is less precise — an implementation change that doesn't affect public types may still trigger downstream recompilation.

See Isolated Declarations for the full explanation.

Architecture¶

The oxc-bazel binary processes each .ts file through:

Parse (oxc_parser)
Semantic analysis (oxc_semantic)
Isolated declarations emit (oxc_isolated_declarations) — before transform
TypeScript/JSX transform (oxc_transformer)
Code generation (oxc_codegen) for .js + .js.map

tsgo type-checking runs as a separate Bazel action with a generated tsconfig.json using rootDirs bridging the source tree and output tree, moduleResolution: "Bundler", and --noEmit.