feat(typescript): worker mode for ts_project

examples/react_webpack/BUILD.bazel

@@ -14,6 +14,8 @@ sass(
 )
 
 ts_project(
+    # Start a tsc daemon to watch for changes to make recompiles faster.
+    supports_workers = True,
     deps = [
         "@npm//@types",
         "@npm//csstype",

examples/react_webpack/tsconfig.json

@@ -1,6 +1,14 @@
 {
     "compilerOptions": {
         "jsx": "react",
-        "lib": ["ES2015", "DOM"]
-    }
+        "lib": [
+            "ES2015",
+            "DOM"
+        ]
+    },
+    // When using ts_project in worker mode, make sure to whitelist the files that should be part of this particular compilation. In worker mode, the CWD is different than by default so typescript will pickup extraneous files without the whitelist.
+    "include": [
+        "*.tsx",
+        "*.ts"
+    ]
 }

internal/node/node.bzl

@@ -37,7 +37,7 @@ def _trim_package_node_modules(package_name):
     for n in package_name.split("/"):
         if n == "node_modules":
             break
-        segments += [n]
+        segments.append(n)
     return "/".join(segments)
 
 def _compute_node_modules_root(ctx):
@@ -250,7 +250,15 @@ fi
     expanded_args = [expand_location_into_runfiles(ctx, a, ctx.attr.data) for a in expanded_args]
 
     # Next expand predefined variables & custom variables
-    expanded_args = [ctx.expand_make_variables("templated_args", e, {}) for e in expanded_args]
+    rule_dir = [f for f in [
+        ctx.bin_dir.path,
+        ctx.label.workspace_root,
+        ctx.label.package,
+    ] if f]
+    additional_substitutions = {}
+    additional_substitutions["@D"] = "/".join([o for o in rule_dir if o])
+    additional_substitutions["RULEDIR"] = "/".join([o for o in rule_dir if o])
+    expanded_args = [ctx.expand_make_variables("templated_args", e, additional_substitutions) for e in expanded_args]
 
     substitutions = {
         # TODO: Split up results of multifile expansions into separate args and qoute them with

packages/typescript/BUILD.bazel

@@ -100,6 +100,7 @@ pkg_npm(
         ":npm_version_check",
         "//packages/typescript/internal:BUILD",
         "//packages/typescript/internal:ts_project_options_validator.js",
+        "//packages/typescript/internal/worker",
     ] + select({
         # FIXME: fix stardoc on Windows; //packages/typescript:index.md generation fails with:
         #   ERROR: D:/b/62unjjin/external/npm_bazel_typescript/BUILD.bazel:36:1: Couldn't build file

packages/typescript/internal/BUILD.bazel

@@ -64,6 +64,7 @@ filegroup(
         "ts_config.bzl",
         "ts_project.bzl",
         "//packages/typescript/internal/devserver:package_contents",
+        "//packages/typescript/internal/worker:package_contents",
     ],
     visibility = ["//packages/typescript:__subpackages__"],
 )

packages/typescript/internal/ts_project.bzl

@@ -2,6 +2,7 @@
 
 load("@build_bazel_rules_nodejs//:providers.bzl", "DeclarationInfo", "NpmPackageInfo", "declaration_info", "js_module_info", "run_node")
 load("@build_bazel_rules_nodejs//internal/linker:link_node_modules.bzl", "module_mappings_aspect")
+load("@build_bazel_rules_nodejs//internal/node:node.bzl", "nodejs_binary")
 load(":ts_config.bzl", "TsConfigInfo", "write_tsconfig")
 
 _DEFAULT_TSC = (
@@ -11,6 +12,13 @@ _DEFAULT_TSC = (
     "//typescript/bin:tsc"
 )
 
+_DEFAULT_TSC_BIN = (
+    # BEGIN-INTERNAL
+    "@npm" +
+    # END-INTERNAL
+    "//:node_modules/typescript/bin/tsc"
+)
+
 _ATTRS = {
     "args": attr.string_list(),
     "declaration_dir": attr.string(),
@@ -24,7 +32,14 @@ _ATTRS = {
     # if you swap out the `compiler` attribute (like with ngtsc)
     # that compiler might allow more sources than tsc does.
     "srcs": attr.label_list(allow_files = True, mandatory = True),
-    "tsc": attr.label(default = Label(_DEFAULT_TSC), executable = True, cfg = "host"),
+    "supports_workers": attr.bool(
+        doc = """Experimental! Use only with caution.
+
+Allows you to enable the Bazel Worker strategy for this project.
+This requires that the tsc binary support it.""",
+        default = False,
+    ),
+    "tsc": attr.label(default = Label(_DEFAULT_TSC), executable = True, cfg = "target"),
     "tsconfig": attr.label(mandatory = True, allow_single_file = [".json"]),
 }
 
@@ -47,6 +62,16 @@ def _join(*elements):
 
 def _ts_project_impl(ctx):
     arguments = ctx.actions.args()
+    execution_requirements = {}
+    progress_prefix = "Compiling TypeScript project"
+
+    if ctx.attr.supports_workers:
+        # Set to use a multiline param-file for worker mode
+        arguments.use_param_file("@%s", use_always = True)
+        arguments.set_param_file_format("multiline")
+        execution_requirements["supports-workers"] = "1"
+        execution_requirements["worker-key-mnemonic"] = "TsProjectMnemonic"
+        progress_prefix = "Compiling TypeScript project (worker mode)"
 
     generated_srcs = False
     for src in ctx.files.srcs:
@@ -150,7 +175,9 @@ def _ts_project_impl(ctx):
             arguments = [arguments],
             outputs = outputs,
             executable = "tsc",
-            progress_message = "Compiling TypeScript project %s [tsc -p %s]" % (
+            execution_requirements = execution_requirements,
+            progress_message = "%s %s [tsc -p %s]" % (
+                progress_prefix,
                 ctx.label,
                 ctx.file.tsconfig.short_path,
             ),
@@ -270,6 +297,7 @@ def ts_project_macro(
         ts_build_info_file = None,
         tsc = None,
         validate = True,
+        supports_workers = False,
         declaration_dir = None,
         out_dir = None,
         root_dir = None,
@@ -437,6 +465,11 @@ def ts_project_macro(
 
         validate: boolean; whether to check that the tsconfig settings match the attributes.
 
+        supports_workers: Experimental! Use only with caution.
+
+            Allows you to enable the Bazel Worker strategy for this project.
+            This requires that the tsc binary support it.
+
         root_dir: a string specifying a subdirectory under the input package which should be consider the
             root directory of all the input files.
             Equivalent to the TypeScript --rootDir option.
@@ -533,6 +566,31 @@ def ts_project_macro(
             )
             extra_deps.append("_validate_%s_options" % name)
 
+    if supports_workers:
+        tsc_worker = "%s_worker" % name
+        nodejs_binary(
+            name = tsc_worker,
+            data = [
+                Label("//packages/typescript/internal/worker:worker"),
+                Label(_DEFAULT_TSC_BIN),
+                tsconfig,
+            ],
+            entry_point = Label("//packages/typescript/internal/worker:worker_adapter"),
+            templated_args = [
+                "--nobazel_patch_module_resolver",
+                "$(execpath {})".format(Label(_DEFAULT_TSC_BIN)),
+                "--project",
+                "$(execpath {})".format(tsconfig),
+                # FIXME: should take out_dir into account
+                "--outDir",
+                "$(RULEDIR)",
+                # FIXME: what about other settings like declaration_dir, root_dir, etc
+                "--watch",
+            ],
+        )
+
+        tsc = ":" + tsc_worker
+
     typings_out_dir = declaration_dir if declaration_dir else out_dir
     tsbuildinfo_path = ts_build_info_file if ts_build_info_file else name + ".tsbuildinfo"
 
@@ -557,5 +615,9 @@ def ts_project_macro(
         buildinfo_out = tsbuildinfo_path if composite or incremental else None,
         tsc = tsc,
         link_workspace_root = link_workspace_root,
+        supports_workers = select({
+            "@bazel_tools//src/conditions:host_windows": False,
+            "//conditions:default": supports_workers,
+        }),
         **kwargs
     )

packages/typescript/internal/worker/BUILD.bazel

@@ -0,0 +1,55 @@
+# BEGIN-INTERNAL
+
+load("//internal/common:copy_to_bin.bzl", "copy_to_bin")
+load("//third_party/github.com/bazelbuild/bazel-skylib:rules/copy_file.bzl", "copy_file")
+
+# Copy the proto file to a matching third_party/... nested directory
+# so the runtime require() statements still work
+_worker_proto_dir = "third_party/github.com/bazelbuild/bazel/src/main/protobuf"
+
+genrule(
+    name = "copy_worker_js",
+    srcs = ["//packages/worker:npm_package"],
+    outs = ["worker.js"],
+    cmd = "cp $(execpath //packages/worker:npm_package)/index.js $@",
+    visibility = ["//visibility:public"],
+)
+
+copy_file(
+    name = "copy_worker_proto",
+    src = "@build_bazel_rules_typescript//%s:worker_protocol.proto" % _worker_proto_dir,
+    out = "%s/worker_protocol.proto" % _worker_proto_dir,
+    visibility = ["//visibility:public"],
+)
+
+copy_to_bin(
+    name = "worker_adapter",
+    srcs = [
+        "worker_adapter.js",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+filegroup(
+    name = "package_contents",
+    srcs = [
+        "BUILD.bazel",
+    ],
+    visibility = ["//packages/typescript:__subpackages__"],
+)
+
+# END-INTERNAL
+
+exports_files([
+    "worker_adapter.js",
+])
+
+filegroup(
+    name = "worker",
+    srcs = [
+        "third_party/github.com/bazelbuild/bazel/src/main/protobuf/worker_protocol.proto",
+        "worker.js",
+        "worker_adapter.js",
+    ],
+    visibility = ["//visibility:public"],
+)

packages/typescript/internal/worker/worker_adapter.js

@@ -0,0 +1,52 @@
+const child_process = require('child_process');
+
+const worker = require('./worker');
+
+const workerArg = process.argv.indexOf('--persistent_worker')
+if (workerArg > 0) {
+  process.argv.splice(workerArg, 1)
+
+  if (process.platform !== 'linux' && process.platform !== 'darwin') {
+    throw new Error('Worker mode is only supported on unix type systems.');
+  }
+
+  worker.runWorkerLoop(awaitOneBuild);
+}
+
+const [tscBin, ...tscArgs] = process.argv.slice(2);
+
+const child = child_process.spawn(
+    tscBin,
+    tscArgs,
+    {stdio: 'pipe'},
+);
+
+function awaitOneBuild() {
+  child.kill('SIGCONT')
+
+  let buffer = [];
+  return new Promise((res) => {
+    function awaitBuild(s) {
+      buffer.push(s);
+
+      if (s.includes('Watching for file changes.')) {
+        child.kill('SIGSTOP')
+
+        const success = s.includes('Found 0 errors.');
+        res(success);
+
+        child.stdout.removeListener('data', awaitBuild);
+
+        if (!success) {
+          console.error(
+              `\nError output from tsc worker:\n\n  ${
+                  buffer.slice(1).map(s => s.toString()).join('').replace(/\n/g, '\n  ')}`,
+          )
+        }
+
+        buffer = [];
+      }
+    };
+    child.stdout.on('data', awaitBuild);
+  });
+}

packages/typescript/replacements.bzl

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-"""Replacements for @npm/typescript package
+"""Replacements for @bazel/typescript package
 """
 
 load("@build_bazel_rules_nodejs//:index.bzl", "COMMON_REPLACEMENTS")
@@ -24,6 +24,7 @@ TYPESCRIPT_REPLACEMENTS = dict(
         # @build_bazel_rules_typescript//:npm_bazel_typescript_package
         # use this alternate fencing
         "(#|\\/\\/)\\s+BEGIN-DEV-ONLY[\\w\\W]+?(#|\\/\\/)\\s+END-DEV-ONLY": "",
+        "//packages/typescript/internal/worker:worker_adapter": "//@bazel/typescript/internal/worker:worker_adapter.js",
         # This file gets vendored into our repo
         "@build_bazel_rules_typescript//internal:common": "//@bazel/typescript/internal:common",
         # Replace the local compiler label with one that comes from npm

packages/typescript/test/ts_project/worker/BUILD.bazel

@@ -0,0 +1,11 @@
+load("//packages/typescript:index.bzl", "ts_project")
+
+ts_project(
+    supports_workers = True,
+    tsconfig = {
+        "compilerOptions": {
+            "declaration": True,
+            "types": [],
+        },
+    },
+)

packages/typescript/test/ts_project/worker/big.ts

@@ -0,0 +1,3 @@
+// TODO: make it big enough to slow down tsc
+
+export const a: number = 2;