WIP: add //tools/gen_browserslist

Author: dgp1130

tools/gen_browserslist/BUILD.bazel

@@ -0,0 +1,29 @@
+load("@aspect_rules_js//js:defs.bzl", "js_binary")
+load("@aspect_rules_ts//ts:defs.bzl", "ts_config")
+load("//tools:defaults2.bzl", "ts_project")
+
+js_binary(
+    name = "gen_browserslist",
+    data = [":gen_browserslist_lib"],
+    entry_point = "index.js",
+    visibility = ["//:__subpackages__"],
+)
+
+ts_project(
+    name = "gen_browserslist_lib",
+    srcs = ["index.ts"],
+    source_map = True,
+    tsconfig = ":tsconfig",
+    deps = [
+        "//:node_modules/baseline-browser-mapping",
+    ],
+)
+
+ts_config(
+    name = "tsconfig",
+    src = "tsconfig.json",
+    deps = [
+        "//:build-tsconfig-esm",
+        "//:node_modules/@types/node",
+    ],
+)

tools/gen_browserslist/index.ts

@@ -0,0 +1,24 @@
+(async () => {
+  const { getCompatibleVersions } = await import('baseline-browser-mapping');
+
+  const browsers = {
+    chrome: 'Chrome',
+    chrome_android: 'ChromeAndroid',
+    edge: 'Edge',
+    firefox: 'Firefox',
+    firefox_android: 'FirefoxAndroid',
+    safari: 'Safari',
+    safari_ios: 'iOS',
+  } as const;
+
+  const baselineBrowserslistConfig = getCompatibleVersions({
+    widelyAvailableOnDate: '2025-01-01',
+    includeDownstreamBrowsers: false,
+  })
+    .filter((version) => browsers[version.browser as keyof typeof browsers])
+    .map(
+      (version) => `${browsers[version.browser as keyof typeof browsers]} >= ${version.version}`,
+    );
+
+  for (const line of baselineBrowserslistConfig) console.log(line);
+})();

tools/gen_browserslist/tsconfig.json

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+{
+  "extends": "../../tsconfig-build-esm.json",
+  "compilerOptions": {
+    "types": ["node"]
+  }
+}