refactor: support i18n

web/i18n/config.test.mjs

@@ -0,0 +1,59 @@
+import assert from "node:assert/strict"
+import test from "node:test"
+import ts from "typescript"
+import { readFile } from "node:fs/promises"
+import vm from "node:vm"
+
+async function loadConfig() {
+  const source = await readFile(new URL("./config.ts", import.meta.url), "utf8")
+  const compiled = ts.transpileModule(source, {
+    compilerOptions: {
+      target: ts.ScriptTarget.ES2017,
+      module: ts.ModuleKind.CommonJS,
+    },
+    fileName: "config.ts",
+  })
+  const sandbox = {
+    exports: {},
+    module: { exports: {} },
+  }
+  sandbox.exports = sandbox.module.exports
+  vm.runInNewContext(compiled.outputText, sandbox)
+  return sandbox.module.exports
+}
+
+test("normalizes supported locale aliases", async () => {
+  const { DEFAULT_LOCALE, normalizeLocale } = await loadConfig()
+
+  assert.equal(normalizeLocale("zh-CN"), "zh-CN")
+  assert.equal(normalizeLocale("zh_CN"), "zh-CN")
+  assert.equal(normalizeLocale("zh"), "zh-CN")
+  assert.equal(normalizeLocale("en-US"), "en-US")
+  assert.equal(normalizeLocale("en_US"), "en-US")
+  assert.equal(normalizeLocale("en"), "en-US")
+  assert.equal(normalizeLocale("fr-FR"), DEFAULT_LOCALE)
+})
+
+test("resolves browser locale from stored value before navigator languages", async () => {
+  const { resolveBrowserLocale } = await loadConfig()
+
+  assert.equal(
+    resolveBrowserLocale({
+      storedLocale: "en-US",
+      navigatorLanguages: ["zh-CN"],
+    }),
+    "en-US"
+  )
+})
+
+test("falls back through navigator languages", async () => {
+  const { resolveBrowserLocale } = await loadConfig()
+
+  assert.equal(
+    resolveBrowserLocale({
+      storedLocale: "",
+      navigatorLanguages: ["fr-FR", "en"],
+    }),
+    "en-US"
+  )
+})