chore(www) Add unit tests for i18n utils (#21941)

* Add unit tests for i18n utils

* get rid of unused import

Author: tesseralis

www/src/utils/__tests__/i18n.js

@@ -0,0 +1,77 @@
+import { localizedPath, getLanguages, getLocaleAndBasePath } from "../i18n"
+
+describe("getLanguages", () => {
+  it("returns an empty list when no languages are passed in", () => {
+    expect(getLanguages("")).toEqual([])
+  })
+
+  it("returns a list of languages", () => {
+    expect(
+      getLanguages("es ja id pl pt-BR zh-Hans").map(lang => lang.code)
+    ).toEqual(["es", "ja", "id", "pl", "pt-BR", "zh-Hans"])
+  })
+
+  it("throws an error if the default language is defined", () => {
+    expect(() => getLanguages("en ja")).toThrow(/default locale/i)
+  })
+
+  it("throws an error if an invalid locale is defined and references the languages file", () => {
+    expect(() => getLanguages("simlish")).toThrow(/invalid locale/i)
+    expect(() => getLanguages("simlish")).toThrow("i18n.json")
+  })
+})
+
+describe("localizedPath", () => {
+  it("returns the path when locale === defaultLang", () => {
+    expect(localizedPath("en", "/")).toEqual("/")
+    expect(localizedPath("en", "/docs/")).toEqual("/docs/")
+    expect(localizedPath("en", "/docs/quick-start/")).toEqual(
+      "/docs/quick-start/"
+    )
+  })
+
+  it("returns a path prefixed with a locale for other languages", () => {
+    expect(localizedPath("es", "/")).toEqual("/es/")
+    expect(localizedPath("es", "/docs/")).toEqual("/es/docs/")
+    expect(localizedPath("es", "/docs/quick-start/")).toEqual(
+      "/es/docs/quick-start/"
+    )
+  })
+
+  it("returns the path when a locale is already in the path", () => {
+    expect(localizedPath("es", "/es/docs/")).toEqual("/es/docs/")
+  })
+})
+
+describe("getLocaleAndBasePath", () => {
+  const codes = ["es", "ja"]
+  it("returns the locale and base path when passed a path with a locale", () => {
+    expect(getLocaleAndBasePath("/es/", codes)).toEqual({
+      locale: "es",
+      basePath: "/",
+    })
+    expect(getLocaleAndBasePath("/es/docs/", codes)).toEqual({
+      locale: "es",
+      basePath: "/docs/",
+    })
+    expect(getLocaleAndBasePath("/es/docs/quick-start/", codes)).toEqual({
+      locale: "es",
+      basePath: "/docs/quick-start/",
+    })
+  })
+
+  it("returns defaultLang when passed a path with no locale", () => {
+    expect(getLocaleAndBasePath("/", codes)).toEqual({
+      locale: "en",
+      basePath: "/",
+    })
+    expect(getLocaleAndBasePath("/docs/", codes)).toEqual({
+      locale: "en",
+      basePath: "/docs/",
+    })
+    expect(getLocaleAndBasePath("/docs/quick-start/", codes)).toEqual({
+      locale: "en",
+      basePath: "/docs/quick-start/",
+    })
+  })
+})

www/src/utils/i18n.js

@@ -4,15 +4,20 @@ const defaultLang = "en"
 // Only allow languages defined in the LOCALES env variable.
 // This allows us to compile only languages that are "complete" or test only
 // a single language
-function getLanguages() {
+function getLanguages(localeStr) {
   // If `LOCALES` isn't defined, only have default language (English)
-  if (!process.env.LOCALES) {
+  if (!localeStr) {
     return []
   }
 
-  const langCodes = process.env.LOCALES.split(" ")
+  const langCodes = localeStr.split(" ")
   const langs = []
   for (let code of langCodes) {
+    if (code === defaultLang) {
+      throw new Error(
+        `${code} is the default locale and should not be put in the locale list.`
+      )
+    }
     const lang = allLangs.find(lang => lang.code === code)
     // Error if one of the locales provided isn't a valid locale
     if (!lang) {
@@ -25,7 +30,7 @@ function getLanguages() {
   return langs
 }
 
-const langs = getLanguages()
+const langs = getLanguages(process.env.LOCALES)
 const langCodes = langs.map(lang => lang.code)
 
 function isDefaultLang(locale) {
@@ -34,12 +39,10 @@ function isDefaultLang(locale) {
 
 /**
  * Get the path prefixed with the locale
- * @param {*} locale the locale to prefix with
- * @param {*} path the path to prefix
+ * @param {string} locale the locale to prefix with
+ * @param {string} path the path to prefix
  */
 function localizedPath(locale, path) {
-  const isIndex = path === `/`
-
   // Our default language isn't prefixed for back-compat
   if (isDefaultLang(locale)) {
     return path
@@ -50,25 +53,25 @@ function localizedPath(locale, path) {
   // If for whatever reason we receive an already localized path
   // (e.g. if the path was made with location.pathname)
   // just return it as-is.
-  if (langCodes.includes(base)) {
+  if (base === locale) {
     return path
   }
 
-  // If it's another language, add the "path"
-  // However, if the homepage/index page is linked don't add the "to"
-  // Because otherwise this would add a trailing slash
-  return `${locale}${isIndex ? `` : `${path}`}`
+  // If it's another language, prefix with the locale
+  return `/${locale}${path}`
 }
 
 /**
  * Split a path into its locale and base path.
  *
  * e.g. /es/tutorial/ -> { locale: "es", basePath: "/tutorial/"}
  * @param {string} path the path to extract locale information from
+ * @param {Array} langCodes a list of valid language codes, defaulting to
+ * the ones defined in `process.env.LOCALES`
  */
-function getLocaleAndBasePath(path) {
+function getLocaleAndBasePath(path, codes = langCodes) {
   const [, code, ...rest] = path.split("/")
-  if (langCodes.includes(code)) {
+  if (codes.includes(code)) {
     return { locale: code, basePath: `/${rest.join("/")}` }
   }
   return { locale: defaultLang, basePath: path }
@@ -78,6 +81,7 @@ module.exports = {
   langCodes,
   langs,
   defaultLang,
+  getLanguages,
   localizedPath,
   getLocaleAndBasePath,
 }

www/src/utils/node/docs.js

@@ -6,7 +6,6 @@ const url = require(`url`)
 const moment = require(`moment`)
 const { langCodes } = require(`../i18n`)
 const { getPrevAndNext } = require(`../get-prev-and-next.js`)
-const { localizedPath } = require(`../i18n.js`)
 
 // convert a string like `/some/long/path/name-of-docs/` to `name-of-docs`
 const slugToAnchor = slug =>