feat: check validity of google language codes using internal data

DESCRIPTION

@@ -30,3 +30,6 @@ Suggests:
     text2vec
 Config/testthat/edition: 3
 VignetteBuilder: knitr
+Depends: 
+    R (>= 2.10)
+LazyData: true

NAMESPACE

@@ -3,6 +3,7 @@
 export("%>%")
 export(create_translation_table)
 export(google_get_supported_languages)
+export(google_is_valid_language_code)
 export(google_translate)
 export(language_detect)
 export(linguee_external_sources)

R/google_is_valid_language_code.R

@@ -0,0 +1,23 @@
+#' Check if a language code is valid
+#'
+#' This function checks if a given language code is in the `google_supported_languages` dataset.
+#'
+#' @param language_code The language code to check.
+#' @return A logical value indicating if the language code is valid.
+#' @export
+#'
+#' @examples
+#' google_is_valid_language_code("en") # TRUE
+#' google_is_valid_language_code("fr") # TRUE
+#' google_is_valid_language_code("xx") # FALSE
+google_is_valid_language_code <- function(language_code) {
+  if (language_code == "auto") {
+    return(TRUE)
+  }
+
+  if (language_code %in% polyglotr::google_supported_languages$`ISO-639 code`) {
+    return(TRUE)
+  } else {
+    return(FALSE)
+  }
+}

R/google_supported_languages.R

@@ -0,0 +1,8 @@
+#' Google Supported Languages
+#'
+#' This dataset contains the language names and iso codes of languages supported by Google Translate API.
+#'
+#' @format A data frame with two variables: language_name and iso_code
+#' @source Google Translate API
+#' @keywords data
+"google_supported_languages"

R/google_translate.R

@@ -17,6 +17,15 @@
 #' google_translate(text_to_translate, "fr", "en")
 #' }
 google_translate <- function(text, target_language = "en", source_language = "auto") {
+
+  if (!google_is_valid_language_code(target_language)) {
+    stop("Invalid target language code.")
+  }
+
+  if (!google_is_valid_language_code(source_language)) {
+    stop("Invalid source language code.")
+  }
+
   is_vector <- is.vector(text) && length(text) > 1
 
   formatted_text <- urltools::url_encode(text)

tests/testthat/test-google_translate.R

@@ -43,3 +43,15 @@ test_that("google translate returns translations with special characters", {
   expected_translation <- "The Nile flows through the Sudanese desert to Egypt towards the north and passes through the city of Cairo, located on the large river delta (Nile Delta), then the river crosses the cities of Damietta and Rosetta and flows..."
   expect_equal(translation, expected_translation)
 })
+
+# Unit tests for checking supported languages in Google Translate
+test_that("google_is_valid_language_code: valid codes", {
+  expect_true(google_is_valid_language_code("en"))
+  expect_true(google_is_valid_language_code("fr"))
+  expect_true(google_is_valid_language_code("auto"))
+  expect_true(google_is_valid_language_code("iw"))
+})
+
+test_that("google_is_valid_language_code: invalid codes", {
+  expect_false(google_is_valid_language_code("xx"))
+})