Deprecate "jp"

Author: tats-u

src/lib/application.ts

@@ -286,16 +286,28 @@ export class Application extends AbstractComponent<
         if (!this.internationalization.hasTranslations(this.lang)) {
             // Not internationalized as by definition we don't know what to include here.
             this.logger.warn(
-                `Options specified "${this.lang}" as the language to use, but TypeDoc does not support it.` as TranslatedString,
+                `Options specified "${this.lang}" as the language to use, but TypeDoc cannot provide translations for it.` as TranslatedString,
             );
-            this.logger.info(
-                ("The supported languages are:\n\t" +
-                    this.internationalization
-                        .getSupportedLanguages()
-                        .join("\n\t")) as TranslatedString,
-            );
-            this.logger.info(
-                "You can define/override local locales with the `locales` option, or contribute them to TypeDoc!" as TranslatedString,
+            if (this.lang !== "jp") {
+                this.logger.info(
+                    ("The languages that translations are available for are:\n\t" +
+                        this.internationalization
+                            .getSupportedLanguages()
+                            .join("\n\t")) as TranslatedString,
+                );
+                this.logger.info(
+                    "You can define/override local locales with the `locales` option, or contribute them to TypeDoc!" as TranslatedString,
+                );
+            } else {
+                this.logger.info(
+                    // Only Japanese see this. Meaning: "jp" has been removed. Please designate "ja" (instead).
+                    "「jp」は削除されました。「ja」を指定してください。" as TranslatedString,
+                );
+            }
+        } else if (this.lang === "jp") {
+            this.logger.warn(
+                // Only Japanese see this. Meaning: "jp" is going to be removed in the future. Please designate "ja" instead.
+                "「jp」は将来削除されます。代わりに「ja」を指定してください。" as TranslatedString,
             );
         }
 

src/lib/internationalization/internationalization.ts

@@ -302,9 +302,9 @@ export class Internationalization {
      */
     getSupportedLanguages(): string[] {
         return unique([
-            ...readdirSync(
-                join(fileURLToPath(import.meta.url), "../locales"),
-            ).map((x) => x.substring(0, x.indexOf("."))),
+            ...readdirSync(join(fileURLToPath(import.meta.url), "../locales"))
+                .map((x) => x.substring(0, x.indexOf(".")))
+                .filter((x) => x !== "jp"),
             ...this.allTranslations.keys(),
         ]).sort();
     }