library: Remove the need for noop code files (#689)

Author: sonnyp

src/Document.js

@@ -68,21 +68,13 @@ async function loadSourceBuffer({ source_file, buffer, lang }) {
     buffer,
     file: source_file,
   });
-  let success;
   try {
-    success = await file_loader.load_async(GLib.PRIORITY_DEFAULT, null, null);
+    await file_loader.load_async(GLib.PRIORITY_DEFAULT, null, null);
   } catch (err) {
-    if (err.code === Gio.IOErrorEnum.NOT_FOUND) {
-      if (lang.placeholder) {
-        buffer.set_text(lang.placeholder, -1);
-      }
-      success = true;
-    } else {
+    if (err.code !== Gio.IOErrorEnum.NOT_FOUND) {
       throw err;
     }
   }
 
-  if (success) {
-    buffer.set_modified(false);
-  }
+  buffer.set_modified(false);
 }

src/Library/EntryRow.js

@@ -31,11 +31,7 @@ class EntryRow extends Adw.PreferencesRow {
   }
 
   #createLanguageTags(demo) {
-    const language = getLanguage("javascript");
-    const language_tag = this.#createLanguageTag(language);
-    this._languages_box.append(language_tag);
-
-    ["vala", "rust"].forEach((id) => {
+    ["javascript", "vala", "rust"].forEach((id) => {
       const language = getLanguage(id);
       if (!demo.languages.includes(language.id)) return;
       const language_tag = this.#createLanguageTag(language);

src/Library/Library.js

@@ -6,6 +6,7 @@ import {
   demos_dir,
   getLanguage,
   settings as global_settings,
+  languages,
 } from "../util.js";
 import Window from "../window.js";
 
@@ -71,7 +72,6 @@ export function getDemo(name) {
   return demos.find((demo) => demo.name === name);
 }
 
-const lang_javascript = getLanguage("javascript");
 async function openDemo({ application, demo_name, language }) {
   const demo = getDemo(demo_name);
   const session = createSessionFromDemo(demo);
@@ -86,9 +86,18 @@ async function openDemo({ application, demo_name, language }) {
     session.settings.set_boolean("show-code", true);
   }
 
-  const is_js =
-    session.settings.get_int("code-language") === lang_javascript.index;
+  const code_languge = session.settings.get_int("code-language");
+  const lang = languages.find((lang) => lang.index === code_languge);
 
+  // Override the user preferred language if the demo doesn't support it
+  if (demo.languages.length > 0 && !demo.languages.includes(lang.id)) {
+    session.settings.set_int(
+      "code-language",
+      getLanguage(demo.languages[0]).index,
+    );
+  }
+
+  const run = demo.autorun && lang.id === "javascript";
   const { load } = Window({ application, session });
-  await load({ run: demo.autorun && is_js });
+  await load({ run });
 }