add: build script that renders index from meals

scripts/build.js

@@ -0,0 +1,90 @@
+const fs = require("fs");
+const path = require("path");
+
+const repoRoot = path.resolve(__dirname, "..");
+const mealsPath = path.join(repoRoot, "data", "meals.json");
+const indexTemplatePath = path.join(repoRoot, "templates", "index.html");
+const indexOutputPath = path.join(repoRoot, "index.html");
+
+function detectEol(text) {
+  return text.includes("\r\n") ? "\r\n" : "\n";
+}
+
+function escapeHtml(value) {
+  return value
+    .replace(/&/g, "&")
+    .replace(/</g, "&lt;")
+    .replace(/"/g, "&quot;");
+}
+
+function validateMeals(meals) {
+  if (!Array.isArray(meals)) {
+    throw new Error("data/meals.json must contain an array");
+  }
+
+  for (const [index, meal] of meals.entries()) {
+    if (!meal || typeof meal !== "object") {
+      throw new Error(`Meal at index ${index} must be an object`);
+    }
+
+    for (const field of ["id", "title", "description"]) {
+      if (typeof meal[field] !== "string" || meal[field].length === 0) {
+        throw new Error(`Meal ${index} is missing required string field "${field}"`);
+      }
+    }
+
+    if (meal.position !== undefined && typeof meal.position !== "string") {
+      throw new Error(`Meal ${index} has a non-string "position" value`);
+    }
+  }
+}
+
+function renderGalleryItem(meal, eol) {
+  const attrs = [`class="thumbnail"`, `href="images/fulls/${meal.id}.jpg"`];
+
+  if (meal.position) {
+    attrs.push(`data-position="${escapeHtml(meal.position)}"`);
+  }
+
+  return [
+    "\t\t\t\t<article>",
+    `\t\t\t\t\t<a ${attrs.join(" ")}><img src="images/thumbs/${meal.id}.jpg" alt="" /></a>`,
+    `\t\t\t\t\t<h2>${escapeHtml(meal.title)}</h2>`,
+    `\t\t\t\t\t<p>${escapeHtml(meal.description)}</p>`,
+    "\t\t\t\t</article>",
+  ].join(eol);
+}
+
+function renderGallery(meals, eol) {
+  return meals.map((meal) => renderGalleryItem(meal, eol)).join(eol);
+}
+
+function replaceBlock(template, token, replacement) {
+  const pattern = new RegExp(`^[\\t ]*\\{\\{${token}\\}\\}$`, "m");
+
+  if (!pattern.test(template)) {
+    throw new Error(`Template is missing required block token "{{${token}}}"`);
+  }
+
+  return template.replace(pattern, () => replacement);
+}
+
+function buildIndex() {
+  const template = fs.readFileSync(indexTemplatePath, "utf8");
+  const eol = detectEol(template);
+  const meals = JSON.parse(fs.readFileSync(mealsPath, "utf8"));
+
+  validateMeals(meals);
+
+  return replaceBlock(template, "gallery_items", renderGallery(meals, eol));
+}
+
+function writeFile(filePath, contents) {
+  fs.writeFileSync(filePath, contents);
+}
+
+function main() {
+  writeFile(indexOutputPath, buildIndex());
+}
+
+main();