Feature: Type Safety for Parsed Markdown Recipes

src/services/markdown/__fixtures__/broken-recipe.md

@@ -0,0 +1,13 @@
+---
+title: Seemingly a correct recipe
+ingredients:
+  - name: Oh
+    amount: wait
+  - name: What
+    amountt: is
+    imageSlug: /going/on.exe
+duration: 420 years
+tags: "Foo, bar, baz"
+---
+
+Lorem ipsum dolor sit amet, set nunc est potandum.

src/services/markdown/__fixtures__/valid-recipe.md

@@ -0,0 +1,17 @@
+---
+title: Title of the recipe
+imageSlug: /images/recipes/valid-recipe.jpg
+ingredients:
+  - name: Bugs
+    amount: Zero
+    imageSlug: /images/ingredients/bugs.png
+  - name: Type safety
+    amount: 1×
+    imageSlug: /images/ingredients/type-safety.png
+duration: P0Y0M0DT0H5M0S
+tags:
+  - Foo
+  - Bar
+---
+
+Lorem ipsum dolor sit amet, set nunc est potandum.

src/services/markdown/parseRecipe.test.ts

@@ -0,0 +1,28 @@
+import fs from "fs";
+
+import { describe, expect, it } from "bun:test";
+
+import { parseRecipe } from ".";
+
+describe("parseRecipe", () => {
+  it("should return a parsed recipe if the contents are correct", () => {
+    const validRecipe = fs.readFileSync(
+      "./src/services/markdown/__fixtures__/valid-recipe.md",
+      "utf-8"
+    );
+
+    expect(parseRecipe(validRecipe)).toBeDefined();
+  });
+
+  it("should return nothing if the recipe is broken or malformed", () => {
+    const brokenRecipe = fs.readFileSync(
+      "./src/services/markdown/__fixtures__/valid-recipe.md",
+      "utf-8"
+    );
+    const huh = parseRecipe(brokenRecipe);
+
+    console.log(huh);
+
+    expect(huh).toBeUndefined();
+  });
+});

src/services/markdown/parseRecipe.ts

@@ -5,6 +5,23 @@ import { RecipeMetadata } from "./types";
 export const parseRecipe = (fileName: string) => {
   const { data: metadata, content } = matter(fileName);
 
+  if (
+    typeof content !== "string" ||
+    typeof metadata.title !== "string" ||
+    typeof metadata.imageSlug !== "string" ||
+    !Array.isArray(metadata.ingredients) ||
+    metadata.ingredients.some((ingredient) => {
+      typeof ingredient.name !== "string" ||
+        typeof ingredient.amount !== "string" ||
+        typeof ingredient.imageSlug !== "string";
+    }) ||
+    typeof metadata.duration !== "string" ||
+    !Array.isArray(metadata.tags) ||
+    metadata.tags.some((tag) => typeof tag !== "string")
+  ) {
+    return;
+  }
+
   return {
     metadata,
     content,