add deterministic rand, satori not cached

Author: nemanjam

docs/working-notes/my-old-code/open-graph/gradients.ts

@@ -0,0 +1,45 @@
+// src/utils/array.ts
+
+export const hashString = (str: string): number => {
+  let hash = 0;
+
+  for (let i = 0; i < str.length; i++) {
+    hash = (hash * 31 + str.charCodeAt(i)) >>> 0;
+  }
+
+  return hash;
+};
+
+/** Deterministic. Enables caching in build. */
+export const getRandomElementFromArrayBySeed = <T>(arr: T[], seed: string, salt = ''): T => {
+  const hash = hashString(seed + salt);
+
+  return arr[hash % arr.length];
+};
+
+
+import { default as twColors } from 'tailwindcss/colors';
+
+import { getRandomElementFromArrayBySeed as rndFn } from '@/utils/array';
+
+import type { DefaultColors } from 'tailwindcss/types/generated/colors';
+
+type ColorKeys = keyof DefaultColors;
+type ShadeKeys = keyof DefaultColors[ColorKeys];
+
+const colors = ['gray', 'indigo', 'yellow', 'blue', 'cyan', 'lime', 'sky', 'white'] as ColorKeys[];
+const shades = [50, 100, 200] as ShadeKeys[];
+const directions = ['to right', 'to bottom', '45deg'];
+
+// to support white
+// Todo: for cached build should depend on title arg
+const getRandomColor = (seed: string, salt: string) => {
+  const rndColor = rndFn(colors, seed, `color-${salt}`);
+  return rndColor === 'white' ? rndColor : twColors[rndColor][rndFn(shades, `shade-${salt}`)];
+};
+
+export const getRandomGradient = (seed: string) =>
+  `background: linear-gradient(${rndFn(directions, seed, 'direction')}, ${getRandomColor(seed, 'start')}, ${getRandomColor(seed, 'end')})`;
+
+export const grayGradient = `background: linear-gradient(to right, ${twColors.gray[100]}, ${twColors.gray[300]})`;
+

src/content/post/2026/02-26-vercel-static-github-actions/index.mdx

@@ -9,7 +9,7 @@ tags:
   - devops
   - serverless
   - astro
-category: tutorial
+category: tutorials
 toc: true
 draft: false
 ---

src/utils/gradients.ts

@@ -1,6 +1,6 @@
 import { default as twColors } from 'tailwindcss/colors';
 
-import { getRandomElementFromArray as rnd } from '@/utils/array';
+import { getRandomElementFromArray as rndFn } from '@/utils/array';
 
 import type { DefaultColors } from 'tailwindcss/types/generated/colors';
 
@@ -12,13 +12,13 @@ const shades = [50, 100, 200] as ShadeKeys[];
 const directions = ['to right', 'to bottom', '45deg'];
 
 // to support white
-// Todo: for cached build should depend on title arg
+// Todo: for cached build should depend on title arg, deterministic random. Won't work. Satori renders each time, no caching, outside of Astro build caching.
 const getRandomColor = () => {
-  const rndColor = rnd(colors);
-  return rndColor === 'white' ? rndColor : twColors[rndColor][rnd(shades)];
+  const rndColor = rndFn(colors);
+  return rndColor === 'white' ? rndColor : twColors[rndColor][rndFn(shades)];
 };
 
 export const getRandomGradient = () =>
-  `background: linear-gradient(${rnd(directions)}, ${getRandomColor()}, ${getRandomColor()})`;
+  `background: linear-gradient(${rndFn(directions)}, ${getRandomColor()}, ${getRandomColor()})`;
 
 export const grayGradient = `background: linear-gradient(to right, ${twColors.gray[100]}, ${twColors.gray[300]})`;