Fix preview action to be able to make PR preview

Author: chvmvd

.github/actions/build/action.yml

@@ -1,5 +1,8 @@
 ---
 name: Build
+inputs:
+  base-url:
+    required: true
 
 runs:
   using: Composite
@@ -9,4 +12,6 @@ runs:
 
     - name: Build
       run: npm run build
+      env:
+        BASE_URL: ${{ inputs.base-url }}
       shell: bash

.github/workflows/build-test.yml

@@ -15,3 +15,5 @@ jobs:
 
       - name: Build
         uses: ./.github/actions/build
+        with:
+          base-url: /

.github/workflows/preview.yml

@@ -22,8 +22,13 @@ jobs:
       - name: Execute Notebooks
         uses: ./.github/actions/execute-notebooks
 
+      - name: Calculate BASE_URL
+        run: echo ${{ github.ref }} | sed "s/[^0-9]//g" | (v=$(cat); echo -e "BASE_URL=/pr-preview/pr-$v/" ) >> $GITHUB_ENV
+
       - name: Build
         uses: ./.github/actions/build
+        with:
+          base-url: $BASE_URL
 
       - name: Deploy preview
         uses: rossjrw/pr-preview-action@v1

docusaurus.config.js

@@ -13,7 +13,7 @@ const config = {
   title: "Introduction to Algorithms",
   // tagline: '',
   url: "https://sikepuri-algorithm.github.io",
-  baseUrl: "/",
+  baseUrl: process.env.BASE_URL,
   onBrokenLinks: "throw",
   onBrokenMarkdownLinks: "warn",
   favicon: "img/favicon.ico",