Update branch in github workflow

Author: sudheerj

.github/workflows/gen-toc.yml

@@ -4,7 +4,7 @@ on:
   pull_request:
   push:
     branches:
-      - master
+      - main
 
 env:
   BRANCH_NAME: ${{ github.head_ref || github.ref_name }}

.gitignore

@@ -0,0 +1,134 @@
+# Cruft
+.DS_Store
+.idea
+
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+.pnpm-debug.log*
+
+# Diagnostic reports (https://nodejs.org/api/report.html)
+report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+*.lcov
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (https://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# Snowpack dependency directory (https://snowpack.dev/)
+web_modules/
+
+# TypeScript cache
+*.tsbuildinfo
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional stylelint cache
+.stylelintcache
+
+# Microbundle cache
+.rpt2_cache/
+.rts2_cache_cjs/
+.rts2_cache_es/
+.rts2_cache_umd/
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variable files
+.env
+.env.development.local
+.env.test.local
+.env.production.local
+.env.local
+
+# parcel-bundler cache (https://parceljs.org/)
+.cache
+.parcel-cache
+
+# Next.js build output
+.next
+out
+
+# Nuxt.js build / generate output
+.nuxt
+dist
+
+# Gatsby files
+.cache/
+# Comment in the public line in if your project uses Gatsby and not Next.js
+# https://nextjs.org/blog/next-9-1#public-directory-support
+# public
+
+# vuepress build output
+.vuepress/dist
+
+# vuepress v2.x temp and cache directory
+.temp
+.cache
+
+# Docusaurus cache and generated files
+.docusaurus
+
+# Serverless directories
+.serverless/
+
+# FuseBox cache
+.fusebox/
+
+# DynamoDB Local files
+.dynamodb/
+
+# TernJS port file
+.tern-port
+
+# Stores VSCode versions used for testing VSCode extensions
+.vscode-test
+
+# yarn v2
+.yarn/cache
+.yarn/unplugged
+.yarn/build-state.yml
+.yarn/install-state.gz
+.pnp.*

package-lock.json

@@ -0,0 +1,12 @@
+{
+  "name": "java-interview-questions",
+  "version": "1.0.0",
+  "description": "Java Interview Questions",
+  "author": "Sudheer Jonna",
+  "scripts": {
+    "gen": "node scripts/toc.mjs"
+  },
+  "dependencies": {
+    "github-slugger": "^2.0.0"
+  }
+}

package.json

@@ -0,0 +1,86 @@
+import GitHubSlugger from "github-slugger";
+import fs from "fs";
+import path, { dirname } from "path";
+import { fileURLToPath } from "url";
+
+const slugger = new GitHubSlugger();
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+const filePath = path.join(__dirname, "../README.md");
+
+const TOC_START_MARKER = "<!-- TOC_START -->";
+const TOC_END_MARKER = "<!-- TOC_END -->";
+const QUESTIONS_START_MARKER = "<!-- QUESTIONS_START -->";
+const QUESTIONS_END_MARKER = "<!-- QUESTIONS_END -->";
+const QUESTION_TITLE_HEADING_LEVEL = "###";
+
+const rawFile = fs.readFileSync(filePath).toString();
+
+const fileAsLines = rawFile.split("\n");
+
+const tocStartIndex = fileAsLines.findIndex(
+  (line) => line === TOC_START_MARKER
+);
+const tocEndIndex = fileAsLines.findIndex((line) => line === TOC_END_MARKER);
+
+const questionsStartIndex = fileAsLines.findIndex(
+  (line) => line === QUESTIONS_START_MARKER
+);
+const questionsEndIndex = fileAsLines.findIndex(
+  (line) => line === QUESTIONS_END_MARKER
+);
+
+if (
+  [tocStartIndex, tocEndIndex, questionsStartIndex, questionsEndIndex].some(
+    (index) => index === -1
+  )
+) {
+  throw "One of the crucial indices markers not found";
+}
+
+const questions = [];
+let currentQuestion = 0;
+
+// Collect the question titles and numbers into an array.
+// Also automatically renames the title line if the number is out-of-order.
+for (
+  let lineNumber = questionsStartIndex;
+  lineNumber < questionsEndIndex;
+  lineNumber++
+) {
+  const line = fileAsLines[lineNumber];
+  if (line.includes(` ${QUESTION_TITLE_HEADING_LEVEL} `)) {
+    currentQuestion++;
+    const lineParts = line.split(` ${QUESTION_TITLE_HEADING_LEVEL} `);
+    const questionTitle = lineParts[1];
+    const questionSlug = slugger.slug(questionTitle);
+    questions.push({
+      number: currentQuestion,
+      title: questionTitle,
+      slug: questionSlug,
+    });
+
+    fileAsLines[lineNumber] =
+      currentQuestion + `. ${QUESTION_TITLE_HEADING_LEVEL} ` + questionTitle;
+  }
+}
+
+// Create lines for table of contents using the collected questions.
+const tableOfContentsLines = ["| No. | Questions |", "| --- | --------- |"];
+
+questions.forEach(({ number, title, slug }) =>
+  tableOfContentsLines.push(`| ${number} | [${title}](#${slug}) |`)
+);
+
+// Create resulting file and write to file system.
+const outputFileLines = [
+  ...fileAsLines.slice(0, tocStartIndex + 1),
+  ...tableOfContentsLines,
+  ...fileAsLines.slice(tocEndIndex),
+];
+
+const outputFile = outputFileLines.join("\n");
+
+fs.writeFileSync(filePath, outputFile);
+console.info(`Processed ${tableOfContentsLines.length} questions.`);