feat: Add markdown lint

src/app/lint/lint.js

@@ -0,0 +1,36 @@
+const titleOrCommentLinePattern = /^\s*(##.*)|(<!-- \.slide: class="page-.*)$/;
+const nPreviousEmpty = 3;
+
+function allEmpty(lines) {
+  return lines.every((l) => l.trim() === "");
+}
+
+export async function containsAnyError(readStream) {
+  // Buffer circulaire pour stocker les nPreviousEmpty lignes précédentes
+  const prevLines = [];
+  var index = 1;
+  var containsError = false;
+
+  for await (const line of readStream) {
+    // Vérifie si la ligne courante match le pattern
+    if (titleOrCommentLinePattern.test(line)) {
+      if (!allEmpty(prevLines)) {
+        console.info(
+          `ligne n°${index}  There must be at least ${nPreviousEmpty} blank lines before the block "${line}" .`
+        );
+        containsError = true;
+      }
+    }
+
+    // Increment du nombre de ligne
+    index += 1;
+
+    // Ajoute la ligne actuelle dans le buffer, limite la taille à nPreviousEmpty
+    prevLines.push(line);
+    if (prevLines.length > nPreviousEmpty) {
+      prevLines.shift(); // enlève la plus vieille ligne
+    }
+  }
+
+  return containsError;
+}

src/app/lint/lint.test.js

@@ -0,0 +1,59 @@
+const test = require("node:test");
+const assert = require("node:assert");
+const readline = require("readline");
+const { containsAnyError } = require("./lint");
+const { Readable } = require("node:stream");
+
+test("Lint - Contains any error should return false using a title that follows 3 empty lines.", async () => {
+  const content = `
+    # Titre de la formation
+
+
+
+    ## Sommaire
+    `;
+
+  const actual = await containsAnyError(createReadStream(content));
+  assert.strictEqual(actual, false);
+});
+
+test("Lint - Contains any error should return true using a title that not follows 3 empty lines.", async () => {
+  const content = `
+  # Titre de la formation
+
+  ## Sommaire
+  `;
+
+  const actual = await containsAnyError(createReadStream(content));
+  assert.strictEqual(actual, true);
+});
+
+test("Lint - Contains any error should return false using a specific html comment that follows 3 empty lines.", async () => {
+  const content = `
+    # Titre de la formation
+
+
+
+    <!-- .slide: class="page-title" -->
+    `;
+
+  const actual = await containsAnyError(createReadStream(content));
+  assert.strictEqual(actual, false);
+});
+
+test("Lint - Contains any error should return true using a specific html comment that not follows 3 empty lines.", async () => {
+  const content = `
+    # Titre de la formation
+
+    <!-- .slide: class="page-title" -->
+    `;
+
+  const actual = await containsAnyError(createReadStream(content));
+  assert.strictEqual(actual, true);
+});
+
+function createReadStream(content) {
+  return readline.createInterface({
+    input: Readable.from(content),
+  });
+}

src/cli/cli.js

@@ -3,11 +3,13 @@
 const spawn = require("child_process").spawn;
 const fork = require("child_process").fork;
 const fs = require("fs");
+const readline = require("readline");
 const path = require("path");
 const WebpackDevServer = require("webpack-dev-server");
 const webpackConfig = require("../build/webpack.config");
 const webpack = require("webpack");
 const yargs = require("yargs/yargs");
+const { containsAnyError } = require("../app/lint/lint");
 
 /**
  *
@@ -36,6 +38,9 @@ async function cli(args, env) {
     case "pdf":
       await pdf(options);
       break;
+    case "lint":
+      await lint(options);
+      break;
     default:
       throw new Error(`unknown command: '${command}'`);
   }
@@ -61,6 +66,45 @@ async function serve(buildOptions, serveOptions) {
   }
 }
 
+async function lint(options) {
+  const material = options.material;
+  console.info(`Start linting from material '${material}...`);
+
+  for (const f of fs.readdirSync(material)) {
+    await lintMardownFiles(path.join(material, f));
+  }
+}
+
+async function lintMardownFiles(file) {
+  if (fs.lstatSync(file).isDirectory()) {
+    console.info(
+      `The path '${file}' is a directory. Recursively reading its contents...`
+    );
+
+    for (const f of fs.readdirSync(file)) {
+      await lintMardownFiles(path.join(file, f));
+    }
+  } else if (fs.lstatSync(file).isFile() && file.endsWith(".md")) {
+    const containsError = await containsAnyError(createReadStream(file));
+
+    if (containsError) {
+      console.error(
+        `\x1b[41m The file "${file}" contains one or more errors..\x1b[0m`
+      );
+    } else {
+      console.debug(`The file "${file}" contains no errors.`);
+      process.exit(-1);
+    }
+  }
+}
+
+function createReadStream(filePath) {
+  console.debug("Create read stream for file at : ", filePath);
+  return readline.createInterface({
+    input: fs.createReadStream(filePath),
+  });
+}
+
 function build(options) {
   console.log("Build slides & labs");
   return new Promise((resolve, reject) => {
@@ -254,6 +298,10 @@ cli(
       "build the static web site",
       describePositionalArguments
     )
+    .command(
+      "lint [material]",
+      "lint each Markdown files (e.g. check the number of empty new lines before new slides)"
+    )
     .option("config", {
       type: "string",
       describe: