feat: json $schema locally => ./node_modules/html-w3c-validator/schema/schema.json

There was an error thrown by `table` library to print validation results
when there were 2 (or more) errors, with one error with line/column
and the other error without specified line/column.

Fixes #6

.commitlintrc.json

@@ -1 +0,0 @@
-{ "extends": ["@commitlint/config-conventional"] }

.eslintrc.json

@@ -1,16 +1,18 @@
 {
-  "extends": ["conventions", "prettier"],
+  "root": true,
-  "plugins": ["prettier", "import", "unicorn"],
+  "extends": ["conventions"],
-  "parserOptions": {
+  "plugins": ["promise", "unicorn"],
-    "project": "./tsconfig.json"
+  "overrides": [
-  },
+    {
-  "env": {
+      "files": ["*.ts", "*.tsx"],
-    "node": true
+      "parser": "@typescript-eslint/parser",
-  },
+      "plugins": ["@typescript-eslint"],
-  "rules": {
+      "parserOptions": {
-    "prettier/prettier": "error",
+        "projectService": true
-    "import/extensions": ["error", "always"],
+      },
-    "unicorn/prevent-abbreviations": "error",
+      "rules": {
-    "unicorn/prefer-node-protocol": "error"
+        "@typescript-eslint/no-unnecessary-condition": "off"
-  }
+      }
+    }
+  ]
 }

.github/ISSUE_TEMPLATE/BUG.md

@@ -6,8 +6,8 @@ labels: "bug"
 ---
 
 <!--
-  Please provide a clear and concise description of what the bug is. Include
+Please provide a clear and concise description of what the bug is.
-  screenshots if needed. Please make sure your issue has not already been fixed.
+Include screenshots if needed. Please make sure your issue has not already been fixed.
 -->
 
 ## Steps To Reproduce

.github/workflows/build.yml

@@ -4,16 +4,16 @@ on:
   push:
     branches: [develop]
   pull_request:
-    branches: [master, develop]
+    branches: [main, develop]
 
 jobs:
   build:
     runs-on: "ubuntu-latest"
     steps:
-      - uses: "actions/checkout@v4.1.1"
+      - uses: "actions/checkout@v4.2.2"
 
       - name: "Setup Node.js"
-        uses: "actions/setup-node@v4.0.1"
+        uses: "actions/setup-node@v4.1.0"
         with:
           node-version: "lts/*"
           cache: "npm"
@@ -22,6 +22,6 @@ jobs:
         run: "npm clean-install"
 
       - name: "Build"
-        run: "npm run build"
+        run: "node --run build"
 
-      - run: "npm run build:typescript"
+      - run: "node --run build:typescript"

.github/workflows/lint.yml

@@ -4,16 +4,16 @@ on:
   push:
     branches: [develop]
   pull_request:
-    branches: [master, develop]
+    branches: [main, develop]
 
 jobs:
   lint:
     runs-on: "ubuntu-latest"
     steps:
-      - uses: "actions/checkout@v4.1.1"
+      - uses: "actions/checkout@v4.2.2"
 
       - name: "Setup Node.js"
-        uses: "actions/setup-node@v4.0.1"
+        uses: "actions/setup-node@v4.1.0"
         with:
           node-version: "lts/*"
           cache: "npm"
@@ -21,8 +21,6 @@ jobs:
       - name: "Install dependencies"
         run: "npm clean-install"
 
-      - run: 'npm run lint:commit -- --to "${{ github.sha }}"'
+      - run: "node --run lint:editorconfig"
-      - run: "npm run lint:editorconfig"
+      - run: "node --run lint:eslint"
-      - run: "npm run lint:markdown"
+      - run: "node --run lint:prettier"
-      - run: "npm run lint:eslint"
-      - run: "npm run lint:prettier"

.github/workflows/release.yml

@@ -2,7 +2,7 @@ name: "Release"
 
 on:
   push:
-    branches: [master]
+    branches: [main, beta]
 
 jobs:
   release:
@@ -13,13 +13,13 @@ jobs:
       pull-requests: "write"
       id-token: "write"
     steps:
-      - uses: "actions/checkout@v4.1.1"
+      - uses: "actions/checkout@v4.2.2"
         with:
           fetch-depth: 0
           persist-credentials: false
 
       - name: "Setup Node.js"
-        uses: "actions/setup-node@v4.0.1"
+        uses: "actions/setup-node@v4.1.0"
         with:
           node-version: "lts/*"
           cache: "npm"
@@ -28,15 +28,15 @@ jobs:
         run: "npm clean-install"
 
       - name: "Build"
-        run: "npm run build"
+        run: "node --run build"
 
-      - run: "npm run build:typescript"
+      - run: "node --run build:typescript"
 
       - name: "Verify the integrity of provenance attestations and registry signatures for installed dependencies"
         run: "npm audit signatures"
 
       - name: "Release"
-        run: "npm run release"
+        run: "node --run release"
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           NPM_TOKEN: ${{ secrets.NPM_TOKEN }}

.github/workflows/test.yml

@@ -4,16 +4,16 @@ on:
   push:
     branches: [develop]
   pull_request:
-    branches: [master, develop]
+    branches: [main, develop]
 
 jobs:
   test:
     runs-on: "ubuntu-latest"
     steps:
-      - uses: "actions/checkout@v4.1.1"
+      - uses: "actions/checkout@v4.2.2"
 
       - name: "Setup Node.js"
-        uses: "actions/setup-node@v4.0.1"
+        uses: "actions/setup-node@v4.1.0"
         with:
           node-version: "lts/*"
           cache: "npm"
@@ -22,7 +22,7 @@ jobs:
         run: "npm clean-install"
 
       - name: "Build"
-        run: "npm run build"
+        run: "node --run build"
 
       - name: "Test"
-        run: "npm run test"
+        run: "node --run test"

.lintstagedrc.json

@@ -1,6 +0,0 @@
-{
-  "*": ["editorconfig-checker"],
-  "*.{js,ts,jsx,tsx}": ["prettier --write", "eslint --fix"],
-  "*.{yml,json}": ["prettier --write"],
-  "*.md": ["prettier --write", "markdownlint --dot --fix"]
-}

.markdownlint-cli2.jsonc

@@ -1,11 +0,0 @@
-{
-  "config": {
-    "extends": "markdownlint/style/prettier",
-    "relative-links": true,
-    "default": true,
-    "MD033": false
-  },
-  "globs": ["**/*.{md,mdx}"],
-  "ignores": ["**/node_modules"],
-  "customRules": ["markdownlint-rule-relative-links"]
-}

.npmrc

@@ -1,2 +1,2 @@
-save-exact=true
+save-exact = true
-provenance=true
+provenance = true

.releaserc.json

@@ -1,18 +1,8 @@
 {
-  "branches": ["master"],
+  "branches": ["main", { "name": "beta", "prerelease": true }],
   "plugins": [
-    [
+    "@semantic-release/commit-analyzer",
-      "@semantic-release/commit-analyzer",
+    "@semantic-release/release-notes-generator",
-      {
-        "preset": "conventionalcommits"
-      }
-    ],
-    [
-      "@semantic-release/release-notes-generator",
-      {
-        "preset": "conventionalcommits"
-      }
-    ],
     "@semantic-release/npm",
     "@semantic-release/github"
   ]

.vscode/extensions.json

@@ -1,8 +0,0 @@
-{
-  "recommendations": [
-    "editorconfig.editorconfig",
-    "esbenp.prettier-vscode",
-    "dbaeumer.vscode-eslint",
-    "davidanson.vscode-markdownlint"
-  ]
-}

.vscode/settings.json

@@ -1,14 +0,0 @@
-{
-  "typescript.tsdk": "node_modules/typescript/lib",
-  "typescript.preferences.importModuleSpecifierEnding": "js",
-  "editor.defaultFormatter": "esbenp.prettier-vscode",
-  "prettier.configPath": ".prettierrc.json",
-  "editor.formatOnSave": true,
-  "editor.codeActionsOnSave": {
-    "source.fixAll": "explicit"
-  },
-  "eslint.options": {
-    "ignorePath": ".gitignore"
-  },
-  "prettier.ignorePath": ".gitignore"
-}

LICENSE

@@ -1,6 +1,6 @@
 # MIT License
 
-Copyright (c) Théo LUDWIG
+Copyright (c) Théo LUDWIG <contact@theoludwig.fr>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -1,9 +1,7 @@
 <h1 align="center">html-w3c-validator</h1>
 
 <p align="center">
-  <strong>CLI for validating multiple html pages using <a href="https://validator.w3.org/">validator.w3.org</a>.</strong>
+  <strong>CLI for validating HTML pages using <a href="https://validator.w3.org/">validator.w3.org</a>.</strong>
-</p>
-
 </p>
 
 <p align="center">
@@ -22,11 +20,11 @@
 
 ## 📜 About
 
-**html-w3c-validator** is a CLI tool to validate multiple html pages using [validator.w3.org](https://validator.w3.org/).
+**html-w3c-validator** is a CLI tool to validate HTML pages using [validator.w3.org](https://validator.w3.org/).
 
 You might use a JavaScript framework or simply use HTML but **you should always validate your production HTML** and this validation should be part of your CI/CD pipeline (tests, linting, etc.).
 
-### Why should I validate my HTML pages?
+### Why is HTML page validation important?
 
 Quote from [https://validator.w3.org/docs/help.html#why-validate](https://validator.w3.org/docs/help.html#why-validate):
 
@@ -40,7 +38,7 @@ You can combine **html-w3c-validator** with [start-server-and-test](https://gith
 
 ### Prerequisites
 
-- [Node.js](https://nodejs.org/) >= 16.0.0
+[Node.js](https://nodejs.org/) >= 16.0.0
 
 ### Installation (with [start-server-and-test](https://github.com/bahmutov/start-server-and-test))
 
@@ -59,8 +57,8 @@ npm install --save-dev html-w3c-validator start-server-and-test
     "start": "serve \"./build\"",
 
     // Command to validate your HTML pages
-    "test:html-w3c-validator": "start-server-and-test \"start\" \"http://127.0.0.1:3000\" \"html-w3c-validator\""
+    "test:html-w3c-validator": "start-server-and-test \"start\" \"http://127.0.0.1:3000\" \"html-w3c-validator\"",
-  }
+  },
 }
 ```
 
@@ -68,20 +66,23 @@ npm install --save-dev html-w3c-validator start-server-and-test
 
 ```jsonc
 {
+  "$schema": "./node_modules/html-w3c-validator/schema/schema.json",
+
+  // URLs to validate.
   "urls": ["http://127.0.0.1:3000/", "http://127.0.0.1:3000/about"],
 
-  // You can also specify HTML files instead of URLs
+  // Files to validate.
   "files": ["./index.html", "./about.html"],
 
-  // Specify the severities of the validator (default: ["warning", "error"])
+  // Specify the severities of the validator messages to report. (default: ["warning", "error"])
-  "severities": ["info", "warning", "error"]
+  "severities": ["info", "warning", "error"],
 }
 ```
 
 ## Usage
 
 ```sh
-npm run test:html-w3c-validator
+node --run test:html-w3c-validator
 ```
 
 Example of output (in case of success):
@@ -98,8 +99,9 @@ See the [./example](./example) folder for practical usage.
 ### Options
 
 ```text
--V, --version       Output the version number.
+--current-working-directory <path>  The current working directory (default: `process.cwd()`).
--h, --help          Display help for command.
+-V, --version                       Output the version number.
+-h, --help                          Display help for command.
 ```
 
 ## 💡 Contributing

example/.html-w3c-validatorrc.json

@@ -1,4 +1,5 @@
 {
+  "$schema": "./node_modules/html-w3c-validator/schema/schema.json",
   "urls": ["http://127.0.0.1:3000/", "http://127.0.0.1:3000/about"],
   "files": ["./build/index.html", "./build/about.html"]
 }

example/package.json

@@ -6,8 +6,8 @@
     "test:html-w3c-validator": "start-server-and-test \"start\" \"http://127.0.0.1:3000\" \"html-w3c-validator\""
   },
   "devDependencies": {
-    "serve": "14.2.1",
+    "serve": "14.2.4",
-    "start-server-and-test": "2.0.3",
+    "start-server-and-test": "2.0.8",
     "html-w3c-validator": "file:.."
   }
 }

package.json

@@ -1,7 +1,7 @@
 {
   "name": "html-w3c-validator",
   "version": "0.0.0-development",
-  "description": "CLI for validating multiple html pages using validator.w3.org.",
+  "description": "CLI for validating HTML pages using validator.w3.org.",
   "public": true,
   "types": "module",
   "type": "module",
@@ -25,6 +25,7 @@
   "bin": "build/index.js",
   "files": [
     "build",
+    "./schema/schema.json",
     "!**/*.test.js",
     "!**/*.map"
   ],
@@ -33,61 +34,44 @@
     "provenance": true
   },
   "engines": {
-    "node": ">=16.0.0",
+    "node": ">=16.0.0"
-    "npm": ">=9.0.0"
   },
   "scripts": {
-    "build": "rimraf ./build && swc ./src --out-dir ./build",
+    "build": "swc ./src --out-dir ./build --strip-leading-paths --delete-dir-on-start",
     "build:typescript": "tsc",
     "start": "node --enable-source-maps build/index.js",
-    "lint:commit": "commitlint",
     "lint:editorconfig": "editorconfig-checker",
-    "lint:markdown": "markdownlint-cli2",
     "lint:eslint": "eslint . --max-warnings 0 --report-unused-disable-directives --ignore-path .gitignore",
     "lint:prettier": "prettier . --check",
-    "lint:staged": "lint-staged",
+    "test": "node --enable-source-maps --test",
-    "test": "node --enable-source-maps --test build/",
     "release": "semantic-release"
   },
   "dependencies": {
     "chalk": "5.3.0",
     "clipanion": "3.2.1",
-    "html-validator": "6.0.1",
     "log-symbols": "6.0.0",
-    "ora": "8.0.1",
+    "ora": "8.1.1",
     "read-pkg": "9.0.1",
-    "table": "6.8.1"
+    "table": "6.8.2"
   },
   "devDependencies": {
-    "@commitlint/cli": "18.4.3",
+    "@swc/cli": "0.5.0",
-    "@commitlint/config-conventional": "18.4.3",
+    "@swc/core": "1.9.1",
-    "@swc/cli": "0.1.63",
+    "@tsconfig/strictest": "2.0.5",
-    "@swc/core": "1.3.101",
+    "@types/node": "22.9.0",
-    "@tsconfig/strictest": "2.0.2",
+    "@types/sinon": "17.0.3",
-    "@types/html-validator": "5.0.6",
+    "@typescript-eslint/eslint-plugin": "8.13.0",
-    "@types/mock-fs": "4.13.4",
+    "@typescript-eslint/parser": "8.13.0",
-    "@types/node": "20.10.5",
+    "editorconfig-checker": "6.0.0",
-    "@types/sinon": "17.0.2",
+    "eslint": "8.57.1",
-    "@typescript-eslint/eslint-plugin": "6.16.0",
+    "eslint-config-conventions": "16.0.1",
-    "@typescript-eslint/parser": "6.16.0",
+    "eslint-plugin-promise": "7.1.0",
-    "editorconfig-checker": "5.1.2",
+    "eslint-plugin-unicorn": "55.0.0",
-    "eslint": "8.56.0",
+    "execa": "9.5.1",
-    "eslint-config-conventions": "13.1.0",
+    "prettier": "3.3.3",
-    "eslint-config-prettier": "9.1.0",
+    "semantic-release": "23.1.1",
-    "eslint-plugin-import": "2.29.1",
+    "serve": "14.2.4",
-    "eslint-plugin-prettier": "5.1.2",
+    "sinon": "19.0.2",
-    "eslint-plugin-promise": "6.1.1",
+    "typescript": "5.6.3"
-    "eslint-plugin-unicorn": "50.0.1",
-    "execa": "8.0.1",
-    "lint-staged": "15.2.0",
-    "markdownlint-cli2": "0.11.0",
-    "markdownlint-rule-relative-links": "2.1.2",
-    "mock-fs": "5.2.0",
-    "prettier": "3.1.1",
-    "rimraf": "5.0.5",
-    "semantic-release": "22.0.12",
-    "serve": "14.2.1",
-    "sinon": "17.0.1",
-    "typescript": "5.3.3"
   }
 }

schema/schema.json

@@ -0,0 +1,48 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema",
+  "$id": "html-w3c-validator://config/schema.json",
+  "title": "html-w3c-validator configuration schema",
+  "type": "object",
+  "properties": {
+    "$schema": {
+      "description": "JSON Schema",
+      "type": "string"
+    },
+    "urls": {
+      "description": "URLs to validate.",
+      "type": "array",
+      "default": [],
+      "minItems": 1,
+      "items": {
+        "description": "URL to validate.",
+        "type": "string",
+        "format": "uri",
+        "minLength": 1
+      }
+    },
+    "files": {
+      "description": "Files to validate.",
+      "type": "array",
+      "minItems": 1,
+      "default": [],
+      "items": {
+        "description": "File to validate.",
+        "type": "string",
+        "format": "uri-reference",
+        "minLength": 1
+      }
+    },
+    "severities": {
+      "description": "Specify the severities to report.",
+      "type": "array",
+      "minItems": 1,
+      "default": ["warning", "error"],
+      "items": {
+        "description": "Severity to report.",
+        "type": "string",
+        "enum": ["error", "warning", "info"]
+      }
+    }
+  },
+  "additionalProperties": false
+}

src/HTMLValidatorCommand.ts

@@ -1,19 +1,15 @@
-import path from "node:path"
 import fs from "node:fs"
+import path from "node:path"
 
-import { Command, Option } from "clipanion"
-import * as typanion from "typanion"
 import chalk from "chalk"
-import ora from "ora"
+import { Command, Option } from "clipanion"
 import logSymbols from "log-symbols"
-import type {
+import ora from "ora"
-  ValidationMessageLocationObject,
-  ParsedJsonAsValidationResults,
-} from "html-validator"
-import validateHTML from "html-validator"
 import { table } from "table"
+import * as typanion from "typanion"
 
-import { isExistingPath } from "./utils/isExistingPath.js"
+import type { ValidateHTMLResult } from "./validateHTML.js"
+import { getHTMLFromURL, validateHTML } from "./validateHTML.js"
 
 export const CONFIG_FILE_NAME = ".html-w3c-validatorrc.json"
 
@@ -50,7 +46,7 @@ const printResults = (results: Result[]): void => {
 export class HTMLValidatorCommand extends Command {
   static override usage = {
     description:
-      "CLI for validating multiple html pages using <https://validator.w3.org/>.",
+      "CLI for validating HTML pages using <https://validator.w3.org/>.",
   }
 
   public currentWorkingDirectory = Option.String(
@@ -65,22 +61,20 @@ export class HTMLValidatorCommand extends Command {
   public async execute(): Promise<number> {
     const configPath = path.join(this.currentWorkingDirectory, CONFIG_FILE_NAME)
     try {
-      if (!(await isExistingPath(configPath))) {
+      let configData: string
+      try {
+        configData = await fs.promises.readFile(configPath, {
+          encoding: "utf-8",
+        })
+      } catch {
         throw new Error(
           `No config file found at ${configPath}. Please create "${CONFIG_FILE_NAME}".`,
         )
       }
-      const configData = await fs.promises.readFile(configPath, {
-        encoding: "utf-8",
-      })
       let config: Config = { urls: [], files: [] }
-      let isValidConfig = true
       try {
         config = JSON.parse(configData)
       } catch {
-        isValidConfig = false
-      }
-      if (!isValidConfig) {
         throw new Error(
           `Invalid config file at "${configPath}". Please check the JSON syntax.`,
         )
@@ -137,29 +131,25 @@ export class HTMLValidatorCommand extends Command {
       await Promise.all(
         dataToValidate.map(async ({ data, type }) => {
           try {
-            const options = {
+            let result: ValidateHTMLResult | undefined
-              format: "json" as "json" | undefined,
-            }
-            let result: ParsedJsonAsValidationResults | undefined
             if (type === "url") {
               result = await validateHTML({
-                url: data,
+                htmlData: await getHTMLFromURL(data),
-                isLocal: true,
-                ...options,
               })
             } else if (type === "file") {
               const htmlPath = path.resolve(this.currentWorkingDirectory, data)
-              if (!(await isExistingPath(htmlPath))) {
+              let html: string
+              try {
+                html = await fs.promises.readFile(htmlPath, {
+                  encoding: "utf-8",
+                })
+              } catch {
                 throw new Error(
                   `No file found at "${htmlPath}". Please check the path.`,
                 )
               }
-              const html = await fs.promises.readFile(htmlPath, {
-                encoding: "utf-8",
-              })
               result = await validateHTML({
-                data: html,
+                htmlData: html,
-                ...options,
               })
             } else {
               throw new Error("Invalid type")
@@ -194,11 +184,17 @@ export class HTMLValidatorCommand extends Command {
                   row.push(chalk.red(message.type))
                 }
                 row.push(message.message)
-                const violation = message as ValidationMessageLocationObject
+                if (
-                if (violation.extract != null) {
+                  message.extract != null &&
+                  message.lastLine != null &&
+                  message.firstColumn != null &&
+                  message.lastColumn != null
+                ) {
                   row.push(
-                    `line: ${violation.lastLine}, column: ${violation.firstColumn}-${violation.lastColumn}`,
+                    `line: ${message.lastLine}, column: ${message.firstColumn}-${message.lastColumn}`,
                   )
+                } else {
+                  row.push("")
                 }
                 messagesTable.push(row)
               }

src/__test__/HTMLValidatorCommand.test.ts

@@ -1,7 +1,9 @@
 import test from "node:test"
 import assert from "node:assert/strict"
 import path from "node:path"
+import fs from "node:fs"
 import { PassThrough } from "node:stream"
+import { fileURLToPath } from "node:url"
 
 import sinon from "sinon"
 import { execa } from "execa"
@@ -33,10 +35,13 @@ await test("html-w3c-validator", async (t) => {
     async () => {
       const exampleURL = new URL("../../example", import.meta.url)
       process.chdir(exampleURL.pathname)
-      await execa("rimraf", ["node_modules"])
+      await fs.promises.rm(
+        path.join(fileURLToPath(exampleURL), "node_modules"),
+        { recursive: true, force: true },
+      )
       await execa("npm", ["install"])
-      const { exitCode } = await execa("npm", [
+      const { exitCode } = await execa("node", [
-        "run",
+        "--run",
         "test:html-w3c-validator",
       ])
       assert.strictEqual(exitCode, 0)
@@ -47,8 +52,8 @@ await test("html-w3c-validator", async (t) => {
     "succeeds and validate the html correctly (example without working directory)",
     async () => {
       const logs: string[] = []
-      sinon.stub(console, "log").value((log: string) => {
+      sinon.stub(console, "log").value((...log: string[]) => {
-        logs.push(log)
+        logs.push(...log)
       })
       const consoleLogSpy = sinon.spy(console, "log")
       const stream = new PassThrough()
@@ -58,7 +63,7 @@ await test("html-w3c-validator", async (t) => {
         stderr: stream,
       })
       stream.end()
-      assert.strictEqual(exitCode, 0)
+      assert.strictEqual(exitCode, 0, logs.join("\n"))
       assert.strictEqual(
         consoleLogSpy.calledWith(
           logSymbols.success,
@@ -83,8 +88,8 @@ await test("html-w3c-validator", async (t) => {
     async () => {
       const workingDirectory = path.join(FIXTURES_PATH, "success")
       const logs: string[] = []
-      sinon.stub(console, "log").value((log: string) => {
+      sinon.stub(console, "log").value((...log: string[]) => {
-        logs.push(log)
+        logs.push(...log)
       })
       const consoleLogSpy = sinon.spy(console, "log")
       const stream = new PassThrough()
@@ -97,7 +102,7 @@ await test("html-w3c-validator", async (t) => {
         },
       )
       stream.end()
-      assert.strictEqual(exitCode, 0)
+      assert.strictEqual(exitCode, 0, logs.join("\n"))
       assert.strictEqual(
         consoleLogSpy.calledWith(logSymbols.success, "./build/index.html"),
         true,
@@ -111,6 +116,53 @@ await test("html-w3c-validator", async (t) => {
     },
   )
 
+  await t.test(
+    "fails by validating the html correctly with 2 errors: one with line/column, the other without (GitHub issue #6)",
+    async () => {
+      const workingDirectory = path.join(FIXTURES_PATH, "issue-6")
+      const errors: string[] = []
+      sinon.stub(console, "error").value((error: string) => {
+        errors.push(error)
+      })
+      const consoleErrorSpy = sinon.spy(console, "error")
+      const stream = new PassThrough()
+      const exitCode = await cli.run(
+        [`--current-working-directory=${workingDirectory}`],
+        {
+          stdin: process.stdin,
+          stdout: stream,
+          stderr: stream,
+        },
+      )
+      stream.end()
+      assert.strictEqual(exitCode, 1)
+      const messagesTable = [
+        [
+          chalk.red("error"),
+          "The character encoding was not declared. Proceeding using “windows-1252”.",
+          "",
+        ],
+        [
+          chalk.yellow("warning"),
+          "Consider adding a “lang” attribute to the “html” start tag to declare the language of this document.",
+          "line: 2, column: 16-7",
+        ],
+      ]
+      assert.strictEqual(
+        consoleErrorSpy.calledWith(
+          chalk.bold.red("Error:") + " HTML validation (W3C) failed!",
+        ),
+        true,
+        errors.join("\n"),
+      )
+      assert.strictEqual(
+        consoleErrorSpy.calledWith(table(messagesTable)),
+        true,
+        errors.join("\n"),
+      )
+    },
+  )
+
   await t.test("fails with not found config", async () => {
     const workingDirectory = path.join(FIXTURES_PATH, "error-config-not-found")
     const configPath = path.join(workingDirectory, CONFIG_FILE_NAME)

src/__test__/fixtures/error-config-invalid-files-and-urls/.html-w3c-validatorrc.json

@@ -1,4 +1,5 @@
 {
+  "$schema": "../../../../schema/schema.json",
   "urls": [],
   "files": []
 }

src/__test__/fixtures/error-config-invalid-files/.html-w3c-validatorrc.json

@@ -1,3 +1,4 @@
 {
+  "$schema": "../../../../schema/schema.json",
   "files": "Invalid"
 }

src/__test__/fixtures/error-config-invalid-severities-empty/.html-w3c-validatorrc.json

@@ -1,4 +1,5 @@
 {
+  "$schema": "../../../../schema/schema.json",
   "files": ["./index.html"],
   "severities": []
 }

src/__test__/fixtures/error-config-invalid-severities/.html-w3c-validatorrc.json

@@ -1,4 +1,5 @@
 {
+  "$schema": "../../../../schema/schema.json",
   "files": ["./index.html"],
   "severities": ["errors-invalid"]
 }

src/__test__/fixtures/error-config-invalid-urls/.html-w3c-validatorrc.json

@@ -1,3 +1,4 @@
 {
+  "$schema": "../../../../schema/schema.json",
   "urls": "Invalid"
 }

src/__test__/fixtures/error-invalid-files-paths-to-check/.html-w3c-validatorrc.json

@@ -1,3 +1,4 @@
 {
+  "$schema": "../../../../schema/schema.json",
   "files": ["./index.html"]
 }

src/__test__/fixtures/error-invalid-w3c-html/.html-w3c-validatorrc.json

@@ -1,3 +1,4 @@
 {
+  "$schema": "../../../../schema/schema.json",
   "files": ["./build/index.html", "./build/about.html"]
 }

src/__test__/fixtures/issue-6/.html-w3c-validatorrc.json

@@ -0,0 +1,5 @@
+{
+  "$schema": "../../../../schema/schema.json",
+  "files": ["./build/index.html"],
+  "severities": ["info", "warning", "error"]
+}

src/__test__/fixtures/issue-6/build/index.html

@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<title>Have We Stopped Killing Yet?</title>
+<link rel=icon href=favicon.ico>
+<link rel=stylesheet href=setup/default.css>
+<meta name=viewport content="initial-scale=1,width=device-width">
+<meta property="og:image" content="https://mirrors.meiert.org/havewestoppedkillingyet.org/media/redrum.png">
+<h1>Have We Stopped Killing Yet?</h1>
+<p><strong>No.</strong>
+<p>This is <a href=https://meiert.com/en/blog/on-taking-life/>unacceptable</a>.
+<p>We don’t need arms and armies and industrial slaughterhouses.
+<p>We need respect for life.
+<p>Everyone can <em>do something</em>. Speaking up is doing something. <a href=https://meiert.com/en/><img src=https://hell.meiert.org/core/png/meiert-logo-80x80-alt.png alt="Jens Oliver Meiert"></a>

src/__test__/fixtures/success/.html-w3c-validatorrc.json

@@ -1,3 +1,4 @@
 {
+  "$schema": "../../../../schema/schema.json",
   "files": ["./build/index.html", "./build/about.html"]
 }

src/utils/__test__/isExistingPath.test.ts

@@ -1,26 +0,0 @@
-import test from "node:test"
-import assert from "node:assert/strict"
-
-import fsMock from "mock-fs"
-
-import { isExistingPath } from "../isExistingPath.js"
-
-await test("utils/isExistingPath", async (t) => {
-  t.afterEach(() => {
-    fsMock.restore()
-  })
-
-  await t.test("should return true if the file exists", async () => {
-    fsMock({
-      "/file.txt": "",
-    })
-    assert.strictEqual(await isExistingPath("/file.txt"), true)
-  })
-
-  await t.test("should return false if the file doesn't exists", async () => {
-    fsMock({
-      "/file.txt": "",
-    })
-    assert.strictEqual(await isExistingPath("/randomfile.txt"), false)
-  })
-})

src/utils/isExistingPath.ts

@@ -1,10 +0,0 @@
-import fs from "node:fs"
-
-export const isExistingPath = async (path: string): Promise<boolean> => {
-  try {
-    await fs.promises.access(path, fs.constants.F_OK)
-    return true
-  } catch {
-    return false
-  }
-}

src/validateHTML.ts

@@ -0,0 +1,46 @@
+export interface ValidateHTMLOptions {
+  htmlData: string
+}
+
+export interface ValidationMessage {
+  type: "error" | "info" | "non-document-error"
+  subType?: "warning" | "fatal" | "internal" | "io" | "schema"
+  message: string
+  extract?: string
+  lastLine?: number
+  firstColumn?: number
+  lastColumn?: number
+}
+
+export interface ValidateHTMLResult {
+  messages: ValidationMessage[]
+}
+
+export const validateHTML = async (
+  options: ValidateHTMLOptions,
+): Promise<ValidateHTMLResult> => {
+  const { htmlData } = options
+  const url = new URL("https://validator.w3.org/nu/")
+  url.searchParams.set("out", "json")
+  const response = await fetch(url, {
+    method: "POST",
+    body: htmlData,
+    headers: {
+      "Content-Type": "text/html",
+    },
+  })
+  if (!response.ok) {
+    throw new Error(response.statusText)
+  }
+  const result = (await response.json()) as ValidateHTMLResult
+  return result
+}
+
+export const getHTMLFromURL = async (url: string): Promise<string> => {
+  const response = await fetch(url)
+  if (!response.ok) {
+    throw new Error(`Failed to fetch HTML from "${url}"`)
+  }
+  const html = await response.text()
+  return html
+}