Monaca Editor syntax highlighting is ok, but editor doesn't show any errors - editor

Question

Syntax highlighting is ok, but doesn't show any errors.
Line 5 should show an error in red at end of the line in editor, but not.
Why could that be?
I'm using monaco webpack plugin, with these config.
index.js
import * as monaco from 'monaco-editor/esm/vs/editor/editor.api';
import 'monaco-editor/esm/vs/basic-languages/javascript/javascript';
import 'monaco-editor/esm/vs/basic-languages/python/python';
monaco.editor.create(document.getElementById('duzenleyici'), {
value: ``,
language: 'python',
theme: 'vs-dark',
wordWrap: true,
automaticLayout: true,
});
webpack-config.js
const MonacoWebpackPlugin = require('monaco-editor-webpack-plugin');
const path = require('path');
module.exports = {
entry: './index.js',
output: {
path: path.resolve(__dirname, 'dist'),
filename: 'monaco.js',
},
module: {
rules: [
{
test: /\.css$/,
use: ['style-loader', 'css-loader'],
},
{
test: /\.ttf$/,
use: ['file-loader'],
},
],
},
plugins: [
new MonacoWebpackPlugin({
languages: ['javascript', 'python'],
features: ['find', 'bracketMatching', 'comment', 'folding', 'suggest', 'contextmenu', 'coreCommands', 'codeAction', 'clipboard', 'linesOperations', 'suggest', 'wordHighlighter'],
globalAPI: true,
// publicPath: '/',
}),
],
};

Answer 1

In index.js :
`
import * as monaco from 'monaco-editor/esm/vs/editor/editor.api';
// validation settings
monaco.languages.typescript.javascriptDefaults.setDiagnosticsOptions({
noSemanticValidation: false,
});
// compiler options
monaco.languages.typescript.javascriptDefaults.setCompilerOptions({
target: monaco.languages.typescript.ScriptTarget.ES6,
allowNonTsExtensions: true
});
`
In webpack-config.js plugins key:
new MonacoWebpackPlugin({
languages: ['javascript', 'typescript']
})