Fix eslint reports (#9)

* setup eslint and fix some obvious issues

* tweak eslint

Author: bigorn0

.prettierignore

@@ -0,0 +1,6 @@
+.git
+.vscode
+.idea
+node_modules
+package.json
+package-lock.json

.prettierrc

@@ -0,0 +1,12 @@
+{
+	"printWidth": 120,
+	"tabWidth": 4,
+	"useTabs": true,
+	"semi": true,
+	"singleQuote": true,
+	"quoteProps": "preserve",
+	"trailingComma": "all",
+	"bracketSpacing": true,
+	"bracketSameLine": false,
+	"arrowParens": "avoid"
+}

eslint.config.js

@@ -0,0 +1,37 @@
+const globals = require('globals');
+const eslintConfigPrettier = require('eslint-config-prettier');
+
+const config = {
+	languageOptions: {
+		ecmaVersion: 2022,
+		sourceType: 'commonjs',
+		globals: {
+			...globals.node,
+			...globals.mocha,
+		},
+	},
+	ignores: ['.git/*', '.vscode/*', '.idea/*', 'node_modules/*', 'grammars/*', 'parser/*'],
+	rules: {
+		'no-cond-assign': 'error',
+		'no-const-assign': 'error',
+		'no-dupe-args': 'error',
+		'no-dupe-keys': 'error',
+		'no-duplicate-case': 'error',
+		'no-unreachable': 'error',
+		'eqeqeq': 'error',
+		'no-var': 'error',
+		'no-undef': 'error',
+		'no-bitwise': 'warn',
+		'no-dupe-else-if': 'warn',
+		'no-duplicate-imports': 'warn',
+		'no-import-assign': 'warn',
+		'no-empty': 'warn',
+		'no-extra-semi': 'error',
+		'no-global-assign': 'warn',
+		'no-redeclare': 'warn',
+		'no-debugger': 'error',
+		'no-console': 'error',
+	},
+};
+
+module.exports = [config, eslintConfigPrettier];

index.js

@@ -4,31 +4,32 @@ const SQLSelectParser = require('./parser/SQLSelectParser');
 const selectStatementListener = require('./selectStatementListener.js');
 
 const parseSelectStatement = (sql, logger) => {
-    const chars = new antlr4.InputStream(sql);
-    const lexer = new SQLSelectLexer(chars);
+	const chars = new antlr4.InputStream(sql);
+	const lexer = new SQLSelectLexer(chars);
 
-    const tokens = new antlr4.CommonTokenStream(lexer);
-    const parser = new SQLSelectParser(tokens);
+	const tokens = new antlr4.CommonTokenStream(lexer);
+	const parser = new SQLSelectParser(tokens);
 
-    parser.removeErrorListeners();
-    class ExprErrorListener extends antlr4.error.ErrorListener {
-        syntaxError(recognizer, offendingSymbol, line, column, msg) {
-            const error = `line ${line}:${column} ${msg}`;
-            if (!logger) {
-                console.log(new Error(error));
-            } else {
-                logger(error);
-            }
-        }
-    }
+	parser.removeErrorListeners();
+	class ExprErrorListener extends antlr4.error.ErrorListener {
+		syntaxError(recognizer, offendingSymbol, line, column, msg) {
+			const error = `line ${line}:${column} ${msg}`;
+			if (!logger) {
+				// eslint-disable-next-line no-console
+				console.log(new Error(error));
+			} else {
+				logger(error);
+			}
+		}
+	}
 
-    parser.addErrorListener(new ExprErrorListener());
-    const tree = parser.query();
+	parser.addErrorListener(new ExprErrorListener());
+	const tree = parser.query();
 
-    const listener = new selectStatementListener(parser);
-    antlr4.tree.ParseTreeWalker.DEFAULT.walk(listener, tree);
+	const listener = new selectStatementListener(parser);
+	antlr4.tree.ParseTreeWalker.DEFAULT.walk(listener, tree);
 
-    return listener.getResult();
+	return listener.getResult();
 };
 
-module.exports = parseSelectStatement;
+module.exports = parseSelectStatement;