Throw error for invalid column names starting with digits to close #1173 (#2278)

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: mathiasrw <[email protected]>
Co-authored-by: Mathias Wulff <[email protected]>

Author: Copilot

src/alasqlparser.jison

@@ -269,6 +269,9 @@ SETS                                        	return 'SET'
 'WHILE'                                         return 'WHILE'
 'WITH'                                          return 'WITH'
 'WORK'                                          return 'TRANSACTION'  /* Is this keyword required? */
+/* Issue #1173: Reject invalid identifiers like 6minAvgOpac (number followed by letters without space) */
+/* This rule must precede NUMBER to catch invalid patterns before they're tokenized as NUMBER + LITERAL */
+\d+[a-zA-Z_][a-zA-Z_0-9]*						return 'INVALID'
 (\d+\.?\d*|\.\d+)([eE][+-]?\d+)?				return 'NUMBER'
 '->'											return 'ARROW'
 '#'												return 'SHARP'

src/alasqlparser.js

@@ -0,0 +1,76 @@
+if (typeof exports === 'object') {
+	var assert = require('assert');
+	var alasql = require('..');
+}
+
+describe('Test 1173 - Parser should error on column names starting with numbers', function () {
+	const test = '1173';
+
+	before(function () {
+		alasql('create database test' + test);
+		alasql('use test' + test);
+	});
+
+	after(function () {
+		alasql('drop database test' + test);
+	});
+
+	it('A) Should parse correctly when column name is properly quoted with []', function () {
+		var sql = 'SELECT ID, [6minAvgOpac] FROM test';
+		var ast = alasql.parse(sql);
+		assert.equal(ast.statements[0].columns.length, 2);
+		assert.equal(ast.statements[0].columns[0].columnid, 'ID');
+		assert.equal(ast.statements[0].columns[1].columnid, '6minAvgOpac');
+	});
+
+	it('B) Should parse correctly when column name is properly quoted with backticks', function () {
+		var sql = 'SELECT ID, `6minAvgOpac` FROM test';
+		var ast = alasql.parse(sql);
+		assert.equal(ast.statements[0].columns.length, 2);
+		assert.equal(ast.statements[0].columns[0].columnid, 'ID');
+		assert.equal(ast.statements[0].columns[1].columnid, '6minAvgOpac');
+	});
+
+	it('C) Should throw error for unquoted column name starting with number', function () {
+		var sql = 'SELECT ID, 6minAvgOpac FROM test';
+		assert.throws(
+			function () {
+				alasql.parse(sql);
+			},
+			function (err) {
+				return err instanceof SyntaxError || err instanceof Error;
+			},
+			'Should throw a SyntaxError for invalid column name starting with number'
+		);
+	});
+
+	it('D) Should throw error for similar invalid identifier pattern', function () {
+		var sql = 'SELECT 123abc FROM test';
+		assert.throws(
+			function () {
+				alasql.parse(sql);
+			},
+			function (err) {
+				return err instanceof SyntaxError || err instanceof Error;
+			},
+			'Should throw a SyntaxError for invalid identifier 123abc'
+		);
+	});
+
+	it('E) Valid number literals followed by proper aliases should still work', function () {
+		var sql = 'SELECT 6 AS minAvgOpac FROM test';
+		var ast = alasql.parse(sql);
+		assert.equal(ast.statements[0].columns.length, 1);
+		assert.equal(ast.statements[0].columns[0].value, 6);
+		assert.equal(ast.statements[0].columns[0].as, 'minAvgOpac');
+	});
+
+	it('F) Number followed by space then literal alias (without AS) should still work', function () {
+		// This is valid SQL: SELECT 6 minAvgOpac means SELECT 6 AS minAvgOpac
+		var sql = 'SELECT 6 minAvgOpac FROM test';
+		var ast = alasql.parse(sql);
+		assert.equal(ast.statements[0].columns.length, 1);
+		assert.equal(ast.statements[0].columns[0].value, 6);
+		assert.equal(ast.statements[0].columns[0].as, 'minAvgOpac');
+	});
+});