Fix should skip spaces before parsing the comment line (#66)

Author: git-hulk

parser/lexer.go

@@ -217,6 +217,10 @@ func (l *Lexer) consumeString() error {
 
 func (l *Lexer) skipComments() {
 	for !l.isEOF() {
+		l.skipSpace()
+		if !l.peekOk(0) {
+			return
+		}
 		switch l.peekN(0) {
 		case '-':
 			if l.peekOk(1) && l.peekN(1) == '-' {
@@ -253,7 +257,6 @@ func (l *Lexer) peekToken() (*Token, error) {
 }
 
 func (l *Lexer) consumeToken() error {
-	l.skipSpace()
 	// clear last token
 	l.lastToken = nil
 	l.skipComments()

parser/testdata/query/format/select_with_multi_line_comment.sql

@@ -0,0 +1,14 @@
+-- Origin SQL:
+select
+    -- first line
+    -- second line
+    *
+from
+    t0
+
+-- Format SQL:
+
+SELECT 
+  *
+FROM
+  t0;

parser/testdata/query/output/select_with_multi_line_comment.sql.golden.json

@@ -0,0 +1,58 @@
+[
+  {
+    "SelectPos": 0,
+    "StatementEnd": 61,
+    "With": null,
+    "Top": null,
+    "SelectColumns": {
+      "ListPos": 48,
+      "ListEnd": 48,
+      "HasDistinct": false,
+      "Items": [
+        {
+          "Name": "*",
+          "QuoteType": 0,
+          "NamePos": 48,
+          "NameEnd": 48
+        }
+      ]
+    },
+    "From": {
+      "FromPos": 50,
+      "Expr": {
+        "Table": {
+          "TablePos": 59,
+          "TableEnd": 61,
+          "Alias": null,
+          "Expr": {
+            "Database": null,
+            "Table": {
+              "Name": "t0",
+              "QuoteType": 1,
+              "NamePos": 59,
+              "NameEnd": 61
+            }
+          },
+          "HasFinal": false
+        },
+        "StatementEnd": 61,
+        "SampleRatio": null,
+        "HasFinal": false
+      }
+    },
+    "ArrayJoin": null,
+    "Window": null,
+    "Prewhere": null,
+    "Where": null,
+    "GroupBy": null,
+    "WithTotal": false,
+    "Having": null,
+    "OrderBy": null,
+    "LimitBy": null,
+    "Limit": null,
+    "Settings": null,
+    "UnionAll": null,
+    "UnionDistinct": null,
+    "Except": null
+  }
+]

parser/testdata/query/select_with_multi_line_comment.sql

@@ -0,0 +1,6 @@
+select
+    -- first line
+    -- second line
+    *
+from
+    t0