spanner/spansql: fix parsing of adjacent inline and leading comments (#…

…2851)

These should be in separate Comment entries, not combined:
	Some INT64,  -- comment 1
        -- comment 2

spanner/spansql/parser.go

@@ -735,6 +735,12 @@ func (p *parser) skipSpace() bool {
 			p.line++
 		}
 		i += ti + len(term)
+
+		// A non-isolated comment is always complete and doesn't get
+		// combined with any future comment.
+		if !com.isolated {
+			com = nil
+		}
 	}
 	p.s = p.s[i:]
 	p.offset += i

spanner/spansql/parser_test.go

@@ -292,8 +292,12 @@ func TestParseDDL(t *testing.T) {
 		CREATE TABLE NonScalars (
 			Dummy INT64 NOT NULL, -- dummy comment
 			Ids ARRAY<INT64>, -- comment on ids
+			-- leading multi comment immediately after inline comment
+			BCol BOOL,
 			Names ARRAY<STRING(MAX)>,
 		) PRIMARY KEY (Dummy);
+
+		-- Trailing comment at end of file.
 		`, &DDL{Filename: "filename", List: []DDLStmt{
 			&CreateTable{
 				Name: "FooBar",
@@ -410,7 +414,8 @@ func TestParseDDL(t *testing.T) {
 				Columns: []ColumnDef{
 					{Name: "Dummy", Type: Type{Base: Int64}, NotNull: true, Position: line(34)},
 					{Name: "Ids", Type: Type{Array: true, Base: Int64}, Position: line(35)},
-					{Name: "Names", Type: Type{Array: true, Base: String, Len: MaxLen}, Position: line(36)},
+					{Name: "BCol", Type: Type{Base: Bool}, Position: line(37)},
+					{Name: "Names", Type: Type{Array: true, Base: String, Len: MaxLen}, Position: line(38)},
 				},
 				PrimaryKey: []KeyPart{{Column: "Dummy"}},
 				Position:   line(33),
@@ -431,6 +436,10 @@ func TestParseDDL(t *testing.T) {
 			// These comments shouldn't get combined:
 			{Marker: "--", Start: line(34), End: line(34), Text: []string{"dummy comment"}},
 			{Marker: "--", Start: line(35), End: line(35), Text: []string{"comment on ids"}},
+			{Marker: "--", Isolated: true, Start: line(36), End: line(36), Text: []string{"leading multi comment immediately after inline comment"}},
+
+			// Comment after everything else.
+			{Marker: "--", Isolated: true, Start: line(41), End: line(41), Text: []string{"Trailing comment at end of file."}},
 		}}},
 		// No trailing comma:
 		{`ALTER TABLE T ADD COLUMN C2 INT64`, &DDL{Filename: "filename", List: []DDLStmt{
@@ -502,9 +511,12 @@ func TestParseDDL(t *testing.T) {
 	} else if com.Text[0] != "This is another comment." {
 		t.Errorf("InlineComment returned the wrong comment (%q) for FooBar.RepoPath", com.Text[0])
 	}
-	// There are no leading comments on the columns of NonScalars,
+	// There are no leading comments on the columns of NonScalars (except for BCol),
 	// even though there's often a comment on the previous line.
 	for _, cd := range tableByName(t, ddl, "NonScalars").Columns {
+		if cd.Name == "BCol" {
+			continue
+		}
 		if com := ddl.LeadingComment(cd); com != nil {
 			t.Errorf("Leading comment found for NonScalars.%s: %v", cd.Name, com)
 		}