Test parsing utility readQualifiedIdentifierList

Signed-off-by: Alejandro García Montoro <alejandro.garciamontoro@gmail.com>

Author: agarciamontoro

sql/parse/util.go

@@ -517,11 +517,17 @@ func maybeList(opening, separator, closing rune, list *[]string) parseFunc {
 	}
 }
 
+// A QualifiedName represents an identifier of type "db_name.table_name"
 type QualifiedName struct {
-	db   string
-	name string
+	qualifier string
+	name      string
 }
 
+// readQualifiedIdentifierList reads a comma-separated list of QualifiedNames.
+// Any number of spaces between the qualified names are accepted. The qualifier
+// may be empty, in which case the period is optional.
+// An example of a correctly formed list is:
+// "my_db.myview, db_2.mytable ,   aTable"
 func readQualifiedIdentifierList(list *[]QualifiedName) parseFunc {
 	return func(rd *bufio.Reader) error {
 		for {
@@ -537,20 +543,23 @@ func readQualifiedIdentifierList(list *[]QualifiedName) parseFunc {
 			}
 
 			if len(newItem) < 1 || len(newItem) > 2 {
-				return errUnexpectedSyntax.New("[db_name.]viewName", strings.Join(newItem, "."))
+				return errUnexpectedSyntax.New(
+					"[qualifier.]name",
+					strings.Join(newItem, "."),
+				)
 			}
 
-			var db, name string
+			var qualifier, name string
 
 			if len(newItem) == 1 {
-				db = ""
+				qualifier = ""
 				name = newItem[0]
 			} else {
-				db = newItem[0]
+				qualifier = newItem[0]
 				name = newItem[1]
 			}
 
-			*list = append(*list, QualifiedName{db, name})
+			*list = append(*list, QualifiedName{qualifier, name})
 
 			r, _, err := rd.ReadRune()
 			if err != nil {

sql/parse/util_test.go

@@ -465,3 +465,60 @@ func TestReadSpaces(t *testing.T) {
 		require.Equal(fixture.expectedRemaining, actualRemaining)
 	}
 }
+
+// Tests that readQualifiedIdentifierList correctly parses well-formed lists,
+// populating the list of identifiers, and that it errors with partial lists
+// and when it does not found any identifiers
+func TestReadQualifiedIdentifierList(t *testing.T) {
+	require := require.New(t)
+
+	testFixtures := []struct {
+		string            string
+		expectedList      []QualifiedName
+		expectedError     bool
+		expectedRemaining string
+	}{
+		{
+			"my_db.myview, db_2.mytable ,   aTable",
+			[]QualifiedName{{"my_db", "myview"}, {"db_2", "mytable"}, {"", "aTable"}},
+			false,
+			"",
+		},
+		{
+			"single_identifier -remaining",
+			[]QualifiedName{{"", "single_identifier"}},
+			false,
+			"-remaining",
+		},
+		{
+			"",
+			nil,
+			true,
+			"",
+		},
+		{
+			"partial_list,",
+			[]QualifiedName{{"", "partial_list"}},
+			true,
+			"",
+		},
+	}
+
+	for _, fixture := range testFixtures {
+		reader := bufio.NewReader(strings.NewReader(fixture.string))
+		var actualList []QualifiedName
+
+		err := readQualifiedIdentifierList(&actualList)(reader)
+
+		if fixture.expectedError {
+			require.Error(err)
+		} else {
+			require.NoError(err)
+		}
+
+		require.Equal(fixture.expectedList, actualList)
+
+		actualRemaining, _ := reader.ReadString('\n')
+		require.Equal(fixture.expectedRemaining, actualRemaining)
+	}
+}

sql/parse/views.go

@@ -128,7 +128,7 @@ func parseDropView(ctx *sql.Context, s string) (sql.Node, error) {
 
 	plans := make([]sql.Node, len(views))
 	for i, view := range views {
-		plans[i] = plan.NewSingleDropView(sql.UnresolvedDatabase(view.db), view.name)
+		plans[i] = plan.NewSingleDropView(sql.UnresolvedDatabase(view.qualifier), view.name)
 	}
 
 	return plan.NewDropView(plans, ifExists), nil