parse_next_test.go

/*
Copyright 2017 Google Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package sqlparser

import (
	"bytes"
	"io"
	"strings"
	"testing"
)

// TestParseNextValid concatenates all the valid SQL test cases and check it can read
// them as one long string.
func TestParseNextValid(t *testing.T) {
	var sql bytes.Buffer
	for _, tcase := range validSQL {
		sql.WriteString(strings.TrimSuffix(tcase.input, ";"))
		sql.WriteRune(';')
	}

	tokens := NewTokenizer(&sql)
	for i, tcase := range validSQL {
		input := tcase.input + ";"
		want := tcase.output
		if want == "" {
			want = tcase.input
		}

		tree, err := ParseNext(tokens)
		if err != nil {
			t.Fatalf("[%d] ParseNext(%q) err: %q, want nil", i, input, err)
			continue
		}

		if got := String(tree); got != want {
			t.Fatalf("[%d] ParseNext(%q) = %q, want %q", i, input, got, want)
		}
	}

	// Read once more and it should be EOF.
	if tree, err := ParseNext(tokens); err != io.EOF {
		t.Errorf("ParseNext(tokens) = (%q, %v) want io.EOF", String(tree), err)
	}
}

// TestParseNextErrors tests all the error cases, and ensures a valid
// SQL statement can be passed afterwards.
func TestParseNextErrors(t *testing.T) {
	for _, tcase := range invalidSQL {
		if tcase.excludeMulti {
			// Skip tests which leave unclosed strings, or comments.
			continue
		}

		sql := tcase.input + "; select 1 from t"
		tokens := NewStringTokenizer(sql)

		// The first statement should be an error
		_, err := ParseNext(tokens)
		if err == nil || err.Error() != tcase.output {
			t.Fatalf("[0] ParseNext(%q) err: %q, want %q", sql, err, tcase.output)
			continue
		}

		// The second should be valid
		tree, err := ParseNext(tokens)
		if err != nil {
			t.Fatalf("[1] ParseNext(%q) err: %q, want nil", sql, err)
			continue
		}

		want := "select 1 from t"
		if got := String(tree); got != want {
			t.Fatalf("[1] ParseNext(%q) = %q, want %q", sql, got, want)
		}

		// Read once more and it should be EOF.
		if tree, err := ParseNext(tokens); err != io.EOF {
			t.Errorf("ParseNext(tokens) = (%q, %v) want io.EOF", String(tree), err)
		}
	}
}

// TestParseNextEdgeCases tests various ParseNext edge cases.
func TestParseNextEdgeCases(t *testing.T) {
	tests := []struct {
		name     string
		input    string
		want     []string
		firstErr string
	}{{
		name:  "Trailing ;",
		input: "select 1 from a; update a set b = 2;",
		want:  []string{"select 1 from a", "update a set b = 2"},
	}, {
		name:  "No trailing ;",
		input: "select 1 from a; update a set b = 2",
		want:  []string{"select 1 from a", "update a set b = 2"},
	}, {
		name:  "Trailing whitespace",
		input: "select 1 from a; update a set b = 2    ",
		want:  []string{"select 1 from a", "update a set b = 2"},
	}, {
		name:  "Trailing whitespace and ;",
		input: "select 1 from a; update a set b = 2   ;   ",
		want:  []string{"select 1 from a", "update a set b = 2"},
	}, {
		name:  "Handle ForceEOF statements",
		input: "set character set utf8; select 1 from a",
		want:  []string{"set charset 'utf8'", "select 1 from a"},
	}, {
		name:  "Handle trigger DDL statements",
		input: "drop trigger if exists trg_one; create trigger trg_two after insert on tbl_one for each row set @v = 1; select 1 from a",
		want:  []string{"drop trigger if exists trg_one", "create trigger trg_two", "select 1 from a"},
	}, {
		name:  "Semicolin inside a string",
		input: "set character set ';'; select 1 from a",
		want:  []string{"set charset ';'", "select 1 from a"},
	}, {
		name:     "Invalid DDL",
		input:    "create table a; select 1 from a",
		firstErr: "syntax error at position 15",
		want:     []string{"select 1 from a"},
	}, {
		name:     "Invalid DDL with trailing garbage",
		input:    "create table a ignore me this is garbage; select 1 from a",
		firstErr: "syntax error at position 22 near 'ignore'",
		want:     []string{"select 1 from a"},
	}}

	for _, test := range tests {
		tokens := NewStringTokenizer(test.input)
		i := 0

		if test.firstErr != "" {
			if _, err := ParseNext(tokens); err == nil || err.Error() != test.firstErr {
				t.Fatalf("[%d] ParseNext(%q) err = %q, want %q", i, test.input, err, test.firstErr)
			}
			i++
		}

		for _, want := range test.want {
			tree, err := ParseNext(tokens)
			if err != nil {
				t.Fatalf("[%d] ParseNext(%q) err = %q, want nil", i, test.input, err)
				continue
			}

			if got := String(tree); got != want {
				t.Fatalf("[%d] ParseNext(%q) = %q, want %q", i, test.input, got, want)
			}
			i++
		}

		// Read once more and it should be EOF.
		if tree, err := ParseNext(tokens); err != io.EOF {
			t.Errorf("ParseNext(%q) = (%q, %v) want io.EOF", test.input, String(tree), err)
		}

		// And again, once more should be EOF.
		if tree, err := ParseNext(tokens); err != io.EOF {
			t.Errorf("ParseNext(%q) = (%q, %v) want io.EOF", test.input, String(tree), err)
		}
	}
}