Added UNION testcases and auxilary code for running tests

go/vt/sqlparser/parse_test.go

@@ -22,13 +22,16 @@ import (
 	"compress/gzip"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"math/rand"
 	"os"
 	"path"
 	"strings"
 	"sync"
 	"testing"
 
+	"github.com/google/go-cmp/cmp"
+
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -3492,3 +3495,172 @@ func BenchmarkParse3(b *testing.B) {
 		largeQueryBenchmark(b, true)
 	})
 }
+
+func TestValidUnionCases(t *testing.T) {
+	testOutputTempDir, err := ioutil.TempDir("", "parse_test")
+	require.NoError(t, err)
+	defer func() {
+		if !t.Failed() {
+			os.RemoveAll(testOutputTempDir)
+		}
+	}()
+
+	testFile(t, "union_cases.txt", testOutputTempDir)
+}
+
+func TestValidSelectCases(t *testing.T) {
+	testOutputTempDir, err := ioutil.TempDir("", "parse_test")
+	require.NoError(t, err)
+	defer func() {
+		if !t.Failed() {
+			os.RemoveAll(testOutputTempDir)
+		}
+	}()
+
+	testFile(t, "select_cases.txt", testOutputTempDir)
+}
+
+type testCase struct {
+	file     string
+	lineno   int
+	input    string
+	output   string
+	errStr   string
+	comments string
+}
+
+func escapeNewLines(in string) string {
+	return strings.ReplaceAll(in, "\n", "\\n")
+}
+
+func testFile(t *testing.T, filename, tempDir string) {
+	t.Run(filename, func(t *testing.T) {
+		fail := false
+		expected := strings.Builder{}
+		for tcase := range iterateExecFile(filename) {
+			t.Run(fmt.Sprintf("%d : %s", tcase.lineno, tcase.comments), func(t *testing.T) {
+				if tcase.output == "" && tcase.errStr == "" {
+					tcase.output = tcase.input
+				}
+				expected.WriteString(fmt.Sprintf("%sINPUT\n%s\nEND\n", tcase.comments, escapeNewLines(tcase.input)))
+				tree, err := Parse(tcase.input)
+				if tcase.errStr != "" {
+					expected.WriteString(fmt.Sprintf("ERROR\n%s\nEND\n", escapeNewLines(err.Error())))
+					if err == nil || tcase.errStr != err.Error() {
+						fail = true
+						t.Errorf("File: %s, Line: %d\nDiff:\n%s\n[%s] \n[%s]", filename, tcase.lineno, cmp.Diff(tcase.errStr, err.Error()), tcase.errStr, err.Error())
+					}
+				} else {
+					if err != nil {
+						expected.WriteString(fmt.Sprintf("ERROR\n%s\nEND\n", escapeNewLines(err.Error())))
+						fail = true
+						t.Errorf("File: %s, Line: %d\nDiff:\n%s\n[%s] \n[%s]", filename, tcase.lineno, cmp.Diff(tcase.errStr, err.Error()), tcase.errStr, err.Error())
+					} else {
+						out := String(tree)
+						expected.WriteString(fmt.Sprintf("OUTPUT\n%s\nEND\n", escapeNewLines(out)))
+						if tcase.output != out {
+							fail = true
+							t.Errorf("Parsing failed. \nExpected/Got:\n%s\n%s", tcase.output, out)
+						}
+					}
+				}
+			})
+		}
+
+		if fail && tempDir != "" {
+			gotFile := fmt.Sprintf("%s/%s", tempDir, filename)
+			_ = ioutil.WriteFile(gotFile, []byte(strings.TrimSpace(expected.String())+"\n"), 0644)
+			fmt.Println(fmt.Sprintf("Errors found in parse tests. If the output is correct, run `cp %s/* testdata/` to update test expectations", tempDir)) // nolint
+		}
+	})
+}
+
+func iterateExecFile(name string) (testCaseIterator chan testCase) {
+	name = locateFile(name)
+	fd, err := os.OpenFile(name, os.O_RDONLY, 0)
+	if err != nil {
+		panic(fmt.Sprintf("Could not open file %s", name))
+	}
+
+	testCaseIterator = make(chan testCase)
+	var comments string
+	go func() {
+		defer close(testCaseIterator)
+
+		r := bufio.NewReader(fd)
+		lineno := 0
+		for {
+			input, lineno, _ := parsePartial(r, []string{"INPUT"}, lineno, name)
+			if input == "" && lineno == 0 {
+				break
+			}
+			output, lineno, returnTypeNumber := parsePartial(r, []string{"OUTPUT", "ERROR"}, lineno, name)
+			var errStr string
+			if returnTypeNumber == 1 {
+				errStr = output
+				output = ""
+			}
+			testCaseIterator <- testCase{
+				file:     name,
+				lineno:   lineno,
+				input:    input,
+				comments: comments,
+				output:   output,
+				errStr:   errStr,
+			}
+			comments = ""
+		}
+	}()
+	return testCaseIterator
+}
+
+func parsePartial(r *bufio.Reader, readType []string, lineno int, fileName string) (string, int, int) {
+	returnTypeNumber := -1
+	for {
+		binput, err := r.ReadBytes('\n')
+		if err != nil {
+			if err != io.EOF {
+				panic(fmt.Errorf("error reading file %s: line %d: %s", fileName, lineno, err.Error()))
+			}
+			return "", 0, 0
+		}
+		lineno++
+		input := string(binput)
+		input = strings.TrimSpace(input)
+		if input == "" || input == "\n" {
+			continue
+		}
+		for i, str := range readType {
+			if input == str {
+				returnTypeNumber = i
+				break
+			}
+		}
+		if returnTypeNumber != -1 {
+			break
+		}
+		panic(fmt.Errorf("error reading file %s: line %d: %s - Expected keyword", fileName, lineno, err.Error()))
+	}
+	input := ""
+	for {
+		l, err := r.ReadBytes('\n')
+		lineno++
+		if err != nil {
+			panic(fmt.Sprintf("error reading file %s line# %d: %s", fileName, lineno, err.Error()))
+		}
+		str := strings.TrimSpace(string(l))
+		if str == "END" {
+			break
+		}
+		if input == "" {
+			input += str
+		} else {
+			input += str + "\n"
+		}
+	}
+	return input, lineno, returnTypeNumber
+}
+
+func locateFile(name string) string {
+	return "testdata/" + name
+}