fix an error for 'bufio.Scanner: token too long'

Signed-off-by: lifubang <[email protected]>

Author: lifubang

testdata/step.judger/datav7.out

@@ -2,6 +2,7 @@ package tool
 
 import (
 	"bufio"
+	"io"
 	"os"
 	"strings"
 )
@@ -15,54 +16,65 @@ func clearString(str string) string {
 	return trimStr
 }
 
-// DiffOut is to diff the output between user and testcase
-func DiffOut(userOut, dataOut string, diffIgnoreHead bool, strictMode bool) (bool, error) {
-	src, err := os.Open(userOut)
+// clearEnter replace all '\r' chars
+func clearEnter(str string) string {
+	trimStr := strings.ReplaceAll(str, "\r", "")
+	return trimStr
+}
+
+func getFileContent(fileName string, diffIgnoreHead bool, strictMode bool) (string, error) {
+	src, err := os.Open(fileName)
 	if err != nil {
-		return false, err
+		return "", err
 	}
 	defer src.Close()
-	dst, err := os.Open(dataOut)
-	if err != nil {
-		return false, err
-	}
-	defer dst.Close()
 
-	var strSrc, strDest strings.Builder
+	if stat, err := src.Stat(); err == nil {
+		if stat.Size() == 0 {
+			return "", err
+		}
+	} else {
+		return "", err
+	}
 
-	rd := bufio.NewScanner(src)
+	var strBuilder strings.Builder
+	rd := bufio.NewReader(src)
 	srcIgnoreHead := diffIgnoreHead
-	for rd.Scan() {
-		str := rd.Text()
-		if srcIgnoreHead {
-			srcIgnoreHead = false
-		} else {
-			trimStr := str
-			if !strictMode {
-				trimStr = clearString(trimStr)
-			}
-			if len(trimStr) > 0 {
-				strSrc.WriteString(trimStr)
+	for {
+		str, err := rd.ReadString('\n')
+		if err == nil || err == io.EOF {
+			if srcIgnoreHead {
+				srcIgnoreHead = false
+			} else {
+				trimStr := str
+				if !strictMode {
+					trimStr = clearString(trimStr)
+				} else {
+					trimStr = clearEnter(trimStr)
+				}
+				if len(trimStr) > 0 {
+					strBuilder.WriteString(trimStr)
+				}
 			}
 		}
+		if err == io.EOF {
+			break
+		}
 	}
+	return strBuilder.String(), nil
+}
 
-	rd = bufio.NewScanner(dst)
-	dstIgnoreHead := diffIgnoreHead
-	for rd.Scan() {
-		str := rd.Text()
-		if dstIgnoreHead {
-			dstIgnoreHead = false
-		} else {
-			trimStr := str
-			if !strictMode {
-				trimStr = clearString(trimStr)
-			}
-			if len(trimStr) > 0 {
-				strDest.WriteString(trimStr)
-			}
-		}
+// DiffOut is to diff the output between user and testcase
+func DiffOut(userOut, dataOut string, diffIgnoreHead bool, strictMode bool) (bool, error) {
+	strSrc, err := getFileContent(userOut, diffIgnoreHead, strictMode)
+	if err != nil {
+		return false, err
+	}
+
+	strDst, err := getFileContent(dataOut, diffIgnoreHead, strictMode)
+	if err != nil {
+		return false, err
 	}
 
-	return strings.Trim(strSrc.String(), " ") == strings.Trim(strDest.String(), " "), nil
+	return strings.Trim(strSrc, " ") == strings.Trim(strDst, " "), nil
 }

testdata/step.judger/userv7.out

@@ -73,7 +73,7 @@ func TestDiffOutFunc(t *testing.T) {
 			dataOut:    "datav3.out",
 			ignoreHead: false,
 			strictMode: true,
-			shouldSame: true,
+			shouldSame: false,
 		},
 		{
 			desc:       "(L)Ignore the first line",
@@ -107,6 +107,14 @@ func TestDiffOutFunc(t *testing.T) {
 			strictMode: false,
 			shouldSame: true,
 		},
+		{
+			desc:       "(L)The size of user.out is zero",
+			userOut:    "userv7.out",
+			dataOut:    "datav7.out",
+			ignoreHead: false,
+			strictMode: false,
+			shouldSame: false,
+		},
 	}
 	for idx, tc := range tests {
 		t.Logf("%d. %s:\n", idx+1, tc.desc)