improve parser error.

services/parsers/mirclike.go

@@ -2,14 +2,26 @@ package parsers
 
 import (
 	"errors"
+	"fmt"
 	"git.aiterp.net/rpdata/api/models"
 	"strconv"
 	"strings"
 	"time"
 )
 
-// ErrNotPost is returned by parsePost if the line is empty or not a post.
-var ErrNotPost = errors.New("not a post")
+type ParseError struct {
+	Line    string
+	Problem string
+}
+
+func (e *ParseError) Error() string {
+	return fmt.Sprintf("Unrecognized post: %s (error: %s)", e.Line, e.Problem)
+}
+
+func IsParseError(err error) bool {
+	_, ok := err.(*ParseError)
+	return ok
+}
 
 // ErrEmptyLog is returned by ParseLog if there are no (valid) posts in the log.
 var ErrEmptyLog = errors.New("no valid posts found in log")
@@ -56,24 +68,36 @@ func MircPost(line string, date time.Time, prev models.Post) (models.Post, error
 	// Do basic validation
 	line = strings.Trim(line, "  \t\n\r")
 	if len(line) == 0 || !strings.HasPrefix(line, "[") {
-		return models.Post{}, ErrNotPost
+		return models.Post{}, &ParseError{
+			Line:    line,
+			Problem: "no timestamp",
+		}
 	}
 
 	// Parse timestamp
 	tsEndIndex := strings.IndexByte(line, ']')
 	if tsEndIndex == -1 || len(line) < tsEndIndex+5 {
-		return models.Post{}, ErrNotPost
+		return models.Post{}, &ParseError{
+			Line:    line,
+			Problem: "incomplete timestamp",
+		}
 	}
 	tsStr := line[1:tsEndIndex]
 	tsSplit := strings.Split(tsStr, ":")
 	tsUnits := make([]int, len(tsSplit))
 	if len(tsSplit) < 2 {
-		return models.Post{}, ErrNotPost
+		return models.Post{}, &ParseError{
+			Line:    line,
+			Problem: "invalid timestamp",
+		}
 	}
 	for i := range tsSplit {
 		n, err := strconv.Atoi(tsSplit[i])
 		if err != nil {
-			return models.Post{}, ErrNotPost
+			return models.Post{}, &ParseError{
+				Line:    line,
+				Problem: "invalid number in timestamp",
+			}
 		}
 
 		tsUnits[i] = n
@@ -94,7 +118,10 @@ func MircPost(line string, date time.Time, prev models.Post) (models.Post, error
 	if line[tsEndIndex+2] == '*' {
 		split := strings.SplitN(line[tsEndIndex+4:], " ", 2)
 		if len(split) == 1 {
-			return models.Post{}, ErrNotPost
+			return models.Post{}, &ParseError{
+				Line:    line,
+				Problem: "post is empty",
+			}
 		}
 
 		post := models.Post{
@@ -115,7 +142,10 @@ func MircPost(line string, date time.Time, prev models.Post) (models.Post, error
 	} else if line[tsEndIndex+2] == '<' {
 		split := strings.SplitN(line[tsEndIndex+2:], " ", 2)
 		if len(split) == 1 {
-			return models.Post{}, ErrNotPost
+			return models.Post{}, &ParseError{
+				Line:    line,
+				Problem: "post is empty",
+			}
 		}
 
 		post := models.Post{
@@ -134,6 +164,9 @@ func MircPost(line string, date time.Time, prev models.Post) (models.Post, error
 
 		return post, nil
 	} else {
-		return models.Post{}, ErrNotPost
+		return models.Post{}, &ParseError{
+			Line:    line,
+			Problem: "line is neither action nor text post",
+		}
 	}
 }

services/parsers/mirclike_test.go

@@ -58,29 +58,38 @@ func TestMircPost(t *testing.T) {
 func TestMircPostErrors(t *testing.T) {
 	table := []struct {
 		Input string
-		Err   error
+		Err   string
 	}{
-		{"[12:34] <Stuff> Things said.", nil},
-		{"[12:34] >Stuff> Things said.", parsers.ErrNotPost},
-		{"12:34] <Stuff> Things said.", parsers.ErrNotPost},
-		{"* Stuff Things said.", parsers.ErrNotPost},
-		{"", parsers.ErrNotPost},
-		{"[12:34 <Stuff> Things said.", parsers.ErrNotPost},
-		{"[TE:XT] <Stuff> Things said.", parsers.ErrNotPost},
-		{"[10] <Stuff> Things said.", parsers.ErrNotPost},
-		{"[12:34:56:789] <Stuff> Things said.", nil},
-		{"[12:34:56.789] <Stuff> Things said.", parsers.ErrNotPost},
-		{"[12:34] <Stuff>", parsers.ErrNotPost},
-		{"[12:34] * Stuff", parsers.ErrNotPost},
-		{"[12:34] =Scene=", parsers.ErrNotPost},
-		{"[12:34] <=Scene=>", parsers.ErrNotPost},
+		{"[12:34] <Stuff> Things said.", ""},
+		{"[12:34] >Stuff> Things said.", "line is neither action nor text post"},
+		{"12:34] <Stuff> Things said.", "no timestamp"},
+		{"* Stuff Things said.", "no timestamp"},
+		{"", "no timestamp"},
+		{"[12:34 <Stuff> Things said.", "incomplete timestamp"},
+		{"[TE:XT] <Stuff> Things said.", "invalid number in timestamp"},
+		{"[10] <Stuff> Things said.", "invalid timestamp"},
+		{"[12:34:56:789] <Stuff> Things said.", ""},
+		{"[12:34:56.789] <Stuff> Things said.", "invalid number in timestamp"},
+		{"[12:34] <Stuff>", "post is empty"},
+		{"[12:34] * Stuff", "post is empty"},
+		{"[12:34] =Scene=", "line is neither action nor text post"},
+		{"[12:34] <=Scene=>", "post is empty"},
 	}
 
 	for i, row := range table {
 		t.Run(fmt.Sprintf("Row_%d", i), func(t *testing.T) {
 			_, err := parsers.MircPost(row.Input, time.Now(), models.Post{})
 
-			assert.Equal(t, row.Err, err, "Error should match")
+			errProblem := ""
+			if err != nil {
+				if e2, ok := err.(*parsers.ParseError); ok {
+					errProblem = e2.Problem
+				} else {
+					errProblem = err.Error()
+				}
+			}
+
+			assert.Equal(t, row.Err, errProblem, "Error should match")
 		})
 	}
 }
@@ -160,7 +169,7 @@ func TestMircLogErrors(t *testing.T) {
 	_, err2 := parsers.MircLog("\n\n\n\n\n[14:57]* Stuff   \n\t\r\n", time.Time{}, true)
 
 	assert.Equal(t, parsers.ErrEmptyLog, err1)
-	assert.Equal(t, parsers.ErrNotPost, err2)
+	assert.True(t, parsers.IsParseError(err2))
 }
 
 func parseDate(t *testing.T, date string) time.Time {