feat: better yaml parsing and error handling (#1619)

errors/error_taskfile_decode.go

@@ -0,0 +1,179 @@
+package errors
+
+import (
+	"bytes"
+	"embed"
+	"errors"
+	"fmt"
+	"regexp"
+	"strings"
+
+	"github.com/alecthomas/chroma/v2"
+	"github.com/alecthomas/chroma/v2/quick"
+	"github.com/alecthomas/chroma/v2/styles"
+	"github.com/fatih/color"
+	"gopkg.in/yaml.v3"
+)
+
+//go:embed themes/*.xml
+var embedded embed.FS
+
+var typeErrorRegex = regexp.MustCompile(`line \d+: (.*)`)
+
+func init() {
+	r, err := embedded.Open("themes/task.xml")
+	if err != nil {
+		panic(err)
+	}
+	style, err := chroma.NewXMLStyle(r)
+	if err != nil {
+		panic(err)
+	}
+	styles.Register(style)
+}
+
+type (
+	TaskfileDecodeError struct {
+		Message  string
+		Location string
+		Line     int
+		Column   int
+		Tag      string
+		Snippet  TaskfileSnippet
+		Err      error
+	}
+	TaskfileSnippet struct {
+		Lines     []string
+		StartLine int
+		EndLine   int
+		Padding   int
+	}
+)
+
+func NewTaskfileDecodeError(err error, node *yaml.Node) *TaskfileDecodeError {
+	// If the error is already a DecodeError, return it
+	taskfileInvalidErr := &TaskfileDecodeError{}
+	if errors.As(err, &taskfileInvalidErr) {
+		return taskfileInvalidErr
+	}
+	return &TaskfileDecodeError{
+		Line:   node.Line,
+		Column: node.Column,
+		Tag:    node.ShortTag(),
+		Err:    err,
+	}
+}
+
+func (err *TaskfileDecodeError) Error() string {
+	buf := &bytes.Buffer{}
+
+	// Print the error message
+	if err.Message != "" {
+		fmt.Fprintln(buf, color.RedString("err:  %s", err.Message))
+	} else {
+		// Extract the errors from the TypeError
+		te := &yaml.TypeError{}
+		if errors.As(err.Err, &te) {
+			if len(te.Errors) > 1 {
+				fmt.Fprintln(buf, color.RedString("errs:"))
+				for _, message := range te.Errors {
+					fmt.Fprintln(buf, color.RedString("- %s", extractTypeErrorMessage(message)))
+				}
+			} else {
+				fmt.Fprintln(buf, color.RedString("err:  %s", extractTypeErrorMessage(te.Errors[0])))
+			}
+		} else {
+			// Otherwise print the error message normally
+			fmt.Fprintln(buf, color.RedString("err:  %s", err.Err))
+		}
+	}
+	fmt.Fprintln(buf, color.RedString("file: %s:%d:%d", err.Location, err.Line, err.Column))
+
+	// Print the snippet
+	maxLineNumberDigits := digits(err.Snippet.EndLine)
+	lineNumberSpacer := strings.Repeat(" ", maxLineNumberDigits)
+	columnSpacer := strings.Repeat(" ", err.Column-1)
+	for i, line := range err.Snippet.Lines {
+		currentLine := err.Snippet.StartLine + i + 1
+
+		lineIndicator := " "
+		if currentLine == err.Line {
+			lineIndicator = ">"
+		}
+		columnIndicator := "^"
+
+		// Print each line
+		lineIndicator = color.RedString(lineIndicator)
+		columnIndicator = color.RedString(columnIndicator)
+		lineNumberFormat := fmt.Sprintf("%%%dd", maxLineNumberDigits)
+		lineNumber := fmt.Sprintf(lineNumberFormat, currentLine)
+		fmt.Fprintf(buf, "%s %s | %s", lineIndicator, lineNumber, line)
+
+		// Print the column indicator
+		if currentLine == err.Line {
+			fmt.Fprintf(buf, "\n  %s | %s%s", lineNumberSpacer, columnSpacer, columnIndicator)
+		}
+
+		// If there are more lines to print, add a newline
+		if i < len(err.Snippet.Lines)-1 {
+			fmt.Fprintln(buf)
+		}
+	}
+
+	return buf.String()
+}
+
+func (err *TaskfileDecodeError) Unwrap() error {
+	return err.Err
+}
+
+func (err *TaskfileDecodeError) Code() int {
+	return CodeTaskfileDecode
+}
+
+func (err *TaskfileDecodeError) WithMessage(format string, a ...any) *TaskfileDecodeError {
+	err.Message = fmt.Sprintf(format, a...)
+	return err
+}
+
+func (err *TaskfileDecodeError) WithTypeMessage(t string) *TaskfileDecodeError {
+	err.Message = fmt.Sprintf("cannot unmarshal %s into %s", err.Tag, t)
+	return err
+}
+
+func (err *TaskfileDecodeError) WithFileInfo(location string, b []byte, padding int) *TaskfileDecodeError {
+	buf := &bytes.Buffer{}
+	if err := quick.Highlight(buf, string(b), "yaml", "terminal", "task"); err != nil {
+		buf.WriteString(string(b))
+	}
+	lines := strings.Split(buf.String(), "\n")
+	start := max(err.Line-1-padding, 0)
+	end := min(err.Line+padding, len(lines)-1)
+
+	err.Location = location
+	err.Snippet = TaskfileSnippet{
+		Lines:     lines[start:end],
+		StartLine: start,
+		EndLine:   end,
+		Padding:   padding,
+	}
+
+	return err
+}
+
+func extractTypeErrorMessage(message string) string {
+	matches := typeErrorRegex.FindStringSubmatch(message)
+	if len(matches) == 2 {
+		return matches[1]
+	}
+	return message
+}
+
+func digits(number int) int {
+	count := 0
+	for number != 0 {
+		number /= 10
+		count += 1
+	}
+	return count
+}