internal/export/markdown/markdown.go

// Package markdown renders a capture as a GitHub-flavoured transcript,
// convenient for pasting into bug reports.
//
// mercemay.top/src/httptap/
package markdown

import (
	"fmt"
	"io"
	"strings"
	"time"

	"mercemay.top/httptap/internal/parser"
)

// Options tunes the rendering of each entry.
type Options struct {
	IncludeBody   bool
	BodyMaxBytes  int
	TimestampForm string // e.g. time.RFC3339
}

// Default returns sensible defaults.
func Default() Options {
	return Options{
		IncludeBody:   true,
		BodyMaxBytes:  8 * 1024,
		TimestampForm: time.RFC3339,
	}
}

// Write renders the request/response pair at time at with duration dur.
func Write(w io.Writer, req, resp parser.Message, at time.Time, dur time.Duration, opts Options) error {
	ts := at.Format(opts.TimestampForm)
	_, err := fmt.Fprintf(w, "### %s  `%s`  →  `%d`  (%s)\n\n",
		ts, parser.Method(req)+" "+parser.URL(req),
		parser.StatusCode(resp), dur)
	if err != nil {
		return err
	}
	if err := writeHeaders(w, "Request headers", req.Headers); err != nil {
		return err
	}
	if opts.IncludeBody && len(req.Body) > 0 {
		if err := writeBody(w, "Request body", parser.Header(req, "Content-Type"), req.Body, opts.BodyMaxBytes); err != nil {
			return err
		}
	}
	if err := writeHeaders(w, "Response headers", resp.Headers); err != nil {
		return err
	}
	if opts.IncludeBody && len(resp.Body) > 0 {
		if err := writeBody(w, "Response body", parser.Header(resp, "Content-Type"), resp.Body, opts.BodyMaxBytes); err != nil {
			return err
		}
	}
	_, err = io.WriteString(w, "\n---\n\n")
	return err
}

func writeHeaders(w io.Writer, title string, h [][2]string) error {
	if _, err := fmt.Fprintf(w, "**%s**\n\n", title); err != nil {
		return err
	}
	if len(h) == 0 {
		_, err := io.WriteString(w, "_(none)_\n\n")
		return err
	}
	if _, err := io.WriteString(w, "| Name | Value |\n|---|---|\n"); err != nil {
		return err
	}
	for _, kv := range h {
		if _, err := fmt.Fprintf(w, "| %s | %s |\n", kv[0], escape(kv[1])); err != nil {
			return err
		}
	}
	_, err := io.WriteString(w, "\n")
	return err
}

func writeBody(w io.Writer, title, mime string, body []byte, max int) error {
	if len(body) > max {
		body = body[:max]
	}
	if _, err := fmt.Fprintf(w, "**%s** (%s)\n\n```\n%s\n```\n\n", title, mime, body); err != nil {
		return err
	}
	return nil
}

func escape(v string) string {
	return strings.ReplaceAll(strings.ReplaceAll(v, "|", `\|`), "\n", " ")
}