[bugfix] html escape special characters in text instead of totally removing them (#719)

* remove minify dependency

* tidy up some tests

* remove pre + postformat funcs

* rework sanitization + formatting

* update tests

* add some more markdown tests

vendor/github.com/tdewolff/parse/v2/position.go

@@ -1,95 +0,0 @@
-package parse
-
-import (
-	"fmt"
-	"io"
-	"strings"
-	"unicode"
-)
-
-// Position returns the line and column number for a certain position in a file. It is useful for recovering the position in a file that caused an error.
-// It only treates \n, \r, and \r\n as newlines, which might be different from some languages also recognizing \f, \u2028, and \u2029 to be newlines.
-func Position(r io.Reader, offset int) (line, col int, context string) {
-	l := NewInput(r)
-	line = 1
-	for l.Pos() < offset {
-		c := l.Peek(0)
-		n := 1
-		newline := false
-		if c == '\n' {
-			newline = true
-		} else if c == '\r' {
-			if l.Peek(1) == '\n' {
-				newline = true
-				n = 2
-			} else {
-				newline = true
-			}
-		} else if c >= 0xC0 {
-			var r rune
-			if r, n = l.PeekRune(0); r == '\u2028' || r == '\u2029' {
-				newline = true
-			}
-		} else if c == 0 && l.Err() != nil {
-			break
-		}
-
-		if 1 < n && offset < l.Pos()+n {
-			break
-		}
-		l.Move(n)
-
-		if newline {
-			line++
-			offset -= l.Pos()
-			l.Skip()
-		}
-	}
-
-	col = len([]rune(string(l.Lexeme()))) + 1
-	context = positionContext(l, line, col)
-	return
-}
-
-func positionContext(l *Input, line, col int) (context string) {
-	for {
-		c := l.Peek(0)
-		if c == 0 && l.Err() != nil || c == '\n' || c == '\r' {
-			break
-		}
-		l.Move(1)
-	}
-	rs := []rune(string(l.Lexeme()))
-
-	// cut off front or rear of context to stay between 60 characters
-	limit := 60
-	offset := 20
-	ellipsisFront := ""
-	ellipsisRear := ""
-	if limit < len(rs) {
-		if col <= limit-offset {
-			ellipsisRear = "..."
-			rs = rs[:limit-3]
-		} else if col >= len(rs)-offset-3 {
-			ellipsisFront = "..."
-			col -= len(rs) - offset - offset - 7
-			rs = rs[len(rs)-offset-offset-4:]
-		} else {
-			ellipsisFront = "..."
-			ellipsisRear = "..."
-			rs = rs[col-offset-1 : col+offset]
-			col = offset + 4
-		}
-	}
-
-	// replace unprintable characters by a space
-	for i, r := range rs {
-		if !unicode.IsGraphic(r) {
-			rs[i] = '·'
-		}
-	}
-
-	context += fmt.Sprintf("%5d: %s%s%s\n", line, ellipsisFront, string(rs), ellipsisRear)
-	context += fmt.Sprintf("%s^", strings.Repeat(" ", 6+col))
-	return
-}