@ -181,64 +181,60 @@ var (
removedCodePrefix = [ ] byte ( ` <span class="removed-code"> ` )
codeTagSuffix = [ ] byte ( ` </span> ` )
)
var addSpanRegex = regexp . MustCompile ( ` <span [class="[a-z]*]*$ ` )
var trailingSpanRegex = regexp . MustCompile ( ` <span\s*[[:alpha:]="]*?[>]?$ ` )
// shouldWriteInline represents combinations where we manually write inline changes
func shouldWriteInline ( diff diffmatchpatch . Diff , lineType DiffLineType ) bool {
if true &&
diff . Type == diffmatchpatch . DiffEqual ||
diff . Type == diffmatchpatch . DiffInsert && lineType == DiffLineAdd ||
diff . Type == diffmatchpatch . DiffDelete && lineType == DiffLineDel {
return true
}
return false
}
func diffToHTML ( fileName string , diffs [ ] diffmatchpatch . Diff , lineType DiffLineType ) template . HTML {
buf := bytes . NewBuffer ( nil )
var addSpan string
for i := range diffs {
switch {
case diffs [ i ] . Type == diffmatchpatch . DiffEqual :
// Looking for the case where our 3rd party diff library previously detected a string difference
// in the middle of a span class because we highlight them first. This happens when added/deleted code
// also changes the chroma class name, either partially or fully. If found, just move the openining span code forward into the next section
// see TestDiffToHTML for examples
if len ( addSpan ) > 0 {
diffs [ i ] . Text = addSpan + diffs [ i ] . Text
addSpan = ""
match := ""
for _ , diff := range diffs {
if shouldWriteInline ( diff , lineType ) {
if len ( match ) > 0 {
diff . Text = match + diff . Text
match = ""
}
m := addSpanRegex . FindStringSubmatchIndex ( diffs [ i ] . Text )
// Chroma HTML syntax highlighting is done before diffing individual lines in order to maintain consistency.
// Since inline changes might split in the middle of a chroma span tag, make we manually put it back together
// before writing so we don't try insert added/removed code spans in the middle of an existing chroma span
// and create broken HTML.
m := trailingSpanRegex . FindStringSubmatchIndex ( diff . Text )
if m != nil {
addSpan = diffs [ i ] . Text [ m [ 0 ] : m [ 1 ] ]
buf . WriteString ( strings . TrimSuffix ( diffs [ i ] . Text , addSpan ) )
} else {
addSpan = ""
buf . WriteString ( getLineContent ( diffs [ i ] . Text ) )
}
case diffs [ i ] . Type == diffmatchpatch . DiffInsert && lineType == DiffLineAdd :
if len ( addSpan ) > 0 {
diffs [ i ] . Text = addSpan + diffs [ i ] . Text
addSpan = ""
match = diff . Text [ m [ 0 ] : m [ 1 ] ]
diff . Text = strings . TrimSuffix ( diff . Text , match )
}
// Print existing closing span first before opening added-code span so it doesn't unintentionally close it
if strings . HasPrefix ( diffs [ i ] . Text , "</span>" ) {
// Print an existing closing span first before opening added/remove-code span so it doesn't unintentionally close it
if strings . HasPrefix ( diff . Text , "</span>" ) {
buf . WriteString ( "</span>" )
diffs [ i ] . Text = strings . TrimPrefix ( diffs [ i ] . Text , "</span>" )
diff . Text = strings . TrimPrefix ( diff . Text , "</span>" )
}
m := addSpanRegex . FindStringSubmatchIndex ( diffs [ i ] . Text )
if m != nil {
addSpan = diffs [ i ] . Text [ m [ 0 ] : m [ 1 ] ]
diffs [ i ] . Text = strings . TrimSuffix ( diffs [ i ] . Text , addSpan )
// If we weren't able to fix it then this should avoid broken HTML by not inserting more spans below
// The previous/next diff section will contain the rest of the tag that is missing here
if strings . Count ( diff . Text , "<" ) != strings . Count ( diff . Text , ">" ) {
buf . WriteString ( diff . Text )
continue
}
}
switch {
case diff . Type == diffmatchpatch . DiffEqual :
buf . WriteString ( diff . Text )
case diff . Type == diffmatchpatch . DiffInsert && lineType == DiffLineAdd :
buf . Write ( addedCodePrefix )
buf . WriteString ( getLineContent ( diffs [ i ] . Text ) )
buf . WriteString ( diff . Text )
buf . Write ( codeTagSuffix )
case diffs [ i ] . Type == diffmatchpatch . DiffDelete && lineType == DiffLineDel :
if len ( addSpan ) > 0 {
diffs [ i ] . Text = addSpan + diffs [ i ] . Text
addSpan = ""
}
if strings . HasPrefix ( diffs [ i ] . Text , "</span>" ) {
buf . WriteString ( "</span>" )
diffs [ i ] . Text = strings . TrimPrefix ( diffs [ i ] . Text , "</span>" )
}
m := addSpanRegex . FindStringSubmatchIndex ( diffs [ i ] . Text )
if m != nil {
addSpan = diffs [ i ] . Text [ m [ 0 ] : m [ 1 ] ]
diffs [ i ] . Text = strings . TrimSuffix ( diffs [ i ] . Text , addSpan )
}
case diff . Type == diffmatchpatch . DiffDelete && lineType == DiffLineDel :
buf . Write ( removedCodePrefix )
buf . WriteString ( getLineContent ( diffs [ i ] . Text ) )
buf . WriteString ( diff . Text )
buf . Write ( codeTagSuffix )
}
}
mrsdizzie
4 years ago
committed by
GitHub