1 files changed, 210 insertions, 0 deletions
diff --git a/vendor/github.com/hexops/gotextdiff/unified.go b/vendor/github.com/hexops/gotextdiff/unified.go
new file mode 100644
index 000000000..b7d85cfcc
--- /dev/null
+++ b/vendor/github.com/hexops/gotextdiff/unified.go
@@ -0,0 +1,210 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gotextdiff
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Unified represents a set of edits as a unified diff.
+type Unified struct {
+	// From is the name of the original file.
+	From string
+	// To is the name of the modified file.
+	To string
+	// Hunks is the set of edit hunks needed to transform the file content.
+	Hunks []*Hunk
+}
+
+// Hunk represents a contiguous set of line edits to apply.
+type Hunk struct {
+	// The line in the original source where the hunk starts.
+	FromLine int
+	// The line in the original source where the hunk finishes.
+	ToLine int
+	// The set of line based edits to apply.
+	Lines []Line
+}
+
+// Line represents a single line operation to apply as part of a Hunk.
+type Line struct {
+	// Kind is the type of line this represents, deletion, insertion or copy.
+	Kind OpKind
+	// Content is the content of this line.
+	// For deletion it is the line being removed, for all others it is the line
+	// to put in the output.
+	Content string
+}
+
+// OpKind is used to denote the type of operation a line represents.
+type OpKind int
+
+const (
+	// Delete is the operation kind for a line that is present in the input
+	// but not in the output.
+	Delete OpKind = iota
+	// Insert is the operation kind for a line that is new in the output.
+	Insert
+	// Equal is the operation kind for a line that is the same in the input and
+	// output, often used to provide context around edited lines.
+	Equal
+)
+
+// String returns a human readable representation of an OpKind. It is not
+// intended for machine processing.
+func (k OpKind) String() string {
+	switch k {
+	case Delete:
+		return "delete"
+	case Insert:
+		return "insert"
+	case Equal:
+		return "equal"
+	default:
+		panic("unknown operation kind")
+	}
+}
+
+const (
+	edge = 3
+	gap  = edge * 2
+)
+
+// ToUnified takes a file contents and a sequence of edits, and calculates
+// a unified diff that represents those edits.
+func ToUnified(from, to string, content string, edits []TextEdit) Unified {
+	u := Unified{
+		From: from,
+		To:   to,
+	}
+	if len(edits) == 0 {
+		return u
+	}
+	c, edits, partial := prepareEdits(content, edits)
+	if partial {
+		edits = lineEdits(content, c, edits)
+	}
+	lines := splitLines(content)
+	var h *Hunk
+	last := 0
+	toLine := 0
+	for _, edit := range edits {
+		start := edit.Span.Start().Line() - 1
+		end := edit.Span.End().Line() - 1
+		switch {
+		case h != nil && start == last:
+			//direct extension
+		case h != nil && start <= last+gap:
+			//within range of previous lines, add the joiners
+			addEqualLines(h, lines, last, start)
+		default:
+			//need to start a new hunk
+			if h != nil {
+				// add the edge to the previous hunk
+				addEqualLines(h, lines, last, last+edge)
+				u.Hunks = append(u.Hunks, h)
+			}
+			toLine += start - last
+			h = &Hunk{
+				FromLine: start + 1,
+				ToLine:   toLine + 1,
+			}
+			// add the edge to the new hunk
+			delta := addEqualLines(h, lines, start-edge, start)
+			h.FromLine -= delta
+			h.ToLine -= delta
+		}
+		last = start
+		for i := start; i < end; i++ {
+			h.Lines = append(h.Lines, Line{Kind: Delete, Content: lines[i]})
+			last++
+		}
+		if edit.NewText != "" {
+			for _, line := range splitLines(edit.NewText) {
+				h.Lines = append(h.Lines, Line{Kind: Insert, Content: line})
+				toLine++
+			}
+		}
+	}
+	if h != nil {
+		// add the edge to the final hunk
+		addEqualLines(h, lines, last, last+edge)
+		u.Hunks = append(u.Hunks, h)
+	}
+	return u
+}
+
+func splitLines(text string) []string {
+	lines := strings.SplitAfter(text, "\n")
+	if lines[len(lines)-1] == "" {
+		lines = lines[:len(lines)-1]
+	}
+	return lines
+}
+
+func addEqualLines(h *Hunk, lines []string, start, end int) int {
+	delta := 0
+	for i := start; i < end; i++ {
+		if i < 0 {
+			continue
+		}
+		if i >= len(lines) {
+			return delta
+		}
+		h.Lines = append(h.Lines, Line{Kind: Equal, Content: lines[i]})
+		delta++
+	}
+	return delta
+}
+
+// Format converts a unified diff to the standard textual form for that diff.
+// The output of this function can be passed to tools like patch.
+func (u Unified) Format(f fmt.State, r rune) {
+	if len(u.Hunks) == 0 {
+		return
+	}
+	fmt.Fprintf(f, "--- %s\n", u.From)
+	fmt.Fprintf(f, "+++ %s\n", u.To)
+	for _, hunk := range u.Hunks {
+		fromCount, toCount := 0, 0
+		for _, l := range hunk.Lines {
+			switch l.Kind {
+			case Delete:
+				fromCount++
+			case Insert:
+				toCount++
+			default:
+				fromCount++
+				toCount++
+			}
+		}
+		fmt.Fprint(f, "@@")
+		if fromCount > 1 {
+			fmt.Fprintf(f, " -%d,%d", hunk.FromLine, fromCount)
+		} else {
+			fmt.Fprintf(f, " -%d", hunk.FromLine)
+		}
+		if toCount > 1 {
+			fmt.Fprintf(f, " +%d,%d", hunk.ToLine, toCount)
+		} else {
+			fmt.Fprintf(f, " +%d", hunk.ToLine)
+		}
+		fmt.Fprint(f, " @@\n")
+		for _, l := range hunk.Lines {
+			switch l.Kind {
+			case Delete:
+				fmt.Fprintf(f, "-%s", l.Content)
+			case Insert:
+				fmt.Fprintf(f, "+%s", l.Content)
+			default:
+				fmt.Fprintf(f, " %s", l.Content)
+			}
+			if !strings.HasSuffix(l.Content, "\n") {
+				fmt.Fprintf(f, "\n\\ No newline at end of file\n")
+			}
+		}
+	}
+}