blob: 46d7dd74bda8bfa31d614f131f1b5235ef0d1e2e [file] [log] [blame]
// 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 hooks
import (
"fmt"
"github.com/sergi/go-diff/diffmatchpatch"
"golang.org/x/tools/internal/lsp/diff"
"golang.org/x/tools/internal/span"
)
func ComputeEdits(uri span.URI, before, after string) (edits []diff.TextEdit, err error) {
// The go-diff library has an unresolved panic (see golang/go#278774).
// TOOD(rstambler): Remove the recover once the issue has been fixed
// upstream.
defer func() {
if r := recover(); r != nil {
edits = nil
err = fmt.Errorf("unable to compute edits for %s: %s", uri.Filename(), r)
}
}()
diffs := diffmatchpatch.New().DiffMain(before, after, true)
edits = make([]diff.TextEdit, 0, len(diffs))
offset := 0
for _, d := range diffs {
start := span.NewPoint(0, 0, offset)
switch d.Type {
case diffmatchpatch.DiffDelete:
offset += len(d.Text)
edits = append(edits, diff.TextEdit{Span: span.New(uri, start, span.NewPoint(0, 0, offset))})
case diffmatchpatch.DiffEqual:
offset += len(d.Text)
case diffmatchpatch.DiffInsert:
edits = append(edits, diff.TextEdit{Span: span.New(uri, start, span.Point{}), NewText: d.Text})
}
}
return edits, nil
}