mirror of
https://github.com/golang/go
synced 2024-11-19 02:54:42 -07:00
b184d1ccfc
This also means we don't need the J2 becasue it is implied by len(Content) Change-Id: I04e2cbaa3e1faa1e3add22ec2d478821b9062419 Reviewed-on: https://go-review.googlesource.com/c/tools/+/170878 Run-TryBot: Ian Cottrell <iancottrell@google.com> Reviewed-by: Rebecca Stambler <rstambler@golang.org>
83 lines
2.6 KiB
Go
83 lines
2.6 KiB
Go
// Copyright 2018 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 source provides core features for use by Go editors and tools.
|
|
package source
|
|
|
|
import (
|
|
"bytes"
|
|
"context"
|
|
"fmt"
|
|
"go/ast"
|
|
"go/format"
|
|
"strings"
|
|
|
|
"golang.org/x/tools/go/ast/astutil"
|
|
"golang.org/x/tools/imports"
|
|
"golang.org/x/tools/internal/lsp/diff"
|
|
"golang.org/x/tools/internal/span"
|
|
)
|
|
|
|
// Format formats a file with a given range.
|
|
func Format(ctx context.Context, f File, rng span.Range) ([]TextEdit, error) {
|
|
fAST := f.GetAST(ctx)
|
|
path, exact := astutil.PathEnclosingInterval(fAST, rng.Start, rng.End)
|
|
if !exact || len(path) == 0 {
|
|
return nil, fmt.Errorf("no exact AST node matching the specified range")
|
|
}
|
|
node := path[0]
|
|
// format.Node can fail when the AST contains a bad expression or
|
|
// statement. For now, we preemptively check for one.
|
|
// TODO(rstambler): This should really return an error from format.Node.
|
|
var isBad bool
|
|
ast.Inspect(node, func(n ast.Node) bool {
|
|
switch n.(type) {
|
|
case *ast.BadDecl, *ast.BadExpr, *ast.BadStmt:
|
|
isBad = true
|
|
return false
|
|
default:
|
|
return true
|
|
}
|
|
})
|
|
if isBad {
|
|
return nil, fmt.Errorf("unable to format file due to a badly formatted AST")
|
|
}
|
|
// format.Node changes slightly from one release to another, so the version
|
|
// of Go used to build the LSP server will determine how it formats code.
|
|
// This should be acceptable for all users, who likely be prompted to rebuild
|
|
// the LSP server on each Go release.
|
|
fset := f.GetFileSet(ctx)
|
|
buf := &bytes.Buffer{}
|
|
if err := format.Node(buf, fset, node); err != nil {
|
|
return nil, err
|
|
}
|
|
return computeTextEdits(ctx, f, buf.String()), nil
|
|
}
|
|
|
|
// Imports formats a file using the goimports tool.
|
|
func Imports(ctx context.Context, f File, rng span.Range) ([]TextEdit, error) {
|
|
formatted, err := imports.Process(f.GetToken(ctx).Name(), f.GetContent(ctx), nil)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return computeTextEdits(ctx, f, string(formatted)), nil
|
|
}
|
|
|
|
func computeTextEdits(ctx context.Context, file File, formatted string) (edits []TextEdit) {
|
|
u := strings.SplitAfter(string(file.GetContent(ctx)), "\n")
|
|
f := strings.SplitAfter(formatted, "\n")
|
|
for _, op := range diff.Operations(u, f) {
|
|
s := span.New(file.URI(), span.NewPoint(op.I1+1, 1, 0), span.NewPoint(op.I2+1, 1, 0))
|
|
switch op.Kind {
|
|
case diff.Delete:
|
|
// Delete: unformatted[i1:i2] is deleted.
|
|
edits = append(edits, TextEdit{Span: s})
|
|
case diff.Insert:
|
|
// Insert: formatted[j1:j2] is inserted at unformatted[i1:i1].
|
|
edits = append(edits, TextEdit{Span: s, NewText: strings.Join(op.Content, "")})
|
|
}
|
|
}
|
|
return edits
|
|
}
|