github.com/jhump/golang-x-tools@v0.0.0-20220218190644-4958d6d39439/internal/lsp/cmd/format.go (about)

     1  // Copyright 2019 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package cmd
     6  
     7  import (
     8  	"context"
     9  	"flag"
    10  	"fmt"
    11  	"io/ioutil"
    12  
    13  	"github.com/jhump/golang-x-tools/internal/lsp/diff"
    14  	"github.com/jhump/golang-x-tools/internal/lsp/protocol"
    15  	"github.com/jhump/golang-x-tools/internal/lsp/source"
    16  	"github.com/jhump/golang-x-tools/internal/span"
    17  	errors "golang.org/x/xerrors"
    18  )
    19  
    20  // format implements the format verb for gopls.
    21  type format struct {
    22  	Diff  bool `flag:"d,diff" help:"display diffs instead of rewriting files"`
    23  	Write bool `flag:"w,write" help:"write result to (source) file instead of stdout"`
    24  	List  bool `flag:"l,list" help:"list files whose formatting differs from gofmt's"`
    25  
    26  	app *Application
    27  }
    28  
    29  func (c *format) Name() string      { return "format" }
    30  func (c *format) Parent() string    { return c.app.Name() }
    31  func (c *format) Usage() string     { return "[format-flags] <filerange>" }
    32  func (c *format) ShortHelp() string { return "format the code according to the go standard" }
    33  func (c *format) DetailedHelp(f *flag.FlagSet) {
    34  	fmt.Fprint(f.Output(), `
    35  The arguments supplied may be simple file names, or ranges within files.
    36  
    37  Example: reformat this file:
    38  
    39  	$ gopls format -w internal/lsp/cmd/check.go
    40  
    41  format-flags:
    42  `)
    43  	printFlagDefaults(f)
    44  }
    45  
    46  // Run performs the check on the files specified by args and prints the
    47  // results to stdout.
    48  func (c *format) Run(ctx context.Context, args ...string) error {
    49  	if len(args) == 0 {
    50  		// no files, so no results
    51  		return nil
    52  	}
    53  	// now we ready to kick things off
    54  	conn, err := c.app.connect(ctx)
    55  	if err != nil {
    56  		return err
    57  	}
    58  	defer conn.terminate(ctx)
    59  	for _, arg := range args {
    60  		spn := span.Parse(arg)
    61  		file := conn.AddFile(ctx, spn.URI())
    62  		if file.err != nil {
    63  			return file.err
    64  		}
    65  		filename := spn.URI().Filename()
    66  		loc, err := file.mapper.Location(spn)
    67  		if err != nil {
    68  			return err
    69  		}
    70  		if loc.Range.Start != loc.Range.End {
    71  			return errors.Errorf("only full file formatting supported")
    72  		}
    73  		p := protocol.DocumentFormattingParams{
    74  			TextDocument: protocol.TextDocumentIdentifier{URI: loc.URI},
    75  		}
    76  		edits, err := conn.Formatting(ctx, &p)
    77  		if err != nil {
    78  			return errors.Errorf("%v: %v", spn, err)
    79  		}
    80  		sedits, err := source.FromProtocolEdits(file.mapper, edits)
    81  		if err != nil {
    82  			return errors.Errorf("%v: %v", spn, err)
    83  		}
    84  		formatted := diff.ApplyEdits(string(file.mapper.Content), sedits)
    85  		printIt := true
    86  		if c.List {
    87  			printIt = false
    88  			if len(edits) > 0 {
    89  				fmt.Println(filename)
    90  			}
    91  		}
    92  		if c.Write {
    93  			printIt = false
    94  			if len(edits) > 0 {
    95  				ioutil.WriteFile(filename, []byte(formatted), 0644)
    96  			}
    97  		}
    98  		if c.Diff {
    99  			printIt = false
   100  			u := diff.ToUnified(filename+".orig", filename, string(file.mapper.Content), sedits)
   101  			fmt.Print(u)
   102  		}
   103  		if printIt {
   104  			fmt.Print(formatted)
   105  		}
   106  	}
   107  	return nil
   108  }