github.com/v2fly/tools@v0.100.0/internal/lsp/cmd/definition.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  	"encoding/json"
    10  	"flag"
    11  	"fmt"
    12  	"os"
    13  	"strings"
    14  
    15  	"github.com/v2fly/tools/internal/lsp/protocol"
    16  	"github.com/v2fly/tools/internal/lsp/source"
    17  	"github.com/v2fly/tools/internal/span"
    18  	"github.com/v2fly/tools/internal/tool"
    19  	errors "golang.org/x/xerrors"
    20  )
    21  
    22  // A Definition is the result of a 'definition' query.
    23  type Definition struct {
    24  	Span        span.Span `json:"span"`        // span of the definition
    25  	Description string    `json:"description"` // description of the denoted object
    26  }
    27  
    28  // These constant is printed in the help, and then used in a test to verify the
    29  // help is still valid.
    30  // They refer to "Set" in "flag.FlagSet" from the DetailedHelp method below.
    31  const (
    32  	exampleLine   = 44
    33  	exampleColumn = 47
    34  	exampleOffset = 1270
    35  )
    36  
    37  // definition implements the definition verb for gopls.
    38  type definition struct {
    39  	app *Application
    40  
    41  	JSON              bool `flag:"json" help:"emit output in JSON format"`
    42  	MarkdownSupported bool `flag:"markdown" help:"support markdown in responses"`
    43  }
    44  
    45  func (d *definition) Name() string      { return "definition" }
    46  func (d *definition) Usage() string     { return "<position>" }
    47  func (d *definition) ShortHelp() string { return "show declaration of selected identifier" }
    48  func (d *definition) DetailedHelp(f *flag.FlagSet) {
    49  	fmt.Fprintf(f.Output(), `
    50  Example: show the definition of the identifier at syntax at offset %[1]v in this file (flag.FlagSet):
    51  
    52  $ gopls definition internal/lsp/cmd/definition.go:%[1]v:%[2]v
    53  $ gopls definition internal/lsp/cmd/definition.go:#%[3]v
    54  
    55  	gopls query definition flags are:
    56  `, exampleLine, exampleColumn, exampleOffset)
    57  	f.PrintDefaults()
    58  }
    59  
    60  // Run performs the definition query as specified by args and prints the
    61  // results to stdout.
    62  func (d *definition) Run(ctx context.Context, args ...string) error {
    63  	if len(args) != 1 {
    64  		return tool.CommandLineErrorf("definition expects 1 argument")
    65  	}
    66  	// Plaintext makes more sense for the command line.
    67  	opts := d.app.options
    68  	d.app.options = func(o *source.Options) {
    69  		if opts != nil {
    70  			opts(o)
    71  		}
    72  		o.PreferredContentFormat = protocol.PlainText
    73  		if d.MarkdownSupported {
    74  			o.PreferredContentFormat = protocol.Markdown
    75  		}
    76  	}
    77  	conn, err := d.app.connect(ctx)
    78  	if err != nil {
    79  		return err
    80  	}
    81  	defer conn.terminate(ctx)
    82  	from := span.Parse(args[0])
    83  	file := conn.AddFile(ctx, from.URI())
    84  	if file.err != nil {
    85  		return file.err
    86  	}
    87  	loc, err := file.mapper.Location(from)
    88  	if err != nil {
    89  		return err
    90  	}
    91  	tdpp := protocol.TextDocumentPositionParams{
    92  		TextDocument: protocol.TextDocumentIdentifier{URI: loc.URI},
    93  		Position:     loc.Range.Start,
    94  	}
    95  	p := protocol.DefinitionParams{
    96  		TextDocumentPositionParams: tdpp,
    97  	}
    98  	locs, err := conn.Definition(ctx, &p)
    99  	if err != nil {
   100  		return errors.Errorf("%v: %v", from, err)
   101  	}
   102  
   103  	if len(locs) == 0 {
   104  		return errors.Errorf("%v: not an identifier", from)
   105  	}
   106  	q := protocol.HoverParams{
   107  		TextDocumentPositionParams: tdpp,
   108  	}
   109  	hover, err := conn.Hover(ctx, &q)
   110  	if err != nil {
   111  		return errors.Errorf("%v: %v", from, err)
   112  	}
   113  	if hover == nil {
   114  		return errors.Errorf("%v: not an identifier", from)
   115  	}
   116  	file = conn.AddFile(ctx, fileURI(locs[0].URI))
   117  	if file.err != nil {
   118  		return errors.Errorf("%v: %v", from, file.err)
   119  	}
   120  	definition, err := file.mapper.Span(locs[0])
   121  	if err != nil {
   122  		return errors.Errorf("%v: %v", from, err)
   123  	}
   124  	description := strings.TrimSpace(hover.Contents.Value)
   125  	result := &Definition{
   126  		Span:        definition,
   127  		Description: description,
   128  	}
   129  	if d.JSON {
   130  		enc := json.NewEncoder(os.Stdout)
   131  		enc.SetIndent("", "\t")
   132  		return enc.Encode(result)
   133  	}
   134  	fmt.Printf("%v: defined here as %s", result.Span, result.Description)
   135  	return nil
   136  }