tools/gopls: add cmd support for signature
This change adds command line support for signatureHelp.
If the location provided corresponds to a function, that
function signature is displayed. In case that function is
documented the related comment is shown as well.
Example:
$ gopls signature ~/tmp/foo/main.go:7:5
$
$ Next(n int) []byte
$
$ Next returns a slice containing the next n bytes from
$ the buffer, advancing the buffer as if the bytes had been
$ returned by Read.
Note that linebreaks shown in the comment are just to adhere
commit message guidelines. The command prints documentation
comments on one line.
Updates golang/go#32875
Change-Id: Ib0dcc3267c594f95d80b74f289c1235c2c0c5f64
Reviewed-on: https://go-review.googlesource.com/c/tools/+/204057
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/internal/lsp/cmd/cmd.go b/internal/lsp/cmd/cmd.go
index 00f9a9d..519c196 100644
--- a/internal/lsp/cmd/cmd.go
+++ b/internal/lsp/cmd/cmd.go
@@ -147,6 +147,7 @@
&query{app: app},
&references{app: app},
&rename{app: app},
+ &signature{app: app},
&suggestedfix{app: app},
&version{app: app},
}
diff --git a/internal/lsp/cmd/signature.go b/internal/lsp/cmd/signature.go
new file mode 100644
index 0000000..7cc91cd
--- /dev/null
+++ b/internal/lsp/cmd/signature.go
@@ -0,0 +1,88 @@
+// 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 cmd
+
+import (
+ "context"
+ "flag"
+ "fmt"
+
+ "golang.org/x/tools/internal/lsp/protocol"
+ "golang.org/x/tools/internal/span"
+ "golang.org/x/tools/internal/tool"
+)
+
+// signature implements the signature verb for gopls
+type signature struct {
+ app *Application
+}
+
+func (r *signature) Name() string { return "signature" }
+func (r *signature) Usage() string { return "<position>" }
+func (r *signature) ShortHelp() string { return "display selected identifier's signature" }
+func (r *signature) DetailedHelp(f *flag.FlagSet) {
+ fmt.Fprint(f.Output(), `
+Example:
+
+ $ # 1-indexed location (:line:column or :#offset) of the target identifier
+ $ gopls signature helper/helper.go:8:6
+ $ gopls signature helper/helper.go:#53
+
+ gopls signature flags are:
+`)
+ f.PrintDefaults()
+}
+
+func (r *signature) Run(ctx context.Context, args ...string) error {
+ if len(args) != 1 {
+ return tool.CommandLineErrorf("signature expects 1 argument (position)")
+ }
+
+ conn, err := r.app.connect(ctx)
+ if err != nil {
+ return err
+ }
+ defer conn.terminate(ctx)
+
+ from := span.Parse(args[0])
+ file := conn.AddFile(ctx, from.URI())
+ if file.err != nil {
+ return file.err
+ }
+
+ loc, err := file.mapper.Location(from)
+ if err != nil {
+ return err
+ }
+
+ tdpp := protocol.TextDocumentPositionParams{
+ TextDocument: protocol.TextDocumentIdentifier{
+ URI: protocol.NewURI(from.URI()),
+ },
+ Position: loc.Range.Start,
+ }
+ p := protocol.SignatureHelpParams{
+ TextDocumentPositionParams: tdpp,
+ }
+
+ s, err := conn.SignatureHelp(ctx, &p)
+ if err != nil {
+ return err
+ }
+
+ if len(s.Signatures) == 0 {
+ return tool.CommandLineErrorf("%v: not a function", from)
+ }
+
+ // there is only ever one possible signature,
+ // see toProtocolSignatureHelp in lsp/signature_help.go
+ signature := s.Signatures[0]
+ fmt.Printf("%s\n", signature.Label)
+ if signature.Documentation != "" {
+ fmt.Printf("\n%s\n", signature.Documentation)
+ }
+
+ return nil
+}
diff --git a/internal/lsp/cmd/test/cmdtest.go b/internal/lsp/cmd/test/cmdtest.go
index 5b51688..2a6276a 100644
--- a/internal/lsp/cmd/test/cmdtest.go
+++ b/internal/lsp/cmd/test/cmdtest.go
@@ -82,10 +82,6 @@
//TODO: add command line symbol tests when it works
}
-func (r *runner) SignatureHelp(t *testing.T, spn span.Span, expectedSignature *source.SignatureInformation) {
- //TODO: add command line signature tests when it works
-}
-
func (r *runner) Link(t *testing.T, uri span.URI, wantLinks []tests.Link) {
//TODO: add command line link tests when it works
}
diff --git a/internal/lsp/cmd/test/signature.go b/internal/lsp/cmd/test/signature.go
new file mode 100644
index 0000000..5ba55bd
--- /dev/null
+++ b/internal/lsp/cmd/test/signature.go
@@ -0,0 +1,39 @@
+// 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 cmdtest
+
+import (
+ "fmt"
+ "testing"
+
+ "golang.org/x/tools/internal/lsp/cmd"
+ "golang.org/x/tools/internal/lsp/source"
+ "golang.org/x/tools/internal/tool"
+
+ "golang.org/x/tools/internal/span"
+)
+
+func (r *runner) SignatureHelp(t *testing.T, spn span.Span, expectedSignature *source.SignatureInformation) {
+ goldenTag := "-signature"
+ if expectedSignature != nil {
+ goldenTag = expectedSignature.Label + goldenTag
+ }
+ uri := spn.URI()
+ filename := uri.Filename()
+ target := filename + fmt.Sprintf(":%v:%v", spn.Start().Line(), spn.Start().Column())
+
+ app := cmd.New("gopls-test", r.data.Config.Dir, r.data.Config.Env, r.options)
+ got := CaptureStdOut(t, func() {
+ tool.Run(r.ctx, app, append([]string{"-remote=internal", "signature"}, target))
+ })
+
+ expect := string(r.data.Golden(goldenTag, filename, func() ([]byte, error) {
+ return []byte(got), nil
+ }))
+
+ if expect != got {
+ t.Errorf("signature failed failed for %s expected:\n%s\ngot:\n%s", filename, expect, got)
+ }
+}
diff --git a/internal/lsp/testdata/signature/signature.go.golden b/internal/lsp/testdata/signature/signature.go.golden
new file mode 100644
index 0000000..dafd426
--- /dev/null
+++ b/internal/lsp/testdata/signature/signature.go.golden
@@ -0,0 +1,40 @@
+-- -signature --
+
+-- Bar(float64, ...byte)-signature --
+Bar(float64, ...byte)
+
+-- Foo(a string, b int) (c bool)-signature --
+Foo(a string, b int) (c bool)
+
+-- Next(n int) []byte-signature --
+Next(n int) []byte
+
+Next returns a slice containing the next n bytes from the buffer, advancing the buffer as if the bytes had been returned by Read.
+
+-- fn(hi string, there string) func(i int) rune-signature --
+fn(hi string, there string) func(i int) rune
+
+-- foo(e *json.Decoder) (*big.Int, error)-signature --
+foo(e *json.Decoder) (*big.Int, error)
+
+-- func(hi string, there string) func(i int) rune-signature --
+func(hi string, there string) func(i int) rune
+
+-- func(i int) rune-signature --
+func(i int) rune
+
+-- func(string, int) bool-signature --
+func(string, int) bool
+
+-- make(t Type, size ...int) Type-signature --
+make(t Type, size ...int) Type
+
+-- myFunc(foo int) string-signature --
+myFunc(foo int) string
+
+-- panic(v interface{})-signature --
+panic(v interface{})
+
+-- println(args ...Type)-signature --
+println(args ...Type)
+
