internal/lsp/cmd: add vulncheck command

Usage: gopls vulncheck <package_pattern>

It prints json-encoded command.VulncheckResult in stdout.

Change-Id: I752b3f06d7c6b2c7de68bd1221283205955c383f
Reviewed-on: https://go-review.googlesource.com/c/tools/+/395676
Trust: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

internal/lsp/cmd/cmd.go

@@ -273,6 +273,7 @@ func (app *Application) featureCommands() []tool.Application {
 		&symbols{app: app},
 		newWorkspace(app),
 		&workspaceSymbol{app: app},
+		&vulncheck{app: app},
 	}
 }
 

internal/lsp/cmd/usage/usage.hlp

@@ -38,6 +38,7 @@ Features
   symbols           display selected file's symbols
   workspace         manage the gopls workspace (experimental: under development)
   workspace_symbol  search symbols in workspace
+  vulncheck         run experimental vulncheck analysis (experimental: under development)
 
 flags:
   -debug=string

internal/lsp/cmd/usage/vulncheck.hlp

@@ -0,0 +1,9 @@
+run experimental vulncheck analysis (experimental: under development)
+
+Usage:
+  gopls [flags] vulncheck
+
+	WARNING: this command is experimental.
+
+	Example:
+	$ gopls vulncheck <packages>

internal/lsp/cmd/vulncheck.go

@@ -0,0 +1,79 @@
+// Copyright 2022 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"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"os"
+
+	"golang.org/x/tools/internal/lsp/command"
+	"golang.org/x/tools/internal/lsp/protocol"
+	"golang.org/x/tools/internal/tool"
+)
+
+// vulncheck implements the vulncheck command.
+type vulncheck struct {
+	app *Application
+}
+
+func (v *vulncheck) Name() string   { return "vulncheck" }
+func (v *vulncheck) Parent() string { return v.app.Name() }
+func (v *vulncheck) Usage() string  { return "" }
+func (v *vulncheck) ShortHelp() string {
+	return "run experimental vulncheck analysis (experimental: under development)"
+}
+func (v *vulncheck) DetailedHelp(f *flag.FlagSet) {
+	fmt.Fprint(f.Output(), `
+	WARNING: this command is experimental.
+
+	Example:
+	$ gopls vulncheck <packages>
+`)
+	printFlagDefaults(f)
+}
+
+func (v *vulncheck) Run(ctx context.Context, args ...string) error {
+	if len(args) > 1 {
+		return tool.CommandLineErrorf("vulncheck accepts at most one package pattern")
+	}
+	pattern := "."
+	if len(args) == 1 {
+		pattern = args[0]
+	}
+
+	conn, err := v.app.connect(ctx)
+	if err != nil {
+		return err
+	}
+	defer conn.terminate(ctx)
+
+	cwd, err := os.Getwd()
+	if err != nil {
+		return err
+	}
+
+	cmd, err := command.NewRunVulncheckExpCommand("", command.VulncheckArgs{
+		Dir:     protocol.URIFromPath(cwd),
+		Pattern: pattern,
+	})
+	if err != nil {
+		return err
+	}
+
+	params := &protocol.ExecuteCommandParams{Command: cmd.Command, Arguments: cmd.Arguments}
+	res, err := conn.ExecuteCommand(ctx, params)
+	if err != nil {
+		return fmt.Errorf("executing server command: %v", err)
+	}
+	data, err := json.MarshalIndent(res, " ", " ")
+	if err != nil {
+		return fmt.Errorf("failed to decode results: %v", err)
+	}
+	fmt.Printf("%s\n", data)
+	return nil
+}