1 files changed, 73 insertions, 0 deletions
diff --git a/gopls/internal/lsp/cmd/check.go b/gopls/internal/lsp/cmd/check.go
new file mode 100644
index 000000000..cf081ca26
--- /dev/null
+++ b/gopls/internal/lsp/cmd/check.go
@@ -0,0 +1,73 @@
+// 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/gopls/internal/span"
+)
+
+// check implements the check verb for gopls.
+type check struct {
+	app *Application
+}
+
+func (c *check) Name() string      { return "check" }
+func (c *check) Parent() string    { return c.app.Name() }
+func (c *check) Usage() string     { return "<filename>" }
+func (c *check) ShortHelp() string { return "show diagnostic results for the specified file" }
+func (c *check) DetailedHelp(f *flag.FlagSet) {
+	fmt.Fprint(f.Output(), `
+Example: show the diagnostic results of this file:
+
+	$ gopls check internal/lsp/cmd/check.go
+`)
+	printFlagDefaults(f)
+}
+
+// Run performs the check on the files specified by args and prints the
+// results to stdout.
+func (c *check) Run(ctx context.Context, args ...string) error {
+	if len(args) == 0 {
+		// no files, so no results
+		return nil
+	}
+	checking := map[span.URI]*cmdFile{}
+	var uris []span.URI
+	// now we ready to kick things off
+	conn, err := c.app.connect(ctx)
+	if err != nil {
+		return err
+	}
+	defer conn.terminate(ctx)
+	for _, arg := range args {
+		uri := span.URIFromPath(arg)
+		uris = append(uris, uri)
+		file := conn.openFile(ctx, uri)
+		if file.err != nil {
+			return file.err
+		}
+		checking[uri] = file
+	}
+	if err := conn.diagnoseFiles(ctx, uris); err != nil {
+		return err
+	}
+	conn.Client.filesMu.Lock()
+	defer conn.Client.filesMu.Unlock()
+
+	for _, file := range checking {
+		for _, d := range file.diagnostics {
+			spn, err := file.mapper.RangeSpan(d.Range)
+			if err != nil {
+				return fmt.Errorf("Could not convert position %v for %q", d.Range, d.Message)
+			}
+			fmt.Printf("%v: %v\n", spn, d.Message)
+		}
+	}
+	return nil
+}