gopls/internal/golang: fix crash in source.test code action

We forgot to set needPkg=true. Clearly this code has never been
tested since its inception in CL 231959.

Also, add the missing test.

Fixes golang/go#72907

Change-Id: I077b27ab4c64900ecefa19cb1329eb47d9cd6f28
Reviewed-on: https://go-review.googlesource.com/c/tools/+/658556
Reviewed-by: Robert Findley <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Auto-Submit: Alan Donovan <[email protected]>

Author: adonovan

gopls/internal/golang/codeaction.go

@@ -240,7 +240,7 @@ var codeActionProducers = [...]codeActionProducer{
 	{kind: settings.GoAssembly, fn: goAssembly, needPkg: true},
 	{kind: settings.GoDoc, fn: goDoc, needPkg: true},
 	{kind: settings.GoFreeSymbols, fn: goFreeSymbols},
-	{kind: settings.GoTest, fn: goTest},
+	{kind: settings.GoTest, fn: goTest, needPkg: true},
 	{kind: settings.GoToggleCompilerOptDetails, fn: toggleCompilerOptDetails},
 	{kind: settings.GoplsDocFeatures, fn: goplsDocFeatures},
 	{kind: settings.RefactorExtractFunction, fn: refactorExtractFunction},

gopls/internal/test/integration/misc/test_test.go

@@ -0,0 +1,82 @@
+// Copyright 2025 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 misc
+
+// This file defines tests of the source.test ("Run tests and
+// benchmarks") code action.
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"golang.org/x/tools/gopls/internal/protocol"
+	"golang.org/x/tools/gopls/internal/settings"
+	. "golang.org/x/tools/gopls/internal/test/integration"
+)
+
+func TestRunTestsAndBenchmarks(t *testing.T) {
+	file := filepath.Join(t.TempDir(), "out")
+	os.Setenv("TESTFILE", file)
+
+	const src = `
+-- go.mod --
+module example.com
+go 1.19
+
+-- a/a.go --
+package a
+
+-- a/a_test.go --
+package a
+
+import (
+	"os"
+	"testing"
+)
+
+func Test(t *testing.T) {
+	os.WriteFile(os.Getenv("TESTFILE"), []byte("ok"), 0644)
+}
+
+`
+	Run(t, src, func(t *testing.T, env *Env) {
+		env.OpenFile("a/a_test.go")
+		loc := env.RegexpSearch("a/a_test.go", "WriteFile")
+
+		// Request code actions. (settings.GoTest is special:
+		// it is returned only when explicitly requested.)
+		actions, err := env.Editor.Server.CodeAction(env.Ctx, &protocol.CodeActionParams{
+			TextDocument: protocol.TextDocumentIdentifier{URI: loc.URI},
+			Range:        loc.Range,
+			Context: protocol.CodeActionContext{
+				Only: []protocol.CodeActionKind{settings.GoTest},
+			},
+		})
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(actions) != 1 {
+			t.Fatalf("CodeAction returned %#v, want one source.test action", actions)
+		}
+		if actions[0].Command == nil {
+			t.Fatalf("CodeActions()[0] has no Command")
+		}
+
+		// Execute test.
+		// (ExecuteCommand fails if the test fails.)
+		t.Logf("Running %s...", actions[0].Title)
+		env.ExecuteCommand(&protocol.ExecuteCommandParams{
+			Command:   actions[0].Command.Command,
+			Arguments: actions[0].Command.Arguments,
+		}, nil)
+
+		// Check test had expected side effect.
+		data, err := os.ReadFile(file)
+		if string(data) != "ok" {
+			t.Fatalf("Test did not write expected content of %s; ReadFile returned (%q, %v)", file, data, err)
+		}
+	})
+}