gopls/internal/regtest: split regtests up into multiple packages

Regtests have gotten large, and started timing out on some slow
builders. They also can't yet be run in parallel, due to some
process-level shared state (e.g. gc_details). Furthermore, there seems
to be some per-process resource leak that we don't yet fully understand
causing slowdown as the tests progress.

Address these problems by splitting the regtests up into multiple
packages. This also makes it easier to run only relevant tests during
development.

For golang/go#42789
For golang/go#39384

Change-Id: I1a74e4c379f3a650f4c434db44f9368e527aa459
Reviewed-on: https://go-review.googlesource.com/c/tools/+/287572
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>

gopls/internal/regtest/bench_test.go → gopls/internal/regtest/bench/bench_test.go

@@ -2,16 +2,22 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package regtest
+package bench
 
 import (
 	"flag"
 	"fmt"
 	"testing"
 
+	. "golang.org/x/tools/gopls/internal/regtest"
+
 	"golang.org/x/tools/internal/lsp/protocol"
 )
 
+func TestMain(m *testing.M) {
+	Main(m)
+}
+
 func printBenchmarkResults(result testing.BenchmarkResult) {
 	fmt.Println("Benchmark Statistics:")
 	fmt.Println(result.String())
@@ -37,7 +43,7 @@ func TestBenchmarkIWL(t *testing.T) {
 
 	results := testing.Benchmark(func(b *testing.B) {
 		for i := 0; i < b.N; i++ {
-			withOptions(opts...).run(t, "", func(t *testing.T, env *Env) {})
+			WithOptions(opts...).Run(t, "", func(t *testing.T, env *Env) {})
 		}
 	})
 
@@ -72,7 +78,7 @@ func TestBenchmarkSymbols(t *testing.T) {
 	}
 	opts = append(opts, conf)
 
-	withOptions(opts...).run(t, "", func(t *testing.T, env *Env) {
+	WithOptions(opts...).Run(t, "", func(t *testing.T, env *Env) {
 		// We can't Await in this test, since we have disabled hooks. Instead, run
 		// one symbol request to completion to ensure all necessary cache entries
 		// are populated.

gopls/internal/regtest/completion_bench_test.go → gopls/internal/regtest/bench/completion_bench_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package regtest
+package bench
 
 import (
 	"flag"
@@ -11,6 +11,8 @@ import (
 	"strings"
 	"testing"
 
+	. "golang.org/x/tools/gopls/internal/regtest"
+
 	"golang.org/x/tools/internal/lsp/fake"
 )
 
@@ -45,7 +47,7 @@ func benchmarkCompletion(options completionBenchOptions, t *testing.T) {
 	// it first (and therefore need hooks).
 	opts = append(opts, SkipHooks(false))
 
-	withOptions(opts...).run(t, "", func(t *testing.T, env *Env) {
+	WithOptions(opts...).Run(t, "", func(t *testing.T, env *Env) {
 		env.OpenFile(options.file)
 
 		// Run edits required for this completion.

gopls/internal/regtest/stress_test.go → gopls/internal/regtest/bench/stress_test.go

@@ -2,14 +2,16 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package regtest
+package bench
 
 import (
 	"context"
 	"flag"
 	"fmt"
 	"testing"
 	"time"
+
+	. "golang.org/x/tools/gopls/internal/regtest"
 )
 
 // Pilosa is a repository that has historically caused significant memory
@@ -50,7 +52,7 @@ func TestPilosaStress(t *testing.T) {
 	}
 	opts := stressTestOptions(*pilosaPath)
 
-	withOptions(opts...).run(t, "", func(t *testing.T, env *Env) {
+	WithOptions(opts...).Run(t, "", func(t *testing.T, env *Env) {
 		files := []string{
 			"cmd.go",
 			"internal/private.pb.go",

gopls/internal/regtest/codelens_test.go → gopls/internal/regtest/codelens/codelens_test.go

@@ -2,20 +2,26 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package regtest
+package codelens
 
 import (
 	"runtime"
 	"strings"
 	"testing"
 
+	. "golang.org/x/tools/gopls/internal/regtest"
+
 	"golang.org/x/tools/internal/lsp/fake"
 	"golang.org/x/tools/internal/lsp/protocol"
 	"golang.org/x/tools/internal/lsp/source"
 	"golang.org/x/tools/internal/lsp/tests"
 	"golang.org/x/tools/internal/testenv"
 )
 
+func TestMain(m *testing.M) {
+	Main(m)
+}
+
 func TestDisablingCodeLens(t *testing.T) {
 	const workspace = `
 -- go.mod --
@@ -52,11 +58,11 @@ const (
 	}
 	for _, test := range tests {
 		t.Run(test.label, func(t *testing.T) {
-			withOptions(
+			WithOptions(
 				EditorConfig{
 					CodeLenses: test.enabled,
 				},
-			).run(t, workspace, func(t *testing.T, env *Env) {
+			).Run(t, workspace, func(t *testing.T, env *Env) {
 				env.OpenFile("lib.go")
 				lens := env.CodeLens("lib.go")
 				if gotCodeLens := len(lens) > 0; gotCodeLens != test.wantCodeLens {
@@ -115,9 +121,9 @@ func main() {
 		"Upgrade direct dependencies",
 	} {
 		t.Run(commandTitle, func(t *testing.T) {
-			withOptions(
+			WithOptions(
 				ProxyFiles(proxyWithLatest),
-			).run(t, shouldUpdateDep, func(t *testing.T, env *Env) {
+			).Run(t, shouldUpdateDep, func(t *testing.T, env *Env) {
 				env.OpenFile("go.mod")
 				var lens protocol.CodeLens
 				var found bool
@@ -195,7 +201,7 @@ func main() {
 	_ = hi.Goodbye
 }
 `
-	runner.Run(t, shouldRemoveDep, func(t *testing.T, env *Env) {
+	WithOptions(ProxyFiles(proxy)).Run(t, shouldRemoveDep, func(t *testing.T, env *Env) {
 		env.OpenFile("go.mod")
 		env.ExecuteCodeLensCommand("go.mod", source.CommandTidy)
 		env.Await(env.DoneWithChangeWatchedFiles())
@@ -209,7 +215,7 @@ require golang.org/x/hello v1.0.0
 		if got != wantGoMod {
 			t.Fatalf("go.mod tidy failed:\n%s", tests.Diff(t, wantGoMod, got))
 		}
-	}, ProxyFiles(proxy))
+	})
 }
 
 func TestRegenerateCgo(t *testing.T) {
@@ -233,7 +239,7 @@ func Foo() {
 	print(C.fortytwo())
 }
 `
-	runner.Run(t, workspace, func(t *testing.T, env *Env) {
+	Run(t, workspace, func(t *testing.T, env *Env) {
 		// Open the file. We should have a nonexistant symbol.
 		env.OpenFile("cgo.go")
 		env.Await(env.DiagnosticAtRegexp("cgo.go", `C\.(fortytwo)`)) // could not determine kind of name for C.fortytwo
@@ -270,12 +276,12 @@ func main() {
 	fmt.Println(x)
 }
 `
-	withOptions(
+	WithOptions(
 		EditorConfig{
 			CodeLenses: map[string]bool{
 				"gc_details": true,
 			}},
-	).run(t, mod, func(t *testing.T, env *Env) {
+	).Run(t, mod, func(t *testing.T, env *Env) {
 		env.OpenFile("main.go")
 		env.ExecuteCodeLensCommand("main.go", source.CommandToggleDetails)
 		d := &protocol.PublishDiagnosticsParams{}

gopls/internal/regtest/completion_test.go → gopls/internal/regtest/completion/completion_test.go

@@ -2,18 +2,43 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package regtest
+package completion
 
 import (
 	"fmt"
 	"strings"
 	"testing"
 
+	. "golang.org/x/tools/gopls/internal/regtest"
+
 	"golang.org/x/tools/internal/lsp/fake"
 	"golang.org/x/tools/internal/lsp/protocol"
 	"golang.org/x/tools/internal/testenv"
 )
 
+func TestMain(m *testing.M) {
+	Main(m)
+}
+
+const proxy = `
+-- example.com@v1.2.3/go.mod --
+module example.com
+
+go 1.12
+-- example.com@v1.2.3/blah/blah.go --
+package blah
+
+const Name = "Blah"
+-- random.org@v1.2.3/go.mod --
+module random.org
+
+go 1.12
+-- random.org@v1.2.3/blah/blah.go --
+package hello
+
+const Name = "Hello"
+`
+
 func TestPackageCompletion(t *testing.T) {
 	testenv.NeedsGo1Point(t, 14)
 	const files = `
@@ -123,7 +148,7 @@ pac
 		},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
-			run(t, files, func(t *testing.T, env *Env) {
+			Run(t, files, func(t *testing.T, env *Env) {
 				if tc.content != nil {
 					env.WriteWorkspaceFile(tc.filename, *tc.content)
 					env.Await(
@@ -180,7 +205,7 @@ package ma
 `
 
 	want := []string{"ma", "ma_test", "main", "math", "math_test"}
-	run(t, files, func(t *testing.T, env *Env) {
+	Run(t, files, func(t *testing.T, env *Env) {
 		env.OpenFile("math/add.go")
 		completions := env.Completion("math/add.go", fake.Pos{
 			Line:   0,
@@ -241,9 +266,9 @@ func _() {
 	_ = blah.Hello
 }
 `
-	withOptions(
+	WithOptions(
 		ProxyFiles(proxy),
-	).run(t, mod, func(t *testing.T, env *Env) {
+	).Run(t, mod, func(t *testing.T, env *Env) {
 		// Make sure the dependency is in the module cache and accessible for
 		// unimported completions, and then remove it before proceeding.
 		env.RemoveWorkspaceFile("main2.go")
@@ -310,7 +335,7 @@ package mainmod
 
 const Name = "mainmod"
 `
-	withOptions(ProxyFiles(proxy)).run(t, files, func(t *testing.T, env *Env) {
+	WithOptions(ProxyFiles(proxy)).Run(t, files, func(t *testing.T, env *Env) {
 		env.CreateBuffer("import.go", "package pkg\nvar _ = mainmod.Name\n")
 		env.SaveBuffer("import.go")
 		content := env.ReadWorkspaceFile("import.go")