1 files changed, 257 insertions, 0 deletions
diff --git a/internal/gcimporter/iexport_go118_test.go b/internal/gcimporter/iexport_go118_test.go
new file mode 100644
index 000000000..c60a9b5ee
--- /dev/null
+++ b/internal/gcimporter/iexport_go118_test.go
@@ -0,0 +1,257 @@
+// Copyright 2021 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.
+
+//go:build go1.18
+// +build go1.18
+
+package gcimporter_test
+
+import (
+	"bytes"
+	"fmt"
+	"go/ast"
+	"go/importer"
+	"go/parser"
+	"go/token"
+	"go/types"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+
+	"golang.org/x/tools/internal/gcimporter"
+	"golang.org/x/tools/internal/testenv"
+)
+
+// TODO(rfindley): migrate this to testdata, as has been done in the standard library.
+func TestGenericExport(t *testing.T) {
+	const src = `
+package generic
+
+type Any any
+
+type T[A, B any] struct { Left A; Right B }
+
+func (T[P, Q]) m() {}
+
+var X T[int, string] = T[int, string]{1, "hi"}
+
+func ToInt[P interface{ ~int }](p P) int { return int(p) }
+
+var IntID = ToInt[int]
+
+type G[C comparable] int
+
+func ImplicitFunc[T ~int]() {}
+
+type ImplicitType[T ~int] int
+
+// Exercise constant import/export
+const C1 = 42
+const C2 int = 42
+const C3 float64 = 42
+
+type Constraint[T any] interface {
+       m(T)
+}
+
+// TODO(rfindley): revert to multiple blanks once the restriction on multiple
+// blanks is removed from the type checker.
+// type Blanks[_ any, _ Constraint[int]] int
+// func (Blanks[_, _]) m() {}
+type Blanks[_ any] int
+func (Blanks[_]) m() {}
+`
+	testExportSrc(t, []byte(src))
+}
+
+func testExportSrc(t *testing.T, src []byte) {
+	// This package only handles gc export data.
+	if runtime.Compiler != "gc" {
+		t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+	}
+
+	fset := token.NewFileSet()
+	f, err := parser.ParseFile(fset, "g.go", src, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	conf := types.Config{
+		Importer: importer.Default(),
+	}
+	pkg, err := conf.Check("", fset, []*ast.File{f}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// export
+	version := gcimporter.IExportVersion
+	data, err := iexport(fset, version, pkg)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	testPkgData(t, fset, version, pkg, data)
+}
+
+func TestImportTypeparamTests(t *testing.T) {
+	testenv.NeedsGoBuild(t) // to find stdlib export data in the build cache
+
+	// Check go files in test/typeparam.
+	rootDir := filepath.Join(runtime.GOROOT(), "test", "typeparam")
+	list, err := os.ReadDir(rootDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if isUnifiedBuilder() {
+		t.Skip("unified export data format is currently unsupported")
+	}
+
+	for _, entry := range list {
+		if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".go") {
+			// For now, only consider standalone go files.
+			continue
+		}
+
+		t.Run(entry.Name(), func(t *testing.T) {
+			filename := filepath.Join(rootDir, entry.Name())
+			src, err := os.ReadFile(filename)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if !bytes.HasPrefix(src, []byte("// run")) && !bytes.HasPrefix(src, []byte("// compile")) {
+				// We're bypassing the logic of run.go here, so be conservative about
+				// the files we consider in an attempt to make this test more robust to
+				// changes in test/typeparams.
+				t.Skipf("not detected as a run test")
+			}
+
+			testExportSrc(t, src)
+		})
+	}
+}
+
+func TestRecursiveExport_Issue51219(t *testing.T) {
+	const srca = `
+package a
+
+type Interaction[DataT InteractionDataConstraint] struct {
+}
+
+type InteractionDataConstraint interface {
+	[]byte |
+		UserCommandInteractionData
+}
+
+type UserCommandInteractionData struct {
+	resolvedInteractionWithOptions
+}
+
+type resolvedInteractionWithOptions struct {
+	Resolved Resolved
+}
+
+type Resolved struct {
+	Users ResolvedData[User]
+}
+
+type ResolvedData[T ResolvedDataConstraint] map[uint64]T
+
+type ResolvedDataConstraint interface {
+	User | Message
+}
+
+type User struct{}
+
+type Message struct {
+	Interaction *Interaction[[]byte]
+}
+`
+
+	const srcb = `
+package b
+
+import (
+	"a"
+)
+
+// InteractionRequest is an incoming request Interaction
+type InteractionRequest[T a.InteractionDataConstraint] struct {
+	a.Interaction[T]
+}
+`
+
+	const srcp = `
+package p
+
+import (
+	"b"
+)
+
+// ResponseWriterMock mocks corde's ResponseWriter interface
+type ResponseWriterMock struct {
+	x b.InteractionRequest[[]byte]
+}
+`
+
+	importer := &testImporter{
+		src: map[string][]byte{
+			"a": []byte(srca),
+			"b": []byte(srcb),
+			"p": []byte(srcp),
+		},
+		pkgs: make(map[string]*types.Package),
+	}
+	_, err := importer.Import("p")
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+// testImporter is a helper to test chains of imports using export data.
+type testImporter struct {
+	src  map[string][]byte         // original source
+	pkgs map[string]*types.Package // memoized imported packages
+}
+
+func (t *testImporter) Import(path string) (*types.Package, error) {
+	if pkg, ok := t.pkgs[path]; ok {
+		return pkg, nil
+	}
+	src, ok := t.src[path]
+	if !ok {
+		return nil, fmt.Errorf("unknown path %v", path)
+	}
+
+	// Type-check, but don't return this package directly.
+	fset := token.NewFileSet()
+	f, err := parser.ParseFile(fset, path+".go", src, 0)
+	if err != nil {
+		return nil, err
+	}
+	conf := types.Config{
+		Importer: t,
+	}
+	pkg, err := conf.Check(path, fset, []*ast.File{f}, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	// Export and import to get the package imported from export data.
+	exportdata, err := iexport(fset, gcimporter.IExportVersion, pkg)
+	if err != nil {
+		return nil, err
+	}
+	imports := make(map[string]*types.Package)
+	fset2 := token.NewFileSet()
+	_, pkg2, err := gcimporter.IImportData(fset2, imports, exportdata, pkg.Path())
+	if err != nil {
+		return nil, err
+	}
+	t.pkgs[path] = pkg2
+	return pkg2, nil
+}