gopls/internal: test fixes for some imports bugs

The CL has tests for two fixed bugs. For the new imports to work
the metadata graph has to be current, which in this CL, is accomplished
with a call to snapshot.WordspaceMetadata which may wait for changes
to be assimilated.

Fixes: golang.go/go#44510
Fixes: golang.go/go#67973
Change-Id: Ieb5a9361a75796a172da953cc58853d38f596ebd
Reviewed-on: https://go-review.googlesource.com/c/tools/+/649315
Reviewed-by: Robert Findley <rfindley@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

Author: pjweinbgo

gopls/internal/cache/source.go

@@ -212,7 +212,7 @@ func (s *goplsSource) resolveWorkspaceReferences(filename string, missing import
 	// keep track of used syms and found results by package name
 	// TODO: avoid import cycles (is current package in forward closure)
 	founds := make(map[string][]found)
-	for i := 0; i < len(ids); i++ {
+	for i := range len(ids) {
 		nm := string(pkgs[i].Name)
 		if satisfies(syms[i], missing[nm]) {
 			got := &imports.Result{

gopls/internal/golang/format.go

@@ -152,6 +152,9 @@ func computeImportEdits(ctx context.Context, pgf *parsego.File, snapshot *cache.
 	case settings.ImportsSourceGoimports:
 		source = isource
 	}
+	// imports require a current metadata graph
+	// TODO(rfindlay) improve the API
+	snapshot.WorkspaceMetadata(ctx)
 	allFixes, err := imports.FixImports(ctx, filename, pgf.Src, goroot, options.Env.Logf, source)
 	if err != nil {
 		return nil, nil, err

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

@@ -401,6 +401,31 @@ return nil
 		}
 	})
 }
+
+// use the import from a different package in the same module
+func Test44510(t *testing.T) {
+	const files = `-- go.mod --
+module test
+go 1.19
+-- foo/foo.go --
+package main
+import strs "strings"
+var _ = strs.Count
+-- bar/bar.go --
+package main
+var _ = strs.Builder
+`
+	WithOptions(
+		WriteGoSum("."),
+	).Run(t, files, func(T *testing.T, env *Env) {
+		env.OpenFile("bar/bar.go")
+		env.SaveBuffer("bar/bar.go")
+		buf := env.BufferText("bar/bar.go")
+		if !strings.Contains(buf, "strs") {
+			t.Error(buf)
+		}
+	})
+}
 func TestRelativeReplace(t *testing.T) {
 	const files = `
 -- go.mod --
@@ -688,3 +713,33 @@ func Test() {
 		}
 	})
 }
+
+// this test replaces 'package bar' with 'package foo'
+// saves the file, and then looks for the import in the main package.s
+func Test67973(t *testing.T) {
+	const files = `-- go.mod --
+module hello
+go 1.19
+-- hello.go --
+package main
+var _ = foo.Bar
+-- internal/foo/foo.go --
+package bar
+func Bar() {}
+`
+	WithOptions(
+		Settings{"importsSource": settings.ImportsSourceGopls},
+	).Run(t, files, func(t *testing.T, env *Env) {
+		env.OpenFile("hello.go")
+		env.AfterChange(env.DoneWithOpen())
+		env.SaveBuffer("hello.go")
+		env.OpenFile("internal/foo/foo.go")
+		env.RegexpReplace("internal/foo/foo.go", "bar", "foo")
+		env.SaveBuffer("internal/foo/foo.go")
+		env.SaveBuffer("hello.go")
+		buf := env.BufferText("hello.go")
+		if !strings.Contains(buf, "internal/foo") {
+			t.Errorf(`expected import "hello/internal/foo" but got %q`, buf)
+		}
+	})
+}