gopls/test/quickfix_test: verify that issue 70755 is fixed

As of last December, quickfixes (and unimported completions) failed to
cope with packages whose name was not the name of their directory.

This test shows that this no longer happens.

Fixes: golang.go/go#70755
Change-Id: Ifb64ca46329b01471a02bb94995032d60d279367
Reviewed-on: https://go-review.googlesource.com/c/tools/+/706256
Reviewed-by: Madeline Kalil <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: pjweinbgo

gopls/internal/test/integration/workspace/quickfix_test.go

@@ -456,3 +456,53 @@ var _ [int("")]byte
 		}
 	})
 }
+
+// quick fix didn't offer add imports
+func TestIssue70755(t *testing.T) {
+	files := `
+-- go.mod --
+module failure.com
+go 1.23
+-- bar/bar.go --
+package notbar
+type NotBar struct{}
+-- baz/baz.go --
+package baz
+type Baz struct{}
+-- foo/foo.go --
+package foo
+type foo struct {
+bar notbar.NotBar
+bzz baz.Baz
+}
+`
+
+	Run(t, files, func(t *testing.T, env *Env) {
+		env.OpenFile("foo/foo.go")
+		var d protocol.PublishDiagnosticsParams
+		env.AfterChange(ReadDiagnostics("foo/foo.go", &d))
+		// should get two, one for undefined notbar
+		// and one for undefined baz
+		fixes := env.GetQuickFixes("foo/foo.go", d.Diagnostics)
+		if len(fixes) != 2 {
+			t.Fatalf("got %v, want 2 quick fixes", fixes)
+		}
+		good := 0
+		failures := ""
+		for _, f := range fixes {
+			ti := f.Title
+			// these may be overly white-space sensitive
+			if ti == "Add import: notbar \"failure.com/bar\"" ||
+				ti == "Add import:  \"failure.com/baz\"" {
+				good++
+			} else {
+				failures += ti
+			}
+		}
+		if good != 2 {
+			t.Errorf("failed to find\n%q, got\n%q\n%q", failures, fixes[0].Title,
+				fixes[1].Title)
+		}
+
+	})
+}