internal/core/export: allow testing imports

Change-Id: I828cb4fdfc3adb7407d306cabfb93db0f370d09b
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/6644
Reviewed-by: CUE cueckoo <cueckoo@gmail.com>
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
diff --git a/internal/core/export/export_test.go b/internal/core/export/export_test.go
index 77032b0..804122e 100644
--- a/internal/core/export/export_test.go
+++ b/internal/core/export/export_test.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package export
+package export_test
 
 import (
 	"flag"
@@ -23,8 +23,10 @@
 	"cuelang.org/go/cue/format"
 	"cuelang.org/go/internal/core/compile"
 	"cuelang.org/go/internal/core/eval"
+	"cuelang.org/go/internal/core/export"
 	"cuelang.org/go/internal/core/runtime"
 	"cuelang.org/go/internal/cuetxtar"
+	"cuelang.org/go/internal/legacy/cue"
 	"github.com/rogpeppe/go-internal/txtar"
 )
 
@@ -37,7 +39,7 @@
 		Update: *update,
 	}
 
-	r := runtime.New()
+	r := cue.NewRuntime()
 
 	test.Run(t, func(t *cuetxtar.Test) {
 		a := t.ValidInstances()
@@ -51,7 +53,7 @@
 		// TODO: do we need to evaluate v? In principle not necessary.
 		// v.Finalize(eval.NewContext(r, v))
 
-		file, errs := Def(r, v)
+		file, errs := export.Def(r, v)
 		errors.Print(t, errs, nil)
 		_, _ = t.Write(formatNode(t.T, file))
 	})
@@ -126,7 +128,7 @@
 	}
 	v.Finalize(eval.NewContext(r, v))
 
-	file, errs := Def(r, v)
+	file, errs := export.Def(r, v)
 	if errs != nil {
 		t.Fatal(errs)
 	}
diff --git a/internal/core/export/extract_test.go b/internal/core/export/extract_test.go
index 354dae7..2d5153d 100644
--- a/internal/core/export/extract_test.go
+++ b/internal/core/export/extract_test.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package export
+package export_test
 
 import (
 	"fmt"
@@ -21,8 +21,9 @@
 	"cuelang.org/go/internal/core/adt"
 	"cuelang.org/go/internal/core/compile"
 	"cuelang.org/go/internal/core/eval"
-	"cuelang.org/go/internal/core/runtime"
+	"cuelang.org/go/internal/core/export"
 	"cuelang.org/go/internal/cuetxtar"
+	"cuelang.org/go/internal/legacy/cue"
 )
 
 func TestExtract(t *testing.T) {
@@ -32,7 +33,7 @@
 		Update: *update,
 	}
 
-	r := runtime.New()
+	r := cue.NewRuntime()
 
 	test.Run(t, func(t *cuetxtar.Test) {
 		a := t.ValidInstances()
@@ -51,7 +52,7 @@
 
 func writeDocs(t *cuetxtar.Test, r adt.Runtime, v *adt.Vertex, path []string) {
 	fmt.Fprintln(t, path)
-	for _, c := range ExtractDoc(v) {
+	for _, c := range export.ExtractDoc(v) {
 		fmt.Fprintln(t, "-", c.Text())
 	}
 
diff --git a/internal/core/export/testdata/simplify.txtar b/internal/core/export/testdata/simplify.txtar
index 2ddd23b..3eaa42e 100644
--- a/internal/core/export/testdata/simplify.txtar
+++ b/internal/core/export/testdata/simplify.txtar
@@ -1,36 +1,45 @@
 -- in.cue --
+import "strings"
 
 x: [string]: int64
 x: {
     y: int
 }
+s: strings.MinRunes(4) & strings.MaxRunes(7)
 -- out/definition --
+import "strings"
+
 x: {
 	{
 		[string]: int64
 	}
 	y: int
 }
+s: strings.MinRunes(4) & strings.MaxRunes(7)
 -- out/doc --
 []
 [x]
 [x y]
+[s]
 -- out/value --
 == Simplified
 {
 	x: {
 		y: int64
 	}
+	s: strings.MinRunes(4) & strings.MaxRunes(7)
 }
 == Raw
 {
 	x: {
 		y: >=-9223372036854775808 & <=9223372036854775807 & int
 	}
+	s: strings.MinRunes(4) & strings.MaxRunes(7)
 }
 == All
 {
 	x: {
 		y: int64
 	}
+	s: strings.MinRunes(4) & strings.MaxRunes(7)
 }
diff --git a/internal/core/export/value_test.go b/internal/core/export/value_test.go
index 2467c3d..ac506cd 100644
--- a/internal/core/export/value_test.go
+++ b/internal/core/export/value_test.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package export
+package export_test
 
 import (
 	"fmt"
@@ -23,8 +23,10 @@
 	"cuelang.org/go/internal/core/adt"
 	"cuelang.org/go/internal/core/compile"
 	"cuelang.org/go/internal/core/eval"
+	"cuelang.org/go/internal/core/export"
 	"cuelang.org/go/internal/core/runtime"
 	"cuelang.org/go/internal/cuetxtar"
+	"cuelang.org/go/internal/legacy/cue"
 	"github.com/rogpeppe/go-internal/txtar"
 )
 
@@ -40,7 +42,7 @@
 		Skip:   exclude,
 	}
 
-	r := runtime.New()
+	r := cue.NewRuntime()
 
 	test.Run(t, func(t *cuetxtar.Test) {
 		a := t.ValidInstances()
@@ -57,9 +59,9 @@
 			name string
 			fn   func(r adt.Runtime, v adt.Value) (ast.Expr, errors.Error)
 		}{
-			{"Simplified", Simplified.Value},
-			{"Raw", Raw.Value},
-			{"All", All.Value},
+			{"Simplified", export.Simplified.Value},
+			{"Raw", export.Raw.Value},
+			{"All", export.All.Value},
 		} {
 			fmt.Fprintln(t, "==", tc.name)
 			x, errs := tc.fn(r, v)
@@ -76,10 +78,10 @@
 
 	in := `
 -- in.cue --
-x: [string]: int64
-x: {
-    y: int
-}
+import "strings"
+
+strings.MinRunes(4) & strings.MaxRunes(7)
+
 	`
 
 	archive := txtar.Parse([]byte(in))
@@ -94,7 +96,7 @@
 	ctx := eval.NewContext(r, v)
 	v.Finalize(ctx)
 
-	x, errs := Value(r, v)
+	x, errs := export.Simplified.Value(r, v)
 	if errs != nil {
 		t.Fatal(errs)
 	}