Separate generic parts of api library into conversion package.

pkg/conversion/converter_test.go

@@ -0,0 +1,81 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package conversion
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestConverter(t *testing.T) {
+	type A struct {
+		Foo string
+	}
+	type B struct {
+		Bar string
+	}
+	type C struct{}
+	c := NewConverter()
+	err := c.Register(func(in *A, out *B) error {
+		out.Bar = in.Foo
+		return nil
+	})
+	if err != nil {
+		t.Fatalf("unexpected error %v", err)
+	}
+	err = c.Register(func(in *B, out *A) error {
+		out.Foo = in.Bar
+		return nil
+	})
+	if err != nil {
+		t.Fatalf("unexpected error %v", err)
+	}
+
+	x := A{"hello, intrepid test reader!"}
+	y := B{}
+
+	err = c.Convert(&x, &y, 0)
+	if err != nil {
+		t.Fatalf("unexpected error %v", err)
+	}
+	if e, a := x.Foo, y.Bar; e != a {
+		t.Errorf("expected %v, got %v", e, a)
+	}
+
+	z := B{"all your test are belong to us"}
+	w := A{}
+
+	err = c.Convert(&z, &w, 0)
+	if err != nil {
+		t.Fatalf("unexpected error %v", err)
+	}
+	if e, a := z.Bar, w.Foo; e != a {
+		t.Errorf("expected %v, got %v", e, a)
+	}
+
+	err = c.Register(func(in *A, out *C) error {
+		return fmt.Errorf("C can't store an A, silly")
+	})
+	if err != nil {
+		t.Fatalf("unexpected error %v", err)
+	}
+
+	err = c.Convert(&A{}, &C{}, 0)
+	if err == nil {
+		t.Errorf("unexpected non-error")
+	}
+}