asteris-llc/converge

// Copyright © 2016 Asteris, LLC
//
// 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 graph_test

import (
    "errors"
    "testing"

    "github.com/asteris-llc/converge/graph"
    "github.com/asteris-llc/converge/graph/node"
    "github.com/asteris-llc/converge/helpers/logging"
    "github.com/stretchr/testify/assert"
    "golang.org/x/net/context"
)

func TestNotifyTransform(t *testing.T) {
    g := graph.New()
    g.Add(node.New("root", 1))

    doNothing := func(*node.Node, *graph.Graph) error { return nil }
    returnError := func(*node.Node, *graph.Graph) error { return errors.New("error") }

    t.Run("pre", func(t *testing.T) {
        defer logging.HideLogs(t)()

        var ran bool

        notifier := &graph.Notifier{
            Pre: func(*node.Node) error {
                ran = true
                return nil
            },
        }

        _, err := g.Transform(
            context.Background(),
            notifier.Transform(doNothing),
        )

        assert.NoError(t, err)
        assert.True(t, ran)
    })

    t.Run("post", func(t *testing.T) {

        var ran bool

        notifier := &graph.Notifier{
            Post: func(*node.Node) error {
                ran = true
                return nil
            },
        }

        t.Run("no error", func(t *testing.T) {
            defer logging.HideLogs(t)()
            ran = false

            _, err := g.Transform(
                context.Background(),
                notifier.Transform(doNothing),
            )

            assert.NoError(t, err)
            assert.True(t, ran)
        })

        t.Run("error", func(t *testing.T) {
            defer logging.HideLogs(t)()
            ran = false

            _, err := g.Transform(
                context.Background(),
                notifier.Transform(returnError),
            )

            assert.Error(t, err)
            assert.False(t, ran)
        })

    })

    t.Run("post gets a fresh node", func(t *testing.T) {
        defer logging.HideLogs(t)()

        var finalValue int
        notifier := &graph.Notifier{
            Post: func(meta *node.Node) error {
                finalValue = meta.Value().(int)
                return nil
            },
        }

        _, err := g.Transform(
            context.Background(),
            notifier.Transform(func(meta *node.Node, g *graph.Graph) error {
                g.Add(meta.WithValue(2))
                return nil
            }),
        )

        assert.NoError(t, err)
        assert.Equal(
            t,
            2,
            finalValue,
            "notifier probably didn't get a fresh value after the transform finished",
        )
    })
}