Preserve YAML comments & style when resolving/applying (#103)

* Preserve YAML comments & style when resolving/applying

This is accomplished by adopting the yaml.v3 lib. It
exposes a Node struct that's used internally by the
yaml encoder/decoder

ko internally now manipulates YAML documents using this struct

Fixes #101

* add/remove vendored modules

* Apply suggestions from code review

Fix comments

Co-Authored-By: jonjohnsonjr <jonjohnson@google.com>

* update doc link

* Fix use of yaml.Decoder in a test

When the yaml.Decoder returns an io.EOF it implies
there were no YAML documents decoded and that there
are no more!

* Update pkg/resolve/resolve.go

resolve comment suggestion

Co-Authored-By: jonjohnsonjr <jonjohnson@google.com>

* leave ko prefix if we're not operating in strict mode

* move testutils to internal/testing

pkg/internal/testing/doc.go

@@ -0,0 +1,16 @@
+// Copyright 2018 Google LLC 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 testing holds a variety test doubles to help with testing
+package testing

pkg/internal/testing/fixed.go

@@ -0,0 +1,80 @@
+// Copyright 2018 Google LLC 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 testing
+
+import (
+	"fmt"
+
+	"github.com/google/go-containerregistry/pkg/name"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/ko/pkg/build"
+	"github.com/google/ko/pkg/publish"
+)
+
+type fixedBuild struct {
+	entries map[string]v1.Image
+}
+
+// NewFixedBuild returns a build.Interface implementation that simply resolves
+// particular references to fixed v1.Image objects
+func NewFixedBuild(entries map[string]v1.Image) build.Interface {
+	return &fixedBuild{entries}
+}
+
+// IsSupportedReference implements build.Interface
+func (f *fixedBuild) IsSupportedReference(s string) bool {
+	_, ok := f.entries[s]
+	return ok
+}
+
+// Build implements build.Interface
+func (f *fixedBuild) Build(s string) (v1.Image, error) {
+	if img, ok := f.entries[s]; ok {
+		return img, nil
+	}
+	return nil, fmt.Errorf("unsupported reference: %q", s)
+}
+
+type fixedPublish struct {
+	base    name.Repository
+	entries map[string]v1.Hash
+}
+
+// NewFixedPublish returns a publish.Interface implementation that simply
+// resolves particular references to fixed name.Digest references.
+func NewFixedPublish(base name.Repository, entries map[string]v1.Hash) publish.Interface {
+	return &fixedPublish{base, entries}
+}
+
+// Publish implements publish.Interface
+func (f *fixedPublish) Publish(_ v1.Image, s string) (name.Reference, error) {
+	h, ok := f.entries[s]
+	if !ok {
+		return nil, fmt.Errorf("unsupported importpath: %q", s)
+	}
+	d, err := name.NewDigest(fmt.Sprintf("%s/%s@%s", f.base, s, h))
+	if err != nil {
+		return nil, err
+	}
+	return &d, nil
+}
+
+func ComputeDigest(base name.Repository, ref string, h v1.Hash) string {
+	d, err := name.NewDigest(fmt.Sprintf("%s/%s@%s", base, ref, h))
+	if err != nil {
+		panic(err)
+	}
+	return d.String()
+}

pkg/internal/testing/fixed_test.go

@@ -0,0 +1,83 @@
+// Copyright 2018 Google LLC 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 testing
+
+import (
+	"testing"
+
+	"github.com/google/go-containerregistry/pkg/name"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/random"
+)
+
+func TestFixedPublish(t *testing.T) {
+	hex1 := "deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef"
+	hex2 := "baadf00dbaadf00dbaadf00dbaadf00dbaadf00dbaadf00dbaadf00dbaadf00d"
+	fixedBaseRepo, _ := name.NewRepository("gcr.io/asdf")
+	f := NewFixedPublish(fixedBaseRepo, map[string]v1.Hash{
+		"foo": {
+			Algorithm: "sha256",
+			Hex:       hex1,
+		},
+		"bar": {
+			Algorithm: "sha256",
+			Hex:       hex2,
+		},
+	})
+
+	fooDigest, err := f.Publish(nil, "foo")
+	if err != nil {
+		t.Errorf("Publish(foo) = %v", err)
+	}
+	if got, want := fooDigest.String(), "gcr.io/asdf/foo@sha256:"+hex1; got != want {
+		t.Errorf("Publish(foo) = %q, want %q", got, want)
+	}
+
+	barDigest, err := f.Publish(nil, "bar")
+	if err != nil {
+		t.Errorf("Publish(bar) = %v", err)
+	}
+	if got, want := barDigest.String(), "gcr.io/asdf/bar@sha256:"+hex2; got != want {
+		t.Errorf("Publish(bar) = %q, want %q", got, want)
+	}
+
+	d, err := f.Publish(nil, "baz")
+	if err == nil {
+		t.Errorf("Publish(baz) = %v, want error", d)
+	}
+}
+
+func TestFixedBuild(t *testing.T) {
+	testImage, _ := random.Image(1024, 5)
+	f := NewFixedBuild(map[string]v1.Image{
+		"asdf": testImage,
+	})
+
+	if got, want := f.IsSupportedReference("asdf"), true; got != want {
+		t.Errorf("IsSupportedReference(asdf) = %v, want %v", got, want)
+	}
+	if got, err := f.Build("asdf"); err != nil {
+		t.Errorf("Build(asdf) = %v, want %v", err, testImage)
+	} else if got != testImage {
+		t.Errorf("Build(asdf) = %v, want %v", got, testImage)
+	}
+
+	if got, want := f.IsSupportedReference("blah"), false; got != want {
+		t.Errorf("IsSupportedReference(blah) = %v, want %v", got, want)
+	}
+	if got, err := f.Build("blah"); err == nil {
+		t.Errorf("Build(blah) = %v, want error", got)
+	}
+}