Add correct lockfile handling

README.md

@@ -17,7 +17,24 @@ All command line flags:
 [embedmd]:# (_output/help.txt)
 ```txt
 $ jb -h
-Usage of jb:
-  -jsonnetpkg-home string
-    	The directory used to cache packages in. (default "vendor")
+usage: jb [<flags>] <command> [<args> ...]
+
+A jsonnet package manager
+
+Flags:
+  -h, --help  Show context-sensitive help (also try --help-long and --help-man).
+      --jsonnetpkg-home="vendor"  
+              The directory used to cache packages in.
+
+Commands:
+  help [<command>...]
+    Show help.
+
+  init
+    Initialize a new empty jsonnetfile
+
+  install [<packages>...]
+    Install all dependencies or install specific ones
+
+
 ```

cmd/jb/main.go

@@ -220,7 +220,21 @@ func parseGithubDependency(urlString string) *spec.Dependency {
 }
 
 func installCommand(jsonnetHome string, urls ...*url.URL) int {
-	m, err := pkg.LoadJsonnetfile(pkg.JsonnetFile)
+	workdir := "."
+
+	useLock, err := pkg.LockExists(workdir)
+	if err != nil {
+		kingpin.Fatalf("failed to check if jsonnetfile.lock.json exists: %v", err)
+		return 1
+	}
+
+	jsonnetfile, err := pkg.ChooseJsonnetFile(workdir)
+	if err != nil {
+		kingpin.Fatalf("failed to choose jsonnetfile: %v", err)
+		return 1
+	}
+
+	m, err := pkg.LoadJsonnetfile(jsonnetfile)
 	if err != nil {
 		kingpin.Fatalf("failed to load jsonnetfile: %v", err)
 		return 1
@@ -269,34 +283,37 @@ func installCommand(jsonnetHome string, urls ...*url.URL) int {
 		return 3
 	}
 
-	lock, err := pkg.Install(context.TODO(), m, jsonnetHome)
+	lock, err := pkg.Install(context.TODO(), jsonnetfile, m, jsonnetHome)
 	if err != nil {
 		kingpin.Fatalf("failed to install: %v", err)
 		return 3
 	}
 
-	b, err := json.MarshalIndent(m, "", "    ")
-	if err != nil {
-		kingpin.Fatalf("failed to encode jsonnet file: %v", err)
-		return 3
-	}
+	// If installing from lock file there is no need to write any files back.
+	if !useLock {
+		b, err := json.MarshalIndent(m, "", "    ")
+		if err != nil {
+			kingpin.Fatalf("failed to encode jsonnet file: %v", err)
+			return 3
+		}
 
-	err = ioutil.WriteFile(pkg.JsonnetFile, b, 0644)
-	if err != nil {
-		kingpin.Fatalf("failed to write jsonnet file: %v", err)
-		return 3
-	}
+		err = ioutil.WriteFile(pkg.JsonnetFile, b, 0644)
+		if err != nil {
+			kingpin.Fatalf("failed to write jsonnet file: %v", err)
+			return 3
+		}
 
-	b, err = json.MarshalIndent(lock, "", "    ")
-	if err != nil {
-		kingpin.Fatalf("failed to encode jsonnet file: %v", err)
-		return 3
-	}
+		b, err = json.MarshalIndent(lock, "", "    ")
+		if err != nil {
+			kingpin.Fatalf("failed to encode jsonnet file: %v", err)
+			return 3
+		}
 
-	err = ioutil.WriteFile(pkg.JsonnetLockFile, b, 0644)
-	if err != nil {
-		kingpin.Fatalf("failed to write lock file: %v", err)
-		return 3
+		err = ioutil.WriteFile(pkg.JsonnetLockFile, b, 0644)
+		if err != nil {
+			kingpin.Fatalf("failed to write lock file: %v", err)
+			return 3
+		}
 	}
 
 	return 0

pkg/packages.go

@@ -33,7 +33,7 @@ var (
 	VersionMismatch = errors.New("multiple colliding versions specified")
 )
 
-func Install(ctx context.Context, m spec.JsonnetFile, dir string) (lock *spec.JsonnetFile, err error) {
+func Install(ctx context.Context, dependencySourceIdentifier string, m spec.JsonnetFile, dir string) (lock *spec.JsonnetFile, err error) {
 	lock = &spec.JsonnetFile{}
 	for _, dep := range m.Dependencies {
 		tmp := filepath.Join(dir, ".tmp")
@@ -58,11 +58,11 @@ func Install(ctx context.Context, m spec.JsonnetFile, dir string) (lock *spec.Js
 		if err != nil {
 			return nil, errors.Wrap(err, "failed to install package")
 		}
-		// need to deduplicate/error when multiple entries
 		lock.Dependencies, err = insertDependency(lock.Dependencies, spec.Dependency{
-			Name:    dep.Name,
-			Source:  dep.Source,
-			Version: lockVersion,
+			Name:      dep.Name,
+			Source:    dep.Source,
+			Version:   lockVersion,
+			DepSource: dependencySourceIdentifier,
 		})
 		if err != nil {
 			return nil, errors.Wrap(err, "failed to insert dependency to lock dependencies")
@@ -87,22 +87,26 @@ func Install(ctx context.Context, m spec.JsonnetFile, dir string) (lock *spec.Js
 			return nil, errors.Wrap(err, "failed to move package")
 		}
 
-		if _, err := os.Stat(path.Join(destPath, JsonnetFile)); !os.IsNotExist(err) {
-			depsDeps, err := LoadJsonnetfile(path.Join(destPath, JsonnetFile))
-			if err != nil {
-				return nil, err
-			}
+		filepath, err := ChooseJsonnetFile(destPath)
+		if err != nil {
+			return nil, err
+		}
+		depsDeps, err := LoadJsonnetfile(filepath)
+		// It is ok for depedencies not to have a JsonnetFile, it just means
+		// they do not have transitive dependencies of their own.
+		if err != nil && !os.IsNotExist(err) {
+			return nil, err
+		}
 
-			depsInstalledByDependency, err := Install(ctx, depsDeps, dir)
-			if err != nil {
-				return nil, err
-			}
+		depsInstalledByDependency, err := Install(ctx, filepath, depsDeps, dir)
+		if err != nil {
+			return nil, err
+		}
 
-			for _, d := range depsInstalledByDependency.Dependencies {
-				lock.Dependencies, err = insertDependency(lock.Dependencies, d)
-				if err != nil {
-					return nil, errors.Wrap(err, "failed to insert dependency to lock dependencies")
-				}
+		for _, d := range depsInstalledByDependency.Dependencies {
+			lock.Dependencies, err = insertDependency(lock.Dependencies, d)
+			if err != nil {
+				return nil, errors.Wrap(err, "failed to insert dependency to lock dependencies")
 			}
 		}
 	}
@@ -116,24 +120,63 @@ func insertDependency(deps []spec.Dependency, newDep spec.Dependency) ([]spec.De
 	}
 
 	res := []spec.Dependency{}
+	newDepPreviouslyPresent := false
 	for _, d := range deps {
 		if d.Name == newDep.Name {
 			if d.Version != newDep.Version {
-				return nil, VersionMismatch
+				return nil, fmt.Errorf("multiple colliding versions specified for %s: %s (from %s) and %s (from %s)", d.Name, d.Version, d.DepSource, newDep.Version, newDep.DepSource)
 			}
 			res = append(res, d)
+			newDepPreviouslyPresent = true
 		} else {
 			res = append(res, d)
 		}
 	}
+	if !newDepPreviouslyPresent {
+		res = append(res, newDep)
+	}
 
 	return res, nil
 }
 
-func LoadJsonnetfile(filename string) (spec.JsonnetFile, error) {
+func LockExists(dir string) (bool, error) {
+	lockfile := path.Join(dir, JsonnetLockFile)
+	_, err := os.Stat(lockfile)
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	if err != nil {
+		return false, err
+	}
+
+	return true, nil
+}
+
+func ChooseJsonnetFile(dir string) (string, error) {
+	lockfile := path.Join(dir, JsonnetLockFile)
+	jsonnetfile := path.Join(dir, JsonnetFile)
+	filename := lockfile
+
+	lockExists, err := LockExists(dir)
+	if err != nil {
+		return "", err
+	}
+
+	if !lockExists {
+		filename = jsonnetfile
+	}
+
+	return filename, err
+}
+
+func LoadJsonnetfile(filepath string) (spec.JsonnetFile, error) {
 	m := spec.JsonnetFile{}
 
-	f, err := os.Open(filename)
+	if _, err := os.Stat(filepath); err != nil {
+		return m, err
+	}
+
+	f, err := os.Open(filepath)
 	if err != nil {
 		return m, err
 	}

pkg/packages_test.go

@@ -0,0 +1,35 @@
+// Copyright 2018 jsonnet-bundler authors
+//
+// 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 pkg
+
+import (
+	"testing"
+
+	"github.com/jsonnet-bundler/jsonnet-bundler/spec"
+)
+
+func TestInsert(t *testing.T) {
+	deps := []*spec.Dependency{&spec.Dependency{Name: "test1", Version: "latest"}}
+	dep := &spec.Dependency{Name: "test2", Version: "latest"}
+
+	res, err := insertDependency(deps, dep)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(res) != 2 {
+		t.Fatal("Incorrectly inserted")
+	}
+}

spec/spec.go

@@ -28,7 +28,8 @@ type GitSource struct {
 }
 
 type Dependency struct {
-	Name    string `json:"name"`
-	Source  Source `json:"source"`
-	Version string `json:"version"`
+	Name      string `json:"name"`
+	Source    Source `json:"source"`
+	Version   string `json:"version"`
+	DepSource string `json:"-"`
 }