Create BrokenImportFeedback and use in FinalizeRootManifest

 - Creates a new feedback type to alert users of broken imports
 - Unit tests for above
 - Utillize new functionality in FinalizeRootManifestAndLock
 - Teach brokenImport String()

Author: zmackie

cmd/dep/root_analyzer.go

@@ -167,6 +167,9 @@ func (a *rootAnalyzer) DeriveManifestAndLock(dir string, pr gps.ProjectRoot) (gp
 func (a *rootAnalyzer) FinalizeRootManifestAndLock(m *dep.Manifest, l *dep.Lock, ol dep.Lock) {
 	// Iterate through the new projects in solved lock and add them to manifest
 	// if they are direct deps and log feedback for all the new projects.
+	diff := gps.DiffLocks(&ol, l)
+	bi := fb.NewBrokenImportFeedback(diff)
+	bi.LogFeedback(a.ctx.Err)
 	for _, y := range l.Projects() {
 		var f *fb.ConstraintFeedback
 		pr := y.Ident().ProjectRoot

internal/feedback/feedback.go

@@ -82,6 +82,53 @@ func (cf ConstraintFeedback) LogFeedback(logger *log.Logger) {
 	}
 }
 
+type brokenImport struct {
+	projectPath string
+	version     *gps.StringDiff
+	revision    *gps.StringDiff
+}
+
+func (bi brokenImport) String() string {
+	var pr string
+	var cr string
+	if bi.revision != nil {
+		pr = fmt.Sprintf("(%s)", trimSHA(bi.revision.Previous))
+		cr = fmt.Sprintf("(%s)", trimSHA(bi.revision.Current))
+	}
+
+	return fmt.Sprintf("%v %s for %s. Locking in %v %s",
+		bi.version.Previous,
+		pr,
+		bi.projectPath,
+		bi.version.Current,
+		cr,
+	)
+}
+
+// ConstraintFeedback holds project constraint feedback data
+type BrokenImportFeedback struct {
+	brokenImports []brokenImport
+}
+
+func NewBrokenImportFeedback(ld *gps.LockDiff) *BrokenImportFeedback {
+	bi := &BrokenImportFeedback{}
+	for _, lpd := range ld.Modify {
+		bi.brokenImports = append(bi.brokenImports, brokenImport{
+			projectPath: string(lpd.Name),
+			version:     lpd.Version,
+			revision:    lpd.Revision,
+		})
+	}
+
+	return bi
+}
+
+func (b BrokenImportFeedback) LogFeedback(logger *log.Logger) {
+	for _, bi := range b.brokenImports {
+		logger.Printf("Warning: Unable to preserve imported lock %v\n", bi)
+	}
+}
+
 // GetUsingFeedback returns a dependency "using" feedback message. For example:
 //
 //    Using ^1.0.0 as constraint for direct dep github.com/foo/bar
@@ -115,3 +162,14 @@ func GetLockingFeedback(version, revision, depType, projectPath string) string {
 	}
 	return fmt.Sprintf("Locking in %s (%s) for %s %s", version, revision, depType, projectPath)
 }
+
+func trimSHA(revision string) string {
+	if len(revision) == 40 {
+		if _, err := hex.DecodeString(revision); err == nil {
+			// Valid SHA1 digest
+			revision = revision[0:7]
+		}
+	}
+
+	return revision
+}

internal/feedback/feedback_test.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/golang/dep"
 	"github.com/golang/dep/gps"
 )
 
@@ -92,3 +93,42 @@ func TestFeedback_LockedProject(t *testing.T) {
 		}
 	}
 }
+
+func TestFeedback_BrokenImport(t *testing.T) {
+	ov := gps.NewVersion("v1.1.4").Pair("bc29b4f")
+	lv := gps.NewVersion("v1.2.0").Pair("ia3da28")
+	pi := gps.ProjectIdentifier{ProjectRoot: gps.ProjectRoot("github.com/foo/bar")}
+
+	ol := dep.Lock{
+		P: []gps.LockedProject{gps.NewLockedProject(pi, ov, nil)},
+	}
+	l := dep.Lock{
+		P: []gps.LockedProject{gps.NewLockedProject(pi, lv, nil)},
+	}
+
+	diff := gps.DiffLocks(&ol, &l)
+
+	cases := []struct {
+		feedback *BrokenImportFeedback
+		want     string
+		name     string
+	}{
+		{
+			feedback: NewBrokenImportFeedback(diff),
+			want:     "Warning: Unable to preserve imported lock v1.1.4 (bc29b4f) for github.com/foo/bar. Locking in v1.2.0 (ia3da28)",
+			name:     "Basic broken import",
+		},
+	}
+
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			buf := &bytes.Buffer{}
+			log := log2.New(buf, "", 0)
+			c.feedback.LogFeedback(log)
+			got := strings.TrimSpace(buf.String())
+			if c.want != got {
+				t.Errorf("Feedbacks are not expected: \n\t(GOT) '%s'\n\t(WNT) '%s'", got, c.want)
+			}
+		})
+	}
+}