Attempt to fetch version for no comment imports

- Fetches versions list of project and looks for version corresponding
to the given revision.
- Adds test TestGodepConvertBadInput_EmptyPackageName for the same.

cmd/dep/godep_config.go

@@ -68,6 +68,32 @@ func (g *godepFile) convert(projectName string, sm gps.SourceManager) (*dep.Mani
 			return nil, nil, err
 		}
 
+		// Rev must not be empty
+		if pkg.Rev == "" {
+			err := errors.New("godep: Invalid godep configuration, Rev is required")
+			return nil, nil, err
+		}
+
+		if pkg.Comment == "" {
+			// When there's no comment, try to get corresponding version for the Rev
+			// and fill Comment.
+			// Get all the versions
+			pi := gps.ProjectIdentifier{ProjectRoot: gps.ProjectRoot(pkg.ImportPath)}
+			versions, err := sm.ListVersions(pi)
+			if err != nil {
+				return nil, nil, err
+			}
+			// Sort the versions in descending order, newer versions first
+			gps.SortPairedForUpgrade(versions)
+			// Match Rev with versions' underlying revision
+			for _, v := range versions {
+				if string(v.Underlying()) == pkg.Rev {
+					pkg.Comment = v.String()
+					break
+				}
+			}
+		}
+
 		if pkg.Comment != "" {
 			// If there's a comment, use it to create project constraint
 			pc, err := g.buildProjectConstraint(pkg, sm)
@@ -77,11 +103,9 @@ func (g *godepFile) convert(projectName string, sm gps.SourceManager) (*dep.Mani
 			manifest.Dependencies[pc.Ident.ProjectRoot] = gps.ProjectProperties{Source: pc.Ident.Source, Constraint: pc.Constraint}
 		}
 
-		if pkg.Rev != "" {
-			// Use the revision to create lock project
-			lp := g.buildLockedProject(pkg, manifest)
-			lock.P = append(lock.P, lp)
-		}
+		// Use the revision and comment to create lock project
+		lp := g.buildLockedProject(pkg, manifest)
+		lock.P = append(lock.P, lp)
 	}
 
 	return manifest, lock, nil

cmd/dep/godep_config_test.go

@@ -76,8 +76,9 @@ func TestGodepConvertProject(t *testing.T) {
 			Imports: []godepPackage{
 				{
 					ImportPath: "github.com/sdboyer/deptest",
-					Rev:        "6a741be0cc55ecbe4f45690ebfd606a956d5f14a",
-					Comment:    "v1.0.0",
+					// This revision has 2 versions attached to it, v1.0.0 & v0.8.0.
+					Rev:     "ff2948a2ac8f538c4ecd55962e919d1e13e74baf",
+					Comment: "v0.8.0",
 				},
 			},
 		},
@@ -93,9 +94,77 @@ func TestGodepConvertProject(t *testing.T) {
 		t.Fatal("Expected the manifest to have a dependency for 'github.com/sdboyer/deptest' but got none")
 	}
 
+	v := d.Constraint.String()
+	if v != "v0.8.0" {
+		t.Fatalf("Expected manifest constraint to be v0.8.0, got %s", v)
+	}
+
+	p := lock.P[0]
+	if p.Ident().ProjectRoot != "github.com/sdboyer/deptest" {
+		t.Fatalf("Expected the lock to have a project for 'github.com/sdboyer/deptest' but got '%s'", p.Ident().ProjectRoot)
+	}
+
+	lv := p.Version()
+	lpv, ok := lv.(gps.PairedVersion)
+	if !ok {
+		t.Fatalf("Expected locked version to be PairedVersion but got %T", lv)
+	}
+
+	rev := lpv.Underlying()
+	if rev != "ff2948a2ac8f538c4ecd55962e919d1e13e74baf" {
+		t.Fatalf("Expected locked revision to be 'ff2948a2ac8f538c4ecd55962e919d1e13e74baf', got %s", rev)
+	}
+
+	ver := lpv.String()
+	if ver != "v0.8.0" {
+		t.Fatalf("Expected locked version to be 'v0.8.0', got %s", ver)
+	}
+}
+
+func TestGodepConvertProject_EmptyComment(t *testing.T) {
+	loggers := &dep.Loggers{
+		Out:     log.New(os.Stdout, "", 0),
+		Err:     log.New(os.Stdout, "", 0),
+		Verbose: true,
+	}
+
+	h := test.NewHelper(t)
+	defer h.Cleanup()
+	h.TempDir("src")
+
+	f := godepFile{
+		loggers: loggers,
+		json: godepJson{
+			Name: "github.com/foo/bar",
+			Imports: []godepPackage{
+				{
+					ImportPath: "github.com/sdboyer/deptest",
+					// This revision has 2 versions attached to it, v1.0.0 & v0.8.0.
+					Rev: "ff2948a2ac8f538c4ecd55962e919d1e13e74baf",
+				},
+			},
+		},
+	}
+
+	sm, err := gps.NewSourceManager(h.Path("."))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer sm.Release()
+
+	manifest, lock, err := f.convert("", sm)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	d, ok := manifest.Dependencies["github.com/sdboyer/deptest"]
+	if !ok {
+		t.Fatal("Expected the manifest to have a dependency for 'github.com/sdboyer/deptest' but got none")
+	}
+
 	v := d.Constraint.String()
 	if v != "v1.0.0" {
-		t.Fatalf("Expected manifest constraint to be master, got %s", v)
+		t.Fatalf("Expected manifest constraint to be v1.0.0, got %s", v)
 	}
 
 	p := lock.P[0]
@@ -110,8 +179,8 @@ func TestGodepConvertProject(t *testing.T) {
 	}
 
 	rev := lpv.Underlying()
-	if rev != "6a741be0cc55ecbe4f45690ebfd606a956d5f14a" {
-		t.Fatalf("Expected locked revision to be '6a741be0cc55ecbe4f45690ebfd606a956d5f14a', got %s", rev)
+	if rev != "ff2948a2ac8f538c4ecd55962e919d1e13e74baf" {
+		t.Fatalf("Expected locked revision to be 'ff2948a2ac8f538c4ecd55962e919d1e13e74baf', got %s", rev)
 	}
 
 	ver := lpv.String()