repository: improve error reporting on validation failures

Related to #183.

repository/repository.go

@@ -293,14 +293,14 @@ func (r *Repository) isValid() (bool, error) {
 		panic(e)
 	}
 	if !m {
-		return false, errors.New("Validation Error: repository name is not valid")
+		return false, &InvalidRepositoryError{message: "repository name is not valid"}
 	}
 	absPath, err := filepath.Abs(barePath(r.Name))
 	if err != nil || !strings.HasPrefix(absPath, bare) {
-		return false, errors.New("Validation Error: repository name is not valid")
+		return false, &InvalidRepositoryError{message: "repository name is not valid"}
 	}
 	if len(r.Users) == 0 {
-		return false, errors.New("Validation Error: repository should have at least one user")
+		return false, &InvalidRepositoryError{message: "repository should have at least one user"}
 	}
 	return true, nil
 }
@@ -910,3 +910,11 @@ func CommitZip(repo string, z *multipart.FileHeader, c GitCommit) (*Ref, error)
 func GetLogs(repo, hash string, total int, path string) (*GitHistory, error) {
 	return retriever().GetLogs(repo, hash, total, path)
 }
+
+type InvalidRepositoryError struct {
+	message string
+}
+
+func (err *InvalidRepositoryError) Error() string {
+	return err.message
+}

repository/repository_test.go

@@ -251,9 +251,9 @@ func (s *S) TestNewPublicRepository(c *check.C) {
 func (s *S) TestNewBreaksOnValidationError(c *check.C) {
 	_, err := New("", []string{"smeagol"}, []string{""}, false)
 	c.Check(err, check.NotNil)
-	expected := "Validation Error: repository name is not valid"
-	got := err.Error()
-	c.Assert(got, check.Equals, expected)
+	e, ok := err.(*InvalidRepositoryError)
+	c.Assert(ok, check.Equals, true)
+	c.Assert(e.message, check.Equals, "repository name is not valid")
 }
 
 func (s *S) TestNewDuplicate(c *check.C) {
@@ -284,44 +284,46 @@ func (s *S) TestRepositoryIsNotValidWithoutAName(c *check.C) {
 	v, err := r.isValid()
 	c.Assert(v, check.Equals, false)
 	c.Check(err, check.NotNil)
-	got := err.Error()
-	expected := "Validation Error: repository name is not valid"
-	c.Assert(got, check.Equals, expected)
+	e, ok := err.(*InvalidRepositoryError)
+	c.Assert(ok, check.Equals, true)
+	c.Assert(e.message, check.Equals, "repository name is not valid")
 }
 
 func (s *S) TestRepositoryIsNotValidWithInvalidName(c *check.C) {
 	r := Repository{Name: "foo bar", Users: []string{"gollum"}, IsPublic: true}
 	v, err := r.isValid()
 	c.Assert(v, check.Equals, false)
 	c.Check(err, check.NotNil)
-	got := err.Error()
-	expected := "Validation Error: repository name is not valid"
-	c.Assert(got, check.Equals, expected)
+	e, ok := err.(*InvalidRepositoryError)
+	c.Assert(ok, check.Equals, true)
+	c.Assert(e.message, check.Equals, "repository name is not valid")
 }
 
 func (s *S) TestRepositoryShoudBeInvalidWIthoutAnyUsers(c *check.C) {
 	r := Repository{Name: "foo_bar", Users: []string{}, IsPublic: true}
 	v, err := r.isValid()
 	c.Assert(v, check.Equals, false)
 	c.Assert(err, check.NotNil)
-	got := err.Error()
-	expected := "Validation Error: repository should have at least one user"
-	c.Assert(got, check.Equals, expected)
+	e, ok := err.(*InvalidRepositoryError)
+	c.Assert(ok, check.Equals, true)
+	c.Assert(e.message, check.Equals, "repository should have at least one user")
 }
 
 func (s *S) TestRepositoryShoudBeInvalidWIthInvalidNamespace(c *check.C) {
 	r := Repository{Name: "../repositories", Users: []string{}}
 	v, err := r.isValid()
 	c.Assert(v, check.Equals, false)
 	c.Assert(err, check.NotNil)
-	expected := "^Validation Error: repository name is not valid$"
-	c.Assert(err, check.ErrorMatches, expected)
+	e, ok := err.(*InvalidRepositoryError)
+	c.Assert(ok, check.Equals, true)
+	c.Assert(e.message, check.Equals, "repository name is not valid")
 	r = Repository{Name: "../../repositories", Users: []string{}}
 	v, err = r.isValid()
 	c.Assert(v, check.Equals, false)
 	c.Assert(err, check.NotNil)
-	expected = "^Validation Error: repository name is not valid$"
-	c.Assert(err, check.ErrorMatches, expected)
+	e, ok = err.(*InvalidRepositoryError)
+	c.Assert(ok, check.Equals, true)
+	c.Assert(e.message, check.Equals, "repository name is not valid")
 }
 
 func (s *S) TestRepositoryAcceptsValidNamespaces(c *check.C) {