Structural changes in spdxId fix for package and files

- Fix capitalized initials of error messages
- Other structural changes to increase code efficiency

Signed-off-by: specter25 <ujjwalcoding012@gmail.com>

16 files changed, 103 insertions, 112 deletions

diff --git a/tvloader/parser2v1/parse_creation_info.go b/tvloader/parser2v1/parse_creation_info.go
index d6986f0..c492884 100644
--- a/tvloader/parser2v1/parse_creation_info.go
+++ b/tvloader/parser2v1/parse_creation_info.go
@@ -12,7 +12,7 @@ import (
 func (parser *tvParser2_1) parsePairFromCreationInfo2_1(tag string, value string) error {
 	// fail if not in Creation Info parser state
 	if parser.st != psCreationInfo2_1 {
-		return fmt.Errorf("Got invalid state %v in parsePairFromCreationInfo2_1", parser.st)
+		return fmt.Errorf("got invalid state %v in parsePairFromCreationInfo2_1", parser.st)
 	}
 
 	// create an SPDX Creation Info data struct if we don't have one already
@@ -76,9 +76,9 @@ func (parser *tvParser2_1) parsePairFromCreationInfo2_1(tag string, value string
 
 	// tag for going on to package section
 	case "PackageName":
-		//Error if last file does not has FileSPDXId
+		// Error if last file does not has FileSPDXId
 		if parser.file != nil && parser.file.FileSPDXIdentifier == spdx.ElementID("") {
-			return fmt.Errorf("Invalid file without a package SPDX identifier")
+			return fmt.Errorf("invalid file without a package SPDX identifier")
 		}
 		parser.st = psPackage2_1
 		parser.pkg = &spdx.Package2_1{
diff --git a/tvloader/parser2v1/parse_file.go b/tvloader/parser2v1/parse_file.go
index a43ba64..772e36e 100644
--- a/tvloader/parser2v1/parse_file.go
+++ b/tvloader/parser2v1/parse_file.go
@@ -18,17 +18,17 @@ func (parser *tvParser2_1) parsePairFromFile2_1(tag string, value string) error
 	switch tag {
 	// tag for creating new file section
 	case "FileName":
-		//check if the previous file contained a spdxId or not
-		if parser.file != nil && parser.file.FileSPDXIdentifier == spdx.ElementID("") {
-			return fmt.Errorf("Invalid file without a file SPDX identifier")
+		// check if the previous file contained a spdxId or not
+		if parser.file != nil && parser.file.FileSPDXIdentifier == nullSpdxElementId2_1 {
+			return fmt.Errorf("invalid file without a file SPDX identifier")
 		}
 		parser.file = &spdx.File2_1{}
 		parser.file.FileName = value
 	// tag for creating new package section and going back to parsing Package
 	case "PackageName":
-		//check if the previous file contained a spdxId or not
-		if parser.file != nil && parser.file.FileSPDXIdentifier == spdx.ElementID("") {
-			return fmt.Errorf("Invalid file without a file SPDX identifier")
+		// check if the previous file contained a spdxId or not
+		if parser.file != nil && parser.file.FileSPDXIdentifier == nullSpdxElementId2_1 {
+			return fmt.Errorf("invalid file without a file SPDX identifier")
 		}
 		parser.st = psPackage2_1
 		parser.file = nil
diff --git a/tvloader/parser2v1/parse_file_test.go b/tvloader/parser2v1/parse_file_test.go
index 05de9ea..481d577 100644
--- a/tvloader/parser2v1/parse_file_test.go
+++ b/tvloader/parser2v1/parse_file_test.go
@@ -887,59 +887,57 @@ func TestParser2_1FailsIfArtifactURIBeforeArtifactName(t *testing.T) {
 }
 
 func TestParser2_1FilesWithoutSpdxIdThrowError(t *testing.T) {
-	//case 1
+	// case 1
 	// Last unpackaged file no packages in doc
 	// Last file of last package in the doc
-	var tvPairs []reader.TagValuePair
-	tvPair1 := reader.TagValuePair{Tag: "SPDXVersion", Value: "SPDX-2.1"}
-	tvPairs = append(tvPairs, tvPair1)
-	tvPair2 := reader.TagValuePair{Tag: "DataLicense", Value: "CC0-1.0"}
-	tvPairs = append(tvPairs, tvPair2)
-	tvPair3 := reader.TagValuePair{Tag: "SPDXID", Value: "SPDXRef-DOCUMENT"}
-	tvPairs = append(tvPairs, tvPair3)
-	tvPair4 := reader.TagValuePair{Tag: "FileName", Value: "f1"}
-	tvPairs = append(tvPairs, tvPair4)
+	tvPairs := []reader.TagValuePair{
+		{Tag: "SPDXVersion", Value: "SPDX-2.1"},
+		{Tag: "DataLicense", Value: "CC0-1.0"},
+		{Tag: "SPDXID", Value: "SPDXRef-DOCUMENT"},
+		{Tag: "FileName", Value: "f1"},
+	}
 	_, err := ParseTagValues(tvPairs)
 	if err == nil {
 		t.Errorf("files withoutSpdx Identifiers getting accepted")
 	}
 
-	//case 2 : The previous file (packaged or unpackaged does not contain spdxID)
-	tvPair5 := reader.TagValuePair{Tag: "FileName", Value: "f2"}
-	tvPairs = append(tvPairs, tvPair5)
+	// case 2 : The previous file (packaged or unpackaged does not contain spdxID)
+	tvPairs = append(tvPairs, reader.TagValuePair{Tag: "FileName", Value: "f2"})
 	_, err = ParseTagValues(tvPairs)
 	if err == nil {
 		t.Errorf("%s", err)
 	}
 
-	//case 3 : Invalid file with snippet
-	//Last unpackaged file before the packges start
-	//Last file of a package and New package starts
+	// case 3 : Invalid file with snippet
+	// Last unpackaged file before the packges start
+	// Last file of a package and New package starts
 	sid1 := spdx.ElementID("s1")
 	parser := tvParser2_1{
 		doc: &spdx.Document2_1{},
 		st:  psCreationInfo2_1,
 	}
 	fileName := "f2.txt"
-	err = parser.parsePair2_1("FileName", fileName)
-	err = parser.parsePair2_1("SnippetSPDXID", string(sid1))
+	_ = parser.parsePair2_1("FileName", fileName)
+	_ = parser.parsePair2_1("SnippetSPDXID", string(sid1))
 	err = parser.parsePair2_1("PackageName", "p2")
 	if err == nil {
 		t.Errorf("files withoutSpdx Identifiers getting accepted")
 	}
 
-	//case 4 : Invalid File without snippets
-	//Last unpackaged file before the packges start
-	//Last file of a package and New package starts
+	// case 4 : Invalid File without snippets
+	// Last unpackaged file before the packges start
+	// Last file of a package and New package starts
 	parser3 := tvParser2_1{
 		doc: &spdx.Document2_1{},
 		st:  psCreationInfo2_1,
 	}
 	fileName = "f3.txt"
 	err = parser3.parsePair2_1("FileName", fileName)
+	if err != nil {
+		t.Errorf("%s", err)
+	}
 	err = parser3.parsePair2_1("PackageName", "p2")
 	if err == nil {
 		t.Errorf("files withoutSpdx Identifiers getting accepted")
 	}
-	err = parser3.parsePair2_1("PackageName", "p2")
 }
diff --git a/tvloader/parser2v1/parse_package.go b/tvloader/parser2v1/parse_package.go
index 9a03e9a..2ac355a 100644
--- a/tvloader/parser2v1/parse_package.go
+++ b/tvloader/parser2v1/parse_package.go
@@ -20,9 +20,9 @@ func (parser *tvParser2_1) parsePairFromPackage2_1(tag string, value string) err
 	case "PackageName":
 		// if package already has a name, create and go on to a new package
 		if parser.pkg == nil || parser.pkg.PackageName != "" {
-			//check if the previous package contained a spdxId or not
-			if parser.pkg != nil && parser.pkg.PackageSPDXIdentifier == spdx.ElementID("") {
-				return fmt.Errorf("Invalid package without a package SPDX identifier")
+			// check if the previous package contained a spdxId or not
+			if parser.pkg != nil && parser.pkg.PackageSPDXIdentifier == nullSpdxElementId2_1 {
+				return fmt.Errorf("invalid package without a package SPDX identifier")
 			}
 			parser.pkg = &spdx.Package2_1{
 				FilesAnalyzed:             true,
diff --git a/tvloader/parser2v1/parse_package_test.go b/tvloader/parser2v1/parse_package_test.go
index e9e095d..3aa0ddb 100644
--- a/tvloader/parser2v1/parse_package_test.go
+++ b/tvloader/parser2v1/parse_package_test.go
@@ -1092,19 +1092,16 @@ func TestParser2_1PackageWithoutSpdxIdentifierThrowsError(t *testing.T) {
 	pkgName := "p2"
 	err := parser.parsePair2_1("PackageName", pkgName)
 	if err == nil {
-		t.Errorf("Packages withoutSpdx Identifiers getting accepted")
-	}
-	var tvPairs []reader.TagValuePair
-	tvPair1 := reader.TagValuePair{Tag: "SPDXVersion", Value: "SPDX-2.1"}
-	tvPairs = append(tvPairs, tvPair1)
-	tvPair2 := reader.TagValuePair{Tag: "DataLicense", Value: "CC0-1.0"}
-	tvPairs = append(tvPairs, tvPair2)
-	tvPair3 := reader.TagValuePair{Tag: "SPDXID", Value: "SPDXRef-DOCUMENT"}
-	tvPairs = append(tvPairs, tvPair3)
-	tvPair4 := reader.TagValuePair{Tag: "PackageName", Value: "p1"}
-	tvPairs = append(tvPairs, tvPair4)
+		t.Errorf("packages withoutSpdx Identifiers getting accepted")
+	}
+	tvPairs := []reader.TagValuePair{
+		{Tag: "SPDXVersion", Value: "SPDX-2.1"},
+		{Tag: "DataLicense", Value: "CC0-1.0"},
+		{Tag: "SPDXID", Value: "SPDXRef-DOCUMENT"},
+		{Tag: "PackageName", Value: "p1"},
+	}
 	_, err = ParseTagValues(tvPairs)
 	if err == nil {
-		t.Errorf("Packages withoutSpdx Identifiers getting accepted")
+		t.Errorf("packages withoutSpdx Identifiers getting accepted")
 	}
 }
diff --git a/tvloader/parser2v1/parse_snippet.go b/tvloader/parser2v1/parse_snippet.go
index fefa9ad..f44c964 100644
--- a/tvloader/parser2v1/parse_snippet.go
+++ b/tvloader/parser2v1/parse_snippet.go
@@ -34,9 +34,9 @@ func (parser *tvParser2_1) parsePairFromSnippet2_1(tag string, value string) err
 	// tag for creating new package section and going back to parsing Package
 	case "PackageName":
 		parser.st = psPackage2_1
-		//check here whether the last file of the previous package contained the FileSpdxIdentifier
-		if parser.file != nil && parser.file.FileSPDXIdentifier == spdx.ElementID("") {
-			return fmt.Errorf("Invalid file without a file SPDX identifier")
+		// check here whether the last file of the previous package contained the FileSpdxIdentifier
+		if parser.file != nil && parser.file.FileSPDXIdentifier == nullSpdxElementId2_1 {
+			return fmt.Errorf("invalid file without a file SPDX identifier")
 		}
 		parser.file = nil
 		parser.snippet = nil
diff --git a/tvloader/parser2v1/parser.go b/tvloader/parser2v1/parser.go
index 9c30fb3..6504474 100644
--- a/tvloader/parser2v1/parser.go
+++ b/tvloader/parser2v1/parser.go
@@ -20,11 +20,11 @@ func ParseTagValues(tvs []reader.TagValuePair) (*spdx.Document2_1, error) {
 			return nil, err
 		}
 	}
-	if parser.file != nil && parser.file.FileSPDXIdentifier == spdx.ElementID("") {
-		return nil, fmt.Errorf("Invalid file without a file SPDX identifier")
+	if parser.file != nil && parser.file.FileSPDXIdentifier == nullSpdxElementId2_1 {
+		return nil, fmt.Errorf("invalid file without a file SPDX identifier")
 	}
-	if parser.pkg != nil && parser.pkg.PackageSPDXIdentifier == spdx.ElementID("") {
-		return nil, fmt.Errorf("Invalid package without a package SPDX identifier")
+	if parser.pkg != nil && parser.pkg.PackageSPDXIdentifier == nullSpdxElementId2_1 {
+		return nil, fmt.Errorf("invalid package without a package SPDX identifier")
 	}
 
 	return parser.doc, nil
@@ -47,14 +47,14 @@ func (parser *tvParser2_1) parsePair2_1(tag string, value string) error {
 	case psReview2_1:
 		return parser.parsePairFromReview2_1(tag, value)
 	default:
-		return fmt.Errorf("Parser state %v not recognized when parsing (%s, %s)", parser.st, tag, value)
+		return fmt.Errorf("parser state %v not recognized when parsing (%s, %s)", parser.st, tag, value)
 	}
 }
 
 func (parser *tvParser2_1) parsePairFromStart2_1(tag string, value string) error {
 	// fail if not in Start parser state
 	if parser.st != psStart2_1 {
-		return fmt.Errorf("Got invalid state %v in parsePairFromStart2_1", parser.st)
+		return fmt.Errorf("got invalid state %v in parsePairFromStart2_1", parser.st)
 	}
 
 	// create an SPDX Document data struct if we don't have one already
diff --git a/tvloader/parser2v1/types.go b/tvloader/parser2v1/types.go
index 5a73864..164f6a8 100644
--- a/tvloader/parser2v1/types.go
+++ b/tvloader/parser2v1/types.go
@@ -52,3 +52,5 @@ const (
 	// in review section
 	psReview2_1
 )
+
+const nullSpdxElementId2_1 = spdx.ElementID("")
diff --git a/tvloader/parser2v2/parse_creation_info.go b/tvloader/parser2v2/parse_creation_info.go
index b70fe84..930ff00 100644
--- a/tvloader/parser2v2/parse_creation_info.go
+++ b/tvloader/parser2v2/parse_creation_info.go
@@ -12,7 +12,7 @@ import (
 func (parser *tvParser2_2) parsePairFromCreationInfo2_2(tag string, value string) error {
 	// fail if not in Creation Info parser state
 	if parser.st != psCreationInfo2_2 {
-		return fmt.Errorf("Got invalid state %v in parsePairFromCreationInfo2_2", parser.st)
+		return fmt.Errorf("got invalid state %v in parsePairFromCreationInfo2_2", parser.st)
 	}
 
 	// create an SPDX Creation Info data struct if we don't have one already
@@ -76,9 +76,9 @@ func (parser *tvParser2_2) parsePairFromCreationInfo2_2(tag string, value string
 
 	// tag for going on to package section
 	case "PackageName":
-		//Error if last file does not has FileSPDXId
-		if parser.file != nil && parser.file.FileSPDXIdentifier == spdx.ElementID("") {
-			return fmt.Errorf("Invalid file without a package SPDX identifier")
+		// Error if last file does not has FileSPDXId
+		if parser.file != nil && parser.file.FileSPDXIdentifier == nullSpdxElementId2_2 {
+			return fmt.Errorf("invalid file without a package SPDX identifier")
 		}
 		parser.st = psPackage2_2
 		parser.pkg = &spdx.Package2_2{
diff --git a/tvloader/parser2v2/parse_file.go b/tvloader/parser2v2/parse_file.go
index f6447fa..7e004e9 100644
--- a/tvloader/parser2v2/parse_file.go
+++ b/tvloader/parser2v2/parse_file.go
@@ -18,18 +18,18 @@ func (parser *tvParser2_2) parsePairFromFile2_2(tag string, value string) error
 	switch tag {
 	// tag for creating new file section
 	case "FileName":
-		//check if the previous file contained a spdxId or not
-		if parser.file != nil && parser.file.FileSPDXIdentifier == spdx.ElementID("") {
-			return fmt.Errorf("Invalid file without a file SPDX identifier")
+		// check if the previous file contained a spdxId or not
+		if parser.file != nil && parser.file.FileSPDXIdentifier == nullSpdxElementId2_2 {
+			return fmt.Errorf("invalid file without a file SPDX identifier")
 		}
 		parser.file = &spdx.File2_2{}
 		parser.file.FileName = value
 	// tag for creating new package section and going back to parsing Package
 	case "PackageName":
 		parser.st = psPackage2_2
-		//check if the previous file containes a spdxId or not
-		if parser.file != nil && parser.file.FileSPDXIdentifier == spdx.ElementID("") {
-			return fmt.Errorf("Invalid file without a file SPDX identifier")
+		// check if the previous file containes a spdxId or not
+		if parser.file != nil && parser.file.FileSPDXIdentifier == nullSpdxElementId2_2 {
+			return fmt.Errorf("invalid file without a file SPDX identifier")
 		}
 		parser.file = nil
 		return parser.parsePairFromPackage2_2(tag, value)
diff --git a/tvloader/parser2v2/parse_file_test.go b/tvloader/parser2v2/parse_file_test.go
index 3af06a1..f5234a2 100644
--- a/tvloader/parser2v2/parse_file_test.go
+++ b/tvloader/parser2v2/parse_file_test.go
@@ -920,59 +920,54 @@ func TestParser2_2FailsIfArtifactURIBeforeArtifactName(t *testing.T) {
 }
 
 func TestParser2_2FilesWithoutSpdxIdThrowError(t *testing.T) {
-	//case 1
+	// case 1
 	// Last unpackaged file no packages in doc
 	// Last file of last package in the doc
-	var tvPairs []reader.TagValuePair
-	tvPair1 := reader.TagValuePair{Tag: "SPDXVersion", Value: "SPDX-2.2"}
-	tvPairs = append(tvPairs, tvPair1)
-	tvPair2 := reader.TagValuePair{Tag: "DataLicense", Value: "CC0-1.0"}
-	tvPairs = append(tvPairs, tvPair2)
-	tvPair3 := reader.TagValuePair{Tag: "SPDXID", Value: "SPDXRef-DOCUMENT"}
-	tvPairs = append(tvPairs, tvPair3)
-	tvPair4 := reader.TagValuePair{Tag: "FileName", Value: "f1"}
-	tvPairs = append(tvPairs, tvPair4)
+	tvPairs := []reader.TagValuePair{
+		{Tag: "SPDXVersion", Value: "SPDX-2.2"},
+		{Tag: "DataLicense", Value: "CC0-1.0"},
+		{Tag: "SPDXID", Value: "SPDXRef-DOCUMENT"},
+		{Tag: "FileName", Value: "f1"},
+	}
 	_, err := ParseTagValues(tvPairs)
 	if err == nil {
 		t.Errorf("files withoutSpdx Identifiers getting accepted")
 	}
 
-	//case 2 : The previous file (packaged or unpackaged does not contain spdxID)
-	tvPair5 := reader.TagValuePair{Tag: "FileName", Value: "f2"}
-	tvPairs = append(tvPairs, tvPair5)
+	// case 2 : The previous file (packaged or unpackaged does not contain spdxID)
+	tvPairs = append(tvPairs, reader.TagValuePair{Tag: "FileName", Value: "f2"})
 	_, err = ParseTagValues(tvPairs)
 	if err == nil {
 		t.Errorf("%s", err)
 	}
 
-	//case 3 : Invalid file with snippet
-	//Last unpackaged file before the packges start
-	//Last file of a package and New package starts
+	// case 3 : Invalid file with snippet
+	// Last unpackaged file before the packges start
+	// Last file of a package and New package starts
 	sid1 := spdx.ElementID("s1")
 	parser := tvParser2_2{
 		doc: &spdx.Document2_2{},
 		st:  psCreationInfo2_2,
 	}
 	fileName := "f2.txt"
-	err = parser.parsePair2_2("FileName", fileName)
-	err = parser.parsePair2_2("SnippetSPDXID", string(sid1))
+	_ = parser.parsePair2_2("FileName", fileName)
+	_ = parser.parsePair2_2("SnippetSPDXID", string(sid1))
 	err = parser.parsePair2_2("PackageName", "p2")
 	if err == nil {
 		t.Errorf("files withoutSpdx Identifiers getting accepted")
 	}
 
-	//case 4 : Invalid File without snippets
-	//Last unpackaged file before the packges start
-	//Last file of a package and New package starts
+	// case 4 : Invalid File without snippets
+	// Last unpackaged file before the packges start
+	// Last file of a package and New package starts
 	parser3 := tvParser2_2{
 		doc: &spdx.Document2_2{},
 		st:  psCreationInfo2_2,
 	}
 	fileName = "f3.txt"
-	err = parser3.parsePair2_2("FileName", fileName)
+	_ = parser3.parsePair2_2("FileName", fileName)
 	err = parser3.parsePair2_2("PackageName", "p2")
 	if err == nil {
 		t.Errorf("files withoutSpdx Identifiers getting accepted")
 	}
-	err = parser3.parsePair2_2("PackageName", "p2")
 }
diff --git a/tvloader/parser2v2/parse_package.go b/tvloader/parser2v2/parse_package.go
index 729db18..3d16272 100644
--- a/tvloader/parser2v2/parse_package.go
+++ b/tvloader/parser2v2/parse_package.go
@@ -20,9 +20,9 @@ func (parser *tvParser2_2) parsePairFromPackage2_2(tag string, value string) err
 	case "PackageName":
 		// if package already has a name, create and go on to a new package
 		if parser.pkg == nil || parser.pkg.PackageName != "" {
-			//check if the previous package contained a spdxId or not
-			if parser.pkg != nil && parser.pkg.PackageSPDXIdentifier == spdx.ElementID("") {
-				return fmt.Errorf("Invalid package without a package SPDX identifier")
+			// check if the previous package contained a spdxId or not
+			if parser.pkg != nil && parser.pkg.PackageSPDXIdentifier == nullSpdxElementId2_2 {
+				return fmt.Errorf("invalid package without a package SPDX identifier")
 			}
 			parser.pkg = &spdx.Package2_2{
 				FilesAnalyzed:             true,
diff --git a/tvloader/parser2v2/parse_package_test.go b/tvloader/parser2v2/parse_package_test.go
index 1983baf..6ed5dce 100644
--- a/tvloader/parser2v2/parse_package_test.go
+++ b/tvloader/parser2v2/parse_package_test.go
@@ -1126,19 +1126,16 @@ func TestParser2_2PackageWithoutSpdxIdentifierThrowsError(t *testing.T) {
 	pkgName := "p2"
 	err := parser.parsePair2_2("PackageName", pkgName)
 	if err == nil {
-		t.Errorf("Packages withoutSpdx Identifiers getting accepted")
-	}
-	var tvPairs []reader.TagValuePair
-	tvPair1 := reader.TagValuePair{Tag: "SPDXVersion", Value: "SPDX-2.2"}
-	tvPairs = append(tvPairs, tvPair1)
-	tvPair2 := reader.TagValuePair{Tag: "DataLicense", Value: "CC0-1.0"}
-	tvPairs = append(tvPairs, tvPair2)
-	tvPair3 := reader.TagValuePair{Tag: "SPDXID", Value: "SPDXRef-DOCUMENT"}
-	tvPairs = append(tvPairs, tvPair3)
-	tvPair4 := reader.TagValuePair{Tag: "PackageName", Value: "p1"}
-	tvPairs = append(tvPairs, tvPair4)
+		t.Errorf("packages withoutSpdx Identifiers getting accepted")
+	}
+	tvPairs := []reader.TagValuePair{
+		{Tag: "SPDXVersion", Value: "SPDX-2.2"},
+		{Tag: "DataLicense", Value: "CC0-1.0"},
+		{Tag: "SPDXID", Value: "SPDXRef-DOCUMENT"},
+		{Tag: "PackageName", Value: "p1"},
+	}
 	_, err = ParseTagValues(tvPairs)
 	if err == nil {
-		t.Errorf("Packages withoutSpdx Identifiers getting accepted")
+		t.Errorf("packages withoutSpdx Identifiers getting accepted")
 	}
 }
diff --git a/tvloader/parser2v2/parse_snippet.go b/tvloader/parser2v2/parse_snippet.go
index 0de54e2..59b8472 100644
--- a/tvloader/parser2v2/parse_snippet.go
+++ b/tvloader/parser2v2/parse_snippet.go
@@ -34,9 +34,9 @@ func (parser *tvParser2_2) parsePairFromSnippet2_2(tag string, value string) err
 	// tag for creating new package section and going back to parsing Package
 	case "PackageName":
 		parser.st = psPackage2_2
-		//check here whether the last file of the previous package contained the FileSpdxIdentifier
-		if parser.file != nil && parser.file.FileSPDXIdentifier == spdx.ElementID("") {
-			return fmt.Errorf("Invalid file without a file SPDX identifier")
+		// check here whether the last file of the previous package contained the FileSpdxIdentifier
+		if parser.file != nil && parser.file.FileSPDXIdentifier == nullSpdxElementId2_2 {
+			return fmt.Errorf("invalid file without a file SPDX identifier")
 		}
 		parser.file = nil
 		parser.snippet = nil
diff --git a/tvloader/parser2v2/parser.go b/tvloader/parser2v2/parser.go
index 8216fbb..4f47de5 100644
--- a/tvloader/parser2v2/parser.go
+++ b/tvloader/parser2v2/parser.go
@@ -20,11 +20,11 @@ func ParseTagValues(tvs []reader.TagValuePair) (*spdx.Document2_2, error) {
 			return nil, err
 		}
 	}
-	if parser.file != nil && parser.file.FileSPDXIdentifier == spdx.ElementID("") {
-		return nil, fmt.Errorf("Invalid file without a file SPDX identifier")
+	if parser.file != nil && parser.file.FileSPDXIdentifier == nullSpdxElementId2_2 {
+		return nil, fmt.Errorf("invalid file without a file SPDX identifier")
 	}
-	if parser.pkg != nil && parser.pkg.PackageSPDXIdentifier == spdx.ElementID("") {
-		return nil, fmt.Errorf("Invalid package without a package SPDX identifier")
+	if parser.pkg != nil && parser.pkg.PackageSPDXIdentifier == nullSpdxElementId2_2 {
+		return nil, fmt.Errorf("invalid package without a package SPDX identifier")
 	}
 	return parser.doc, nil
 }
@@ -46,14 +46,14 @@ func (parser *tvParser2_2) parsePair2_2(tag string, value string) error {
 	case psReview2_2:
 		return parser.parsePairFromReview2_2(tag, value)
 	default:
-		return fmt.Errorf("Parser state %v not recognized when parsing (%s, %s)", parser.st, tag, value)
+		return fmt.Errorf("parser state %v not recognized when parsing (%s, %s)", parser.st, tag, value)
 	}
 }
 
 func (parser *tvParser2_2) parsePairFromStart2_2(tag string, value string) error {
 	// fail if not in Start parser state
 	if parser.st != psStart2_2 {
-		return fmt.Errorf("Got invalid state %v in parsePairFromStart2_2", parser.st)
+		return fmt.Errorf("got invalid state %v in parsePairFromStart2_2", parser.st)
 	}
 
 	// create an SPDX Document data struct if we don't have one already
diff --git a/tvloader/parser2v2/types.go b/tvloader/parser2v2/types.go
index 6039a1c..1cdbcef 100644
--- a/tvloader/parser2v2/types.go
+++ b/tvloader/parser2v2/types.go
@@ -52,3 +52,5 @@ const (
 	// in review section
 	psReview2_2
 )
+
+const nullSpdxElementId2_2 = spdx.ElementID("")