Populate Files and Relationship fields for spdx-json output (#507)

* update spdx22 Document model to include relationships field

Signed-off-by: Christopher Angelo Phillips <christopher.phillips@anchore.com>

* update document and relationship to match current JSON spec
https://github.com/spdx/spdx-spec/blob/development/v2.2.1/schemas/spdx-schema.json
https://github.com/spdx/spdx-spec/pull/528
https://github.com/spdx/spdx-spec/pull/528#issuecomment-904180177

Signed-off-by: Christopher Angelo Phillips <christopher.phillips@anchore.com>

* update File struct based on SPDX schema

Required fields:
[ "SPDXID", "fileName", "copyrightText", "licenseConcluded" ]
Signed-off-by: Christopher Angelo Phillips <christopher.phillips@anchore.com>

internal/presenter/packages/model/spdx22/document.go

@@ -40,4 +40,6 @@ type Document struct {
 	Files []File `json:"files,omitempty"`
 	// Snippets referenced in the SPDX document
 	Snippets []Snippet `json:"snippets,omitempty"`
+	// Relationships referenced in the SPDX document
+	Relationships []Relationship `json:"relationships,omitempty"`
 }

internal/presenter/packages/model/spdx22/file.go

@@ -20,22 +20,22 @@ type File struct {
 	Item
 	// (At least one is required.) The checksum property provides a mechanism that can be used to verify that the
 	// contents of a File or Package have not changed.
-	Checksums []Checksum `json:"checksums"`
+	Checksums []Checksum `json:"checksums,omitempty"`
 	// This field provides a place for the SPDX file creator to record file contributors. Contributors could include
 	// names of copyright holders and/or authors who may not be copyright holders yet contributed to the file content.
-	FileContributors []string `json:"fileContributors"`
+	FileContributors []string `json:"fileContributors,omitempty"`
 	// Each element is a SPDX ID for a File.
-	FileDependencies []string `json:"fileDependencies"`
+	FileDependencies []string `json:"fileDependencies,omitempty"`
 	// The name of the file relative to the root of the package.
 	FileName string `json:"fileName"`
 	// The type of the file
-	FileTypes []string `json:"fileTypes"`
+	FileTypes []string `json:"fileTypes,omitempty"`
 	// This field provides a place for the SPDX file creator to record potential legal notices found in the file.
 	// This may or may not include copyright statements.
 	NoticeText string `json:"noticeText,omitempty"`
 	// Indicates the project in which the SpdxElement originated. Tools must preserve doap:homepage and doap:name
 	// properties and the URI (if one is known) of doap:Project resources that are values of this property. All other
 	// properties of doap:Projects are not directly supported by SPDX and may be dropped when translating to or
-	// from some SPDX formats.
-	ArtifactOf []string `json:"artifactOf"`
+	// from some SPDX formats(deprecated).
+	ArtifactOf []string `json:"artifactOf,omitempty"`
 }

internal/presenter/packages/model/spdx22/relationship.go

@@ -1,11 +1,13 @@
 package spdx22
 
 type Relationship struct {
-	// SPDX ID for SpdxElement. A related SpdxElement.
-	RelatedSpdxElement string `json:"relatedSpdxElement"`
+	// Id to which the SPDX element is related
+	SpdxElementID string `json:"spdxElementId"`
 	// Describes the type of relationship between two SPDX elements.
 	RelationshipType RelationshipType `json:"relationshipType"`
-	Comment          string           `json:"comment,omitempty"`
+	// SPDX ID for SpdxElement.  A related SpdxElement.
+	RelatedSpdxElement string `json:"relatedSpdxElement"`
+	Comment            string `json:"comment,omitempty"`
 }
 
 // source: https://spdx.github.io/spdx-spec/7-relationships-between-SPDX-elements/