Validate Custom JSON-LD Context

Issue の Verify コマンドを sbom-output.spdx.json に対して実行し、その後、expand-custom-context.sh によって生成された expanded-sbom-output.spdx.json と比較します。Verify コマンドの JSON-LD コンテキスト検証から始め、カスタムコンテキストマッピングをどのように扱うべきかを判断します。完了の条件は、外部の展開スクリプトを必要とせずに元のドキュメントが検証に通ることです。

According to the Serialization Information section in the SPDX 3.0.1 spec serializing NamespaceMaps within the @context field for JSON-LD serializations is valid.

When serializing a physical SpdxDocument, any property of the logical element that can be natively represented within the chosen serialization format (e.g., @context prefixes in JSON-LD instead of the namespaceMap) may utilize these native mechanisms. All remaining properties shall be serialized within the SpdxDocument element itself.
[...]
Additional namespace mappings may be defined within a separate object within the context.

The java spdx tools however do not currently support this.
Take for example the following document: sbom-output.spdx.json

export SPDX_TOOLS_VERSION=2.0.2
curl -sLO "https://github.com/spdx/tools-java/releases/download/v${SPDX_TOOLS_VERSION}/tools-java-${SPDX_TOOLS_VERSION}.zip"
unzip -j "tools-java-${SPDX_TOOLS_VERSION}.zip" "tools-java-${SPDX_TOOLS_VERSION}-jar-with-dependencies.jar"
java -jar "tools-java-${SPDX_TOOLS_VERSION}-jar-with-dependencies.jar" Verify "sbom-output.spdx.json"

The java tools fail with

This SPDX Document is not valid due to:
        $.@context: must be the constant value 'https://spdx.org/rdf/3.0.1/spdx-context.jsonld'

even though the document should be valid.

An easy way to fix this would be to expand the custom context before processing the SPDX document.
See for example expand-custom-context.sh

./expand-custom-context.sh sbom-output.spdx.json

This small script expands the custom context and outputs expanded-sbom-output.spdx.json which successfully gets validated by the java tools.

java -jar "tools-java-${SPDX_TOOLS_VERSION}-jar-with-dependencies.jar" Verify "expanded-sbom-output.spdx.json"
This SPDX Document is valid.

It would be helpful if this behavior could be supported directly by the java-tools.