jsonsaver: omit empty lists rather than null

[CatalinStratu]

Fixes #103

[swinslow]

Hi @CatalinStratu, thanks for this! Looks like there's one test which is failing:

 === RUN   Test_renderSnippets2_2/success_empty
    save_snippets_test.go:142: renderSnippets2_2() = map[SPDXID:SPDXRef- ranges:[map[endPointer:map[offset:0 reference:SPDXRef-] startPointer:map[offset:0 reference:SPDXRef-]] map[endPointer:map[lineNumber:0 reference:SPDXRef-] startPointer:map[lineNumber:0 reference:SPDXRef-]]]], want map[ranges:[map[] map[]]]
--- FAIL: Test_renderSnippets2_2 (0.00s)
    --- PASS: Test_renderSnippets2_2/success (0.00s)
    --- FAIL: Test_renderSnippets2_2/success_empty (0.00s)
FAIL
coverage: 95.1% of statements
FAIL	github.com/spdx/tools-golang/jsonsaver/saver2v2	0.005s

Looks like it perhaps isn't correctly rendering the "empty" snippet case, can you take a look and see what's going on here? Once this is addressed I think the rest of it is good to merge. Thank you!

[CatalinStratu]

Hi @CatalinStratu, thanks for this! Looks like there's one test which is failing:

 === RUN   Test_renderSnippets2_2/success_empty
    save_snippets_test.go:142: renderSnippets2_2() = map[SPDXID:SPDXRef- ranges:[map[endPointer:map[offset:0 reference:SPDXRef-] startPointer:map[offset:0 reference:SPDXRef-]] map[endPointer:map[lineNumber:0 reference:SPDXRef-] startPointer:map[lineNumber:0 reference:SPDXRef-]]]], want map[ranges:[map[] map[]]]
--- FAIL: Test_renderSnippets2_2 (0.00s)
    --- PASS: Test_renderSnippets2_2/success (0.00s)
    --- FAIL: Test_renderSnippets2_2/success_empty (0.00s)
FAIL
coverage: 95.1% of statements
FAIL	github.com/spdx/tools-golang/jsonsaver/saver2v2	0.005s

Looks like it perhaps isn't correctly rendering the "empty" snippet case, can you take a look and see what's going on here? Once this is addressed I think the rest of it is good to merge. Thank you!

Hi, thank you very much. I tried to fix the problem. Thanks!

[swinslow]

Thanks @CatalinStratu! I see that reduces the "empty" test to just an empty document, which may be sufficient for the time being. I'm going to try out a couple more things with this PR, and if that looks good then I'll merge it shortly. Thanks for your quick updates on this one!

[swinslow]

OK - as far as I can tell, this addresses the issues that were raised in #103. Thanks very much @CatalinStratu! Merging now.

[CatalinStratu]

OK - as far as I can tell, this addresses the issues that were raised in #103. Thanks very much @CatalinStratu! Merging now.

Thank you very much!