feat: Added support for PlantUML using Confluence PlantUML macro

[artur-kacen]

Added support of PlantUML based diagrams using Confluence PlantUML macro.

All rendering will be done by Confluence if PlantUML plugin is installed.

[artur-kacen]

Hi @kovetskiy , can you re-run unit tests? Locally failing test is working fine

$ make test
go test -race -coverprofile=profile.cov ./... -v
=== RUN   Test_setLogLevel
=== RUN   Test_setLogLevel/warning
=== RUN   Test_setLogLevel/error
=== RUN   Test_setLogLevel/fatal
=== RUN   Test_setLogLevel/invalid
=== RUN   Test_setLogLevel/empty
=== RUN   Test_setLogLevel/info
=== RUN   Test_setLogLevel/debug
=== RUN   Test_setLogLevel/trace
--- PASS: Test_setLogLevel (0.00s)
    --- PASS: Test_setLogLevel/warning (0.00s)
    --- PASS: Test_setLogLevel/error (0.00s)
    --- PASS: Test_setLogLevel/fatal (0.00s)
    --- PASS: Test_setLogLevel/invalid (0.00s)
    --- PASS: Test_setLogLevel/empty (0.00s)
    --- PASS: Test_setLogLevel/info (0.00s)
    --- PASS: Test_setLogLevel/debug (0.00s)
    --- PASS: Test_setLogLevel/trace (0.00s)
PASS
coverage: 0.0% of statements
ok      github.com/kovetskiy/mark       (cached)        coverage: 0.0% of statements
=== RUN   TestPrepareAttachmentsWithWorkDirBase
    attachment_test.go:48: attaches: <nil>
--- PASS: TestPrepareAttachmentsWithWorkDirBase (0.00s)
=== RUN   TestPrepareAttachmentsWithSubDirBase
--- PASS: TestPrepareAttachmentsWithSubDirBase (0.00s)
PASS
coverage: 13.3% of statements
ok      github.com/kovetskiy/mark/attachment    (cached)        coverage: 13.3% of statements
        github.com/kovetskiy/mark/confluence            coverage: 0.0% of statements
=== RUN   TestExtractD2Image
=== RUN   TestExtractD2Image/example
--- PASS: TestExtractD2Image (3.03s)
    --- PASS: TestExtractD2Image/example (3.03s)
PASS
coverage: 81.6% of statements
ok      github.com/kovetskiy/mark/d2    (cached)        coverage: 81.6% of statements
        github.com/kovetskiy/mark/includes              coverage: 0.0% of statements
        github.com/kovetskiy/mark/macro         coverage: 0.0% of statements
=== RUN   TestCompileMarkdown
Testing: testdata/admonitions.md
Testing: testdata/codes.md
Testing: testdata/header.md
Testing: testdata/issue-64-broken-link.md
Testing: testdata/links.md
Testing: testdata/lists.md
Testing: testdata/macro-include.md
Testing: testdata/mention.md
Testing: testdata/newlines.md
Testing: testdata/pagelayout.md
Testing: testdata/quotes.md
Testing: testdata/table.md
Testing: testdata/tags.md
--- PASS: TestCompileMarkdown (0.10s)
=== RUN   TestCompileMarkdownDropH1
--- PASS: TestCompileMarkdownDropH1 (0.07s)
=== RUN   TestCompileMarkdownStripNewlines
--- PASS: TestCompileMarkdownStripNewlines (0.06s)
=== RUN   TestContinueOnError
2026-02-21 11:49:47.498 INFO  processing testdata/batch-tests/bad-test.md
2026-02-21 11:49:47.499 ERROR specified file doesn't contain metadata and URL is not specified via command line or doesn't contain pageId GET-parameter
2026-02-21 11:49:47.499 INFO  processing testdata/batch-tests/errord-test.md
2026-02-21 11:49:47.500 ERROR specified file doesn't contain metadata and URL is not specified via command line or doesn't contain pageId GET-parameter
2026-02-21 11:49:47.500 INFO  processing testdata/batch-tests/good-test.md
<h2 id="Foo">Foo</h2>
<blockquote>
<p><strong>TL;DR:</strong> Thingy!
More stuff</p>
</blockquote>
<p>Foo</p>

2026-02-21 11:49:47.507 INFO  processing testdata/batch-tests/invalid-test.md
2026-02-21 11:49:47.509 ERROR specified file doesn't contain metadata and URL is not specified via command line or doesn't contain pageId GET-parameter
2026-02-21 11:49:47.509 INFO  processing testdata/batch-tests/valid-test.md
<h1 id="a">a</h1>
<h2 id="b">b</h2>
<h3 id="c">c</h3>
<h4 id="d">d</h4>
<h5 id="e">e</h5>
<h1 id="f">f</h1>
<h2 id="g">g</h2>
<h1 id="This/is-some_Heading.yml">This/is some_Heading.yml</h1>

--- PASS: TestContinueOnError (0.04s)
PASS
coverage: 95.2% of statements
ok      github.com/kovetskiy/mark/markdown      (cached)        coverage: 95.2% of statements
=== RUN   TestExtractMermaidImage
=== RUN   TestExtractMermaidImage/example
--- PASS: TestExtractMermaidImage (2.21s)
    --- PASS: TestExtractMermaidImage/example (2.21s)
PASS
coverage: 81.0% of statements
ok      github.com/kovetskiy/mark/mermaid       (cached)        coverage: 81.0% of statements
=== RUN   TestExtractDocumentLeadingH1
--- PASS: TestExtractDocumentLeadingH1 (0.00s)
=== RUN   TestSetTitleFromFilename
=== RUN   TestSetTitleFromFilename/set_title_from_filename
=== RUN   TestSetTitleFromFilename/replace_underscores_with_spaces
=== RUN   TestSetTitleFromFilename/replace_dashes_with_spaces
=== RUN   TestSetTitleFromFilename/mixed_underscores_and_dashes
=== RUN   TestSetTitleFromFilename/already_title_cased
--- PASS: TestSetTitleFromFilename (0.00s)
    --- PASS: TestSetTitleFromFilename/set_title_from_filename (0.00s)
    --- PASS: TestSetTitleFromFilename/replace_underscores_with_spaces (0.00s)
    --- PASS: TestSetTitleFromFilename/replace_dashes_with_spaces (0.00s)
    --- PASS: TestSetTitleFromFilename/mixed_underscores_and_dashes (0.00s)
    --- PASS: TestSetTitleFromFilename/already_title_cased (0.00s)
PASS
coverage: 12.3% of statements
ok      github.com/kovetskiy/mark/metadata      (cached)        coverage: 12.3% of statements
=== RUN   TestParseLinks
--- PASS: TestParseLinks (0.00s)
=== RUN   TestEncodeTinyLinkID
=== RUN   TestEncodeTinyLinkID/small_page_ID
=== RUN   TestEncodeTinyLinkID/another_small_page_ID
=== RUN   TestEncodeTinyLinkID/large_page_ID_(Confluence_Cloud)
=== RUN   TestEncodeTinyLinkID/page_ID_1
=== RUN   TestEncodeTinyLinkID/page_ID_255
=== RUN   TestEncodeTinyLinkID/page_ID_256
--- PASS: TestEncodeTinyLinkID (0.00s)
    --- PASS: TestEncodeTinyLinkID/small_page_ID (0.00s)
    --- PASS: TestEncodeTinyLinkID/another_small_page_ID (0.00s)
    --- PASS: TestEncodeTinyLinkID/large_page_ID_(Confluence_Cloud) (0.00s)
    --- PASS: TestEncodeTinyLinkID/page_ID_1 (0.00s)
    --- PASS: TestEncodeTinyLinkID/page_ID_255 (0.00s)
    --- PASS: TestEncodeTinyLinkID/page_ID_256 (0.00s)
=== RUN   TestGenerateTinyLink
=== RUN   TestGenerateTinyLink/cloud_URL_with_trailing_slash
=== RUN   TestGenerateTinyLink/cloud_URL_without_trailing_slash
=== RUN   TestGenerateTinyLink/server_URL
=== RUN   TestGenerateTinyLink/invalid_page_ID
--- PASS: TestGenerateTinyLink (0.00s)
    --- PASS: TestGenerateTinyLink/cloud_URL_with_trailing_slash (0.00s)
    --- PASS: TestGenerateTinyLink/cloud_URL_without_trailing_slash (0.00s)
    --- PASS: TestGenerateTinyLink/server_URL (0.00s)
    --- PASS: TestGenerateTinyLink/invalid_page_ID (0.00s)
=== RUN   TestEncodeTinyLinkIDMatchesPerl
--- PASS: TestEncodeTinyLinkIDMatchesPerl (0.00s)
=== RUN   TestEncodeTinyLinkIDLargeIDs
--- PASS: TestEncodeTinyLinkIDLargeIDs (0.00s)
PASS
coverage: 12.1% of statements
ok      github.com/kovetskiy/mark/page  (cached)        coverage: 12.1% of statements
        github.com/kovetskiy/mark/parser                coverage: 0.0% of statements
        github.com/kovetskiy/mark/renderer              coverage: 0.0% of statements
        github.com/kovetskiy/mark/stdlib                coverage: 0.0% of statements
?       github.com/kovetskiy/mark/types [no test files]
=== RUN   TestCheckMutuallyExclusiveTitleFlags
=== RUN   TestCheckMutuallyExclusiveTitleFlags/neither_flag_set
=== RUN   TestCheckMutuallyExclusiveTitleFlags/only_title-from-h1_set
=== RUN   TestCheckMutuallyExclusiveTitleFlags/only_title-from-filename_set
=== RUN   TestCheckMutuallyExclusiveTitleFlags/both_flags_set
--- PASS: TestCheckMutuallyExclusiveTitleFlags (0.00s)
    --- PASS: TestCheckMutuallyExclusiveTitleFlags/neither_flag_set (0.00s)
    --- PASS: TestCheckMutuallyExclusiveTitleFlags/only_title-from-h1_set (0.00s)
    --- PASS: TestCheckMutuallyExclusiveTitleFlags/only_title-from-filename_set (0.00s)
    --- PASS: TestCheckMutuallyExclusiveTitleFlags/both_flags_set (0.00s)
PASS
coverage: 2.3% of statements
ok      github.com/kovetskiy/mark/util  (cached)        coverage: 2.3% of statements
        github.com/kovetskiy/mark/vfs           coverage: 0.0% of statements