[Misc] Use instanceof pattern matching instead of explicit casts (SonarQube java:S6201)

[claude]

Jira URL

N/A — [Misc] commit, no JIRA issue (SonarQube cleanup).

Changes

Description

• Fixes 52 open SonarCloud java:S6201 issues — "Replace this instanceof check and cast with 'instanceof Foo foo'" — across:
  • xwiki-rendering-api (24, mostly the equals() implementations of the Block hierarchy)
  • xwiki-rendering-transformation-macro (10) and xwiki-rendering-transformation-icon (2)
  • xwiki-rendering-syntax-xdomxml10 (7), -xhtml (2), -xwiki20 (1)
  • xwiki-rendering-macro-footnotes (3), xwiki-rendering-test (2), xwiki-rendering-wikimodel (1)
• Each redundant cast is replaced by the pattern variable bound by the enclosing instanceof check; where an explicit local was declared just to hold the cast, that declaration is removed and the pattern variable takes its name.

Clarifications

• The change is behaviour-neutral: the pattern variable has exactly the static type of the cast it replaces, so overload resolution (e.g. XDOMXMLChainingStreamRenderer.serializeParameter) is unchanged.
• Two sites use flow scoping rather than a plain positive guard, which is why they read slightly differently:
  • XHTMLXWikiGeneratorListener.onImage — if (!(reference instanceof XWikiWikiReference xwikiReference)), the variable being used in the else branch.
  • AbstractX509FileSystemStore.isMulti — !(store instanceof FileStoreReference fileStore) || fileStore.isMulti(), where the || right-hand side only runs when the check succeeded.
• In PutFootnotesMacro two conditions had to be re-wrapped to stay under the 120-character line limit once the pattern variable was added.

Screenshots & Video

N/A — no UI change.

Executed Tests

mvn clean install -B -ntp -Plegacy,quality -pl \
  xwiki-rendering-api,xwiki-rendering-wikimodel,xwiki-rendering-test,\
  xwiki-rendering-macros/xwiki-rendering-macro-footnotes,\
  xwiki-rendering-syntaxes/xwiki-rendering-syntax-xdomxml10,\
  xwiki-rendering-syntaxes/xwiki-rendering-syntax-xhtml,\
  xwiki-rendering-syntaxes/xwiki-rendering-syntax-xwiki20,\
  xwiki-rendering-transformations/xwiki-rendering-transformation-icon,\
  xwiki-rendering-transformations/xwiki-rendering-transformation-macro

BUILD SUCCESS — full unit-test suites, Checkstyle, Revapi and the JaCoCo coverage gate all pass.

Expected merging strategy

• Prefers squash: Yes
• Backport on branches:
  • None — cleanup only, no need to backport.

Related

Part of the same SonarQube sweep (one PR per repo, mergeable independently):

• [Misc] Use instanceof pattern matching instead of explicit casts (SonarQube java:S6201) xwiki-commons#1854 — 73 java:S6201 fixes in the crypto modules
• [Misc] Use instanceof pattern matching instead of explicit casts (SonarQube java:S6201) #391 — 52 java:S6201 fixes across the rendering modules
• [Misc] Use static imports for Mockito methods in unit tests (SonarQube java:S8924) xwiki-platform#6012 — 27 java:S8924 fixes in unit tests

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Generated by Claude Code