ContextSuggestField's class javadoc example calls new ContextSuggestField(name, "suggestion", Arrays.asList("context1", "context2"), 4), but the only constructor is (String name, String value, int weight, CharSequence... contexts), so the example has not compiled on any release since the class was added in 5.3.0 (documentation defect)

Finding LFV-1029Area: suggest / document suggesters (ContextSuggestField class javadoc example)Priority: lowImpact: minorNovelty: new

Finding page for LFV-1029

AI-assisted finding, confirmed by automated checks, not yet triaged by a human Lucene committer. This site files nothing upstream.

What it shows

The ContextSuggestField javadoc shows how to add a suggestion with two contexts: document.add(new ContextSuggestField(name, "suggestion", Arrays.asList("context1", "context2"), 4)). Copied into code, that line does not compile on any release, because the only constructor takes the weight third and the contexts last, as a varargs list: (name, value, weight, contexts...). Written as new ContextSuggestField(name, "suggestion", 4, "context1", "context2") it compiles, and a ContextQuery on context1 finds the suggestion with weight 4, so only the javadoc is wrong.

Expected vs actual

Expected: The example compiles, and a context1 query for "sugg" returns "suggestion" with score 4, as the corrected call does on main.
Actual: javac reports 1 error at the constructor call: incompatible types: no instance(s) of type variable(s) T exist so that List<T> conforms to int (the test prints it as java.util.List<T>); the same with assertions off.

Files

src/org/apache/lucene/search/suggest/document/TestContextSuggestFieldJavadocExample.java (JUnit test)

Run it

Tested on Lucene main e1faeba08bde (2026-11-02): still reproduces.
Tested on Lucene main 645d4fe14a20 (2026-10-28): reproduced.
How to read the outcome: a failing test is the finding reproducing (the failure message states expected against actual).
Seeds: a rerun with the same seed replays the same random choices. Assertions off (-da -dsa -Dtests.asserts=false) is the production-like setting.

# Lucene checkout at the tested commit, built with: ./gradlew --no-daemon assemble   (JDK 25)
LUCENE=/path/to/lucene; V=12.0.0-SNAPSHOT
CP=$LUCENE/lucene/core/build/libs/lucene-core-$V.jar
CP=$CP:$LUCENE/lucene/codecs/build/libs/lucene-codecs-$V.jar
CP=$CP:$LUCENE/lucene/test-framework/build/libs/lucene-test-framework-$V.jar
CP=$CP:$LUCENE/lucene/analysis/common/build/libs/lucene-analysis-common-$V.jar
CP=$CP:$LUCENE/lucene/suggest/build/libs/lucene-suggest-$V.jar
CP=$CP:randomizedtesting-runner-2.9.2.jar:junit-4.13.2.jar:hamcrest-3.0.jar   # test-framework dependencies (Maven Central)
CP=$CP:junit-platform-console-standalone-6.1.3.jar   # JUnit Platform console launcher (Maven Central)

javac -d classes -cp "$CP" $(find src -name '*.java')

# run 1: assertions on, seed DEADBEEF
java -ea -esa --add-modules jdk.incubator.vector --enable-native-access=ALL-UNNAMED -Dtests.seed=DEADBEEF \
     -cp "classes:$CP" org.junit.platform.console.ConsoleLauncher \
     execute --select-class org.apache.lucene.search.suggest.document.TestContextSuggestFieldJavadocExample

Gradle alternative: copy the test into the matching module's src/test/ tree of the checkout and run ./gradlew -p lucene/<module> test --tests <class> -Ptests.seed=<seed> (add -Ptests.asserts=false for a run without assertions).

Files shown on the finding page

TestContextSuggestFieldJavadocExample.java

Feedback

Open an issue in lucene-ai-bug-hunt. Please do not open issues or pull requests in apache/lucene about this finding unless a Lucene committer agrees it should be filed.

Snapshot of 2026-11-04. AI-assisted; not yet triaged by a human Lucene committer. Feedback: open an issue in lucene-ai-bug-hunt.