Extend Commands API

Extend the Jedis Commands API

Implement a new Redis command (or extend an existing one) in Jedis, following the conventions Jedis maintainers enforce in review.

Phase 0 — Gather evidence BEFORE planning

Do all of the following before writing any plan or code:

1. Ask the user for the HLD. Interactively ask the user for the path to a markdown file containing the High-Level Design for the command(s) (or confirm that no HLD exists). If a path is given, read it fully — it is the primary source for syntax, semantics, reply shape, and edge cases.

2. Find the server-side PR in the redis/redis GitHub repo. First verify that gh works in the current (sandboxed) environment:

   gh auth status
   

   Sandboxes often block access to credential files (~/.netrc, gh config), so gh may report unauthenticated here even though it works on the user's machine. If gh auth status fails or reports no authentication, ask the user for permission to run the gh commands outside the sandbox (e.g. with the sandbox override for these specific read-only commands), explaining that gh cannot reach its credentials from inside the sandbox. Only if the user declines (or gh is genuinely not logged in anywhere) fall back to the unauthenticated GitHub REST API or fetching https://github.com/redis/redis/pulls?q=<command>.

   Then search for the PR that adds/extends the command on the server:

   gh search prs --repo redis/redis "<COMMAND NAME>" --limit 10
   gh pr view <num> --repo redis/redis
   gh pr diff <num> --repo redis/redis   # look at src/commands/*.json for exact syntax
   

   From the server PR, extract: exact wire syntax (argument order and optionality), reply type per RESP2/RESP3, error conditions, time complexity, and — critically — the first server version carrying the feature (RC builds like 8.7.225 = Redis 8.8 RC are used for test gating). Note whether the server marks the feature experimental / in preview.

3. Verify the command exists on the "next" Redis OSS version. Start the integration environment using the latest .env.vX.XX file under src/test/resources/env/ (pick the highest version numerically, not lexicographically — e.g. 8.10 > 8.8):

   ls src/test/resources/env/.env.v* | sort -V | tail -1   # → e.g. .env.v8.10
   make start version=8.10
   

   Then probe the standalone0 endpoint. Read its connection details from src/test/resources/endpoints.json (currently redis://localhost:6379, password foobared) and check the target command via redis-cli:

   redis-cli -u redis://localhost:6379 -a foobared INFO server | grep redis_version
   redis-cli -u redis://localhost:6379 -a foobared COMMAND INFO <COMMAND>   # non-empty → command exists
   redis-cli -u redis://localhost:6379 -a foobared COMMAND DOCS <COMMAND>   # arity/args — compare with the server PR
   

   For a NEW command, COMMAND INFO must return a non-empty reply. For an EXTENDED command, additionally invoke it with the new syntax against a scratch key and confirm the server accepts it (no ERR syntax error / ERR unknown argument).

   If the command/option is missing on the latest env version, the image tag pinned in the .env.vX.XX file is too old for the target change. Interactively ask the user for a redislabs/client-libs-test image tag that contains it (e.g. an RC/edge/milestone build — tags are listed at https://hub.docker.com/r/redislabs/client-libs-test/tags; you may check them yourself and suggest candidates). Then restart the environment with that tag and re-run the probes:

   make stop
   make start CLIENT_LIBS_TEST_IMAGE_TAG=<tag>
   

   If the user has no tag to offer (or the probe still fails), report it and proceed anyway: the implementation can continue, but integration tests will be gated/skipped until a redislabs/client-libs-test image ships the change. Keep the environment running for later test runs, or make stop if you won't need it soon.

4. Create redis-cli showcase test cases. Once the command is available on the running environment, derive a small set of redis-cli scenarios from the HLD and the server PR and run them against standalone0. These serve two purposes at once:

   • Smoke test: prove the documented behavior actually holds on the target server — happy path, each new option/keyword, reply shape (run with redis-cli -3 too if RESP3 replies differ), edge cases and error conditions called out in the HLD (empty/missing key, out-of-range args, conflicting options), so the Java implementation is built against observed replies, not assumptions.
   • Showcase: each scenario should read as a mini use-case that explains WHY the command/option exists — what a user could not do (or could only do awkwardly) before, and how the new API covers it. Prefer realistic data over foo/bar (e.g. rate-limit counters for a bounded INCR, sensor readings for a time-series aggregator).

   Save the scenarios as a commented script in a scratch file (one block per use-case: a one-line "what this demonstrates" comment, the redis-cli commands, and the observed reply pasted back as comments). Carry this material forward: it feeds the Phase 1 plan (as the explanation of the feature and the source of expected values for tests), the Java test assertions, and the PR description. If the command could not be made available on any image (see step 3), still write the scenarios from the HLD/PR as expected transcripts and mark them unverified.

5. Read docs/integration-testing.md in the Jedis repo — it defines the test environment, endpoint discovery, *Test vs *IT naming, and how to run tests.

6. Trace one analogous existing command end-to-end in the codebase (same command group, similar reply shape) so the plan mirrors real code, not guesswork.

7. Determine the @since version:

   mvn help:evaluate -Dexpression=project.version -q -DforceStdout
   

   Strip -SNAPSHOT (e.g. 8.0.0-SNAPSHOT → @since 8.0).

Phase 1 — Plan mode, then explicit approval

Enter plan mode. Using the evidence, classify the change with the decision tree below, enumerate the exact file-by-file touch list, the test matrix, and the gating annotations. Open the plan with a short "what this feature enables" section built from the redis-cli showcase scenarios (Phase 0 step 4), including one or two representative command/reply transcripts, so the user sees the use-case before the file list. Present the plan to the user and explicitly ask permission to execute in auto-accept mode before implementing. Do not start editing files until the user approves.

Decision tree — what kind of change is this?

A. Extension of an existing command that fits an existing params class (e.g. new enum value / new option token):

• Touch ONLY the params/model classes + tests. Do NOT touch command interfaces, CommandObjects, UnifiedJedis, PipeliningBase, or Jedis — the existing IParams.addParams(CommandArguments) delegation carries the new option through automatically, for both String and binary surfaces.
• If the option is a bare token: add an enum constant implementing Rawable (bytes come from SafeEncoder.encode(name()) — self-wiring).
• If it's a new field: add a fluent setter returning this, extend addParams(), and update equals/hashCode in sync.
• If the reply shape grows (e.g. more array elements): extend the response model class backward-compatibly — keep old constructors/getters working, add new accessors, update the builder in the relevant *BuilderFactory to branch on reply size. Jedis does not defensively copy response collections (stated maintainer convention).

B. New core command(s) — the FULL matrix, every layer:

1. Protocol.java — new Command enum constant(s); new Keyword constants for sub-tokens, grouped under a // <FEATURE> keywords comment, alphabetical. Never add a Keyword that duplicates a token already carried by a dedicated Rawable enum (dead keywords get flagged in review).
2. Command interfaces in commands/: <Group>Commands, <Group>BinaryCommands, <Group>PipelineCommands, <Group>PipelineBinaryCommands. For a whole new command family, create four new <Family>*Commands interfaces and add one extends entry to JedisCommands, JedisBinaryCommands, PipelineCommands, PipelineBinaryCommands.
3. CommandObjects — String and byte[] factory methods side by side under a // <Feature> commands section. ClusterCommandObjects needs overrides ONLY for multi-key commands requiring slot checks; single-key commands need nothing.
4. UnifiedJedis — one-line @Override delegating to executeCommand(commandObjects.xxx(...)).
5. PipeliningBase — appendCommand(commandObjects.xxx(...)) returning Response<T>.
6. Jedis (legacy) — checkIsInMultiOrPipeline(); connection.executeCommand(commandObjects.xxx(...)).
7. pom.xml — add every new file to the formatter-maven-plugin includes list (this repo format-enforces an allowlist; new files must be registered).

C. Extension needing new overloads / a new params class (hybrid): new methods go through the full matrix of B; the option plumbing follows the params conventions below.

D. Module command (search / timeseries / json / bloom):

• Module interfaces are String-only — there are NO *BinaryCommands variants for modules; never create them.
• Module commands/keywords live in the module protocol class (TimeSeriesProtocol.TimeSeriesCommand/TimeSeriesKeyword, SearchProtocol.SearchCommand/SearchKeyword, …), each an enum implementing ProtocolCommand/Rawable with SafeEncoder.encode()-cached bytes.
• Strongly prefer extending the module's params/builder classes over adding interface methods — PRs #4504 and #4534 shipped whole features with ZERO changes to interfaces, CommandObjects, UnifiedJedis, or PipeliningBase.
• Search aggregation builders (Reducer subclasses) build a List<Object> via getOwnArgs(); the parent computes narg automatically. Canonicalize clause order at serialization time regardless of builder call order.
• Module response parsing lives in the module's builder factory (TimeSeriesBuilderFactory, SearchBuilderFactory); search aggregation results are loosely typed and often absorb new reply content with no parsing changes.

Binary (byte[]) variant policy

• Core commands: full String/byte[] parity is mandatory — all four interfaces, paired CommandObjects methods, and all three clients. Reviewers explicitly request binary integration tests too.
• Only keys and textual values get byte[] overloads. Numeric/structural args (long index, ranges, booleans, enums) stay identical.
• Params classes are shared, never duplicated: one params class serves both surfaces; if a param carries text, give the params class both foo(String) and foo(byte[]) setters (see ArgrepParams).
• Return types mirror the key type (String→byte[], List<String>→List<byte[]>); count/index/model results stay shared.
• Modules: no binary variants at all.

Params class conventions (params/)

• Implement IParams with addParams(CommandArguments args). Fluent setters return this; provide a static factory named after the class (increxParams(), rangeParams()).
• Do NOT extend another command's params hierarchy. If two overloads share options but differ in a typed field (long vs double), create a self-typed abstract base: BaseFooParams<T extends BaseFooParams<T>> with a private self() cast, plus two concrete subclasses — compile-time type safety over a polymorphic single class.
• Implement equals/hashCode (needed for Mockito matching in mocked tests) and keep them in sync with every new field. toString is not required on params classes.
• Validate eagerly in setters with descriptive IllegalArgumentException / IllegalStateException messages, consistent wording across sibling classes (e.g. "Aggregators must be non-null and non-empty"). Required-config checks may run at serialization time. No client-side server-version checks — an old server returning an error is acceptable and should be noted in the PR description.
• Expiration-style option groups are single-slot, last-wins (mirror SetParams).
• Document the wire-emission order in javadoc and lock it down in unit tests.

Response mapping (BuilderFactory / resps/)

• Reuse existing generic builders whenever the reply maps to a standard shape (LONG_LIST, DOUBLE_LIST, STRING, ENCODED_OBJECT_MAP, …). Maintainers actively reject bespoke response classes for 2-element arrays and the like.
• Reuse redis.clients.jedis.util.KeyValue<K,V> for pair replies.
• When a model class is genuinely needed (map-shaped INFO replies), put it in resps/: public String constants for reply field names, a Map<String,Object>-taking constructor, typed getters, plus a raw-map accessor for forward compatibility; subclass for FULL/extended variants.
• Nullable numeric replies are boxed Long — never Optional/OptionalLong in the command API; consistency with existing signatures (e.g. zrank) wins.
• Multi-mode commands (one wire command, several reply types by mode) are split into distinctly-named typed Java methods (aropAggregate/aropBitwise/aropCount) rather than one polymorphic method. But mode selected by argument type uses overloads of one name (increx(key, long, …) / increx(key, double, …)), with the mode keyword (BYINT/BYFLOAT) implied by the overload.

Encoding & enum rules

• String ↔ bytes: SafeEncoder.encode() — never String.getBytes().
• Numeric → bytes: Protocol.toByteArray().
• Token-valued argument enums live in args/ and implement Rawable with raw = SafeEncoder.encode(name()) cached in the constructor.
• Compose multi-token byte values (e.g. comma-joined lists) at the byte level.

Javadoc, @since, @Experimental

• Interface methods only carry javadoc; implementations (UnifiedJedis, Jedis, PipeliningBase, CommandObjects) carry none.
• String-interface javadoc: <b><a href="https://redis.io/commands/xxx">XXX Command</a></b>, prose semantics, Time complexity: O(...), @param, @return, @since <version>. Binary variants get short javadoc with @see to the String variant. Pipeline variants: one line — "Pipeline variant of {@link ...}" + @since.
• @since on every new public method and class, computed from pom.xml.
• If the server feature is preview/experimental, annotate ALL new public API (interfaces, methods, params, args, resps) with redis.clients.jedis.annots.Experimental and label the PR experimental. Do NOT use @Experimental for stable GA features.

Test matrix — what to write

Follow docs/integration-testing.md for environment, layout, and naming. The established per-command test layers (write all that apply):

1. Params unit test (params/FooParamsTest, plain *Test, no Redis): @Nested groups (ValidationTests, AddParamsTests, overload-equivalence), asserting exact wire args and order with redis.clients.jedis.util.CommandArgumentsMatchers (hasArgumentCount, hasArguments) and RawableFactory.from(...); also test the equals/hashCode contract.
2. Mocked delegation tests (unit, Mockito): add @Mock CommandObject<T> fields to MockedCommandObjectsTestBase (name them by TYPE, e.g. listLongCommandObject — reuse existing ones when the type matches), then when/verify tests in mocked/unified/UnifiedJedis<Group>CommandsTest and mocked/pipeline/PipeliningBase<Group>CommandsTest.
3. Unified integration tests: add methods to the existing abstract commands/unified/<Group>CommandsTestBase when one exists; for a new family, create <Family>CommandsTestBase extends UnifiedJedisCommandsTestBase plus thin per-topology runners — standalone (RedisClientCommandsTestHelper.getClient(protocol)) and cluster (ClusterCommandsTestHelper.getCleanCluster(protocol)). New concrete integration classes MUST be named *IT — never *IntegrationTest, never @Tag("integration") on new classes.
4. Cluster handling: multi-key commands need cluster test overrides using hash-tagged keys (s1{:}) so keys share a slot; tests semantically incompatible with cluster get @Test @Override + @Disabled("<reason>") empty bodies.
5. Legacy Jedis coverage: extend commands/jedis/<Group>*CommandsTest (which extends JedisCommandsTestBase) — can be minimal (smoke/missing-key) when the unified base covers behavior fully. Binary variants get their own integration tests (reviewers ask for these explicitly).

Cross-cutting test conventions:

• RESP2/RESP3 comes free: test bases are @ParameterizedClass + @MethodSource("redis.clients.jedis.commands.CommandsTestsParameters#respVersions") (or #jedisRespVersions for legacy) — no per-test work; just make sure new classes inherit the right base.
• Gating: command already released → @SinceRedisVersion("<RC build>") (e.g. "8.7.225" for 8.8) at the shared base-class level ONCE — do not repeat it on subclasses (maintainers remove redundant ones). Command not yet in any GA server → @EnabledOnCommand("<COMMAND>") (capability probe via COMMAND INFO). Module presence as precondition → assumeTrue(hasCommand(...)) probes. Environment exclusions → @ConditionalOnEnv(value = TestEnvUtil.ENV_..., enabled = false) (e.g. skip Redis Enterprise for brand-new features).
• Cover the whole family the option touches (store + non-store variants, with/without optional args, standalone + cluster), asserting real semantics, not just "no error". Avoid brittle assertions (no hard-coded hashCode() literals).

Running the tests

Jedis pins the CI JDK (Java 8) for the test build — check .github/workflows/ for the exact version and use a matching local JDK. Verify with java -version before running anything; a newer JDK may fail the build or silently produce the wrong bytecode target.

• Unit tests (Surefire, no Redis): mvn -B test, or mvn -Dtest=FooParamsTest test.
• Integration tests (Failsafe) need the Docker env and the verify lifecycle:

  make start version=8.8        # pick the version that carries the new command
  mvn -B verify                 # or: mvn -Dtest=FooIT verify
  make stop
  

  Never run integration coverage via mvn test/surefire:test — Failsafe owns *IT classes. If a brand-new command isn't in any published redislabs/client-libs-test tag yet, say so: the integration tests will be skipped/gated (that is expected and acceptable — @EnabledOnCommand / @SinceRedisVersion handle it), but they must still be written and compile.

PR hygiene checklist (verify before finishing)

• Every layer of the chosen matrix updated consistently (a return-type change must propagate across all 4 interfaces × 3 implementations × all test layers).
• New files added to the pom.xml formatter-plugin includes.
• @since (and @Experimental if preview) on all new public API.
• No unused imports, no wildcard imports, no dead Protocol.Keyword constants.
• equals/hashCode on params updated and unit-tested.
• docs/ updated if user-facing behavior/configuration changed; migration guide entry if anything breaks.
• PR description states: server PR link, version gate choice and why, which layers intentionally did NOT change and why, and behavior against older servers.