@@ -152,7 +152,10 @@ import { ZMScoreCommand } from "./commands/zmscore.ts";
152152import { HRandFieldCommand } from "./commands/hrandfield.ts" ;
153153import { ZDiffStoreCommand } from "./commands/zdiffstore.ts" ;
154154
155- type Chain = < T > ( command : Command < any , T > ) => Pipeline ;
155+ // Given a tuple of commands, returns a tuple of the response data of each command
156+ type InferResponseData < T extends unknown [ ] > = {
157+ [ K in keyof T ] : T [ K ] extends Command < any , infer TData > ? TData : unknown ;
158+ } ;
156159
157160/**
158161 * Upstash REST API supports command pipelining to send multiple commands in
@@ -182,7 +185,7 @@ type Chain = <T>(command: Command<any, T>) => Pipeline;
182185 * const res = await p.set("key","value").get("key").exec()
183186 * ```
184187 *
185- * It's not possible to infer correct types with a dynamic pipeline, so you can
188+ * Return types are inferred if all commands are chained, but you can still
186189 * override the response type manually:
187190 * ```ts
188191 * redis.pipeline()
@@ -192,9 +195,9 @@ type Chain = <T>(command: Command<any, T>) => Pipeline;
192195 *
193196 * ```
194197 */
195- export class Pipeline {
198+ export class Pipeline < TCommands extends Command < any , any > [ ] = [ ] > {
196199 private client : Requester ;
197- private commands : Command < unknown , unknown > [ ] ;
200+ private commands : TCommands ;
198201 private commandOptions ?: CommandOptions < any , any > ;
199202 private multiExec : boolean ;
200203 constructor ( opts : {
@@ -204,7 +207,7 @@ export class Pipeline {
204207 } ) {
205208 this . client = opts . client ;
206209
207- this . commands = [ ] ;
210+ this . commands = ( [ ] as unknown ) as TCommands ; // the TCommands generic in the class definition is only used for carrying through chained command types and should never be explicitly set when instantiating the class
208211 this . commandOptions = opts . commandOptions ;
209212 this . multiExec = opts . multiExec ?? false ;
210213 }
@@ -214,13 +217,16 @@ export class Pipeline {
214217 *
215218 * Returns an array with the results of all pipelined commands.
216219 *
217- * You can define a return type manually to make working in typescript easier
220+ * If all commands are statically chained from start to finish, types are inferred. You can still define a return type manually if necessary though:
218221 * ```ts
219- * redis.pipeline().get("key").exec<[{ greeting: string }]>()
222+ * const p = redis.pipeline()
223+ * p.get("key")
224+ * const result = p.exec<[{ greeting: string }]>()
220225 * ```
221226 */
222227 exec = async <
223- TCommandResults extends unknown [ ] = unknown [ ] ,
228+ TCommandResults extends unknown [ ] = [ ] extends TCommands ? unknown [ ]
229+ : InferResponseData < TCommands > ,
224230 > ( ) : Promise < TCommandResults > => {
225231 if ( this . commands . length === 0 ) {
226232 throw new Error ( "Pipeline is empty" ) ;
@@ -245,12 +251,14 @@ export class Pipeline {
245251 } ;
246252
247253 /**
248- * Pushes a command into the pipelien and returns a chainable instance of the
254+ * Pushes a command into the pipeline and returns a chainable instance of the
249255 * pipeline
250256 */
251- private chain < T > ( command : Command < any , T > ) : this {
257+ private chain < T > (
258+ command : Command < any , T > ,
259+ ) : Pipeline < [ ...TCommands , Command < any , T > ] > {
252260 this . commands . push ( command ) ;
253- return this ;
261+ return this as any ; // TS thinks we're returning Pipeline<[]> here, because we're not creating a new instance of the class, hence the cast
254262 }
255263
256264 /**
@@ -274,14 +282,18 @@ export class Pipeline {
274282 destinationKey : string ,
275283 sourceKey : string ,
276284 ...sourceKeys : string [ ]
277- ) : Pipeline ;
278- ( op : "not" , destinationKey : string , sourceKey : string ) : Pipeline ;
285+ ) : Pipeline < [ ...TCommands , BitOpCommand ] > ;
286+ (
287+ op : "not" ,
288+ destinationKey : string ,
289+ sourceKey : string ,
290+ ) : Pipeline < [ ...TCommands , BitOpCommand ] > ;
279291 } = (
280292 op : "and" | "or" | "xor" | "not" ,
281293 destinationKey : string ,
282294 sourceKey : string ,
283295 ...sourceKeys : string [ ]
284- ) : Pipeline =>
296+ ) =>
285297 this . chain (
286298 new BitOpCommand (
287299 [ op as any , destinationKey , sourceKey , ...sourceKeys ] ,
@@ -549,7 +561,7 @@ export class Pipeline {
549561 direction : "before" | "after" ,
550562 pivot : TData ,
551563 value : TData ,
552- ) : Pipeline =>
564+ ) =>
553565 this . chain (
554566 new LInsertCommand < TData > (
555567 [ key , direction , pivot , value ] ,
@@ -1070,30 +1082,7 @@ export class Pipeline {
10701082 /**
10711083 * @see https://redis.io/commands/?group=json
10721084 */
1073- get json ( ) : {
1074- arrappend : ( ...args : CommandArgs < typeof JsonArrAppendCommand > ) => Pipeline ;
1075- arrindex : ( ...args : CommandArgs < typeof JsonArrIndexCommand > ) => Pipeline ;
1076- arrinsert : ( ...args : CommandArgs < typeof JsonArrInsertCommand > ) => Pipeline ;
1077- arrlen : ( ...args : CommandArgs < typeof JsonArrLenCommand > ) => Pipeline ;
1078- arrpop : ( ...args : CommandArgs < typeof JsonArrPopCommand > ) => Pipeline ;
1079- arrtrim : ( ...args : CommandArgs < typeof JsonArrTrimCommand > ) => Pipeline ;
1080- clear : ( ...args : CommandArgs < typeof JsonClearCommand > ) => Pipeline ;
1081- del : ( ...args : CommandArgs < typeof JsonDelCommand > ) => Pipeline ;
1082- forget : ( ...args : CommandArgs < typeof JsonForgetCommand > ) => Pipeline ;
1083- get : ( ...args : CommandArgs < typeof JsonGetCommand > ) => Pipeline ;
1084- mget : ( ...args : CommandArgs < typeof JsonMGetCommand > ) => Pipeline ;
1085- numincrby : ( ...args : CommandArgs < typeof JsonNumIncrByCommand > ) => Pipeline ;
1086- nummultby : ( ...args : CommandArgs < typeof JsonNumMultByCommand > ) => Pipeline ;
1087- objkeys : ( ...args : CommandArgs < typeof JsonObjKeysCommand > ) => Pipeline ;
1088- objlen : ( ...args : CommandArgs < typeof JsonObjLenCommand > ) => Pipeline ;
1089- resp : ( ...args : CommandArgs < typeof JsonRespCommand > ) => Pipeline ;
1090- set : ( ...args : CommandArgs < typeof JsonSetCommand > ) => Pipeline ;
1091- strappend : ( ...args : CommandArgs < typeof JsonStrAppendCommand > ) => Pipeline ;
1092- strlen : ( ...args : CommandArgs < typeof JsonStrLenCommand > ) => Pipeline ;
1093- toggle : ( ...args : CommandArgs < typeof JsonToggleCommand > ) => Pipeline ;
1094- type : ( ...args : CommandArgs < typeof JsonTypeCommand > ) => Pipeline ;
1095- } {
1096- // For some reason we needed to define the types manually, otherwise Deno wouldn't build it
1085+ get json ( ) {
10971086 return {
10981087 /**
10991088 * @see https://redis.io/commands/json.arrappend
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