generatorFunctionYields

Reports generator functions that do not yield values.

✅ This rule is included in the ts logical presets.

Generator functions use the function* syntax to create iterators that can produce multiple values over time. Without a yield expression, the generator will not produce any values and behaves like an empty iterator. This is likely unintentional and indicates incomplete implementation or a misunderstanding of generator functions.

function* 
function emptyGenerator(): Generator<never, void, unknown>
emptyGenerator() {
  
var console: Console
The console module provides a simple debugging console that is similar to the
JavaScript console mechanism provided by web browsers.
The module exports two specific components:

A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
A global console instance configured to write to process.stdout and
process.stderr. The global console can be used without importing the node:console module.

Warning: The global console object's methods are neither consistently
synchronous like the browser APIs they resemble, nor are they consistently
asynchronous like all other Node.js streams. See the note on process I/O for
more information.
Example using the global console:
console.log('hello world');
// Prints: hello world, to stdout
console.log('hello %s', 'world');
// Prints: hello world, to stdout
console.error(new Error('Whoops, something bad happened'));
// Prints error message and stack trace to stderr:
//   Error: Whoops, something bad happened
//     at [eval]:5:15
//     at Script.runInThisContext (node:vm:132:18)
//     at Object.runInThisContext (node:vm:309:38)
//     at node:internal/process/execution:77:19
//     at [eval]-wrapper:6:22
//     at evalScript (node:internal/process/execution:76:60)
//     at node:internal/main/eval_string:23:3

const name = 'Will Robinson';
console.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
const out = getStreamSomehow();
const err = getStreamSomehow();
const myConsole = new console.Console(out, err);

myConsole.log('hello world');
// Prints: hello world, to out
myConsole.log('hello %s', 'world');
// Prints: hello world, to out
myConsole.error(new Error('Whoops, something bad happened'));
// Prints: [Error: Whoops, something bad happened], to err

const name = 'Will Robinson';
myConsole.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to err
@see ― source
console.
Console.log(message?: any, ...optionalParams: any[]): void
Prints to stdout with newline. Multiple arguments can be passed, with the
first used as the primary message and all additional used as substitution
values similar to printf(3)
(the arguments are all passed to util.format()).
const count = 5;
console.log('count: %d', count);
// Prints: count: 5, to stdout
console.log('count:', count);
// Prints: count: 5, to stdout
See util.format() for more information.
@since ― v0.1.100
log("No yield here");
}

function* 
function generatorThatReturns(): Generator<never, number, unknown>
generatorThatReturns() {
  return 42;
}

class 
class Collection
Collection {
  *
Collection.iterator(): Generator<never, void, unknown>
iterator() {
    this.process();Error ts(2339)  ― Property 'process' does not exist on type 'Collection'.
  }
}

function* 
function numbers(): Generator<1 | 2 | 3, void, unknown>
numbers() {
  yield 1;
  yield 2;
  yield 3;
}

function* 
function range(start: number, end: number): Generator<number, void, unknown>
range(
start: number
start: number, 
end: number
end: number) {
  for (let 
let i: number
i = 
start: number
start; 
let i: number
i < 
end: number
end; 
let i: number
i++) {
    yield 
let i: number
i;
  }
}

class 
class Collection
Collection {
  *
Collection.iterator(): Generator<any, void, any>
iterator() {
    yield* this.items;Error ts(2339)  ― Property 'items' does not exist on type 'Collection'.
  }
}

Options

This rule is not configurable.

When Not To Use It

If you intentionally want to create generator functions that produce no values (empty iterators), you can disable this rule. However, in most cases, such functions should not be generators.

Equivalents in Other Linters

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generatorFunctionYields

Examples

Options

When Not To Use It

Further Reading

Equivalents in Other Linters