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Fix type inference for first() and last() #2001

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Merged
merged 2 commits into from
Jul 22, 2024
Merged

Fix type inference for first() and last() #2001

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07d057c
Add failing type tests for first() and last()
butchler Jun 21, 2024
8b3cd07
Fix types of first() and last()
butchler Jun 21, 2024
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10 changes: 10 additions & 0 deletions type-definitions/flow-tests/immutable-flow.js
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Original file line number Diff line number Diff line change
Expand Up @@ -130,6 +130,16 @@ var item: number = numberList.get(4);
var nullableItem: ?number = numberList.get(4);
var itemOrDefault: number = numberList.get(4, 10);

// $FlowExpectedError[incompatible-type]
var item: number = numberList.first();
// $FlowExpectedError[incompatible-type]
var func: () => number = () => numberList.first();

// $FlowExpectedError[incompatible-type]
var item: number = numberList.last();
// $FlowExpectedError[incompatible-type]
var func: () => number = () => numberList.last();

numberList = List().insert(0, 0);
numberOrStringList = List.of(0).insert(1, 'a');
// $FlowExpectedError[incompatible-call]
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6 changes: 4 additions & 2 deletions type-definitions/immutable.d.ts
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Expand Up @@ -4208,15 +4208,17 @@ declare namespace Immutable {
* In case the `Collection` is empty returns the optional default
* value if provided, if no default value is provided returns undefined.
*/
first<NSV = undefined>(notSetValue?: NSV): V | NSV;
first<NSV>(notSetValue: NSV): V | NSV;
first(): V | undefined;

/**
* In case the `Collection` is not empty returns the last element of the
* `Collection`.
* In case the `Collection` is empty returns the optional default
* value if provided, if no default value is provided returns undefined.
*/
last<NSV = undefined>(notSetValue?: NSV): V | NSV;
last<NSV>(notSetValue: NSV): V | NSV;
last(): V | undefined;

// Reading deep values

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6 changes: 4 additions & 2 deletions type-definitions/immutable.js.flow
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Expand Up @@ -76,8 +76,10 @@ declare class _Collection<K, +V> implements ValueObject {
has(key: K): boolean;
includes(value: V): boolean;
contains(value: V): boolean;
first<NSV>(notSetValue?: NSV): V | NSV;
last<NSV>(notSetValue?: NSV): V | NSV;
first(): V | void;
first<NSV>(notSetValue: NSV): V | NSV;
last(): V | void;
last<NSV>(notSetValue: NSV): V | NSV;
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I've never used Flow before. Is this the correct way to define these types?

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@jdeniau jdeniau Jul 22, 2024 •
edited
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Never used flow either.
Honestly, I'd like to remove flow types from the main immutable repository as there is no maintenance on it :/ (and I think that flow did loose the battle against typescript)


hasIn(keyPath: Iterable<mixed>): boolean;

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20 changes: 20 additions & 0 deletions type-definitions/ts-tests/list.ts
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Expand Up @@ -76,6 +76,26 @@ import {
get(List<number>(), 4, 'a');
}

{
// #first

// $ExpectType number | undefined
List<number>().first();

// $ExpectError
(): number => List<number>().first();
}

{
// #last

// $ExpectType number | undefined
List<number>().last();

// $ExpectError
(): number => List<number>().last();
}

{
// #set

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