Create type for autocapitalize propertie of input and textarea

[rangzen]

Fix #21463

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• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

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• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
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• Other (please describe):

What is the current behavior?

Issue Number: #21463

What is the new behavior?

• Add a type

Does this introduce a breaking change?

• Yes
• No

Probably not cause everybody use 'on' and 'off' already and browser compatibility is poor right now so probably few people use it.

Other information

[liamdebeasi]

Thanks for the PR! There are a few things that we will need to correct before this gets merged in:

1. autocapitalize accepts more values than just "on" or "off": https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/autocapitalize. The following strings are accepted: on, off, none, sentences, words, characters.

2. The build is failing. When you make your changes you need to run npm run lint.fix and npm run build from the core directory.

3. The ion-textarea component also has an autocapitalize property, so we should make these changes there as well: https://github.com/ionic-team/ionic/blob/master/core/src/components/textarea/textarea.tsx#L40

When you update the types, you should add it as an AutocapitalizeTypes type in interface.d.ts. See https://github.com/ionic-team/ionic/blob/4fd7c0cc5a6c97100fa380e4ff1be0bb84c7006b/core/src/interface.d.ts#L40 as an example.

So you would do something like:

export type AutocapitalizeTypes = 'off' | 'on' | 'none' | 'sentences' | 'words' | 'characters';

[rangzen]

[ ERROR ]  TypeScript: ./src/components.d.ts:2837:15
           Interface 'HTMLIonInputElement' cannot simultaneously extend types
           'IonInput' and 'HTMLStencilElement'.Named property 'autocapitalize'
           of types 'IonInput' and 'HTMLStencilElement' are not identical.
   L2836:  };
   L2837:  interface HTMLIonInputElement extends Components.IonInput, HTMLStencilElement {
   L2838:  }
[ ERROR ]  TypeScript: ./src/components.d.ts:3149:15
           Interface 'HTMLIonTextareaElement' cannot simultaneously extend
           types 'IonTextarea' and 'HTMLStencilElement'.Named property
           'autocapitalize' of types 'IonTextarea' and 'HTMLStencilElement' are
           not identical.
   L3148:  };
   L3149:  interface HTMLIonTextareaElement extends Components.IonTextarea, HTMLStencilElement {
   L3150:  }

https://github.com/ionic-team/ionic/blob/master/core/src/components.d.ts#L2837 implements two interfaces and it seems that there is a conflict with the internal definitions of the DOM in Typescript

/node_modules/typescript/lib/lib.dom.d.ts

interface HTMLElement extends Element, DocumentAndElementEventHandlers, ElementCSSInlineStyle, ElementContentEditable, GlobalEventHandlers, HTMLOrSVGElement {
[...]
    autocapitalize: string;

Any idea about dealing with that?

[liamdebeasi]

There need to be some changes in Stencil in order to account for this, so I will make sure that gets merged first.

[liamdebeasi]

Thanks for the PR, and apologies for the delay. We appreciate the work you put into creating this PR. However, we are unable to accept the PR at this time. While the experience here is not ideal, the autocapitalize property is working as intended.

The underlying problem is with how TypeScript types the autocapitalize property: https://github.com/microsoft/TypeScript/blob/9c87ded2b3fc4ba4a9a7656e9be39d5e404e6ab6/lib/lib.dom.d.ts#L6360

As shown in the link, the autocapitalize property is of type string in TypeScript's codebase. This means that any type narrowing we do is going to cause a TypeScript error. In this case 'off' | 'on' | 'none' | 'sentences' | 'words' | 'characters' is narrower than the expected string type which is why you got the errors in #21464 (comment).

If TypeScript narrows their types, we will be more than happy to reconsider adding this change to Ionic's codebase. I am going to close this, but let me know if you have any questions. Thank you!

[rangzen]

Whooo almost 2 years and half :) Thank you for the answer and the links to TypeScript DOM 👍