chore: add @ui-kitten/metro-config package

[artyorsh]

Please read and mark the following check list before creating a pull request:

• I read and followed the CONTRIBUTING.md guide.
• I read and followed the New Feature Checklist guide.

Short description of what this resolves:

Computes Eva styles during the build time allowing the application load much faster.

• Closes ApplicationProvider shouldn't process mappings everytime it's mounted #613
• Closes Updating custom-mapping.json make the application very slow to load #855

---

Integration (Guide)

1. yarn add -D @ui-kitten/metro-config
2. Add or modify metro.config.js with following configuration

+ const MetroConfig = require('@ui-kitten/metro-config');

+ const evaConfig = { 
+   evaPackage: '@eva-design/eva', // Required (Can be `@eva-design/material`)
+   customMappingPath: './custom-mapping.json', // Optional
+ };

+ module.exports = MetroConfig.create(evaConfig, {
+   // Whatever was in previous metro.config.js 
+ });

3. Modify props of ApplicationProvider

- import { mapping, light } from '@eva-design/eva';
+ import * as eva from '@eva-design/eva'; 
- import { customMapping } from './custom-mapping.js'

export default = () => (
- <ApplicationProvider mapping={mapping} theme={light} />
+ <ApplicationProvider {...eva} theme={eva.light} />
);

Limitations

Not compatible with Fast Refresh - will reload app completely whenever custom mapping is changed if it is used.

How it works

[github-actions]

Try running it with Kitten Tricks

.

[alansoliditydev]

please merge this, my app have issues with the boot time. approx 6 - 7 secs for fully loaded :(

[artyorsh]

@TRANDINHKHANG do you use custom mapping or React Native Navigation by Wix?

[YIZHUANG]

@artyorsh have you tested this change reduce the load time to almost 0?

[artyorsh]

@YIZHUANG yes, I already run it locally in Kitten Tricks

[YIZHUANG]

@artyorsh nice, good job!

[YIZHUANG]

Any guides on how i can test this in my app already before it's merged?

[YIZHUANG]

I ended up just copying the end output (2.6mb) json, and remove the "process" function