swc-plugin-transform-import-declaration

swc-plugin-transform-import declaration is a swc-loader plugin used in webpack for demanding import.

1import Button from '@mui/material';
2// swc-loader equipped with this plugin will compile the above as follows 
3const _button = require('@mui/material/Button')

The example above is much more simplified, BUT it's clear that for most cases' demanding import for UI library, we just use a plugin to compile importing code slightly more flexibly, i.e. transforming the import declaration, whether it's a babel-plugin or swc-plugin.
This is because if we don't transform the import declaration, the un-transformed declaration will be mean to import whole stuff, hundreds of dependencies in view of dependency tree.

About this npm package

Forked and revised from Ankit Chouhan's swc-plugin-transform-import changed the use of skipDefaultConversion, now whether transforming named import into export is now controlled by business logics. More specifically, making option property skipDefaultConversion fully CONTROL whether import declaration is named import or default import, because it's more about business logic which should have more flexiblity and even diffs from UI library.

1// Ankit Chouhan's version: swc-plugin-transform-import
2// while setting skipDefaultConversion to false
3import { Button } from '@mui/material';
4// swc-loader equipped with this plugin will compile the above as follows 
5const _button = require('@mui/material/Button').default
6
7// ----------------------------------------------------
8
9// this package's version: swc-plugin-transform-import-declaration
10// while setting skipDefaultConversion to false
11import { Button } from '@mui/material';
12// swc-loader equipped with this plugin will compile the above as follows 
13const _button = require('@mui/material/Button')

---

❗❗❗ Orginal README is as follows, and the use of the this plugin can also be found here. Just pay more attention of the tricking property skipDefaultConversion, whose implemention is fully changed.

swc-plugin-transform-import

Inspired from babel-plugin-transform-imports

Installation

1npm i -D swc-plugin-transform-import

Uses with webpack-config

1// webpack.config.js
2
3const PluginTransformImport = require('swc-plugin-transform-import').default;
4
5module: {
6    rules: [
7      {
8        test: /\.(ts|tsx|js|jsx)$/,
9        exclude: /node_modules/,
10        use: [{
11          loader: 'swc-loader',
12          options: {
13            plugin: (m) => new PluginTransformImport({
14              "lodash": {
15                "transform": "lodash/${member}",
16                "preventFullImport": true
17              }
18            }).visitProgram(m),
19          }
20        }]
21      },
22    ],
23};
24

1import { Row, Grid as MyGrid } from 'react-bootstrap';
2import { merge } from 'lodash';

...into default style imports:

1import Row from 'react-bootstrap/lib/Row';
2import MyGrid from 'react-bootstrap/lib/Grid';
3import merge from 'lodash/merge';

Note: this plugin is not restricted to the react-bootstrap and lodash libraries. You may use it with any library.

That's stupid, why would you do that?

When SWC encounters a member style import such as:

1import { Grid, Row, Col } from 'react-bootstrap';

it will generate something similarish to:

1var reactBootstrap = require('react-bootstrap');
2var Grid = reactBootstrap.Grid;
3var Row = reactBootstrap.Row;
4var Col = reactBootstrap.Col;

Some libraries, such as react-bootstrap and lodash, are rather large and pulling in the entire module just to use a few pieces would cause unnecessary bloat to your client optimized (webpack etc.) bundle. The only way around this is to use default style imports:

1import Grid from 'react-bootstrap/lib/Grid';
2import Row from 'react-bootstrap/lib/Row';
3import Col from 'react-bootstrap/lib/Col';

But, the more pieces we need, the more this sucks. This plugin will allow you to pull in just the pieces you need, without a separate import for each item. Additionally, it can be configured to throw when somebody accidentally writes an import which would cause the entire module to resolve, such as:

1import Bootstrap, { Grid } from 'react-bootstrap';
2// -- or --
3import * as Bootstrap from 'react-bootstrap';

Installation

npm install --save-dev swc-plugin-transform-import

Advanced Transformations

In cases where the provided default string replacement transformation is not sufficient (for example, needing to execute a RegExp on the import name), you may instead provide a path to a .js file which exports a function to run instead. Keep in mind that the .js file will be required relative from this plugin's path, likely located in /node_modules/babel-plugin-transform-imports. You may provide any filename, as long as it ends with .js.

.babelrc:

1{
2    "plugins": [
3        ["transform-imports", {
4            "my-library": {
5                "transform": "../../path/to/transform.js",
6                "preventFullImport": true
7            }
8        }]
9    ]
10}

/path/to/transform.js:

1module.exports = function(importName) {
2    return 'my-library/etc/' + importName.toUpperCase();
3};

Options

Name	Type	Required	Default	Description
transform	string	yes	undefined	The library name to use instead of the one specified in the import statement. ${member} will be replaced with the member, aka Grid/Row/Col/etc. Alternatively, pass a path to a .js file which exports a function to process the transform (see Advanced Transformations)
preventFullImport	boolean	no	false	Whether or not to throw when an import is encountered which would cause the entire module to be imported.
skipDefaultConversion	boolean	no	false	When set to true, will preserve import { X } syntax instead of converting to import X.
style	boolean or function	no	false	When set to true, will add side effect import of transformed path concatenated with /style. When set as a function, receive an argument as the transformed path, return the tramsformed style module path