@a-la/import

@a-la/import

@a-la/import is a a set of rules for alamode to transpile an import statement into require in Node.js.

À La Mode is a RegExp-based transpiler which works faster than AST-based transpilers such as @babel, and occupies only 10KB of disk space.

yarn add -E @a-la/import

Table Of Contents

• Table Of Contents
• API
  • ALaImport Sequence
• Output Example
• Lines Preservation
  • Named Imports
  • Named & Default
• Checklist
• Copyright

API

The ALaImport is the default export and an array containing a sequence of rules for Replaceable.

import ALaImport from '@a-la/import'

ALaImport Sequence

The rule set exported as an array by ALaImport has multiple regexes and replacer functions to match all possible cases.

/* yarn example/ */
import { Replaceable } from 'restream'
import ALaImport from '@a-la/import'

const STRING = `import aLaMode from 'alamode'
import ALaImport from "@a-la/import"
import App from 'koa'
`

;(async () => {
  const stream = new Replaceable([
    ...ALaImport,
  ])
  await new Promise((r, j) => {
    stream.end(STRING, r)
    stream.on('error', j)
  })
  stream.pipe(process.stdout)
})()

let aLaMode = require('alamode'); if (aLaMode && aLaMode.__esModule) aLaMode = aLaMode.default;
let ALaImport = require("@a-la/import"); if (ALaImport && ALaImport.__esModule) ALaImport = ALaImport.default;
let App = require('koa'); if (App && App.__esModule) App = App.default;

Output Example

The set of rules changes import to require statements. When importing a default module, a check will be made to see if it was transpiled with Babel which is indicated by the presence of the __esModule property, and if it was, then the default property is reassinged to the variable.

import aLaMode from 'alamode'
import scopeALaMode from "@a-la/import"

import { methodA, methodB } from 'alamode'
import { methodC, methodD as aliasD } from 'alamode'
import defaultALaMode, {
  methodE, methodF,
} from 'alamode'

let aLaMode = require('alamode'); if (aLaMode && aLaMode.__esModule) aLaMode = aLaMode.default;
let scopeALaMode = require("@a-la/import"); if (scopeALaMode && scopeALaMode.__esModule) scopeALaMode = scopeALaMode.default;

const { methodA, methodB } = require('alamode')
const { methodC, methodD: aliasD } = require('alamode')
let defaultALaMode = require('alamode'); if (defaultALaMode && defaultALaMode.__esModule) defaultALaMode = defaultALaMode.default; const {
  methodE, methodF,
} = defaultALaMode

Lines Preservation

The transform will attempt to preserve lines as they are for easier generation of source maps by alamode. In future, this might change.

Named Imports

The named imports are only changed to replace as into :, otherwise the destructuring syntax is the same as for imports themselves.

import { test, test2,
  test3 as alias3 }
from 'package'

const { test, test2,
  test3: alias3 }
= require('package')

Named & Default

When there is a default import along with named once, the line numbers will be respected.

import def, {
  test, test2,
  test3 as alias3,
  test4
    as
  alias4,
}
  from
  'package'

let def = require('package'); if (def && def.__esModule) def = def.default; const {
  test, test2,
  test3: alias3,
  test4
    :
  alias4,
}
  =
  def

Checklist

• import defaultExport from "module-name"
• import * as name from "module-name";
• import { export } from "module-name";
• import { export as alias } from "module-name";
• import { export1 , export2 } from "module-name";
• import { export1 , export2 as alias2 , [...] } from "module-name";
• import defaultExport, { export [ , [...] ] } from "module-name";
• import defaultExport, * as name from "module-name";
• import "module-name";
• var promise = import(module-name);

Copyright

(c) À La Mode 2018

Changelog

1.3.0

• [feature] Preserve lines.
• [dep] Update to zoroaster@2.2 for mask testing.

11 August 2018