Dk-file-generator NPM

Creates reexport files

coverage

This library is a powerful helper for Front-End developers that leverages a lot of manual work. Thoroughly tested and nicely optimized, successfully used in medium and large scale Enterprise projects with a huge amount of plugins' configs.

Through plugins it can create:

js (ts) files from .css theme files
reexport files (and modular reexport files) with corresponding package.json
js realtime validators from TypeScript models

Also it can watch your filesystem and recreate files on fly.

Installation

Add dk-file-generator to package.json and install
Execute overall generation before build (create some file and execute via node or add to your current build file)

import { generateFiles } from 'dk-file-generator';

generateFiles({
  configs: [],
  timeLogs: true,
  timeLogsOverall: true,
  fileModificationLogs: true,

  // If you use watch mode for local development
  watch: {
    paths: [path.resolve(__dirname, 'src')],
    changedFilesLogs: true,
    aggregationTimeout: 500,
  }
});

generateFiles works synchronously. Basic installation is complete, use plugins to add some functionality.

Plugin: theme

When work with CSS variables for theming, you need some JS implementation to apply them to <html> tag. This plugin helps to create corresponding js/ts file.

For example, you got file src/styles/theme.scss:

.light {
  --white: #fff;
  --black-param: #000;
}

.dark {
  --white: #aaa;
  --black-param: #ddd;
}

and want to create src/const/theme.ts:

/* eslint-disable */
// This file is auto-generated

export const theme = {
  "light": {
    "--white": "#fff",
    "--black-param": "#000"
  },
  "dark": {
    "--white": "#aaa",
    "--black-param": "#ddd"
  }
}

Use this recipe:

import { TypeGenerateFilesParams } from 'dk-file-generator';

const headerTemplate = `/* eslint-disable */\n// This file is auto-generated\n\n`;

const configs: TypeGenerateFilesParams['configs'] = [
  {
    plugin: 'theme',
    config: [
      {
        file: path.resolve(__dirname, 'src/styles/theme.scss'),
        targetFile: path.resolve(__dirname, 'src/const/theme.ts'),
        exportTemplate: ({ targetFileNameNoExt, themes }) =>
          `${headerTemplate}${targetFileNameNoExt} = ${JSON.stringify(themes, null, 2)}`,
      },
    ],
  }
]

It is recommended to disable ESLint with a comment for generated files, so they could be consistent across all developers and CI

Then you will need just include this theme into html markup like this

import { theme } from 'src/const/theme';

function setThemeToHTML(themeParams: Record<string, string>) {
  const root = document.documentElement;

  Object.entries(themeParams).forEach(([cssVar, cssVarValue]) => {
    root.style.setProperty(cssVar, cssVarValue);
  });
}

setThemeToHTML(theme.light)

Also you could use theme.ts in you code for mappings, inline style variables and SSR.

Features:

ensures that every theme has the same CSS variables
not CSS variables (like margin-top, height etc.) are ignored
no file rewritings when content is the same

Params:

file absolute path to css file
targetFile absolute path to target file (choose extension as you like)
exportTemplate({ targetFileNameNoExt, themes })

targetFileNameNoExt - target file name without extension

themes: Record<TypeThemeName, Record<TypeVariableName, TypeVariableValue>> - js object that represents themes

returns string

Plugin: reexport

Reads folder content and creates someReexportFile.ts(.js) and package.json in that folder. Highly customizable.

Typical scenario. You have folder src/utils

utils /
-- fileOne.ts
-- fileTwo.ts

and want to import their content from one place like

import { fnFromFileOne, fnFromFileTwo } from 'src/utils';

Use this recipe:

import { TypeGenerateFilesParams } from 'dk-file-generator';

const headerTemplate = `/* eslint-disable */\n// This file is auto-generated\n\n`;

const configs: TypeGenerateFilesParams['configs'] = [
  {
    plugin: 'reexport',
    config: [
      {
        folder: path.resolve(__dirname, 'src/utils'),
        importTemplate: ({ fileNameNoExt }) => `export * from './${fileNameNoExt}';\n`,
        fileNameTemplate: ({ folderName }) => `_${folderName}.ts`,
        headerTemplate,
      },
    ],
  }
]

it creates a file src/utils/_utils.ts

/* eslint-disable */
// This file is auto-generated

export * from './fileOne';
export * from './fileTwo';

and src/utils/package.json

{
  "main": "_utils.ts",
  "types": "_utils.ts"
}

In need of a deep reexport of folders just add corresponding configs (children first)

utils /
-- folderOne
---- fileOne.ts
---- fileTwo.ts
-- folderTwo
---- fileOne.ts
---- fileTwo.ts

import { TypeGenerateFilesParams } from 'dk-file-generator';

const headerTemplate = `/* eslint-disable */\n// This file is auto-generated\n\n`;

const configs: TypeGenerateFilesParams['configs'] = [
  {
    plugin: 'reexport',
    config: [
      {
        folder: path.resolve(__dirname, 'src/utils/folderOne'),
        importTemplate: ({ fileNameNoExt }) => `export * from './${fileNameNoExt}';\n`,
        fileNameTemplate: ({ folderName }) => `_${folderName}.ts`,
        headerTemplate,
      },
      {
        folder: path.resolve(__dirname, 'src/utils/folderTwo'),
        importTemplate: ({ fileNameNoExt }) => `export * from './${fileNameNoExt}';\n`,
        fileNameTemplate: ({ folderName }) => `_${folderName}.ts`,
        headerTemplate,
      },
      {
        folder: path.resolve(__dirname, 'src/utils'),
        importTemplate: ({ fileNameNoExt }) => `export * from './${fileNameNoExt}';\n`,
        fileNameTemplate: ({ folderName }) => `_${folderName}.ts`,
        headerTemplate,
      },
    ],
  }
]

So all functions from children files could be imported like import { someFn } from 'src/utils'.

Typical scenario when need to reexport default exports

import { TypeGenerateFilesParams } from 'dk-file-generator';

const headerTemplate = `/* eslint-disable */\n// This file is auto-generated\n\n`;

const configs: TypeGenerateFilesParams['configs'] = [
  {
    plugin: 'reexport',
    config: [
      {
        folder: path.resolve(__dirname, 'src/utils'),
        importTemplate: ({ fileNameNoExt }) => `export { default as ${fileNameNoExt} } from './${fileNameNoExt}';\n`,
        fileNameTemplate: () => `_customReexportFileName.ts`,
        headerTemplate,
      },
    ],
  }
]

it creates a file src/utils/_customReexportFileName.ts and src/utils/package.json

/* eslint-disable */
// This file is auto-generated

export { default as fileOne } from './fileOne';
export { default as fileTwo } from './fileTwo';

Export as object (example with icons)

icons /
-- iconOne.svg
-- iconTwo.svg

import { TypeGenerateFilesParams } from 'dk-file-generator';

const headerTemplate = `/* eslint-disable */\n// This file is auto-generated\n\n`;

const configs: TypeGenerateFilesParams['configs'] = [
  {
    plugin: 'reexport',
    config: [
      {
        folder: path.resolve(__dirname, 'src/icons'),
        importTemplate: ({ fileNameNoExt, fileName }) =>
          `import ${fileNameNoExt} from './${fileName}';\n`,
        exportTemplate: ({ fileNamesNoExt, folderName }) =>
          `\nexport const ${folderName} = { ${fileNamesNoExt.join(', ')} }`,
        fileNameTemplate: ({ folderName }) => `_${folderName}.ts`,
        headerTemplate,
      },
    ],
  }
]

it creates a file src/icons/_icons.ts and src/icons/package.json

/* eslint-disable */
// This file is auto-generated

import iconOne from './iconOne.svg';
import iconTwo from './iconTwo.svg';

export const icons = { iconOne, iconTwo };

Features:

package.json and reexport file are excluded by default during reading folder content, so no cycle imports occur
file names are passed "as-is", so it's better to name them in camelCase or snake_case, because names like some-file-name cannot be keys of JS object without parentheses. You can still use it, but tune you reexport config accordingly

When reexport file is used, constants' and functions' names in children files must not be the same! Just some obvious warning.

Params:

folder absolute path to folder
headerTemplate (optional) some text in the beginning of the file
includeChildrenMask (optional) look at this section
importTemplate({ fileNameNoExt, fileName })

fileNameNoExt - child file name without extension

fileName - child file name with extension

returns string

fileNameTemplate({ folderName })

folderName - folder name

returns string

exportTemplate({ fileNamesNoExt, folderName }) (optional)

fileNamesNoExt - array of children files' names without extension

folderName - folder name

returns string

Plugin: reexport-modular

Deep reads folder children and creates someReexportFile.ts(.js).

For example, you have modular structure of pages and want to extract types from every modular store.

pages /
-- pageOne
---- store.ts
-- pageTwo
---- store.ts
-- pageThree
---- noStore.ts

Use this recipe:

import { TypeGenerateFilesParams } from 'dk-file-generator';

const headerTemplate = `/* eslint-disable */\n// This file is auto-generated\n\n`;

const configs: TypeGenerateFilesParams['configs'] = [
  {
    plugin: 'reexport-modular',
    config: [
      {
        folder: path.resolve(__dirname, 'src/pages'),
        targetFile: path.resolve(__dirname, 'modularStores.ts'),
        childFileOrFolderName: 'store.ts',
        exportTemplate: ({ subFoldersOfFiles }) =>
          `\nexport default { pages: { ${subFoldersOfFiles
            .map(({ moduleName }) => moduleName)
            .join(', ')} } };`,
        importTemplate: ({ moduleName, relativePath }) =>
          `import * as ${moduleName} from './${relativePath}';\n`,
        headerTemplate,
      },
    ],
  }
]

it creates a file src/modularStores.ts

/* eslint-disable */
// This file is auto-generated

import pageOne from './pages/pageOne/store';
import pageTwo from './pages/pageTwo/store';

export default { pages: { pageOne, pageTwo } };

as you can see pageThree is not exported because it has no store.ts file.

Params:

folder absolute path to folder
targetFile absolute path to target reexport file
childFileOrFolderName file name (with extension) or folder name
headerTemplate (optional) some text in the beginning of the file
includeChildrenMask (optional) look at this section
importTemplate({ moduleName, relativePath })

moduleName - first-level page name

relativePath - relative path from targetFile to childFileOrFolderName

returns string

exportTemplate({ subFoldersOfFiles })

subFoldersOfFiles - array of { subFolderOrFilePath: string; moduleName: string }

returns string

Plugin: validators

Converts files in folder to validators using customized version of ts-interface-builder, that can be used by ts-interface-checker.

api /
-- getUser.ts
models /
-- TypeUser.ts

where api/getUser.ts

import { TypeUser } from '../models/TypeUser';

type TypeRequest = {};

type TypeResponse = TypeUser;

export const getUser: {
  url: string;
  request: TypeRequest;
  response: TypeResponse;
} = {
  url: `/api/user`,
  request: {} as TypeRequest,
  response: {} as TypeResponse,
};

and models/TypeUser.ts

export type TypeUser = {
  email: string;
  name: string;
  someData: Array<[number, string]>;
};

Use this recipe:

import { TypeGenerateFilesParams } from 'dk-file-generator';

const headerTemplate = `/* eslint-disable */\n// This file is auto-generated\n\n`;

// Example of reuse compilerOptions from tsconfig.json, but you can pass custom rules
const { compilerOptions } = JSON.parse(
  fs.readFileSync(path.resolve(__dirname, 'tsconfig.json'), 'utf-8')
);

const configs: TypeGenerateFilesParams['configs'] = [
  {
    plugin: 'validators',
    config: [
      {
        folder: path.resolve(__dirname, 'src/api'),
        targetFolder: path.resolve(__dirname, 'src/validators'),
        triggerFolder: path.resolve(__dirname, 'src/models'),
        headerTemplate,
        compilerOptions,
      },
    ],
  }
]

it creates a file src/validators/getUser.ts

/* eslint-disable */
// This file is auto-generated

import * as t from "ts-interface-checker";
// tslint:disable:object-literal-key-quotes

export const TypeUser = t.iface([], {
  "email": "string",
  "name": "string",
  "someData": t.array(t.tuple("number", "string")),
});

export const TypeRequest = t.iface([], {
});

export const TypeResponse = t.name("TypeUser");

const exportedTypeSuite: t.ITypeSuite = {
  TypeUser,
  TypeRequest,
  TypeResponse,
};
export default exportedTypeSuite;

Params:

folder absolute path to folder
targetFolder absolute path to target folder
triggerFolder (optional) absolute path to folder from which some models are imported.
IMPORTANT: in watch mode you should define this param if models are imported from some folder. Otherwise changes in src/models will not trigger new validators generation! Watcher does not build dependencies graph and does not know whether you have import statements in your files
headerTemplate (optional) some text in the beginning of the file
compilerOptions (optional) TypeScript CompilerOptions
includeChildrenMask (optional) look at this section